/*
* Copyright (C) 2011 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.
*/
//#define LOG_NDEBUG 0
#define LOG_TAG "FLACExtractor"
#include <utils/Log.h>
#include <stdint.h>
#include "FLACExtractor.h"
// libFLAC parser
#include "FLAC/stream_decoder.h"
#include <android/binder_ibinder.h> // for AIBinder_getCallingUid
#include <audio_utils/primitives.h>
#include <media/MediaExtractorPluginApi.h>
#include <media/NdkMediaFormat.h>
#include <media/stagefright/foundation/ABuffer.h>
#include <media/stagefright/foundation/ADebug.h>
#include <media/stagefright/foundation/base64.h>
#include <media/stagefright/MediaBufferGroup.h>
#include <media/stagefright/MediaDefs.h>
#include <media/stagefright/MediaErrors.h>
#include <media/stagefright/MetaData.h>
#include <media/stagefright/MetaDataUtils.h>
#include <private/android_filesystem_config.h> // for AID_MEDIA
#include <system/audio.h>
namespace android {
// MediaServer is capable of handling float extractor output, but general processes
// may not be able to do so.
// TODO: Improve API to set extractor float output.
// (Note: duplicated with WAVExtractor.cpp)
static inline bool shouldExtractorOutputFloat(int bitsPerSample)
{
return bitsPerSample > 16 && AIBinder_getCallingUid() == AID_MEDIA;
}
class FLACParser;
class FLACSource : public MediaTrackHelper {
public:
FLACSource(
DataSourceHelper *dataSource,
AMediaFormat *meta,
bool outputFloat);
virtual media_status_t start();
virtual media_status_t stop();
virtual media_status_t getFormat(AMediaFormat *meta);
virtual media_status_t read(
MediaBufferHelper **buffer, const ReadOptions *options = NULL);
protected:
virtual ~FLACSource();
private:
DataSourceHelper *mDataSource;
AMediaFormat *mTrackMetadata;
const bool mOutputFloat;
FLACParser *mParser;
bool mInitCheck;
bool mStarted;
// no copy constructor or assignment
FLACSource(const FLACSource &);
FLACSource &operator=(const FLACSource &);
};
// FLACParser wraps a C libFLAC parser aka stream decoder
class FLACParser {
public:
enum {
kMaxChannels = FCC_8,
};
explicit FLACParser(
DataSourceHelper *dataSource,
bool outputFloat,
// If metadata pointers aren't provided, we don't fill them
AMediaFormat *fileMetadata = 0,
AMediaFormat *trackMetadata = 0);
virtual ~FLACParser();
status_t initCheck() const {
return mInitCheck;
}
// stream properties
unsigned getMaxBlockSize() const {
return mStreamInfo.max_blocksize;
}
unsigned getSampleRate() const {
return mStreamInfo.sample_rate;
}
unsigned getChannels() const {
return mStreamInfo.channels;
}
unsigned getBitsPerSample() const {
return mStreamInfo.bits_per_sample;
}
FLAC__uint64 getTotalSamples() const {
return mStreamInfo.total_samples;
}
// media buffers
void allocateBuffers(MediaBufferGroupHelper *group);
void releaseBuffers();
MediaBufferHelper *readBuffer() {
return readBuffer(false, 0LL);
}
MediaBufferHelper *readBuffer(FLAC__uint64 sample) {
return readBuffer(true, sample);
}
private:
DataSourceHelper *mDataSource;
const bool mOutputFloat;
AMediaFormat *mFileMetadata;
AMediaFormat *mTrackMetadata;
bool mInitCheck;
// media buffers
size_t mMaxBufferSize;
MediaBufferGroupHelper *mGroup;
void (*mCopy)(int16_t *dst, const int * src[kMaxChannels], unsigned nSamples, unsigned nChannels);
// handle to underlying libFLAC parser
FLAC__StreamDecoder *mDecoder;
// current position within the data source
off64_t mCurrentPos;
bool mEOF;
// cached when the STREAMINFO metadata is parsed by libFLAC
FLAC__StreamMetadata_StreamInfo mStreamInfo;
bool mStreamInfoValid;
// cached when a decoded PCM block is "written" by libFLAC parser
bool mWriteRequested;
bool mWriteCompleted;
FLAC__FrameHeader mWriteHeader;
FLAC__int32 const * mWriteBuffer[kMaxChannels];
// most recent error reported by libFLAC parser
FLAC__StreamDecoderErrorStatus mErrorStatus;
status_t init();
MediaBufferHelper *readBuffer(bool doSeek, FLAC__uint64 sample);
// no copy constructor or assignment
FLACParser(const FLACParser &);
FLACParser &operator=(const FLACParser &);
// FLAC parser callbacks as C++ instance methods
FLAC__StreamDecoderReadStatus readCallback(
FLAC__byte buffer[], size_t *bytes);
FLAC__StreamDecoderSeekStatus seekCallback(
FLAC__uint64 absolute_byte_offset);
FLAC__StreamDecoderTellStatus tellCallback(
FLAC__uint64 *absolute_byte_offset);
FLAC__StreamDecoderLengthStatus lengthCallback(
FLAC__uint64 *stream_length);
FLAC__bool eofCallback();
FLAC__StreamDecoderWriteStatus writeCallback(
const FLAC__Frame *frame, const FLAC__int32 * const buffer[]);
void metadataCallback(const FLAC__StreamMetadata *metadata);
void errorCallback(FLAC__StreamDecoderErrorStatus status);
size_t getOutputSampleSize() const { return mOutputFloat ? sizeof(float) : sizeof(int16_t); }
// FLAC parser callbacks as C-callable functions
static FLAC__StreamDecoderReadStatus read_callback(
const FLAC__StreamDecoder *decoder,
FLAC__byte buffer[], size_t *bytes,
void *client_data);
static FLAC__StreamDecoderSeekStatus seek_callback(
const FLAC__StreamDecoder *decoder,
FLAC__uint64 absolute_byte_offset,
void *client_data);
static FLAC__StreamDecoderTellStatus tell_callback(
const FLAC__StreamDecoder *decoder,
FLAC__uint64 *absolute_byte_offset,
void *client_data);
static FLAC__StreamDecoderLengthStatus length_callback(
const FLAC__StreamDecoder *decoder,
FLAC__uint64 *stream_length,
void *client_data);
static FLAC__bool eof_callback(
const FLAC__StreamDecoder *decoder,
void *client_data);
static FLAC__StreamDecoderWriteStatus write_callback(
const FLAC__StreamDecoder *decoder,
const FLAC__Frame *frame, const FLAC__int32 * const buffer[],
void *client_data);
static void metadata_callback(
const FLAC__StreamDecoder *decoder,
const FLAC__StreamMetadata *metadata,
void *client_data);
static void error_callback(
const FLAC__StreamDecoder *decoder,
FLAC__StreamDecoderErrorStatus status,
void *client_data);
};
// The FLAC parser calls our C++ static callbacks using C calling conventions,
// inside FLAC__stream_decoder_process_until_end_of_metadata
// and FLAC__stream_decoder_process_single.
// We immediately then call our corresponding C++ instance methods
// with the same parameter list, but discard redundant information.
FLAC__StreamDecoderReadStatus FLACParser::read_callback(
const FLAC__StreamDecoder * /* decoder */, FLAC__byte buffer[],
size_t *bytes, void *client_data)
{
return ((FLACParser *) client_data)->readCallback(buffer, bytes);
}
FLAC__StreamDecoderSeekStatus FLACParser::seek_callback(
const FLAC__StreamDecoder * /* decoder */,
FLAC__uint64 absolute_byte_offset, void *client_data)
{
return ((FLACParser *) client_data)->seekCallback(absolute_byte_offset);
}
FLAC__StreamDecoderTellStatus FLACParser::tell_callback(
const FLAC__StreamDecoder * /* decoder */,
FLAC__uint64 *absolute_byte_offset, void *client_data)
{
return ((FLACParser *) client_data)->tellCallback(absolute_byte_offset);
}
FLAC__StreamDecoderLengthStatus FLACParser::length_callback(
const FLAC__StreamDecoder * /* decoder */,
FLAC__uint64 *stream_length, void *client_data)
{
return ((FLACParser *) client_data)->lengthCallback(stream_length);
}
FLAC__bool FLACParser::eof_callback(
const FLAC__StreamDecoder * /* decoder */, void *client_data)
{
return ((FLACParser *) client_data)->eofCallback();
}
FLAC__StreamDecoderWriteStatus FLACParser::write_callback(
const FLAC__StreamDecoder * /* decoder */, const FLAC__Frame *frame,
const FLAC__int32 * const buffer[], void *client_data)
{
return ((FLACParser *) client_data)->writeCallback(frame, buffer);
}
void FLACParser::metadata_callback(
const FLAC__StreamDecoder * /* decoder */,
const FLAC__StreamMetadata *metadata, void *client_data)
{
((FLACParser *) client_data)->metadataCallback(metadata);
}
void FLACParser::error_callback(
const FLAC__StreamDecoder * /* decoder */,
FLAC__StreamDecoderErrorStatus status, void *client_data)
{
((FLACParser *) client_data)->errorCallback(status);
}
// These are the corresponding callbacks with C++ calling conventions
FLAC__StreamDecoderReadStatus FLACParser::readCallback(
FLAC__byte buffer[], size_t *bytes)
{
size_t requested = *bytes;
ssize_t actual = mDataSource->readAt(mCurrentPos, buffer, requested);
if (0 > actual) {
*bytes = 0;
return FLAC__STREAM_DECODER_READ_STATUS_ABORT;
} else if (0 == actual) {
*bytes = 0;
mEOF = true;
return FLAC__STREAM_DECODER_READ_STATUS_END_OF_STREAM;
} else {
assert(actual <= requested);
*bytes = actual;
mCurrentPos += actual;
return FLAC__STREAM_DECODER_READ_STATUS_CONTINUE;
}
}
FLAC__StreamDecoderSeekStatus FLACParser::seekCallback(
FLAC__uint64 absolute_byte_offset)
{
mCurrentPos = absolute_byte_offset;
mEOF = false;
return FLAC__STREAM_DECODER_SEEK_STATUS_OK;
}
FLAC__StreamDecoderTellStatus FLACParser::tellCallback(
FLAC__uint64 *absolute_byte_offset)
{
*absolute_byte_offset = mCurrentPos;
return FLAC__STREAM_DECODER_TELL_STATUS_OK;
}
FLAC__StreamDecoderLengthStatus FLACParser::lengthCallback(
FLAC__uint64 *stream_length)
{
off64_t size;
if (OK == mDataSource->getSize(&size)) {
*stream_length = size;
return FLAC__STREAM_DECODER_LENGTH_STATUS_OK;
} else {
return FLAC__STREAM_DECODER_LENGTH_STATUS_UNSUPPORTED;
}
}
FLAC__bool FLACParser::eofCallback()
{
return mEOF;
}
FLAC__StreamDecoderWriteStatus FLACParser::writeCallback(
const FLAC__Frame *frame, const FLAC__int32 * const buffer[])
{
if (mWriteRequested) {
mWriteRequested = false;
// FLAC parser doesn't free or realloc buffer until next frame or finish
mWriteHeader = frame->header;
memmove(mWriteBuffer, buffer, sizeof(const FLAC__int32 * const) * getChannels());
mWriteCompleted = true;
return FLAC__STREAM_DECODER_WRITE_STATUS_CONTINUE;
} else {
ALOGE("FLACParser::writeCallback unexpected");
return FLAC__STREAM_DECODER_WRITE_STATUS_ABORT;
}
}
void FLACParser::metadataCallback(const FLAC__StreamMetadata *metadata)
{
switch (metadata->type) {
case FLAC__METADATA_TYPE_STREAMINFO:
if (!mStreamInfoValid) {
mStreamInfo = metadata->data.stream_info;
mStreamInfoValid = true;
} else {
ALOGE("FLACParser::metadataCallback unexpected STREAMINFO");
}
break;
case FLAC__METADATA_TYPE_VORBIS_COMMENT:
{
const FLAC__StreamMetadata_VorbisComment *vc;
vc = &metadata->data.vorbis_comment;
for (FLAC__uint32 i = 0; i < vc->num_comments; ++i) {
FLAC__StreamMetadata_VorbisComment_Entry *vce;
vce = &vc->comments[i];
if (mFileMetadata != 0 && vce->entry != NULL) {
parseVorbisComment(mFileMetadata, (const char *) vce->entry,
vce->length);
}
}
}
break;
case FLAC__METADATA_TYPE_PICTURE:
if (mFileMetadata != 0) {
const FLAC__StreamMetadata_Picture *p = &metadata->data.picture;
AMediaFormat_setBuffer(mFileMetadata, AMEDIAFORMAT_KEY_ALBUMART,
p->data, p->data_length);
}
break;
default:
ALOGW("FLACParser::metadataCallback unexpected type %u", metadata->type);
break;
}
}
void FLACParser::errorCallback(FLAC__StreamDecoderErrorStatus status)
{
ALOGE("FLACParser::errorCallback status=%d", status);
mErrorStatus = status;
}
// Copy samples from FLAC native 32-bit non-interleaved to 16-bit signed
// or 32-bit float interleaved.
// TODO: Consider moving to audio_utils.
// These are candidates for optimization if needed.
static void copyTo16Signed(
short *dst,
const int *const *src,
unsigned nSamples,
unsigned nChannels,
unsigned bitsPerSample) {
const int leftShift = 16 - (int)bitsPerSample; // cast to int to prevent unsigned overflow.
if (leftShift >= 0) {
for (unsigned i = 0; i < nSamples; ++i) {
for (unsigned c = 0; c < nChannels; ++c) {
*dst++ = src[c][i] << leftShift;
}
}
} else {
const int rightShift = -leftShift;
for (unsigned i = 0; i < nSamples; ++i) {
for (unsigned c = 0; c < nChannels; ++c) {
*dst++ = src[c][i] >> rightShift;
}
}
}
}
static void copyToFloat(
float *dst,
const int *const *src,
unsigned nSamples,
unsigned nChannels,
unsigned bitsPerSample) {
const unsigned leftShift = 32 - bitsPerSample;
for (unsigned i = 0; i < nSamples; ++i) {
for (unsigned c = 0; c < nChannels; ++c) {
*dst++ = float_from_i32(src[c][i] << leftShift);
}
}
}
// FLACParser
FLACParser::FLACParser(
DataSourceHelper *dataSource,
bool outputFloat,
AMediaFormat *fileMetadata,
AMediaFormat *trackMetadata)
: mDataSource(dataSource),
mOutputFloat(outputFloat),
mFileMetadata(fileMetadata),
mTrackMetadata(trackMetadata),
mInitCheck(false),
mMaxBufferSize(0),
mGroup(NULL),
mDecoder(NULL),
mCurrentPos(0LL),
mEOF(false),
mStreamInfoValid(false),
mWriteRequested(false),
mWriteCompleted(false),
mErrorStatus((FLAC__StreamDecoderErrorStatus) -1)
{
ALOGV("FLACParser::FLACParser");
memset(&mStreamInfo, 0, sizeof(mStreamInfo));
memset(&mWriteHeader, 0, sizeof(mWriteHeader));
mInitCheck = init();
}
FLACParser::~FLACParser()
{
ALOGV("FLACParser::~FLACParser");
if (mDecoder != NULL) {
FLAC__stream_decoder_delete(mDecoder);
mDecoder = NULL;
}
}
status_t FLACParser::init()
{
// setup libFLAC parser
mDecoder = FLAC__stream_decoder_new();
if (mDecoder == NULL) {
// The new should succeed, since probably all it does is a malloc
// that always succeeds in Android. But to avoid dependence on the
// libFLAC internals, we check and log here.
ALOGE("new failed");
return NO_INIT;
}
FLAC__stream_decoder_set_md5_checking(mDecoder, false);
FLAC__stream_decoder_set_metadata_ignore_all(mDecoder);
FLAC__stream_decoder_set_metadata_respond(
mDecoder, FLAC__METADATA_TYPE_STREAMINFO);
FLAC__stream_decoder_set_metadata_respond(
mDecoder, FLAC__METADATA_TYPE_PICTURE);
FLAC__stream_decoder_set_metadata_respond(
mDecoder, FLAC__METADATA_TYPE_VORBIS_COMMENT);
FLAC__StreamDecoderInitStatus initStatus;
initStatus = FLAC__stream_decoder_init_stream(
mDecoder,
read_callback, seek_callback, tell_callback,
length_callback, eof_callback, write_callback,
metadata_callback, error_callback, (void *) this);
if (initStatus != FLAC__STREAM_DECODER_INIT_STATUS_OK) {
// A failure here probably indicates a programming error and so is
// unlikely to happen. But we check and log here similarly to above.
ALOGE("init_stream failed %d", initStatus);
return NO_INIT;
}
// parse all metadata
if (!FLAC__stream_decoder_process_until_end_of_metadata(mDecoder)) {
ALOGE("end_of_metadata failed");
return NO_INIT;
}
if (mStreamInfoValid) {
// check channel count
if (getChannels() == 0 || getChannels() > kMaxChannels) {
ALOGE("unsupported channel count %u", getChannels());
return NO_INIT;
}
// check bit depth
switch (getBitsPerSample()) {
case 8:
case 16:
case 24:
case 32: // generally not expected for FLAC
break;
default:
// Note: internally the FLAC extractor supports 2-32 bits.
ALOGE("unsupported bits per sample %u", getBitsPerSample());
return NO_INIT;
}
// check sample rate
// Note: flac supports arbitrary sample rates up to 655350 Hz, but Android
// supports sample rates from 8kHz to 192kHz, so use that as the limit.
if (getSampleRate() < 8000 || getSampleRate() > 192000) {
ALOGE("unsupported sample rate %u", getSampleRate());
return NO_INIT;
}
// populate track metadata
if (mTrackMetadata != 0) {
AMediaFormat_setString(mTrackMetadata,
AMEDIAFORMAT_KEY_MIME, MEDIA_MIMETYPE_AUDIO_RAW);
AMediaFormat_setInt32(mTrackMetadata,
AMEDIAFORMAT_KEY_CHANNEL_COUNT, getChannels());
AMediaFormat_setInt32(mTrackMetadata,
AMEDIAFORMAT_KEY_SAMPLE_RATE, getSampleRate());
AMediaFormat_setInt32(mTrackMetadata,
AMEDIAFORMAT_KEY_BITS_PER_SAMPLE, getBitsPerSample());
// sample rate is non-zero, so division by zero not possible
AMediaFormat_setInt64(mTrackMetadata,
AMEDIAFORMAT_KEY_DURATION, (getTotalSamples() * 1000000LL) / getSampleRate());
}
} else {
ALOGE("missing STREAMINFO");
return NO_INIT;
}
if (mFileMetadata != 0) {
AMediaFormat_setString(mFileMetadata,
AMEDIAFORMAT_KEY_MIME, MEDIA_MIMETYPE_AUDIO_FLAC);
}
return OK;
}
void FLACParser::allocateBuffers(MediaBufferGroupHelper *group)
{
CHECK(mGroup == NULL);
mGroup = group;
mMaxBufferSize = getMaxBlockSize() * getChannels() * getOutputSampleSize();
AMediaFormat_setInt32(mTrackMetadata, AMEDIAFORMAT_KEY_MAX_INPUT_SIZE, mMaxBufferSize);
mGroup->add_buffer(mMaxBufferSize);
}
void FLACParser::releaseBuffers()
{
}
MediaBufferHelper *FLACParser::readBuffer(bool doSeek, FLAC__uint64 sample)
{
mWriteRequested = true;
mWriteCompleted = false;
if (doSeek) {
// We implement the seek callback, so this works without explicit flush
if (!FLAC__stream_decoder_seek_absolute(mDecoder, sample)) {
ALOGE("FLACParser::readBuffer seek to sample %lld failed", (long long)sample);
return NULL;
}
ALOGV("FLACParser::readBuffer seek to sample %lld succeeded", (long long)sample);
} else {
if (!FLAC__stream_decoder_process_single(mDecoder)) {
ALOGE("FLACParser::readBuffer process_single failed");
return NULL;
}
}
if (!mWriteCompleted) {
ALOGV("FLACParser::readBuffer write did not complete");
return NULL;
}
// verify that block header keeps the promises made by STREAMINFO
unsigned blocksize = mWriteHeader.blocksize;
if (blocksize == 0 || blocksize > getMaxBlockSize()) {
ALOGE("FLACParser::readBuffer write invalid blocksize %u", blocksize);
return NULL;
}
if (mWriteHeader.sample_rate != getSampleRate() ||
mWriteHeader.channels != getChannels() ||
mWriteHeader.bits_per_sample != getBitsPerSample()) {
ALOGE("FLACParser::readBuffer write changed parameters mid-stream: %d/%d/%d -> %d/%d/%d",
getSampleRate(), getChannels(), getBitsPerSample(),
mWriteHeader.sample_rate, mWriteHeader.channels, mWriteHeader.bits_per_sample);
return NULL;
}
// acquire a media buffer
CHECK(mGroup != NULL);
MediaBufferHelper *buffer;
status_t err = mGroup->acquire_buffer(&buffer);
if (err != OK) {
return NULL;
}
const size_t bufferSize = blocksize * getChannels() * getOutputSampleSize();
CHECK(bufferSize <= mMaxBufferSize);
buffer->set_range(0, bufferSize);
// copy PCM from FLAC write buffer to our media buffer, with interleaving
const unsigned bitsPerSample = getBitsPerSample();
if (mOutputFloat) {
copyToFloat(reinterpret_cast<float*>(buffer->data()),
mWriteBuffer,
blocksize,
getChannels(),
bitsPerSample);
} else {
copyTo16Signed(reinterpret_cast<short*>(buffer->data()),
mWriteBuffer,
blocksize,
getChannels(),
bitsPerSample);
}
// fill in buffer metadata
CHECK(mWriteHeader.number_type == FLAC__FRAME_NUMBER_TYPE_SAMPLE_NUMBER);
FLAC__uint64 sampleNumber = mWriteHeader.number.sample_number;
int64_t timeUs = (1000000LL * sampleNumber) / getSampleRate();
AMediaFormat *meta = buffer->meta_data();
AMediaFormat_setInt64(meta, AMEDIAFORMAT_KEY_TIME_US, timeUs);
AMediaFormat_setInt32(meta, AMEDIAFORMAT_KEY_IS_SYNC_FRAME, 1);
return buffer;
}
// FLACsource
FLACSource::FLACSource(
DataSourceHelper *dataSource,
AMediaFormat *trackMetadata,
bool outputFloat)
: mDataSource(dataSource),
mTrackMetadata(trackMetadata),
mOutputFloat(outputFloat),
mParser(new FLACParser(mDataSource, outputFloat, 0, mTrackMetadata)),
mInitCheck(mParser->initCheck()),
mStarted(false)
{
ALOGV("FLACSource::FLACSource");
}
FLACSource::~FLACSource()
{
ALOGV("~FLACSource::FLACSource");
if (mStarted) {
stop();
}
delete mParser;
}
media_status_t FLACSource::start()
{
ALOGV("FLACSource::start");
CHECK(!mStarted);
mParser->allocateBuffers(mBufferGroup);
mStarted = true;
return AMEDIA_OK;
}
media_status_t FLACSource::stop()
{
ALOGV("FLACSource::stop");
CHECK(mStarted);
mParser->releaseBuffers();
mStarted = false;
return AMEDIA_OK;
}
media_status_t FLACSource::getFormat(AMediaFormat *meta)
{
const media_status_t status = AMediaFormat_copy(meta, mTrackMetadata);
if (status == OK) {
AMediaFormat_setInt32(meta, AMEDIAFORMAT_KEY_PCM_ENCODING,
mOutputFloat ? kAudioEncodingPcmFloat : kAudioEncodingPcm16bit);
}
return status;
}
media_status_t FLACSource::read(
MediaBufferHelper **outBuffer, const ReadOptions *options)
{
MediaBufferHelper *buffer;
// process an optional seek request
int64_t seekTimeUs;
ReadOptions::SeekMode mode;
if ((NULL != options) && options->getSeekTo(&seekTimeUs, &mode)) {
FLAC__uint64 sample;
if (seekTimeUs <= 0LL) {
sample = 0LL;
} else {
// sample and total samples are both zero-based, and seek to EOF ok
sample = (seekTimeUs * mParser->getSampleRate()) / 1000000LL;
if (sample >= mParser->getTotalSamples()) {
sample = mParser->getTotalSamples();
}
}
buffer = mParser->readBuffer(sample);
// otherwise read sequentially
} else {
buffer = mParser->readBuffer();
}
*outBuffer = buffer;
return buffer != NULL ? AMEDIA_OK : AMEDIA_ERROR_END_OF_STREAM;
}
// FLACExtractor
FLACExtractor::FLACExtractor(
DataSourceHelper *dataSource)
: mDataSource(dataSource),
mParser(nullptr),
mInitCheck(false)
{
ALOGV("FLACExtractor::FLACExtractor");
// FLACParser will fill in the metadata for us
mFileMetadata = AMediaFormat_new();
mTrackMetadata = AMediaFormat_new();
mParser = new FLACParser(mDataSource, false /* outputFloat */, mFileMetadata, mTrackMetadata);
mInitCheck = mParser->initCheck();
}
FLACExtractor::~FLACExtractor()
{
ALOGV("~FLACExtractor::FLACExtractor");
delete mParser;
delete mDataSource;
AMediaFormat_delete(mFileMetadata);
AMediaFormat_delete(mTrackMetadata);
}
size_t FLACExtractor::countTracks()
{
return mInitCheck == OK ? 1 : 0;
}
MediaTrackHelper *FLACExtractor::getTrack(size_t index)
{
if (mInitCheck != OK || index > 0) {
return NULL;
}
return new FLACSource(
mDataSource, mTrackMetadata, shouldExtractorOutputFloat(mParser->getBitsPerSample()));
}
media_status_t FLACExtractor::getTrackMetaData(
AMediaFormat *meta,
size_t index, uint32_t /* flags */) {
if (mInitCheck != OK || index > 0) {
return AMEDIA_ERROR_UNKNOWN;
}
const media_status_t status = AMediaFormat_copy(meta, mTrackMetadata);
if (status == OK) {
AMediaFormat_setInt32(meta, AMEDIAFORMAT_KEY_PCM_ENCODING,
shouldExtractorOutputFloat(mParser->getBitsPerSample())
? kAudioEncodingPcmFloat : kAudioEncodingPcm16bit);
}
return status;
}
media_status_t FLACExtractor::getMetaData(AMediaFormat *meta)
{
return AMediaFormat_copy(meta, mFileMetadata);
}
// Sniffer
bool SniffFLAC(DataSourceHelper *source, float *confidence)
{
// Skip ID3 tags
off64_t pos = 0;
uint8_t header[10];
for (;;) {
if (source->readAt(pos, header, sizeof(header)) != sizeof(header)) {
return false; // no more file to read.
}
// check for ID3 tag
if (memcmp("ID3", header, 3) != 0) {
break; // not an ID3 tag.
}
// skip the ID3v2 data and check again
const unsigned id3Len = 10 +
(((header[6] & 0x7f) << 21)
| ((header[7] & 0x7f) << 14)
| ((header[8] & 0x7f) << 7)
| (header[9] & 0x7f));
pos += id3Len;
ALOGV("skipped ID3 tag of len %u new starting offset is %#016llx",
id3Len, (long long)pos);
}
// Check FLAC header.
// https://xiph.org/flac/format.html#stream
//
// Note: content stored big endian.
// byte offset bit size content
// 0 32 fLaC
// 4 8 metadata type STREAMINFO (0) (note: OR with 0x80 if last metadata)
// 5 24 size of metadata, for STREAMINFO (0x22).
if (memcmp("fLaC\x00\x00\x00\x22", header, 8) != 0 &&
memcmp("fLaC\x80\x00\x00\x22", header, 8) != 0) {
return false;
}
*confidence = 0.5;
return true;
}
static const char *extensions[] = {
"flac",
"fl",
NULL
};
extern "C" {
// This is the only symbol that needs to be exported
__attribute__ ((visibility ("default")))
ExtractorDef GETEXTRACTORDEF() {
return {
EXTRACTORDEF_VERSION,
UUID("1364b048-cc45-4fda-9934-327d0ebf9829"),
1,
"FLAC Extractor",
{
.v3 = {
[](
CDataSource *source,
float *confidence,
void **,
FreeMetaFunc *) -> CreatorFunc {
DataSourceHelper helper(source);
if (SniffFLAC(&helper, confidence)) {
return [](
CDataSource *source,
void *) -> CMediaExtractor* {
return wrap(new FLACExtractor(new DataSourceHelper(source)));};
}
return NULL;
},
extensions
}
},
};
}
} // extern "C"
} // namespace android