/*
* Copyright 2007, The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "SkImageDecoder.h"
#include "SkImageEncoder.h"
#include "SkColorPriv.h"
#include "SkDither.h"
#include "SkScaledBitmapSampler.h"
#include "SkStream.h"
#include "SkTemplates.h"
#include "SkUtils.h"
#include <stdio.h>
extern "C" {
#include "jpeglib.h"
#include "jerror.h"
}
// this enables timing code to report milliseconds for an encode
//#define TIME_ENCODE
//#define TIME_DECODE
// this enables our rgb->yuv code, which is faster than libjpeg on ARM
// disable for the moment, as we have some glitches when width != multiple of 4
#define WE_CONVERT_TO_YUV
//////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////
class SkJPEGImageDecoder : public SkImageDecoder {
public:
virtual Format getFormat() const {
return kJPEG_Format;
}
protected:
virtual bool onDecode(SkStream* stream, SkBitmap* bm,
SkBitmap::Config pref, Mode);
};
//////////////////////////////////////////////////////////////////////////
#include "SkTime.h"
class AutoTimeMillis {
public:
AutoTimeMillis(const char label[]) : fLabel(label) {
if (!fLabel) {
fLabel = "";
}
fNow = SkTime::GetMSecs();
}
~AutoTimeMillis() {
SkDebugf("---- Time (ms): %s %d\n", fLabel, SkTime::GetMSecs() - fNow);
}
private:
const char* fLabel;
SkMSec fNow;
};
/* our source struct for directing jpeg to our stream object
*/
struct sk_source_mgr : jpeg_source_mgr {
sk_source_mgr(SkStream* stream, SkImageDecoder* decoder);
SkStream* fStream;
const void* fMemoryBase;
size_t fMemoryBaseSize;
SkImageDecoder* fDecoder;
enum {
kBufferSize = 1024
};
char fBuffer[kBufferSize];
};
/* Automatically clean up after throwing an exception */
class JPEGAutoClean {
public:
JPEGAutoClean(): cinfo_ptr(NULL) {}
~JPEGAutoClean() {
if (cinfo_ptr) {
jpeg_destroy_decompress(cinfo_ptr);
}
}
void set(jpeg_decompress_struct* info) {
cinfo_ptr = info;
}
private:
jpeg_decompress_struct* cinfo_ptr;
};
static void sk_init_source(j_decompress_ptr cinfo) {
sk_source_mgr* src = (sk_source_mgr*)cinfo->src;
src->next_input_byte = (const JOCTET*)src->fBuffer;
src->bytes_in_buffer = 0;
}
static boolean sk_fill_input_buffer(j_decompress_ptr cinfo) {
sk_source_mgr* src = (sk_source_mgr*)cinfo->src;
if (src->fDecoder != NULL && src->fDecoder->shouldCancelDecode()) {
return FALSE;
}
size_t bytes = src->fStream->read(src->fBuffer, sk_source_mgr::kBufferSize);
// note that JPEG is happy with less than the full read,
// as long as the result is non-zero
if (bytes == 0) {
return FALSE;
}
src->next_input_byte = (const JOCTET*)src->fBuffer;
src->bytes_in_buffer = bytes;
return TRUE;
}
static void sk_skip_input_data(j_decompress_ptr cinfo, long num_bytes) {
SkASSERT(num_bytes > 0);
sk_source_mgr* src = (sk_source_mgr*)cinfo->src;
long bytesToSkip = num_bytes - src->bytes_in_buffer;
// check if the skip amount exceeds the current buffer
if (bytesToSkip > 0) {
size_t bytes = src->fStream->skip(bytesToSkip);
if (bytes != (size_t)bytesToSkip) {
// SkDebugf("xxxxxxxxxxxxxx failure to skip request %d actual %d\n", bytesToSkip, bytes);
cinfo->err->error_exit((j_common_ptr)cinfo);
}
src->next_input_byte = (const JOCTET*)src->fBuffer;
src->bytes_in_buffer = 0;
} else {
src->next_input_byte += num_bytes;
src->bytes_in_buffer -= num_bytes;
}
}
static boolean sk_resync_to_restart(j_decompress_ptr cinfo, int desired) {
sk_source_mgr* src = (sk_source_mgr*)cinfo->src;
// what is the desired param for???
if (!src->fStream->rewind()) {
SkDebugf("xxxxxxxxxxxxxx failure to rewind\n");
cinfo->err->error_exit((j_common_ptr)cinfo);
return FALSE;
}
src->next_input_byte = (const JOCTET*)src->fBuffer;
src->bytes_in_buffer = 0;
return TRUE;
}
static void sk_term_source(j_decompress_ptr /*cinfo*/) {}
///////////////////////////////////////////////////////////////////////////////
static void skmem_init_source(j_decompress_ptr cinfo) {
sk_source_mgr* src = (sk_source_mgr*)cinfo->src;
src->next_input_byte = (const JOCTET*)src->fMemoryBase;
src->bytes_in_buffer = src->fMemoryBaseSize;
}
static boolean skmem_fill_input_buffer(j_decompress_ptr cinfo) {
SkDebugf("xxxxxxxxxxxxxx skmem_fill_input_buffer called\n");
return FALSE;
}
static void skmem_skip_input_data(j_decompress_ptr cinfo, long num_bytes) {
sk_source_mgr* src = (sk_source_mgr*)cinfo->src;
// SkDebugf("xxxxxxxxxxxxxx skmem_skip_input_data called %d\n", num_bytes);
src->next_input_byte = (const JOCTET*)((const char*)src->next_input_byte + num_bytes);
src->bytes_in_buffer -= num_bytes;
}
static boolean skmem_resync_to_restart(j_decompress_ptr cinfo, int desired) {
SkDebugf("xxxxxxxxxxxxxx skmem_resync_to_restart called\n");
return TRUE;
}
static void skmem_term_source(j_decompress_ptr /*cinfo*/) {}
///////////////////////////////////////////////////////////////////////////////
sk_source_mgr::sk_source_mgr(SkStream* stream, SkImageDecoder* decoder) : fStream(stream) {
fDecoder = decoder;
const void* baseAddr = stream->getMemoryBase();
if (baseAddr && false) {
fMemoryBase = baseAddr;
fMemoryBaseSize = stream->getLength();
init_source = skmem_init_source;
fill_input_buffer = skmem_fill_input_buffer;
skip_input_data = skmem_skip_input_data;
resync_to_restart = skmem_resync_to_restart;
term_source = skmem_term_source;
} else {
fMemoryBase = NULL;
fMemoryBaseSize = 0;
init_source = sk_init_source;
fill_input_buffer = sk_fill_input_buffer;
skip_input_data = sk_skip_input_data;
resync_to_restart = sk_resync_to_restart;
term_source = sk_term_source;
}
// SkDebugf("**************** use memorybase %p %d\n", fMemoryBase, fMemoryBaseSize);
}
#include <setjmp.h>
struct sk_error_mgr : jpeg_error_mgr {
jmp_buf fJmpBuf;
};
static void sk_error_exit(j_common_ptr cinfo) {
sk_error_mgr* error = (sk_error_mgr*)cinfo->err;
(*error->output_message) (cinfo);
/* Let the memory manager delete any temp files before we die */
jpeg_destroy(cinfo);
longjmp(error->fJmpBuf, -1);
}
///////////////////////////////////////////////////////////////////////////////
static bool skip_src_rows(jpeg_decompress_struct* cinfo, void* buffer,
int count) {
for (int i = 0; i < count; i++) {
JSAMPLE* rowptr = (JSAMPLE*)buffer;
int row_count = jpeg_read_scanlines(cinfo, &rowptr, 1);
if (row_count != 1) {
return false;
}
}
return true;
}
// This guy exists just to aid in debugging, as it allows debuggers to just
// set a break-point in one place to see all error exists.
static bool return_false(const jpeg_decompress_struct& cinfo,
const SkBitmap& bm, const char msg[]) {
#if 0
SkDebugf("libjpeg error %d <%s> from %s [%d %d]", cinfo.err->msg_code,
cinfo.err->jpeg_message_table[cinfo.err->msg_code], msg,
bm.width(), bm.height());
#endif
return false; // must always return false
}
bool SkJPEGImageDecoder::onDecode(SkStream* stream, SkBitmap* bm,
SkBitmap::Config prefConfig, Mode mode) {
#ifdef TIME_DECODE
AutoTimeMillis atm("JPEG Decode");
#endif
SkAutoMalloc srcStorage;
JPEGAutoClean autoClean;
jpeg_decompress_struct cinfo;
sk_error_mgr sk_err;
sk_source_mgr sk_stream(stream, this);
cinfo.err = jpeg_std_error(&sk_err);
sk_err.error_exit = sk_error_exit;
// All objects need to be instantiated before this setjmp call so that
// they will be cleaned up properly if an error occurs.
if (setjmp(sk_err.fJmpBuf)) {
return return_false(cinfo, *bm, "setjmp");
}
jpeg_create_decompress(&cinfo);
autoClean.set(&cinfo);
//jpeg_stdio_src(&cinfo, file);
cinfo.src = &sk_stream;
int status = jpeg_read_header(&cinfo, true);
if (status != JPEG_HEADER_OK) {
return return_false(cinfo, *bm, "read_header");
}
/* Try to fulfill the requested sampleSize. Since jpeg can do it (when it
can) much faster that we, just use their num/denom api to approximate
the size.
*/
int sampleSize = this->getSampleSize();
cinfo.dct_method = JDCT_IFAST;
cinfo.scale_num = 1;
cinfo.scale_denom = sampleSize;
/* this gives about 30% performance improvement. In theory it may
reduce the visual quality, in practice I'm not seeing a difference
*/
cinfo.do_fancy_upsampling = 0;
/* this gives another few percents */
cinfo.do_block_smoothing = 0;
/* default format is RGB */
cinfo.out_color_space = JCS_RGB;
SkBitmap::Config config = prefConfig;
// if no user preference, see what the device recommends
if (config == SkBitmap::kNo_Config)
config = SkImageDecoder::GetDeviceConfig();
// only these make sense for jpegs
if (config != SkBitmap::kARGB_8888_Config &&
config != SkBitmap::kARGB_4444_Config &&
config != SkBitmap::kRGB_565_Config) {
config = SkBitmap::kARGB_8888_Config;
}
#ifdef ANDROID_RGB
cinfo.dither_mode = JDITHER_NONE;
if (config == SkBitmap::kARGB_8888_Config) {
cinfo.out_color_space = JCS_RGBA_8888;
} else if (config == SkBitmap::kRGB_565_Config) {
if (sampleSize == 1) {
// SkScaledBitmapSampler can't handle RGB_565 yet,
// so don't even try.
cinfo.out_color_space = JCS_RGB_565;
if (this->getDitherImage()) {
cinfo.dither_mode = JDITHER_ORDERED;
}
}
}
#endif
if (sampleSize == 1 && mode == SkImageDecoder::kDecodeBounds_Mode) {
bm->setConfig(config, cinfo.image_width, cinfo.image_height);
bm->setIsOpaque(true);
return true;
}
/* image_width and image_height are the original dimensions, available
after jpeg_read_header(). To see the scaled dimensions, we have to call
jpeg_start_decompress(), and then read output_width and output_height.
*/
if (!jpeg_start_decompress(&cinfo)) {
return return_false(cinfo, *bm, "start_decompress");
}
/* If we need to better match the request, we might examine the image and
output dimensions, and determine if the downsampling jpeg provided is
not sufficient. If so, we can recompute a modified sampleSize value to
make up the difference.
To skip this additional scaling, just set sampleSize = 1; below.
*/
sampleSize = sampleSize * cinfo.output_width / cinfo.image_width;
// should we allow the Chooser (if present) to pick a config for us???
if (!this->chooseFromOneChoice(config, cinfo.output_width,
cinfo.output_height)) {
return return_false(cinfo, *bm, "chooseFromOneChoice");
}
#ifdef ANDROID_RGB
/* short-circuit the SkScaledBitmapSampler when possible, as this gives
a significant performance boost.
*/
if (sampleSize == 1 &&
((config == SkBitmap::kARGB_8888_Config &&
cinfo.out_color_space == JCS_RGBA_8888) ||
(config == SkBitmap::kRGB_565_Config &&
cinfo.out_color_space == JCS_RGB_565)))
{
bm->setConfig(config, cinfo.output_width, cinfo.output_height);
bm->setIsOpaque(true);
if (SkImageDecoder::kDecodeBounds_Mode == mode) {
return true;
}
if (!this->allocPixelRef(bm, NULL)) {
return return_false(cinfo, *bm, "allocPixelRef");
}
SkAutoLockPixels alp(*bm);
JSAMPLE* rowptr = (JSAMPLE*)bm->getPixels();
INT32 const bpr = bm->rowBytes();
while (cinfo.output_scanline < cinfo.output_height) {
int row_count = jpeg_read_scanlines(&cinfo, &rowptr, 1);
// if row_count == 0, then we didn't get a scanline, so abort.
// if we supported partial images, we might return true in this case
if (0 == row_count) {
return return_false(cinfo, *bm, "read_scanlines");
}
if (this->shouldCancelDecode()) {
return return_false(cinfo, *bm, "shouldCancelDecode");
}
rowptr += bpr;
}
jpeg_finish_decompress(&cinfo);
return true;
}
#endif
// check for supported formats
SkScaledBitmapSampler::SrcConfig sc;
if (3 == cinfo.out_color_components && JCS_RGB == cinfo.out_color_space) {
sc = SkScaledBitmapSampler::kRGB;
#ifdef ANDROID_RGB
} else if (JCS_RGBA_8888 == cinfo.out_color_space) {
sc = SkScaledBitmapSampler::kRGBX;
//} else if (JCS_RGB_565 == cinfo.out_color_space) {
// sc = SkScaledBitmapSampler::kRGB_565;
#endif
} else if (1 == cinfo.out_color_components &&
JCS_GRAYSCALE == cinfo.out_color_space) {
sc = SkScaledBitmapSampler::kGray;
} else {
return return_false(cinfo, *bm, "jpeg colorspace");
}
SkScaledBitmapSampler sampler(cinfo.output_width, cinfo.output_height,
sampleSize);
bm->setConfig(config, sampler.scaledWidth(), sampler.scaledHeight());
// jpegs are always opauqe (i.e. have no per-pixel alpha)
bm->setIsOpaque(true);
if (SkImageDecoder::kDecodeBounds_Mode == mode) {
return true;
}
if (!this->allocPixelRef(bm, NULL)) {
return return_false(cinfo, *bm, "allocPixelRef");
}
SkAutoLockPixels alp(*bm);
if (!sampler.begin(bm, sc, this->getDitherImage())) {
return return_false(cinfo, *bm, "sampler.begin");
}
uint8_t* srcRow = (uint8_t*)srcStorage.alloc(cinfo.output_width * 4);
// Possibly skip initial rows [sampler.srcY0]
if (!skip_src_rows(&cinfo, srcRow, sampler.srcY0())) {
return return_false(cinfo, *bm, "skip rows");
}
// now loop through scanlines until y == bm->height() - 1
for (int y = 0;; y++) {
JSAMPLE* rowptr = (JSAMPLE*)srcRow;
int row_count = jpeg_read_scanlines(&cinfo, &rowptr, 1);
if (0 == row_count) {
return return_false(cinfo, *bm, "read_scanlines");
}
if (this->shouldCancelDecode()) {
return return_false(cinfo, *bm, "shouldCancelDecode");
}
sampler.next(srcRow);
if (bm->height() - 1 == y) {
// we're done
break;
}
if (!skip_src_rows(&cinfo, srcRow, sampler.srcDY() - 1)) {
return return_false(cinfo, *bm, "skip rows");
}
}
// we formally skip the rest, so we don't get a complaint from libjpeg
if (!skip_src_rows(&cinfo, srcRow,
cinfo.output_height - cinfo.output_scanline)) {
return return_false(cinfo, *bm, "skip rows");
}
jpeg_finish_decompress(&cinfo);
// SkDebugf("------------------- bm2 size %d [%d %d] %d\n", bm->getSize(), bm->width(), bm->height(), bm->config());
return true;
}
///////////////////////////////////////////////////////////////////////////////
#include "SkColorPriv.h"
// taken from jcolor.c in libjpeg
#if 0 // 16bit - precise but slow
#define CYR 19595 // 0.299
#define CYG 38470 // 0.587
#define CYB 7471 // 0.114
#define CUR -11059 // -0.16874
#define CUG -21709 // -0.33126
#define CUB 32768 // 0.5
#define CVR 32768 // 0.5
#define CVG -27439 // -0.41869
#define CVB -5329 // -0.08131
#define CSHIFT 16
#else // 8bit - fast, slightly less precise
#define CYR 77 // 0.299
#define CYG 150 // 0.587
#define CYB 29 // 0.114
#define CUR -43 // -0.16874
#define CUG -85 // -0.33126
#define CUB 128 // 0.5
#define CVR 128 // 0.5
#define CVG -107 // -0.41869
#define CVB -21 // -0.08131
#define CSHIFT 8
#endif
static void rgb2yuv_32(uint8_t dst[], SkPMColor c) {
int r = SkGetPackedR32(c);
int g = SkGetPackedG32(c);
int b = SkGetPackedB32(c);
int y = ( CYR*r + CYG*g + CYB*b ) >> CSHIFT;
int u = ( CUR*r + CUG*g + CUB*b ) >> CSHIFT;
int v = ( CVR*r + CVG*g + CVB*b ) >> CSHIFT;
dst[0] = SkToU8(y);
dst[1] = SkToU8(u + 128);
dst[2] = SkToU8(v + 128);
}
static void rgb2yuv_4444(uint8_t dst[], U16CPU c) {
int r = SkGetPackedR4444(c);
int g = SkGetPackedG4444(c);
int b = SkGetPackedB4444(c);
int y = ( CYR*r + CYG*g + CYB*b ) >> (CSHIFT - 4);
int u = ( CUR*r + CUG*g + CUB*b ) >> (CSHIFT - 4);
int v = ( CVR*r + CVG*g + CVB*b ) >> (CSHIFT - 4);
dst[0] = SkToU8(y);
dst[1] = SkToU8(u + 128);
dst[2] = SkToU8(v + 128);
}
static void rgb2yuv_16(uint8_t dst[], U16CPU c) {
int r = SkGetPackedR16(c);
int g = SkGetPackedG16(c);
int b = SkGetPackedB16(c);
int y = ( 2*CYR*r + CYG*g + 2*CYB*b ) >> (CSHIFT - 2);
int u = ( 2*CUR*r + CUG*g + 2*CUB*b ) >> (CSHIFT - 2);
int v = ( 2*CVR*r + CVG*g + 2*CVB*b ) >> (CSHIFT - 2);
dst[0] = SkToU8(y);
dst[1] = SkToU8(u + 128);
dst[2] = SkToU8(v + 128);
}
///////////////////////////////////////////////////////////////////////////////
typedef void (*WriteScanline)(uint8_t* SK_RESTRICT dst,
const void* SK_RESTRICT src, int width,
const SkPMColor* SK_RESTRICT ctable);
static void Write_32_YUV(uint8_t* SK_RESTRICT dst,
const void* SK_RESTRICT srcRow, int width,
const SkPMColor*) {
const uint32_t* SK_RESTRICT src = (const uint32_t*)srcRow;
while (--width >= 0) {
#ifdef WE_CONVERT_TO_YUV
rgb2yuv_32(dst, *src++);
#else
uint32_t c = *src++;
dst[0] = SkGetPackedR32(c);
dst[1] = SkGetPackedG32(c);
dst[2] = SkGetPackedB32(c);
#endif
dst += 3;
}
}
static void Write_4444_YUV(uint8_t* SK_RESTRICT dst,
const void* SK_RESTRICT srcRow, int width,
const SkPMColor*) {
const SkPMColor16* SK_RESTRICT src = (const SkPMColor16*)srcRow;
while (--width >= 0) {
#ifdef WE_CONVERT_TO_YUV
rgb2yuv_4444(dst, *src++);
#else
SkPMColor16 c = *src++;
dst[0] = SkPacked4444ToR32(c);
dst[1] = SkPacked4444ToG32(c);
dst[2] = SkPacked4444ToB32(c);
#endif
dst += 3;
}
}
static void Write_16_YUV(uint8_t* SK_RESTRICT dst,
const void* SK_RESTRICT srcRow, int width,
const SkPMColor*) {
const uint16_t* SK_RESTRICT src = (const uint16_t*)srcRow;
while (--width >= 0) {
#ifdef WE_CONVERT_TO_YUV
rgb2yuv_16(dst, *src++);
#else
uint16_t c = *src++;
dst[0] = SkPacked16ToR32(c);
dst[1] = SkPacked16ToG32(c);
dst[2] = SkPacked16ToB32(c);
#endif
dst += 3;
}
}
static void Write_Index_YUV(uint8_t* SK_RESTRICT dst,
const void* SK_RESTRICT srcRow, int width,
const SkPMColor* SK_RESTRICT ctable) {
const uint8_t* SK_RESTRICT src = (const uint8_t*)srcRow;
while (--width >= 0) {
#ifdef WE_CONVERT_TO_YUV
rgb2yuv_32(dst, ctable[*src++]);
#else
uint32_t c = ctable[*src++];
dst[0] = SkGetPackedR32(c);
dst[1] = SkGetPackedG32(c);
dst[2] = SkGetPackedB32(c);
#endif
dst += 3;
}
}
static WriteScanline ChooseWriter(const SkBitmap& bm) {
switch (bm.config()) {
case SkBitmap::kARGB_8888_Config:
return Write_32_YUV;
case SkBitmap::kRGB_565_Config:
return Write_16_YUV;
case SkBitmap::kARGB_4444_Config:
return Write_4444_YUV;
case SkBitmap::kIndex8_Config:
return Write_Index_YUV;
default:
return NULL;
}
}
struct sk_destination_mgr : jpeg_destination_mgr {
sk_destination_mgr(SkWStream* stream);
SkWStream* fStream;
enum {
kBufferSize = 1024
};
uint8_t fBuffer[kBufferSize];
};
static void sk_init_destination(j_compress_ptr cinfo) {
sk_destination_mgr* dest = (sk_destination_mgr*)cinfo->dest;
dest->next_output_byte = dest->fBuffer;
dest->free_in_buffer = sk_destination_mgr::kBufferSize;
}
static boolean sk_empty_output_buffer(j_compress_ptr cinfo) {
sk_destination_mgr* dest = (sk_destination_mgr*)cinfo->dest;
// if (!dest->fStream->write(dest->fBuffer, sk_destination_mgr::kBufferSize - dest->free_in_buffer))
if (!dest->fStream->write(dest->fBuffer, sk_destination_mgr::kBufferSize)) {
ERREXIT(cinfo, JERR_FILE_WRITE);
return false;
}
dest->next_output_byte = dest->fBuffer;
dest->free_in_buffer = sk_destination_mgr::kBufferSize;
return TRUE;
}
static void sk_term_destination (j_compress_ptr cinfo) {
sk_destination_mgr* dest = (sk_destination_mgr*)cinfo->dest;
size_t size = sk_destination_mgr::kBufferSize - dest->free_in_buffer;
if (size > 0) {
if (!dest->fStream->write(dest->fBuffer, size)) {
ERREXIT(cinfo, JERR_FILE_WRITE);
return;
}
}
dest->fStream->flush();
}
sk_destination_mgr::sk_destination_mgr(SkWStream* stream)
: fStream(stream) {
this->init_destination = sk_init_destination;
this->empty_output_buffer = sk_empty_output_buffer;
this->term_destination = sk_term_destination;
}
class SkJPEGImageEncoder : public SkImageEncoder {
protected:
virtual bool onEncode(SkWStream* stream, const SkBitmap& bm, int quality) {
#ifdef TIME_ENCODE
AutoTimeMillis atm("JPEG Encode");
#endif
const WriteScanline writer = ChooseWriter(bm);
if (NULL == writer) {
return false;
}
SkAutoLockPixels alp(bm);
if (NULL == bm.getPixels()) {
return false;
}
jpeg_compress_struct cinfo;
sk_error_mgr sk_err;
sk_destination_mgr sk_wstream(stream);
// allocate these before set call setjmp
SkAutoMalloc oneRow;
SkAutoLockColors ctLocker;
cinfo.err = jpeg_std_error(&sk_err);
sk_err.error_exit = sk_error_exit;
if (setjmp(sk_err.fJmpBuf)) {
return false;
}
jpeg_create_compress(&cinfo);
cinfo.dest = &sk_wstream;
cinfo.image_width = bm.width();
cinfo.image_height = bm.height();
cinfo.input_components = 3;
#ifdef WE_CONVERT_TO_YUV
cinfo.in_color_space = JCS_YCbCr;
#else
cinfo.in_color_space = JCS_RGB;
#endif
cinfo.input_gamma = 1;
jpeg_set_defaults(&cinfo);
jpeg_set_quality(&cinfo, quality, TRUE /* limit to baseline-JPEG values */);
cinfo.dct_method = JDCT_IFAST;
jpeg_start_compress(&cinfo, TRUE);
const int width = bm.width();
uint8_t* oneRowP = (uint8_t*)oneRow.alloc(width * 3);
const SkPMColor* colors = ctLocker.lockColors(bm);
const void* srcRow = bm.getPixels();
while (cinfo.next_scanline < cinfo.image_height) {
JSAMPROW row_pointer[1]; /* pointer to JSAMPLE row[s] */
writer(oneRowP, srcRow, width, colors);
row_pointer[0] = oneRowP;
(void) jpeg_write_scanlines(&cinfo, row_pointer, 1);
srcRow = (const void*)((const char*)srcRow + bm.rowBytes());
}
jpeg_finish_compress(&cinfo);
jpeg_destroy_compress(&cinfo);
return true;
}
};
///////////////////////////////////////////////////////////////////////////////
#include "SkTRegistry.h"
static SkImageDecoder* DFactory(SkStream* stream) {
static const char gHeader[] = { 0xFF, 0xD8, 0xFF };
static const size_t HEADER_SIZE = sizeof(gHeader);
char buffer[HEADER_SIZE];
size_t len = stream->read(buffer, HEADER_SIZE);
if (len != HEADER_SIZE) {
return NULL; // can't read enough
}
if (memcmp(buffer, gHeader, HEADER_SIZE)) {
return NULL;
}
return SkNEW(SkJPEGImageDecoder);
}
static SkImageEncoder* EFactory(SkImageEncoder::Type t) {
return (SkImageEncoder::kJPEG_Type == t) ? SkNEW(SkJPEGImageEncoder) : NULL;
}
static SkTRegistry<SkImageDecoder*, SkStream*> gDReg(DFactory);
static SkTRegistry<SkImageEncoder*, SkImageEncoder::Type> gEReg(EFactory);