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Kernel | 3.14

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<title>DVB Video Device</title>
<para>The DVB video device controls the MPEG2 video decoder of the DVB hardware. It
can be accessed through <emphasis role="tt">/dev/dvb/adapter0/video0</emphasis>. Data types and and
ioctl definitions can be accessed by including <emphasis role="tt">linux/dvb/video.h</emphasis> in your
application.
</para>
<para>Note that the DVB video device only controls decoding of the MPEG video stream, not
its presentation on the TV or computer screen. On PCs this is typically handled by an
associated video4linux device, e.g. <emphasis role="tt">/dev/video</emphasis>, which allows scaling and defining output
windows.
</para>
<para>Some DVB cards don’t have their own MPEG decoder, which results in the omission of
the audio and video device as well as the video4linux device.
</para>
<para>The ioctls that deal with SPUs (sub picture units) and navigation packets are only
supported on some MPEG decoders made for DVD playback.
</para>
<para>
These ioctls were also used by V4L2 to control MPEG decoders implemented in V4L2. The use
of these ioctls for that purpose has been made obsolete and proper V4L2 ioctls or controls
have been created to replace that functionality.</para>
<section id="video_types">
<title>Video Data Types</title>

<section id="video-format-t">
<title>video_format_t</title>
<para>The <emphasis role="tt">video_format_t</emphasis> data type defined by
</para>
<programlisting>
typedef enum {
	VIDEO_FORMAT_4_3,     /⋆ Select 4:3 format ⋆/
	VIDEO_FORMAT_16_9,    /⋆ Select 16:9 format. ⋆/
	VIDEO_FORMAT_221_1    /⋆ 2.21:1 ⋆/
} video_format_t;
</programlisting>
<para>is used in the VIDEO_SET_FORMAT function (??) to tell the driver which aspect ratio
the output hardware (e.g. TV) has. It is also used in the data structures video_status
(??) returned by VIDEO_GET_STATUS (??) and video_event (??) returned by
VIDEO_GET_EVENT (??) which report about the display format of the current video
stream.
</para>
</section>

<section id="video-displayformat-t">
<title>video_displayformat_t</title>
<para>In case the display format of the video stream and of the display hardware differ the
application has to specify how to handle the cropping of the picture. This can be done using
the VIDEO_SET_DISPLAY_FORMAT call (??) which accepts
</para>
<programlisting>
typedef enum {
	VIDEO_PAN_SCAN,       /⋆ use pan and scan format ⋆/
	VIDEO_LETTER_BOX,     /⋆ use letterbox format ⋆/
	VIDEO_CENTER_CUT_OUT  /⋆ use center cut out format ⋆/
} video_displayformat_t;
</programlisting>
<para>as argument.
</para>
</section>

<section id="video-stream-source-t">
<title>video_stream_source_t</title>
<para>The video stream source is set through the VIDEO_SELECT_SOURCE call and can take
the following values, depending on whether we are replaying from an internal (demuxer) or
external (user write) source.
</para>
<programlisting>
typedef enum {
	VIDEO_SOURCE_DEMUX, /⋆ Select the demux as the main source ⋆/
	VIDEO_SOURCE_MEMORY /⋆ If this source is selected, the stream
			       comes from the user through the write
			       system call ⋆/
} video_stream_source_t;
</programlisting>
<para>VIDEO_SOURCE_DEMUX selects the demultiplexer (fed either by the frontend or the
DVR device) as the source of the video stream. If VIDEO_SOURCE_MEMORY
is selected the stream comes from the application through the <emphasis role="tt">write()</emphasis> system
call.
</para>
</section>

<section id="video-play-state-t">
<title>video_play_state_t</title>
<para>The following values can be returned by the VIDEO_GET_STATUS call representing the
state of video playback.
</para>
<programlisting>
typedef enum {
	VIDEO_STOPPED, /⋆ Video is stopped ⋆/
	VIDEO_PLAYING, /⋆ Video is currently playing ⋆/
	VIDEO_FREEZED  /⋆ Video is freezed ⋆/
} video_play_state_t;
</programlisting>
</section>

<section id="video-command">
<title>struct video_command</title>
<para>The structure must be zeroed before use by the application
This ensures it can be extended safely in the future.</para>
<programlisting>
struct video_command {
	__u32 cmd;
	__u32 flags;
	union {
		struct {
			__u64 pts;
		} stop;

struct {
			/⋆ 0 or 1000 specifies normal speed,
			   1 specifies forward single stepping,
			   -1 specifies backward single stepping,
			   >>1: playback at speed/1000 of the normal speed,
			   <-1: reverse playback at (-speed/1000) of the normal speed. ⋆/
			__s32 speed;
			__u32 format;
		} play;

struct {
			__u32 data[16];
		} raw;
	};
};
</programlisting>
</section>

<section id="video-size-t">
<title>video_size_t</title>
<programlisting>
typedef struct {
	int w;
	int h;
	video_format_t aspect_ratio;
} video_size_t;
</programlisting>
</section>

<section id="video-event">
<title>struct video_event</title>
<para>The following is the structure of a video event as it is returned by the VIDEO_GET_EVENT
call.
</para>
<programlisting>
struct video_event {
	__s32 type;
#define VIDEO_EVENT_SIZE_CHANGED	1
#define VIDEO_EVENT_FRAME_RATE_CHANGED	2
#define VIDEO_EVENT_DECODER_STOPPED 	3
#define VIDEO_EVENT_VSYNC 		4
	__kernel_time_t timestamp;
	union {
		video_size_t size;
		unsigned int frame_rate;	/⋆ in frames per 1000sec ⋆/
		unsigned char vsync_field;	/⋆ unknown/odd/even/progressive ⋆/
	} u;
};
</programlisting>
</section>

<section id="video-status">
<title>struct video_status</title>
<para>The VIDEO_GET_STATUS call returns the following structure informing about various
states of the playback operation.
</para>
<programlisting>
struct video_status {
	int                   video_blank;   /⋆ blank video on freeze? ⋆/
	video_play_state_t    play_state;    /⋆ current state of playback ⋆/
	video_stream_source_t stream_source; /⋆ current source (demux/memory) ⋆/
	video_format_t        video_format;  /⋆ current aspect ratio of stream ⋆/
	video_displayformat_t display_format;/⋆ selected cropping mode ⋆/
};
</programlisting>
<para>If video_blank is set video will be blanked out if the channel is changed or if playback is
stopped. Otherwise, the last picture will be displayed. play_state indicates if the video is
currently frozen, stopped, or being played back. The stream_source corresponds to the seleted
source for the video stream. It can come either from the demultiplexer or from memory.
The video_format indicates the aspect ratio (one of 4:3 or 16:9) of the currently
played video stream. Finally, display_format corresponds to the selected cropping
mode in case the source video format is not the same as the format of the output
device.
</para>
</section>

<section id="video-still-picture">
<title>struct video_still_picture</title>
<para>An I-frame displayed via the VIDEO_STILLPICTURE call is passed on within the
following structure.
</para>
<programlisting>
/⋆ pointer to and size of a single iframe in memory ⋆/
struct video_still_picture {
	char ⋆iFrame;        /⋆ pointer to a single iframe in memory ⋆/
	int32_t size;
};
</programlisting>
</section>

<section id="video_caps">
<title>video capabilities</title>
<para>A call to VIDEO_GET_CAPABILITIES returns an unsigned integer with the following
bits set according to the hardwares capabilities.
</para>
<programlisting>
 /⋆ bit definitions for capabilities: ⋆/
 /⋆ can the hardware decode MPEG1 and/or MPEG2? ⋆/
 #define VIDEO_CAP_MPEG1   1
 #define VIDEO_CAP_MPEG2   2
 /⋆ can you send a system and/or program stream to video device?
    (you still have to open the video and the audio device but only
     send the stream to the video device) ⋆/
 #define VIDEO_CAP_SYS     4
 #define VIDEO_CAP_PROG    8
 /⋆ can the driver also handle SPU, NAVI and CSS encoded data?
    (CSS API is not present yet) ⋆/
 #define VIDEO_CAP_SPU    16
 #define VIDEO_CAP_NAVI   32
 #define VIDEO_CAP_CSS    64
</programlisting>
</section>

<section id="video-system">
<title>video_system_t</title>
<para>A call to VIDEO_SET_SYSTEM sets the desired video system for TV output. The
following system types can be set:
</para>
<programlisting>
typedef enum {
	 VIDEO_SYSTEM_PAL,
	 VIDEO_SYSTEM_NTSC,
	 VIDEO_SYSTEM_PALN,
	 VIDEO_SYSTEM_PALNc,
	 VIDEO_SYSTEM_PALM,
	 VIDEO_SYSTEM_NTSC60,
	 VIDEO_SYSTEM_PAL60,
	 VIDEO_SYSTEM_PALM60
} video_system_t;
</programlisting>
</section>

<section id="video-highlight">
<title>struct video_highlight</title>
<para>Calling the ioctl VIDEO_SET_HIGHLIGHTS posts the SPU highlight information. The
call expects the following format for that information:
</para>
<programlisting>
 typedef
 struct video_highlight {
	 boolean active;      /⋆    1=show highlight, 0=hide highlight ⋆/
	 uint8_t contrast1;   /⋆    7- 4  Pattern pixel contrast ⋆/
			      /⋆    3- 0  Background pixel contrast ⋆/
	 uint8_t contrast2;   /⋆    7- 4  Emphasis pixel-2 contrast ⋆/
			      /⋆    3- 0  Emphasis pixel-1 contrast ⋆/
	 uint8_t color1;      /⋆    7- 4  Pattern pixel color ⋆/
			      /⋆    3- 0  Background pixel color ⋆/
	 uint8_t color2;      /⋆    7- 4  Emphasis pixel-2 color ⋆/
			      /⋆    3- 0  Emphasis pixel-1 color ⋆/
	 uint32_t ypos;       /⋆   23-22  auto action mode ⋆/
			      /⋆   21-12  start y ⋆/
			      /⋆    9- 0  end y ⋆/
	 uint32_t xpos;       /⋆   23-22  button color number ⋆/
			      /⋆   21-12  start x ⋆/
			      /⋆    9- 0  end x ⋆/
 } video_highlight_t;
</programlisting>

</section>
<section id="video-spu">
<title>struct video_spu</title>
<para>Calling VIDEO_SET_SPU deactivates or activates SPU decoding, according to the
following format:
</para>
<programlisting>
 typedef
 struct video_spu {
	 boolean active;
	 int stream_id;
 } video_spu_t;
</programlisting>

</section>
<section id="video-spu-palette">
<title>struct video_spu_palette</title>
<para>The following structure is used to set the SPU palette by calling VIDEO_SPU_PALETTE:
</para>
<programlisting>
 typedef
 struct video_spu_palette {
	 int length;
	 uint8_t ⋆palette;
 } video_spu_palette_t;
</programlisting>

</section>
<section id="video-navi-pack">
<title>struct video_navi_pack</title>
<para>In order to get the navigational data the following structure has to be passed to the ioctl
VIDEO_GET_NAVI:
</para>
<programlisting>
 typedef
 struct video_navi_pack {
	 int length;         /⋆ 0 ... 1024 ⋆/
	 uint8_t data[1024];
 } video_navi_pack_t;
</programlisting>
</section>

<section id="video-attributes-t">
<title>video_attributes_t</title>
<para>The following attributes can be set by a call to VIDEO_SET_ATTRIBUTES:
</para>
<programlisting>
 typedef uint16_t video_attributes_t;
 /⋆   bits: descr. ⋆/
 /⋆   15-14 Video compression mode (0=MPEG-1, 1=MPEG-2) ⋆/
 /⋆   13-12 TV system (0=525/60, 1=625/50) ⋆/
 /⋆   11-10 Aspect ratio (0=4:3, 3=16:9) ⋆/
 /⋆    9- 8 permitted display mode on 4:3 monitor (0=both, 1=only pan-sca ⋆/
 /⋆    7    line 21-1 data present in GOP (1=yes, 0=no) ⋆/
 /⋆    6    line 21-2 data present in GOP (1=yes, 0=no) ⋆/
 /⋆    5- 3 source resolution (0=720x480/576, 1=704x480/576, 2=352x480/57 ⋆/
 /⋆    2    source letterboxed (1=yes, 0=no) ⋆/
 /⋆    0    film/camera mode (0=camera, 1=film (625/50 only)) ⋆/
</programlisting>
</section></section>

<section id="video_function_calls">
<title>Video Function Calls</title>

<section id="video_fopen">
<title>open()</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This system call opens a named video device (e.g. /dev/dvb/adapter0/video0)
 for subsequent use.</para>
<para>When an open() call has succeeded, the device will be ready for use.
 The significance of blocking or non-blocking mode is described in the
 documentation for functions where there is a difference. It does not affect the
 semantics of the open() call itself. A device opened in blocking mode can later
 be put into non-blocking mode (and vice versa) using the F_SETFL command
 of the fcntl system call. This is a standard system call, documented in the Linux
 manual page for fcntl. Only one user can open the Video Device in O_RDWR
 mode. All other attempts to open the device in this mode will fail, and an
 error-code will be returned. If the Video Device is opened in O_RDONLY
 mode, the only ioctl call that can be used is VIDEO_GET_STATUS. All other
 call will return an error code.</para>
</entry>
 </row></tbody></tgroup></informaltable>

<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int open(const char ⋆deviceName, int flags);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>const char
 *deviceName</para>
</entry><entry
 align="char">
<para>Name of specific video device.</para>
</entry>
 </row><row><entry
 align="char">
<para>int flags</para>
</entry><entry
 align="char">
<para>A bit-wise OR of the following flags:</para>
</entry>
 </row><row><entry
 align="char">
</entry><entry
 align="char">
<para>O_RDONLY read-only access</para>
</entry>
 </row><row><entry
 align="char">
</entry><entry
 align="char">
<para>O_RDWR read/write access</para>
</entry>
 </row><row><entry
 align="char">
</entry><entry
 align="char">
<para>O_NONBLOCK open in non-blocking mode</para>
</entry>
 </row><row><entry
 align="char">
</entry><entry
 align="char">
<para>(blocking mode is the default)</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>RETURN VALUE</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>ENODEV</para>
</entry><entry
 align="char">
<para>Device driver not loaded/available.</para>
</entry>
 </row><row><entry
 align="char">
<para>EINTERNAL</para>
</entry><entry
 align="char">
<para>Internal error.</para>
</entry>
 </row><row><entry
 align="char">
<para>EBUSY</para>
</entry><entry
 align="char">
<para>Device or resource busy.</para>
</entry>
 </row><row><entry
 align="char">
<para>EINVAL</para>
</entry><entry
 align="char">
<para>Invalid argument.</para>
</entry>
 </row></tbody></tgroup></informaltable>

</section>
<section id="video_fclose">
<title>close()</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This system call closes a previously opened video device.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int close(int fd);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>RETURN VALUE</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>EBADF</para>
</entry><entry
 align="char">
<para>fd is not a valid open file descriptor.</para>
</entry>
 </row></tbody></tgroup></informaltable>

</section>
<section id="video_fwrite">
<title>write()</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This system call can only be used if VIDEO_SOURCE_MEMORY is selected
 in the ioctl call VIDEO_SELECT_SOURCE. The data provided shall be in
 PES format, unless the capability allows other formats. If O_NONBLOCK is
 not specified the function will block until buffer space is available. The amount
 of data to be transferred is implied by count.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>size_t write(int fd, const void ⋆buf, size_t count);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>void *buf</para>
</entry><entry
 align="char">
<para>Pointer to the buffer containing the PES data.</para>
</entry>
 </row><row><entry
 align="char">
<para>size_t count</para>
</entry><entry
 align="char">
<para>Size of buf.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>RETURN VALUE</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>EPERM</para>
</entry><entry
 align="char">
<para>Mode VIDEO_SOURCE_MEMORY not selected.</para>
</entry>
 </row><row><entry
 align="char">
<para>ENOMEM</para>
</entry><entry
 align="char">
<para>Attempted to write more data than the internal buffer can
 hold.</para>
</entry>
 </row><row><entry
 align="char">
<para>EBADF</para>
</entry><entry
 align="char">
<para>fd is not a valid open file descriptor.</para>
</entry>
 </row></tbody></tgroup></informaltable>

</section><section id="VIDEO_STOP"
role="subsection"><title>VIDEO_STOP</title>
<para>DESCRIPTION
</para>
<para>This ioctl is for DVB devices only. To control a V4L2 decoder use the V4L2
&VIDIOC-DECODER-CMD; instead.</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call asks the Video Device to stop playing the current stream.
 Depending on the input parameter, the screen can be blanked out or displaying
 the last decoded frame.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(fd, int request = VIDEO_STOP, boolean
 mode);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_STOP for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>Boolean mode</para>
</entry><entry
 align="char">
<para>Indicates how the screen shall be handled.</para>
</entry>
 </row><row><entry
 align="char">
</entry><entry
 align="char">
<para>TRUE: Blank screen when stop.</para>
</entry>
 </row><row><entry
 align="char">
</entry><entry
 align="char">
<para>FALSE: Show last decoded frame.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_PLAY"
role="subsection"><title>VIDEO_PLAY</title>
<para>DESCRIPTION
</para>
<para>This ioctl is for DVB devices only. To control a V4L2 decoder use the V4L2
&VIDIOC-DECODER-CMD; instead.</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call asks the Video Device to start playing a video stream from the
 selected source.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(fd, int request = VIDEO_PLAY);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_PLAY for this command.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_FREEZE"
role="subsection"><title>VIDEO_FREEZE</title>
<para>DESCRIPTION
</para>
<para>This ioctl is for DVB devices only. To control a V4L2 decoder use the V4L2
&VIDIOC-DECODER-CMD; instead.</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call suspends the live video stream being played. Decoding
 and playing are frozen. It is then possible to restart the decoding
 and playing process of the video stream using the VIDEO_CONTINUE
 command. If VIDEO_SOURCE_MEMORY is selected in the ioctl call
 VIDEO_SELECT_SOURCE, the DVB subsystem will not decode any more
 data until the ioctl call VIDEO_CONTINUE or VIDEO_PLAY is performed.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(fd, int request = VIDEO_FREEZE);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_FREEZE for this command.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_CONTINUE"
role="subsection"><title>VIDEO_CONTINUE</title>
<para>DESCRIPTION
</para>
<para>This ioctl is for DVB devices only. To control a V4L2 decoder use the V4L2
&VIDIOC-DECODER-CMD; instead.</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call restarts decoding and playing processes of the video stream
 which was played before a call to VIDEO_FREEZE was made.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(fd, int request = VIDEO_CONTINUE);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_CONTINUE for this command.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_SELECT_SOURCE"
role="subsection"><title>VIDEO_SELECT_SOURCE</title>
<para>DESCRIPTION
</para>
<para>This ioctl is for DVB devices only. This ioctl was also supported by the
V4L2 ivtv driver, but that has been replaced by the ivtv-specific
<constant>IVTV_IOC_PASSTHROUGH_MODE</constant> ioctl.</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call informs the video device which source shall be used for the input
 data. The possible sources are demux or memory. If memory is selected, the
 data is fed to the video device through the write command.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(fd, int request = VIDEO_SELECT_SOURCE,
 video_stream_source_t source);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_SELECT_SOURCE for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>video_stream_source_t
 source</para>
</entry><entry
 align="char">
<para>Indicates which source shall be used for the Video stream.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_SET_BLANK"
role="subsection"><title>VIDEO_SET_BLANK</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call asks the Video Device to blank out the picture.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(fd, int request = VIDEO_SET_BLANK, boolean
 mode);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_SET_BLANK for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>boolean mode</para>
</entry><entry
 align="char">
<para>TRUE: Blank screen when stop.</para>
</entry>
 </row><row><entry
 align="char">
</entry><entry
 align="char">
<para>FALSE: Show last decoded frame.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_GET_STATUS"
role="subsection"><title>VIDEO_GET_STATUS</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call asks the Video Device to return the current status of the device.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para> int ioctl(fd, int request = VIDEO_GET_STATUS, struct
 video_status ⋆status);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_GET_STATUS for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>struct video_status
 *status</para>
</entry><entry
 align="char">
<para>Returns the current status of the Video Device.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_GET_FRAME_COUNT"
role="subsection"><title>VIDEO_GET_FRAME_COUNT</title>
<para>DESCRIPTION
</para>
<para>This ioctl is obsolete. Do not use in new drivers. For V4L2 decoders this
ioctl has been replaced by the <constant>V4L2_CID_MPEG_VIDEO_DEC_FRAME</constant> control.</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call asks the Video Device to return the number of displayed frames
since the decoder was started.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(int fd, int request =
 VIDEO_GET_FRAME_COUNT, __u64 *pts);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_GET_FRAME_COUNT for this
 command.</para>
</entry>
 </row><row><entry
 align="char">
<para>__u64 *pts
</para>
</entry><entry
 align="char">
<para>Returns the number of frames displayed since the decoder was started.
</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_GET_PTS"
role="subsection"><title>VIDEO_GET_PTS</title>
<para>DESCRIPTION
</para>
<para>This ioctl is obsolete. Do not use in new drivers. For V4L2 decoders this
ioctl has been replaced by the <constant>V4L2_CID_MPEG_VIDEO_DEC_PTS</constant> control.</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call asks the Video Device to return the current PTS timestamp.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(int fd, int request =
 VIDEO_GET_PTS, __u64 *pts);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_GET_PTS for this
 command.</para>
</entry>
 </row><row><entry
 align="char">
<para>__u64 *pts
</para>
</entry><entry
 align="char">
<para>Returns the 33-bit timestamp as defined in ITU T-REC-H.222.0 / ISO/IEC 13818-1.
</para>
<para>
The PTS should belong to the currently played
frame if possible, but may also be a value close to it
like the PTS of the last decoded frame or the last PTS
extracted by the PES parser.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_GET_FRAME_RATE"
role="subsection"><title>VIDEO_GET_FRAME_RATE</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call asks the Video Device to return the current framerate.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(int fd, int request =
 VIDEO_GET_FRAME_RATE, unsigned int *rate);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_GET_FRAME_RATE for this
 command.</para>
</entry>
 </row><row><entry
 align="char">
<para>unsigned int *rate
</para>
</entry><entry
 align="char">
<para>Returns the framerate in number of frames per 1000 seconds.
</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_GET_EVENT"
role="subsection"><title>VIDEO_GET_EVENT</title>
<para>DESCRIPTION
</para>
<para>This ioctl is for DVB devices only. To get events from a V4L2 decoder use the V4L2
&VIDIOC-DQEVENT; ioctl instead.</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call returns an event of type video_event if available. If an event is
 not available, the behavior depends on whether the device is in blocking or
 non-blocking mode. In the latter case, the call fails immediately with errno
 set to EWOULDBLOCK. In the former case, the call blocks until an event
 becomes available. The standard Linux poll() and/or select() system calls can
 be used with the device file descriptor to watch for new events. For select(),
 the file descriptor should be included in the exceptfds argument, and for
 poll(), POLLPRI should be specified as the wake-up condition. Read-only
 permissions are sufficient for this ioctl call.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para> int ioctl(fd, int request = VIDEO_GET_EVENT, struct
 video_event ⋆ev);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_GET_EVENT for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>struct video_event
 *ev</para>
</entry><entry
 align="char">
<para>Points to the location where the event, if any, is to be
 stored.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>EWOULDBLOCK</para>
</entry><entry
 align="char">
<para>There is no event pending, and the device is in
 non-blocking mode.</para>
</entry>
 </row><row><entry
 align="char">
<para>EOVERFLOW</para>
</entry><entry
 align="char">
<para>Overflow in event queue - one or more events were lost.</para>
</entry>
 </row></tbody></tgroup></informaltable>

</section><section id="VIDEO_COMMAND"
role="subsection"><title>VIDEO_COMMAND</title>
<para>DESCRIPTION
</para>
<para>This ioctl is obsolete. Do not use in new drivers. For V4L2 decoders this
ioctl has been replaced by the &VIDIOC-DECODER-CMD; ioctl.</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl commands the decoder. The <constant>video_command</constant> struct
is a subset of the <constant>v4l2_decoder_cmd</constant> struct, so refer to the
&VIDIOC-DECODER-CMD; documentation for more information.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(int fd, int request =
 VIDEO_COMMAND, struct video_command *cmd);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_COMMAND for this
 command.</para>
</entry>
 </row><row><entry
 align="char">
<para>struct video_command *cmd
</para>
</entry><entry
 align="char">
<para>Commands the decoder.
</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_TRY_COMMAND"
role="subsection"><title>VIDEO_TRY_COMMAND</title>
<para>DESCRIPTION
</para>
<para>This ioctl is obsolete. Do not use in new drivers. For V4L2 decoders this
ioctl has been replaced by the &VIDIOC-TRY-DECODER-CMD; ioctl.</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl tries a decoder command. The <constant>video_command</constant> struct
is a subset of the <constant>v4l2_decoder_cmd</constant> struct, so refer to the
&VIDIOC-TRY-DECODER-CMD; documentation for more information.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(int fd, int request =
 VIDEO_TRY_COMMAND, struct video_command *cmd);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_TRY_COMMAND for this
 command.</para>
</entry>
 </row><row><entry
 align="char">
<para>struct video_command *cmd
</para>
</entry><entry
 align="char">
<para>Try a decoder command.
</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_GET_SIZE"
role="subsection"><title>VIDEO_GET_SIZE</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl returns the size and aspect ratio.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(int fd, int request =
 VIDEO_GET_SIZE, video_size_t *size);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_GET_SIZE for this
 command.</para>
</entry>
 </row><row><entry
 align="char">
<para>video_size_t *size
</para>
</entry><entry
 align="char">
<para>Returns the size and aspect ratio.
</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_SET_DISPLAY_FORMAT"
role="subsection"><title>VIDEO_SET_DISPLAY_FORMAT</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call asks the Video Device to select the video format to be applied
 by the MPEG chip on the video.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para> int ioctl(fd, int request =
 VIDEO_SET_DISPLAY_FORMAT, video_display_format_t
 format);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_SET_DISPLAY_FORMAT for this
 command.</para>
</entry>
 </row><row><entry
 align="char">
<para>video_display_format_t
 format</para>
</entry><entry
 align="char">
<para>Selects the video format to be used.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_STILLPICTURE"
role="subsection"><title>VIDEO_STILLPICTURE</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call asks the Video Device to display a still picture (I-frame). The
 input data shall contain an I-frame. If the pointer is NULL, then the current
 displayed still picture is blanked.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(fd, int request = VIDEO_STILLPICTURE,
 struct video_still_picture ⋆sp);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_STILLPICTURE for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>struct
 video_still_picture
 *sp</para>
</entry><entry
 align="char">
<para>Pointer to a location where an I-frame and size is stored.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_FAST_FORWARD"
role="subsection"><title>VIDEO_FAST_FORWARD</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call asks the Video Device to skip decoding of N number of I-frames.
 This call can only be used if VIDEO_SOURCE_MEMORY is selected.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(fd, int request = VIDEO_FAST_FORWARD, int
 nFrames);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_FAST_FORWARD for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>int nFrames</para>
</entry><entry
 align="char">
<para>The number of frames to skip.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>EPERM</para>
</entry><entry
 align="char">
<para>Mode VIDEO_SOURCE_MEMORY not selected.</para>
</entry>
 </row></tbody></tgroup></informaltable>

</section><section id="VIDEO_SLOWMOTION"
role="subsection"><title>VIDEO_SLOWMOTION</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call asks the video device to repeat decoding frames N number of
 times. This call can only be used if VIDEO_SOURCE_MEMORY is selected.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(fd, int request = VIDEO_SLOWMOTION, int
 nFrames);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_SLOWMOTION for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>int nFrames</para>
</entry><entry
 align="char">
<para>The number of times to repeat each frame.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>EPERM</para>
</entry><entry
 align="char">
<para>Mode VIDEO_SOURCE_MEMORY not selected.</para>
</entry>
 </row></tbody></tgroup></informaltable>

</section><section id="VIDEO_GET_CAPABILITIES"
role="subsection"><title>VIDEO_GET_CAPABILITIES</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call asks the video device about its decoding capabilities. On success
 it returns and integer which has bits set according to the defines in section ??.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(fd, int request = VIDEO_GET_CAPABILITIES,
 unsigned int ⋆cap);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_GET_CAPABILITIES for this
 command.</para>
</entry>
 </row><row><entry
 align="char">
<para>unsigned int *cap</para>
</entry><entry
 align="char">
<para>Pointer to a location where to store the capability
 information.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_SET_ID"
role="subsection"><title>VIDEO_SET_ID</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl selects which sub-stream is to be decoded if a program or system
 stream is sent to the video device.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(int fd, int request = VIDEO_SET_ID, int
 id);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_SET_ID for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>int id</para>
</entry><entry
 align="char">
<para>video sub-stream id</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>EINVAL</para>
</entry><entry
 align="char">
<para>Invalid sub-stream id.</para>
</entry>
 </row></tbody></tgroup></informaltable>

</section><section id="VIDEO_CLEAR_BUFFER"
role="subsection"><title>VIDEO_CLEAR_BUFFER</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call clears all video buffers in the driver and in the decoder hardware.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(fd, int request = VIDEO_CLEAR_BUFFER);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_CLEAR_BUFFER for this command.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_SET_STREAMTYPE"
role="subsection"><title>VIDEO_SET_STREAMTYPE</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl tells the driver which kind of stream to expect being written to it. If
 this call is not used the default of video PES is used. Some drivers might not
 support this call and always expect PES.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(fd, int request = VIDEO_SET_STREAMTYPE,
 int type);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_SET_STREAMTYPE for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>int type</para>
</entry><entry
 align="char">
<para>stream type</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_SET_FORMAT"
role="subsection"><title>VIDEO_SET_FORMAT</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl sets the screen format (aspect ratio) of the connected output device
 (TV) so that the output of the decoder can be adjusted accordingly.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para> int ioctl(fd, int request = VIDEO_SET_FORMAT,
 video_format_t format);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_SET_FORMAT for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>video_format_t
 format</para>
</entry><entry
 align="char">
<para>video format of TV as defined in section ??.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>EINVAL</para>
</entry><entry
 align="char">
<para>format is not a valid video format.</para>
</entry>
 </row></tbody></tgroup></informaltable>

</section><section id="VIDEO_SET_SYSTEM"
role="subsection"><title>VIDEO_SET_SYSTEM</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl sets the television output format. The format (see section ??) may
 vary from the color format of the displayed MPEG stream. If the hardware is
 not able to display the requested format the call will return an error.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para> int ioctl(fd, int request = VIDEO_SET_SYSTEM ,
 video_system_t system);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_SET_FORMAT for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>video_system_t
 system</para>
</entry><entry
 align="char">
<para>video system of TV output.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>EINVAL</para>
</entry><entry
 align="char">
<para>system is not a valid or supported video system.</para>
</entry>
 </row></tbody></tgroup></informaltable>

</section><section id="VIDEO_SET_HIGHLIGHT"
role="subsection"><title>VIDEO_SET_HIGHLIGHT</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl sets the SPU highlight information for the menu access of a DVD.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para> int ioctl(fd, int request = VIDEO_SET_HIGHLIGHT
 ,video_highlight_t ⋆vhilite)</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_SET_HIGHLIGHT for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>video_highlight_t
 *vhilite</para>
</entry><entry
 align="char">
<para>SPU Highlight information according to section ??.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_SET_SPU"
role="subsection"><title>VIDEO_SET_SPU</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl activates or deactivates SPU decoding in a DVD input stream. It can
 only be used, if the driver is able to handle a DVD stream.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para> int ioctl(fd, int request = VIDEO_SET_SPU ,
 video_spu_t ⋆spu)</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_SET_SPU for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>video_spu_t *spu</para>
</entry><entry
 align="char">
<para>SPU decoding (de)activation and subid setting according
 to section ??.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>EINVAL</para>
</entry><entry
 align="char">
<para>input is not a valid spu setting or driver cannot handle
 SPU.</para>
</entry>
 </row></tbody></tgroup></informaltable>

</section><section id="VIDEO_SET_SPU_PALETTE"
role="subsection"><title>VIDEO_SET_SPU_PALETTE</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl sets the SPU color palette.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para> int ioctl(fd, int request = VIDEO_SET_SPU_PALETTE
 ,video_spu_palette_t ⋆palette )</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_SET_SPU_PALETTE for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>video_spu_palette_t
 *palette</para>
</entry><entry
 align="char">
<para>SPU palette according to section ??.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>EINVAL</para>
</entry><entry
 align="char">
<para>input is not a valid palette or driver doesn’t handle SPU.</para>
</entry>
 </row></tbody></tgroup></informaltable>

</section><section id="VIDEO_GET_NAVI"
role="subsection"><title>VIDEO_GET_NAVI</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl returns navigational information from the DVD stream. This is
 especially needed if an encoded stream has to be decoded by the hardware.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para> int ioctl(fd, int request = VIDEO_GET_NAVI ,
 video_navi_pack_t ⋆navipack)</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_GET_NAVI for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>video_navi_pack_t
 *navipack</para>
</entry><entry
 align="char">
<para>PCI or DSI pack (private stream 2) according to section
 ??.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>EFAULT</para>
</entry><entry
 align="char">
<para>driver is not able to return navigational information</para>
</entry>
 </row></tbody></tgroup></informaltable>

</section><section id="VIDEO_SET_ATTRIBUTES"
role="subsection"><title>VIDEO_SET_ATTRIBUTES</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl is intended for DVD playback and allows you to set certain
 information about the stream. Some hardware may not need this information,
 but the call also tells the hardware to prepare for DVD playback.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para> int ioctl(fd, int request = VIDEO_SET_ATTRIBUTE
 ,video_attributes_t vattr)</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_SET_ATTRIBUTE for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>video_attributes_t
 vattr</para>
</entry><entry
 align="char">
<para>video attributes according to section ??.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>EINVAL</para>
</entry><entry
 align="char">
<para>input is not a valid attribute setting.</para>
</entry>
 </row></tbody></tgroup></informaltable>
 </section></section>

Xml文件 | 1969行 | 55.59 KB

<title>DVB Video Device</title>
<para>The DVB video device controls the MPEG2 video decoder of the DVB hardware. It
can be accessed through <emphasis role="tt">/dev/dvb/adapter0/video0</emphasis>. Data types and and
ioctl definitions can be accessed by including <emphasis role="tt">linux/dvb/video.h</emphasis> in your
application.
</para>
<para>Note that the DVB video device only controls decoding of the MPEG video stream, not
its presentation on the TV or computer screen. On PCs this is typically handled by an
associated video4linux device, e.g. <emphasis role="tt">/dev/video</emphasis>, which allows scaling and defining output
windows.
</para>
<para>Some DVB cards don&#8217;t have their own MPEG decoder, which results in the omission of
the audio and video device as well as the video4linux device.
</para>
<para>The ioctls that deal with SPUs (sub picture units) and navigation packets are only
supported on some MPEG decoders made for DVD playback.
</para>
<para>
These ioctls were also used by V4L2 to control MPEG decoders implemented in V4L2. The use
of these ioctls for that purpose has been made obsolete and proper V4L2 ioctls or controls
have been created to replace that functionality.</para>
<section id="video_types">
<title>Video Data Types</title>

<section id="video-format-t">
<title>video_format_t</title>
<para>The <emphasis role="tt">video_format_t</emphasis> data type defined by
</para>
<programlisting>
typedef enum {
	VIDEO_FORMAT_4_3,     /&#x22C6; Select 4:3 format &#x22C6;/
	VIDEO_FORMAT_16_9,    /&#x22C6; Select 16:9 format. &#x22C6;/
	VIDEO_FORMAT_221_1    /&#x22C6; 2.21:1 &#x22C6;/
} video_format_t;
</programlisting>
<para>is used in the VIDEO_SET_FORMAT function (??) to tell the driver which aspect ratio
the output hardware (e.g. TV) has. It is also used in the data structures video_status
(??) returned by VIDEO_GET_STATUS (??) and video_event (??) returned by
VIDEO_GET_EVENT (??) which report about the display format of the current video
stream.
</para>
</section>

<section id="video-displayformat-t">
<title>video_displayformat_t</title>
<para>In case the display format of the video stream and of the display hardware differ the
application has to specify how to handle the cropping of the picture. This can be done using
the VIDEO_SET_DISPLAY_FORMAT call (??) which accepts
</para>
<programlisting>
typedef enum {
	VIDEO_PAN_SCAN,       /&#x22C6; use pan and scan format &#x22C6;/
	VIDEO_LETTER_BOX,     /&#x22C6; use letterbox format &#x22C6;/
	VIDEO_CENTER_CUT_OUT  /&#x22C6; use center cut out format &#x22C6;/
} video_displayformat_t;
</programlisting>
<para>as argument.
</para>
</section>

<section id="video-stream-source-t">
<title>video_stream_source_t</title>
<para>The video stream source is set through the VIDEO_SELECT_SOURCE call and can take
the following values, depending on whether we are replaying from an internal (demuxer) or
external (user write) source.
</para>
<programlisting>
typedef enum {
	VIDEO_SOURCE_DEMUX, /&#x22C6; Select the demux as the main source &#x22C6;/
	VIDEO_SOURCE_MEMORY /&#x22C6; If this source is selected, the stream
			       comes from the user through the write
			       system call &#x22C6;/
} video_stream_source_t;
</programlisting>
<para>VIDEO_SOURCE_DEMUX selects the demultiplexer (fed either by the frontend or the
DVR device) as the source of the video stream. If VIDEO_SOURCE_MEMORY
is selected the stream comes from the application through the <emphasis role="tt">write()</emphasis> system
call.
</para>
</section>

<section id="video-play-state-t">
<title>video_play_state_t</title>
<para>The following values can be returned by the VIDEO_GET_STATUS call representing the
state of video playback.
</para>
<programlisting>
typedef enum {
	VIDEO_STOPPED, /&#x22C6; Video is stopped &#x22C6;/
	VIDEO_PLAYING, /&#x22C6; Video is currently playing &#x22C6;/
	VIDEO_FREEZED  /&#x22C6; Video is freezed &#x22C6;/
} video_play_state_t;
</programlisting>
</section>

<section id="video-command">
<title>struct video_command</title>
<para>The structure must be zeroed before use by the application
This ensures it can be extended safely in the future.</para>
<programlisting>
struct video_command {
	__u32 cmd;
	__u32 flags;
	union {
		struct {
			__u64 pts;
		} stop;

		struct {
			/&#x22C6; 0 or 1000 specifies normal speed,
			   1 specifies forward single stepping,
			   -1 specifies backward single stepping,
			   &gt;>1: playback at speed/1000 of the normal speed,
			   &lt;-1: reverse playback at (-speed/1000) of the normal speed. &#x22C6;/
			__s32 speed;
			__u32 format;
		} play;

		struct {
			__u32 data[16];
		} raw;
	};
};
</programlisting>
</section>

<section id="video-size-t">
<title>video_size_t</title>
<programlisting>
typedef struct {
	int w;
	int h;
	video_format_t aspect_ratio;
} video_size_t;
</programlisting>
</section>


<section id="video-event">
<title>struct video_event</title>
<para>The following is the structure of a video event as it is returned by the VIDEO_GET_EVENT
call.
</para>
<programlisting>
struct video_event {
	__s32 type;
#define VIDEO_EVENT_SIZE_CHANGED	1
#define VIDEO_EVENT_FRAME_RATE_CHANGED	2
#define VIDEO_EVENT_DECODER_STOPPED 	3
#define VIDEO_EVENT_VSYNC 		4
	__kernel_time_t timestamp;
	union {
		video_size_t size;
		unsigned int frame_rate;	/&#x22C6; in frames per 1000sec &#x22C6;/
		unsigned char vsync_field;	/&#x22C6; unknown/odd/even/progressive &#x22C6;/
	} u;
};
</programlisting>
</section>

<section id="video-status">
<title>struct video_status</title>
<para>The VIDEO_GET_STATUS call returns the following structure informing about various
states of the playback operation.
</para>
<programlisting>
struct video_status {
	int                   video_blank;   /&#x22C6; blank video on freeze? &#x22C6;/
	video_play_state_t    play_state;    /&#x22C6; current state of playback &#x22C6;/
	video_stream_source_t stream_source; /&#x22C6; current source (demux/memory) &#x22C6;/
	video_format_t        video_format;  /&#x22C6; current aspect ratio of stream &#x22C6;/
	video_displayformat_t display_format;/&#x22C6; selected cropping mode &#x22C6;/
};
</programlisting>
<para>If video_blank is set video will be blanked out if the channel is changed or if playback is
stopped. Otherwise, the last picture will be displayed. play_state indicates if the video is
currently frozen, stopped, or being played back. The stream_source corresponds to the seleted
source for the video stream. It can come either from the demultiplexer or from memory.
The video_format indicates the aspect ratio (one of 4:3 or 16:9) of the currently
played video stream. Finally, display_format corresponds to the selected cropping
mode in case the source video format is not the same as the format of the output
device.
</para>
</section>

<section id="video-still-picture">
<title>struct video_still_picture</title>
<para>An I-frame displayed via the VIDEO_STILLPICTURE call is passed on within the
following structure.
</para>
<programlisting>
/&#x22C6; pointer to and size of a single iframe in memory &#x22C6;/
struct video_still_picture {
	char &#x22C6;iFrame;        /&#x22C6; pointer to a single iframe in memory &#x22C6;/
	int32_t size;
};
</programlisting>
</section>

<section id="video_caps">
<title>video capabilities</title>
<para>A call to VIDEO_GET_CAPABILITIES returns an unsigned integer with the following
bits set according to the hardwares capabilities.
</para>
<programlisting>
 /&#x22C6; bit definitions for capabilities: &#x22C6;/
 /&#x22C6; can the hardware decode MPEG1 and/or MPEG2? &#x22C6;/
 #define VIDEO_CAP_MPEG1   1
 #define VIDEO_CAP_MPEG2   2
 /&#x22C6; can you send a system and/or program stream to video device?
    (you still have to open the video and the audio device but only
     send the stream to the video device) &#x22C6;/
 #define VIDEO_CAP_SYS     4
 #define VIDEO_CAP_PROG    8
 /&#x22C6; can the driver also handle SPU, NAVI and CSS encoded data?
    (CSS API is not present yet) &#x22C6;/
 #define VIDEO_CAP_SPU    16
 #define VIDEO_CAP_NAVI   32
 #define VIDEO_CAP_CSS    64
</programlisting>
</section>

<section id="video-system">
<title>video_system_t</title>
<para>A call to VIDEO_SET_SYSTEM sets the desired video system for TV output. The
following system types can be set:
</para>
<programlisting>
typedef enum {
	 VIDEO_SYSTEM_PAL,
	 VIDEO_SYSTEM_NTSC,
	 VIDEO_SYSTEM_PALN,
	 VIDEO_SYSTEM_PALNc,
	 VIDEO_SYSTEM_PALM,
	 VIDEO_SYSTEM_NTSC60,
	 VIDEO_SYSTEM_PAL60,
	 VIDEO_SYSTEM_PALM60
} video_system_t;
</programlisting>
</section>

<section id="video-highlight">
<title>struct video_highlight</title>
<para>Calling the ioctl VIDEO_SET_HIGHLIGHTS posts the SPU highlight information. The
call expects the following format for that information:
</para>
<programlisting>
 typedef
 struct video_highlight {
	 boolean active;      /&#x22C6;    1=show highlight, 0=hide highlight &#x22C6;/
	 uint8_t contrast1;   /&#x22C6;    7- 4  Pattern pixel contrast &#x22C6;/
			      /&#x22C6;    3- 0  Background pixel contrast &#x22C6;/
	 uint8_t contrast2;   /&#x22C6;    7- 4  Emphasis pixel-2 contrast &#x22C6;/
			      /&#x22C6;    3- 0  Emphasis pixel-1 contrast &#x22C6;/
	 uint8_t color1;      /&#x22C6;    7- 4  Pattern pixel color &#x22C6;/
			      /&#x22C6;    3- 0  Background pixel color &#x22C6;/
	 uint8_t color2;      /&#x22C6;    7- 4  Emphasis pixel-2 color &#x22C6;/
			      /&#x22C6;    3- 0  Emphasis pixel-1 color &#x22C6;/
	 uint32_t ypos;       /&#x22C6;   23-22  auto action mode &#x22C6;/
			      /&#x22C6;   21-12  start y &#x22C6;/
			      /&#x22C6;    9- 0  end y &#x22C6;/
	 uint32_t xpos;       /&#x22C6;   23-22  button color number &#x22C6;/
			      /&#x22C6;   21-12  start x &#x22C6;/
			      /&#x22C6;    9- 0  end x &#x22C6;/
 } video_highlight_t;
</programlisting>

</section>
<section id="video-spu">
<title>struct video_spu</title>
<para>Calling VIDEO_SET_SPU deactivates or activates SPU decoding, according to the
following format:
</para>
<programlisting>
 typedef
 struct video_spu {
	 boolean active;
	 int stream_id;
 } video_spu_t;
</programlisting>

</section>
<section id="video-spu-palette">
<title>struct video_spu_palette</title>
<para>The following structure is used to set the SPU palette by calling VIDEO_SPU_PALETTE:
</para>
<programlisting>
 typedef
 struct video_spu_palette {
	 int length;
	 uint8_t &#x22C6;palette;
 } video_spu_palette_t;
</programlisting>

</section>
<section id="video-navi-pack">
<title>struct video_navi_pack</title>
<para>In order to get the navigational data the following structure has to be passed to the ioctl
VIDEO_GET_NAVI:
</para>
<programlisting>
 typedef
 struct video_navi_pack {
	 int length;         /&#x22C6; 0 ... 1024 &#x22C6;/
	 uint8_t data[1024];
 } video_navi_pack_t;
</programlisting>
</section>


<section id="video-attributes-t">
<title>video_attributes_t</title>
<para>The following attributes can be set by a call to VIDEO_SET_ATTRIBUTES:
</para>
<programlisting>
 typedef uint16_t video_attributes_t;
 /&#x22C6;   bits: descr. &#x22C6;/
 /&#x22C6;   15-14 Video compression mode (0=MPEG-1, 1=MPEG-2) &#x22C6;/
 /&#x22C6;   13-12 TV system (0=525/60, 1=625/50) &#x22C6;/
 /&#x22C6;   11-10 Aspect ratio (0=4:3, 3=16:9) &#x22C6;/
 /&#x22C6;    9- 8 permitted display mode on 4:3 monitor (0=both, 1=only pan-sca &#x22C6;/
 /&#x22C6;    7    line 21-1 data present in GOP (1=yes, 0=no) &#x22C6;/
 /&#x22C6;    6    line 21-2 data present in GOP (1=yes, 0=no) &#x22C6;/
 /&#x22C6;    5- 3 source resolution (0=720x480/576, 1=704x480/576, 2=352x480/57 &#x22C6;/
 /&#x22C6;    2    source letterboxed (1=yes, 0=no) &#x22C6;/
 /&#x22C6;    0    film/camera mode (0=camera, 1=film (625/50 only)) &#x22C6;/
</programlisting>
</section></section>


<section id="video_function_calls">
<title>Video Function Calls</title>


<section id="video_fopen">
<title>open()</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This system call opens a named video device (e.g. /dev/dvb/adapter0/video0)
 for subsequent use.</para>
<para>When an open() call has succeeded, the device will be ready for use.
 The significance of blocking or non-blocking mode is described in the
 documentation for functions where there is a difference. It does not affect the
 semantics of the open() call itself. A device opened in blocking mode can later
 be put into non-blocking mode (and vice versa) using the F_SETFL command
 of the fcntl system call. This is a standard system call, documented in the Linux
 manual page for fcntl. Only one user can open the Video Device in O_RDWR
 mode. All other attempts to open the device in this mode will fail, and an
 error-code will be returned. If the Video Device is opened in O_RDONLY
 mode, the only ioctl call that can be used is VIDEO_GET_STATUS. All other
 call will return an error code.</para>
</entry>
 </row></tbody></tgroup></informaltable>

<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int open(const char &#x22C6;deviceName, int flags);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>const char
 *deviceName</para>
</entry><entry
 align="char">
<para>Name of specific video device.</para>
</entry>
 </row><row><entry
 align="char">
<para>int flags</para>
</entry><entry
 align="char">
<para>A bit-wise OR of the following flags:</para>
</entry>
 </row><row><entry
 align="char">
</entry><entry
 align="char">
<para>O_RDONLY read-only access</para>
</entry>
 </row><row><entry
 align="char">
</entry><entry
 align="char">
<para>O_RDWR read/write access</para>
</entry>
 </row><row><entry
 align="char">
</entry><entry
 align="char">
<para>O_NONBLOCK open in non-blocking mode</para>
</entry>
 </row><row><entry
 align="char">
</entry><entry
 align="char">
<para>(blocking mode is the default)</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>RETURN VALUE</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>ENODEV</para>
</entry><entry
 align="char">
<para>Device driver not loaded/available.</para>
</entry>
 </row><row><entry
 align="char">
<para>EINTERNAL</para>
</entry><entry
 align="char">
<para>Internal error.</para>
</entry>
 </row><row><entry
 align="char">
<para>EBUSY</para>
</entry><entry
 align="char">
<para>Device or resource busy.</para>
</entry>
 </row><row><entry
 align="char">
<para>EINVAL</para>
</entry><entry
 align="char">
<para>Invalid argument.</para>
</entry>
 </row></tbody></tgroup></informaltable>

</section>
<section id="video_fclose">
<title>close()</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This system call closes a previously opened video device.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int close(int fd);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>RETURN VALUE</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>EBADF</para>
</entry><entry
 align="char">
<para>fd is not a valid open file descriptor.</para>
</entry>
 </row></tbody></tgroup></informaltable>

</section>
<section id="video_fwrite">
<title>write()</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This system call can only be used if VIDEO_SOURCE_MEMORY is selected
 in the ioctl call VIDEO_SELECT_SOURCE. The data provided shall be in
 PES format, unless the capability allows other formats. If O_NONBLOCK is
 not specified the function will block until buffer space is available. The amount
 of data to be transferred is implied by count.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>size_t write(int fd, const void &#x22C6;buf, size_t count);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>void *buf</para>
</entry><entry
 align="char">
<para>Pointer to the buffer containing the PES data.</para>
</entry>
 </row><row><entry
 align="char">
<para>size_t count</para>
</entry><entry
 align="char">
<para>Size of buf.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>RETURN VALUE</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>EPERM</para>
</entry><entry
 align="char">
<para>Mode VIDEO_SOURCE_MEMORY not selected.</para>
</entry>
 </row><row><entry
 align="char">
<para>ENOMEM</para>
</entry><entry
 align="char">
<para>Attempted to write more data than the internal buffer can
 hold.</para>
</entry>
 </row><row><entry
 align="char">
<para>EBADF</para>
</entry><entry
 align="char">
<para>fd is not a valid open file descriptor.</para>
</entry>
 </row></tbody></tgroup></informaltable>

</section><section id="VIDEO_STOP"
role="subsection"><title>VIDEO_STOP</title>
<para>DESCRIPTION
</para>
<para>This ioctl is for DVB devices only. To control a V4L2 decoder use the V4L2
&VIDIOC-DECODER-CMD; instead.</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call asks the Video Device to stop playing the current stream.
 Depending on the input parameter, the screen can be blanked out or displaying
 the last decoded frame.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(fd, int request = VIDEO_STOP, boolean
 mode);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_STOP for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>Boolean mode</para>
</entry><entry
 align="char">
<para>Indicates how the screen shall be handled.</para>
</entry>
 </row><row><entry
 align="char">
</entry><entry
 align="char">
<para>TRUE: Blank screen when stop.</para>
</entry>
 </row><row><entry
 align="char">
</entry><entry
 align="char">
<para>FALSE: Show last decoded frame.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_PLAY"
role="subsection"><title>VIDEO_PLAY</title>
<para>DESCRIPTION
</para>
<para>This ioctl is for DVB devices only. To control a V4L2 decoder use the V4L2
&VIDIOC-DECODER-CMD; instead.</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call asks the Video Device to start playing a video stream from the
 selected source.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(fd, int request = VIDEO_PLAY);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_PLAY for this command.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_FREEZE"
role="subsection"><title>VIDEO_FREEZE</title>
<para>DESCRIPTION
</para>
<para>This ioctl is for DVB devices only. To control a V4L2 decoder use the V4L2
&VIDIOC-DECODER-CMD; instead.</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call suspends the live video stream being played. Decoding
 and playing are frozen. It is then possible to restart the decoding
 and playing process of the video stream using the VIDEO_CONTINUE
 command. If VIDEO_SOURCE_MEMORY is selected in the ioctl call
 VIDEO_SELECT_SOURCE, the DVB subsystem will not decode any more
 data until the ioctl call VIDEO_CONTINUE or VIDEO_PLAY is performed.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(fd, int request = VIDEO_FREEZE);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_FREEZE for this command.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_CONTINUE"
role="subsection"><title>VIDEO_CONTINUE</title>
<para>DESCRIPTION
</para>
<para>This ioctl is for DVB devices only. To control a V4L2 decoder use the V4L2
&VIDIOC-DECODER-CMD; instead.</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call restarts decoding and playing processes of the video stream
 which was played before a call to VIDEO_FREEZE was made.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(fd, int request = VIDEO_CONTINUE);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_CONTINUE for this command.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_SELECT_SOURCE"
role="subsection"><title>VIDEO_SELECT_SOURCE</title>
<para>DESCRIPTION
</para>
<para>This ioctl is for DVB devices only. This ioctl was also supported by the
V4L2 ivtv driver, but that has been replaced by the ivtv-specific
<constant>IVTV_IOC_PASSTHROUGH_MODE</constant> ioctl.</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call informs the video device which source shall be used for the input
 data. The possible sources are demux or memory. If memory is selected, the
 data is fed to the video device through the write command.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(fd, int request = VIDEO_SELECT_SOURCE,
 video_stream_source_t source);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_SELECT_SOURCE for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>video_stream_source_t
 source</para>
</entry><entry
 align="char">
<para>Indicates which source shall be used for the Video stream.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_SET_BLANK"
role="subsection"><title>VIDEO_SET_BLANK</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call asks the Video Device to blank out the picture.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(fd, int request = VIDEO_SET_BLANK, boolean
 mode);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_SET_BLANK for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>boolean mode</para>
</entry><entry
 align="char">
<para>TRUE: Blank screen when stop.</para>
</entry>
 </row><row><entry
 align="char">
</entry><entry
 align="char">
<para>FALSE: Show last decoded frame.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_GET_STATUS"
role="subsection"><title>VIDEO_GET_STATUS</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call asks the Video Device to return the current status of the device.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para> int ioctl(fd, int request = VIDEO_GET_STATUS, struct
 video_status &#x22C6;status);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_GET_STATUS for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>struct video_status
 *status</para>
</entry><entry
 align="char">
<para>Returns the current status of the Video Device.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_GET_FRAME_COUNT"
role="subsection"><title>VIDEO_GET_FRAME_COUNT</title>
<para>DESCRIPTION
</para>
<para>This ioctl is obsolete. Do not use in new drivers. For V4L2 decoders this
ioctl has been replaced by the <constant>V4L2_CID_MPEG_VIDEO_DEC_FRAME</constant> control.</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call asks the Video Device to return the number of displayed frames
since the decoder was started.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(int fd, int request =
 VIDEO_GET_FRAME_COUNT, __u64 *pts);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_GET_FRAME_COUNT for this
 command.</para>
</entry>
 </row><row><entry
 align="char">
<para>__u64 *pts
</para>
</entry><entry
 align="char">
<para>Returns the number of frames displayed since the decoder was started.
</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_GET_PTS"
role="subsection"><title>VIDEO_GET_PTS</title>
<para>DESCRIPTION
</para>
<para>This ioctl is obsolete. Do not use in new drivers. For V4L2 decoders this
ioctl has been replaced by the <constant>V4L2_CID_MPEG_VIDEO_DEC_PTS</constant> control.</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call asks the Video Device to return the current PTS timestamp.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(int fd, int request =
 VIDEO_GET_PTS, __u64 *pts);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_GET_PTS for this
 command.</para>
</entry>
 </row><row><entry
 align="char">
<para>__u64 *pts
</para>
</entry><entry
 align="char">
<para>Returns the 33-bit timestamp as defined in ITU T-REC-H.222.0 / ISO/IEC 13818-1.
</para>
<para>
The PTS should belong to the currently played
frame if possible, but may also be a value close to it
like the PTS of the last decoded frame or the last PTS
extracted by the PES parser.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_GET_FRAME_RATE"
role="subsection"><title>VIDEO_GET_FRAME_RATE</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call asks the Video Device to return the current framerate.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(int fd, int request =
 VIDEO_GET_FRAME_RATE, unsigned int *rate);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_GET_FRAME_RATE for this
 command.</para>
</entry>
 </row><row><entry
 align="char">
<para>unsigned int *rate
</para>
</entry><entry
 align="char">
<para>Returns the framerate in number of frames per 1000 seconds.
</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_GET_EVENT"
role="subsection"><title>VIDEO_GET_EVENT</title>
<para>DESCRIPTION
</para>
<para>This ioctl is for DVB devices only. To get events from a V4L2 decoder use the V4L2
&VIDIOC-DQEVENT; ioctl instead.</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call returns an event of type video_event if available. If an event is
 not available, the behavior depends on whether the device is in blocking or
 non-blocking mode. In the latter case, the call fails immediately with errno
 set to EWOULDBLOCK. In the former case, the call blocks until an event
 becomes available. The standard Linux poll() and/or select() system calls can
 be used with the device file descriptor to watch for new events. For select(),
 the file descriptor should be included in the exceptfds argument, and for
 poll(), POLLPRI should be specified as the wake-up condition. Read-only
 permissions are sufficient for this ioctl call.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para> int ioctl(fd, int request = VIDEO_GET_EVENT, struct
 video_event &#x22C6;ev);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_GET_EVENT for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>struct video_event
 *ev</para>
</entry><entry
 align="char">
<para>Points to the location where the event, if any, is to be
 stored.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>EWOULDBLOCK</para>
</entry><entry
 align="char">
<para>There is no event pending, and the device is in
 non-blocking mode.</para>
</entry>
 </row><row><entry
 align="char">
<para>EOVERFLOW</para>
</entry><entry
 align="char">
<para>Overflow in event queue - one or more events were lost.</para>
</entry>
 </row></tbody></tgroup></informaltable>

</section><section id="VIDEO_COMMAND"
role="subsection"><title>VIDEO_COMMAND</title>
<para>DESCRIPTION
</para>
<para>This ioctl is obsolete. Do not use in new drivers. For V4L2 decoders this
ioctl has been replaced by the &VIDIOC-DECODER-CMD; ioctl.</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl commands the decoder. The <constant>video_command</constant> struct
is a subset of the <constant>v4l2_decoder_cmd</constant> struct, so refer to the
&VIDIOC-DECODER-CMD; documentation for more information.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(int fd, int request =
 VIDEO_COMMAND, struct video_command *cmd);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_COMMAND for this
 command.</para>
</entry>
 </row><row><entry
 align="char">
<para>struct video_command *cmd
</para>
</entry><entry
 align="char">
<para>Commands the decoder.
</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_TRY_COMMAND"
role="subsection"><title>VIDEO_TRY_COMMAND</title>
<para>DESCRIPTION
</para>
<para>This ioctl is obsolete. Do not use in new drivers. For V4L2 decoders this
ioctl has been replaced by the &VIDIOC-TRY-DECODER-CMD; ioctl.</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl tries a decoder command. The <constant>video_command</constant> struct
is a subset of the <constant>v4l2_decoder_cmd</constant> struct, so refer to the
&VIDIOC-TRY-DECODER-CMD; documentation for more information.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(int fd, int request =
 VIDEO_TRY_COMMAND, struct video_command *cmd);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_TRY_COMMAND for this
 command.</para>
</entry>
 </row><row><entry
 align="char">
<para>struct video_command *cmd
</para>
</entry><entry
 align="char">
<para>Try a decoder command.
</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_GET_SIZE"
role="subsection"><title>VIDEO_GET_SIZE</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl returns the size and aspect ratio.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(int fd, int request =
 VIDEO_GET_SIZE, video_size_t *size);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_GET_SIZE for this
 command.</para>
</entry>
 </row><row><entry
 align="char">
<para>video_size_t *size
</para>
</entry><entry
 align="char">
<para>Returns the size and aspect ratio.
</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_SET_DISPLAY_FORMAT"
role="subsection"><title>VIDEO_SET_DISPLAY_FORMAT</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call asks the Video Device to select the video format to be applied
 by the MPEG chip on the video.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para> int ioctl(fd, int request =
 VIDEO_SET_DISPLAY_FORMAT, video_display_format_t
 format);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_SET_DISPLAY_FORMAT for this
 command.</para>
</entry>
 </row><row><entry
 align="char">
<para>video_display_format_t
 format</para>
</entry><entry
 align="char">
<para>Selects the video format to be used.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_STILLPICTURE"
role="subsection"><title>VIDEO_STILLPICTURE</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call asks the Video Device to display a still picture (I-frame). The
 input data shall contain an I-frame. If the pointer is NULL, then the current
 displayed still picture is blanked.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(fd, int request = VIDEO_STILLPICTURE,
 struct video_still_picture &#x22C6;sp);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_STILLPICTURE for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>struct
 video_still_picture
 *sp</para>
</entry><entry
 align="char">
<para>Pointer to a location where an I-frame and size is stored.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_FAST_FORWARD"
role="subsection"><title>VIDEO_FAST_FORWARD</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call asks the Video Device to skip decoding of N number of I-frames.
 This call can only be used if VIDEO_SOURCE_MEMORY is selected.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(fd, int request = VIDEO_FAST_FORWARD, int
 nFrames);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_FAST_FORWARD for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>int nFrames</para>
</entry><entry
 align="char">
<para>The number of frames to skip.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>EPERM</para>
</entry><entry
 align="char">
<para>Mode VIDEO_SOURCE_MEMORY not selected.</para>
</entry>
 </row></tbody></tgroup></informaltable>

</section><section id="VIDEO_SLOWMOTION"
role="subsection"><title>VIDEO_SLOWMOTION</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call asks the video device to repeat decoding frames N number of
 times. This call can only be used if VIDEO_SOURCE_MEMORY is selected.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(fd, int request = VIDEO_SLOWMOTION, int
 nFrames);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_SLOWMOTION for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>int nFrames</para>
</entry><entry
 align="char">
<para>The number of times to repeat each frame.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>EPERM</para>
</entry><entry
 align="char">
<para>Mode VIDEO_SOURCE_MEMORY not selected.</para>
</entry>
 </row></tbody></tgroup></informaltable>

</section><section id="VIDEO_GET_CAPABILITIES"
role="subsection"><title>VIDEO_GET_CAPABILITIES</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call asks the video device about its decoding capabilities. On success
 it returns and integer which has bits set according to the defines in section ??.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(fd, int request = VIDEO_GET_CAPABILITIES,
 unsigned int &#x22C6;cap);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_GET_CAPABILITIES for this
 command.</para>
</entry>
 </row><row><entry
 align="char">
<para>unsigned int *cap</para>
</entry><entry
 align="char">
<para>Pointer to a location where to store the capability
 information.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_SET_ID"
role="subsection"><title>VIDEO_SET_ID</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl selects which sub-stream is to be decoded if a program or system
 stream is sent to the video device.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(int fd, int request = VIDEO_SET_ID, int
 id);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_SET_ID for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>int id</para>
</entry><entry
 align="char">
<para>video sub-stream id</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>EINVAL</para>
</entry><entry
 align="char">
<para>Invalid sub-stream id.</para>
</entry>
 </row></tbody></tgroup></informaltable>

</section><section id="VIDEO_CLEAR_BUFFER"
role="subsection"><title>VIDEO_CLEAR_BUFFER</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call clears all video buffers in the driver and in the decoder hardware.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(fd, int request = VIDEO_CLEAR_BUFFER);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_CLEAR_BUFFER for this command.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_SET_STREAMTYPE"
role="subsection"><title>VIDEO_SET_STREAMTYPE</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl tells the driver which kind of stream to expect being written to it. If
 this call is not used the default of video PES is used. Some drivers might not
 support this call and always expect PES.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(fd, int request = VIDEO_SET_STREAMTYPE,
 int type);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_SET_STREAMTYPE for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>int type</para>
</entry><entry
 align="char">
<para>stream type</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_SET_FORMAT"
role="subsection"><title>VIDEO_SET_FORMAT</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl sets the screen format (aspect ratio) of the connected output device
 (TV) so that the output of the decoder can be adjusted accordingly.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para> int ioctl(fd, int request = VIDEO_SET_FORMAT,
 video_format_t format);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_SET_FORMAT for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>video_format_t
 format</para>
</entry><entry
 align="char">
<para>video format of TV as defined in section ??.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>EINVAL</para>
</entry><entry
 align="char">
<para>format is not a valid video format.</para>
</entry>
 </row></tbody></tgroup></informaltable>

</section><section id="VIDEO_SET_SYSTEM"
role="subsection"><title>VIDEO_SET_SYSTEM</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl sets the television output format. The format (see section ??) may
 vary from the color format of the displayed MPEG stream. If the hardware is
 not able to display the requested format the call will return an error.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para> int ioctl(fd, int request = VIDEO_SET_SYSTEM ,
 video_system_t system);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_SET_FORMAT for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>video_system_t
 system</para>
</entry><entry
 align="char">
<para>video system of TV output.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>EINVAL</para>
</entry><entry
 align="char">
<para>system is not a valid or supported video system.</para>
</entry>
 </row></tbody></tgroup></informaltable>

</section><section id="VIDEO_SET_HIGHLIGHT"
role="subsection"><title>VIDEO_SET_HIGHLIGHT</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl sets the SPU highlight information for the menu access of a DVD.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para> int ioctl(fd, int request = VIDEO_SET_HIGHLIGHT
 ,video_highlight_t &#x22C6;vhilite)</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_SET_HIGHLIGHT for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>video_highlight_t
 *vhilite</para>
</entry><entry
 align="char">
<para>SPU Highlight information according to section ??.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;

</section><section id="VIDEO_SET_SPU"
role="subsection"><title>VIDEO_SET_SPU</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl activates or deactivates SPU decoding in a DVD input stream. It can
 only be used, if the driver is able to handle a DVD stream.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para> int ioctl(fd, int request = VIDEO_SET_SPU ,
 video_spu_t &#x22C6;spu)</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_SET_SPU for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>video_spu_t *spu</para>
</entry><entry
 align="char">
<para>SPU decoding (de)activation and subid setting according
 to section ??.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>EINVAL</para>
</entry><entry
 align="char">
<para>input is not a valid spu setting or driver cannot handle
 SPU.</para>
</entry>
 </row></tbody></tgroup></informaltable>

</section><section id="VIDEO_SET_SPU_PALETTE"
role="subsection"><title>VIDEO_SET_SPU_PALETTE</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl sets the SPU color palette.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para> int ioctl(fd, int request = VIDEO_SET_SPU_PALETTE
 ,video_spu_palette_t &#x22C6;palette )</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_SET_SPU_PALETTE for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>video_spu_palette_t
 *palette</para>
</entry><entry
 align="char">
<para>SPU palette according to section ??.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>EINVAL</para>
</entry><entry
 align="char">
<para>input is not a valid palette or driver doesn&#8217;t handle SPU.</para>
</entry>
 </row></tbody></tgroup></informaltable>

</section><section id="VIDEO_GET_NAVI"
role="subsection"><title>VIDEO_GET_NAVI</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl returns navigational information from the DVD stream. This is
 especially needed if an encoded stream has to be decoded by the hardware.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para> int ioctl(fd, int request = VIDEO_GET_NAVI ,
 video_navi_pack_t &#x22C6;navipack)</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_GET_NAVI for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>video_navi_pack_t
 *navipack</para>
</entry><entry
 align="char">
<para>PCI or DSI pack (private stream 2) according to section
 ??.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>EFAULT</para>
</entry><entry
 align="char">
<para>driver is not able to return navigational information</para>
</entry>
 </row></tbody></tgroup></informaltable>

</section><section id="VIDEO_SET_ATTRIBUTES"
role="subsection"><title>VIDEO_SET_ATTRIBUTES</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl is intended for DVD playback and allows you to set certain
 information about the stream. Some hardware may not need this information,
 but the call also tells the hardware to prepare for DVD playback.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para> int ioctl(fd, int request = VIDEO_SET_ATTRIBUTE
 ,video_attributes_t vattr)</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int request</para>
</entry><entry
 align="char">
<para>Equals VIDEO_SET_ATTRIBUTE for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>video_attributes_t
 vattr</para>
</entry><entry
 align="char">
<para>video attributes according to section ??.</para>
</entry>
 </row></tbody></tgroup></informaltable>
&return-value-dvb;
<informaltable><tgroup cols="2"><tbody><row><entry
 align="char">
<para>EINVAL</para>
</entry><entry
 align="char">
<para>input is not a valid attribute setting.</para>
</entry>
 </row></tbody></tgroup></informaltable>
 </section></section>

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