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// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "media/mp4/mp4_stream_parser.h"
#include "base/callback.h"
#include "base/callback_helpers.h"
#include "base/logging.h"
#include "base/time.h"
#include "media/base/audio_decoder_config.h"
#include "media/base/stream_parser_buffer.h"
#include "media/base/video_decoder_config.h"
#include "media/base/video_util.h"
#include "media/mp4/box_definitions.h"
#include "media/mp4/box_reader.h"
#include "media/mp4/es_descriptor.h"
#include "media/mp4/rcheck.h"
namespace media {
namespace mp4 {
// TODO(xhwang): Figure out the init data type appropriately once it's spec'ed.
static const char kMp4InitDataType[] = "video/mp4";
MP4StreamParser::MP4StreamParser(const std::set<int>& audio_object_types,
bool has_sbr)
: state_(kWaitingForInit),
moof_head_(0),
mdat_tail_(0),
has_audio_(false),
has_video_(false),
audio_track_id_(0),
video_track_id_(0),
audio_object_types_(audio_object_types),
has_sbr_(has_sbr),
is_audio_track_encrypted_(false),
is_video_track_encrypted_(false) {
}
MP4StreamParser::~MP4StreamParser() {}
void MP4StreamParser::Init(const InitCB& init_cb,
const NewConfigCB& config_cb,
const NewBuffersCB& audio_cb,
const NewBuffersCB& video_cb,
const NeedKeyCB& need_key_cb,
const NewMediaSegmentCB& new_segment_cb,
const base::Closure& end_of_segment_cb,
const LogCB& log_cb) {
DCHECK_EQ(state_, kWaitingForInit);
DCHECK(init_cb_.is_null());
DCHECK(!init_cb.is_null());
DCHECK(!config_cb.is_null());
DCHECK(!audio_cb.is_null() || !video_cb.is_null());
DCHECK(!need_key_cb.is_null());
DCHECK(!end_of_segment_cb.is_null());
ChangeState(kParsingBoxes);
init_cb_ = init_cb;
config_cb_ = config_cb;
audio_cb_ = audio_cb;
video_cb_ = video_cb;
need_key_cb_ = need_key_cb;
new_segment_cb_ = new_segment_cb;
end_of_segment_cb_ = end_of_segment_cb;
log_cb_ = log_cb;
}
void MP4StreamParser::Reset() {
queue_.Reset();
moov_.reset();
runs_.reset();
moof_head_ = 0;
mdat_tail_ = 0;
}
void MP4StreamParser::Flush() {
DCHECK_NE(state_, kWaitingForInit);
Reset();
ChangeState(kParsingBoxes);
}
bool MP4StreamParser::Parse(const uint8* buf, int size) {
DCHECK_NE(state_, kWaitingForInit);
if (state_ == kError)
return false;
queue_.Push(buf, size);
BufferQueue audio_buffers;
BufferQueue video_buffers;
bool result, err = false;
do {
if (state_ == kParsingBoxes) {
result = ParseBox(&err);
} else {
DCHECK_EQ(kEmittingSamples, state_);
result = EnqueueSample(&audio_buffers, &video_buffers, &err);
if (result) {
int64 max_clear = runs_->GetMaxClearOffset() + moof_head_;
err = !ReadAndDiscardMDATsUntil(max_clear);
}
}
} while (result && !err);
if (!err)
err = !SendAndFlushSamples(&audio_buffers, &video_buffers);
if (err) {
DLOG(ERROR) << "Error while parsing MP4";
Reset();
ChangeState(kError);
return false;
}
return true;
}
bool MP4StreamParser::ParseBox(bool* err) {
const uint8* buf;
int size;
queue_.Peek(&buf, &size);
if (!size) return false;
scoped_ptr<BoxReader> reader(
BoxReader::ReadTopLevelBox(buf, size, log_cb_, err));
if (reader.get() == NULL) return false;
if (reader->type() == FOURCC_MOOV) {
*err = !ParseMoov(reader.get());
} else if (reader->type() == FOURCC_MOOF) {
moof_head_ = queue_.head();
*err = !ParseMoof(reader.get());
// Set up first mdat offset for ReadMDATsUntil().
mdat_tail_ = queue_.head() + reader->size();
// Return early to avoid evicting 'moof' data from queue. Auxiliary info may
// be located anywhere in the file, including inside the 'moof' itself.
// (Since 'default-base-is-moof' is mandated, no data references can come
// before the head of the 'moof', so keeping this box around is sufficient.)
return !(*err);
} else {
MEDIA_LOG(log_cb_) << "Skipping unrecognized top-level box: "
<< FourCCToString(reader->type());
}
queue_.Pop(reader->size());
return !(*err);
}
bool MP4StreamParser::ParseMoov(BoxReader* reader) {
moov_.reset(new Movie);
RCHECK(moov_->Parse(reader));
runs_.reset(new TrackRunIterator(moov_.get(), log_cb_));
has_audio_ = false;
has_video_ = false;
AudioDecoderConfig audio_config;
VideoDecoderConfig video_config;
for (std::vector<Track>::const_iterator track = moov_->tracks.begin();
track != moov_->tracks.end(); ++track) {
// TODO(strobe): Only the first audio and video track present in a file are
// used. (Track selection is better accomplished via Source IDs, though, so
// adding support for track selection within a stream is low-priority.)
const SampleDescription& samp_descr =
track->media.information.sample_table.description;
// TODO(strobe): When codec reconfigurations are supported, detect and send
// a codec reconfiguration for fragments using a sample description index
// different from the previous one
size_t desc_idx = 0;
for (size_t t = 0; t < moov_->extends.tracks.size(); t++) {
const TrackExtends& trex = moov_->extends.tracks[t];
if (trex.track_id == track->header.track_id) {
desc_idx = trex.default_sample_description_index;
break;
}
}
RCHECK(desc_idx > 0);
desc_idx -= 1; // BMFF descriptor index is one-based
if (track->media.handler.type == kAudio && !audio_config.IsValidConfig()) {
RCHECK(!samp_descr.audio_entries.empty());
// It is not uncommon to find otherwise-valid files with incorrect sample
// description indices, so we fail gracefully in that case.
if (desc_idx >= samp_descr.audio_entries.size())
desc_idx = 0;
const AudioSampleEntry& entry = samp_descr.audio_entries[desc_idx];
const AAC& aac = entry.esds.aac;
if (!(entry.format == FOURCC_MP4A ||
(entry.format == FOURCC_ENCA &&
entry.sinf.format.format == FOURCC_MP4A))) {
MEDIA_LOG(log_cb_) << "Unsupported audio format 0x"
<< std::hex << entry.format << " in stsd box.";
return false;
}
int audio_type = entry.esds.object_type;
DVLOG(1) << "audio_type " << std::hex << audio_type;
if (audio_object_types_.find(audio_type) == audio_object_types_.end()) {
MEDIA_LOG(log_cb_) << "audio object type 0x" << std::hex << audio_type
<< " does not match what is specified in the"
<< " mimetype.";
return false;
}
// Check if it is MPEG4 AAC defined in ISO 14496 Part 3 or
// supported MPEG2 AAC varients.
if (audio_type != kISO_14496_3 && audio_type != kISO_13818_7_AAC_LC) {
MEDIA_LOG(log_cb_) << "Unsupported audio object type 0x" << std::hex
<< audio_type << " in esds.";
return false;
}
SampleFormat sample_format;
if (entry.samplesize == 8) {
sample_format = kSampleFormatU8;
} else if (entry.samplesize == 16) {
sample_format = kSampleFormatS16;
} else if (entry.samplesize == 32) {
sample_format = kSampleFormatS32;
} else {
LOG(ERROR) << "Unsupported sample size.";
return false;
}
is_audio_track_encrypted_ = entry.sinf.info.track_encryption.is_encrypted;
DVLOG(1) << "is_audio_track_encrypted_: " << is_audio_track_encrypted_;
audio_config.Initialize(kCodecAAC, sample_format,
aac.channel_layout(),
aac.GetOutputSamplesPerSecond(has_sbr_),
NULL, 0, is_audio_track_encrypted_, false);
has_audio_ = true;
audio_track_id_ = track->header.track_id;
}
if (track->media.handler.type == kVideo && !video_config.IsValidConfig()) {
RCHECK(!samp_descr.video_entries.empty());
if (desc_idx >= samp_descr.video_entries.size())
desc_idx = 0;
const VideoSampleEntry& entry = samp_descr.video_entries[desc_idx];
if (!(entry.format == FOURCC_AVC1 ||
(entry.format == FOURCC_ENCV &&
entry.sinf.format.format == FOURCC_AVC1))) {
MEDIA_LOG(log_cb_) << "Unsupported video format 0x"
<< std::hex << entry.format << " in stsd box.";
return false;
}
// TODO(strobe): Recover correct crop box
gfx::Size coded_size(entry.width, entry.height);
gfx::Rect visible_rect(coded_size);
gfx::Size natural_size = GetNaturalSize(visible_rect.size(),
entry.pixel_aspect.h_spacing,
entry.pixel_aspect.v_spacing);
is_video_track_encrypted_ = entry.sinf.info.track_encryption.is_encrypted;
DVLOG(1) << "is_video_track_encrypted_: " << is_video_track_encrypted_;
video_config.Initialize(kCodecH264, H264PROFILE_MAIN, VideoFrame::YV12,
coded_size, visible_rect, natural_size,
// No decoder-specific buffer needed for AVC;
// SPS/PPS are embedded in the video stream
NULL, 0, is_video_track_encrypted_, true);
has_video_ = true;
video_track_id_ = track->header.track_id;
}
}
RCHECK(config_cb_.Run(audio_config, video_config));
base::TimeDelta duration;
if (moov_->extends.header.fragment_duration > 0) {
duration = TimeDeltaFromRational(moov_->extends.header.fragment_duration,
moov_->header.timescale);
} else if (moov_->header.duration > 0) {
duration = TimeDeltaFromRational(moov_->header.duration,
moov_->header.timescale);
} else {
duration = kInfiniteDuration();
}
if (!init_cb_.is_null())
base::ResetAndReturn(&init_cb_).Run(true, duration);
RCHECK(EmitNeedKeyIfNecessary(moov_->pssh));
return true;
}
bool MP4StreamParser::ParseMoof(BoxReader* reader) {
RCHECK(moov_.get()); // Must already have initialization segment
MovieFragment moof;
RCHECK(moof.Parse(reader));
RCHECK(runs_->Init(moof));
RCHECK(EmitNeedKeyIfNecessary(moof.pssh));
new_segment_cb_.Run(runs_->GetMinDecodeTimestamp());
ChangeState(kEmittingSamples);
return true;
}
bool MP4StreamParser::EmitNeedKeyIfNecessary(
const std::vector<ProtectionSystemSpecificHeader>& headers) {
// TODO(strobe): ensure that the value of init_data (all PSSH headers
// concatenated in arbitrary order) matches the EME spec.
// See https://www.w3.org/Bugs/Public/show_bug.cgi?id=17673.
if (headers.empty())
return true;
size_t total_size = 0;
for (size_t i = 0; i < headers.size(); i++)
total_size += headers[i].raw_box.size();
scoped_array<uint8> init_data(new uint8[total_size]);
size_t pos = 0;
for (size_t i = 0; i < headers.size(); i++) {
memcpy(&init_data.get()[pos], &headers[i].raw_box[0],
headers[i].raw_box.size());
pos += headers[i].raw_box.size();
}
return need_key_cb_.Run(kMp4InitDataType, init_data.Pass(), total_size);
}
bool MP4StreamParser::PrepareAVCBuffer(
const AVCDecoderConfigurationRecord& avc_config,
std::vector<uint8>* frame_buf,
std::vector<SubsampleEntry>* subsamples) const {
// Convert the AVC NALU length fields to Annex B headers, as expected by
// decoding libraries. Since this may enlarge the size of the buffer, we also
// update the clear byte count for each subsample if encryption is used to
// account for the difference in size between the length prefix and Annex B
// start code.
RCHECK(AVC::ConvertFrameToAnnexB(avc_config.length_size, frame_buf));
if (!subsamples->empty()) {
const int nalu_size_diff = 4 - avc_config.length_size;
size_t expected_size = runs_->sample_size() +
subsamples->size() * nalu_size_diff;
RCHECK(frame_buf->size() == expected_size);
for (size_t i = 0; i < subsamples->size(); i++)
(*subsamples)[i].clear_bytes += nalu_size_diff;
}
if (runs_->is_keyframe()) {
// If this is a keyframe, we (re-)inject SPS and PPS headers at the start of
// a frame. If subsample info is present, we also update the clear byte
// count for that first subsample.
std::vector<uint8> param_sets;
RCHECK(AVC::ConvertConfigToAnnexB(avc_config, ¶m_sets));
frame_buf->insert(frame_buf->begin(),
param_sets.begin(), param_sets.end());
if (!subsamples->empty())
(*subsamples)[0].clear_bytes += param_sets.size();
}
return true;
}
bool MP4StreamParser::PrepareAACBuffer(
const AAC& aac_config, std::vector<uint8>* frame_buf,
std::vector<SubsampleEntry>* subsamples) const {
// Append an ADTS header to every audio sample.
RCHECK(aac_config.ConvertEsdsToADTS(frame_buf));
// As above, adjust subsample information to account for the headers. AAC is
// not required to use subsample encryption, so we may need to add an entry.
if (subsamples->empty()) {
SubsampleEntry entry;
entry.clear_bytes = AAC::kADTSHeaderSize;
entry.cypher_bytes = frame_buf->size() - AAC::kADTSHeaderSize;
subsamples->push_back(entry);
} else {
(*subsamples)[0].clear_bytes += AAC::kADTSHeaderSize;
}
return true;
}
bool MP4StreamParser::EnqueueSample(BufferQueue* audio_buffers,
BufferQueue* video_buffers,
bool* err) {
if (!runs_->IsRunValid()) {
// Flush any buffers we've gotten in this chunk so that buffers don't
// cross NewSegment() calls
*err = !SendAndFlushSamples(audio_buffers, video_buffers);
if (*err)
return false;
// Remain in kEnqueueingSamples state, discarding data, until the end of
// the current 'mdat' box has been appended to the queue.
if (!queue_.Trim(mdat_tail_))
return false;
ChangeState(kParsingBoxes);
end_of_segment_cb_.Run();
return true;
}
if (!runs_->IsSampleValid()) {
runs_->AdvanceRun();
return true;
}
DCHECK(!(*err));
const uint8* buf;
int buf_size;
queue_.Peek(&buf, &buf_size);
if (!buf_size) return false;
bool audio = has_audio_ && audio_track_id_ == runs_->track_id();
bool video = has_video_ && video_track_id_ == runs_->track_id();
// Skip this entire track if it's not one we're interested in
if (!audio && !video)
runs_->AdvanceRun();
// Attempt to cache the auxiliary information first. Aux info is usually
// placed in a contiguous block before the sample data, rather than being
// interleaved. If we didn't cache it, this would require that we retain the
// start of the segment buffer while reading samples. Aux info is typically
// quite small compared to sample data, so this pattern is useful on
// memory-constrained devices where the source buffer consumes a substantial
// portion of the total system memory.
if (runs_->AuxInfoNeedsToBeCached()) {
queue_.PeekAt(runs_->aux_info_offset() + moof_head_, &buf, &buf_size);
if (buf_size < runs_->aux_info_size()) return false;
*err = !runs_->CacheAuxInfo(buf, buf_size);
return !*err;
}
queue_.PeekAt(runs_->sample_offset() + moof_head_, &buf, &buf_size);
if (buf_size < runs_->sample_size()) return false;
scoped_ptr<DecryptConfig> decrypt_config;
std::vector<SubsampleEntry> subsamples;
if (runs_->is_encrypted()) {
decrypt_config = runs_->GetDecryptConfig();
subsamples = decrypt_config->subsamples();
}
std::vector<uint8> frame_buf(buf, buf + runs_->sample_size());
if (video) {
if (!PrepareAVCBuffer(runs_->video_description().avcc,
&frame_buf, &subsamples)) {
MEDIA_LOG(log_cb_) << "Failed to prepare AVC sample for decode";
*err = true;
return false;
}
}
if (audio) {
if (!PrepareAACBuffer(runs_->audio_description().esds.aac,
&frame_buf, &subsamples)) {
MEDIA_LOG(log_cb_) << "Failed to prepare AAC sample for decode";
*err = true;
return false;
}
}
if (decrypt_config) {
if (!subsamples.empty()) {
// Create a new config with the updated subsamples.
decrypt_config.reset(new DecryptConfig(
decrypt_config->key_id(),
decrypt_config->iv(),
decrypt_config->data_offset(),
subsamples));
}
// else, use the existing config.
} else if ((audio && is_audio_track_encrypted_) ||
(video && is_video_track_encrypted_)) {
// The media pipeline requires a DecryptConfig with an empty |iv|.
// TODO(ddorwin): Refactor so we do not need a fake key ID ("1");
decrypt_config.reset(
new DecryptConfig("1", "", 0, std::vector<SubsampleEntry>()));
}
scoped_refptr<StreamParserBuffer> stream_buf =
StreamParserBuffer::CopyFrom(&frame_buf[0], frame_buf.size(),
runs_->is_keyframe());
if (decrypt_config)
stream_buf->SetDecryptConfig(decrypt_config.Pass());
stream_buf->SetDuration(runs_->duration());
stream_buf->SetTimestamp(runs_->cts());
stream_buf->SetDecodeTimestamp(runs_->dts());
DVLOG(3) << "Pushing frame: aud=" << audio
<< ", key=" << runs_->is_keyframe()
<< ", dur=" << runs_->duration().InMilliseconds()
<< ", dts=" << runs_->dts().InMilliseconds()
<< ", cts=" << runs_->cts().InMilliseconds()
<< ", size=" << runs_->sample_size();
if (audio) {
audio_buffers->push_back(stream_buf);
} else {
video_buffers->push_back(stream_buf);
}
runs_->AdvanceSample();
return true;
}
bool MP4StreamParser::SendAndFlushSamples(BufferQueue* audio_buffers,
BufferQueue* video_buffers) {
bool err = false;
if (!audio_buffers->empty()) {
err |= (audio_cb_.is_null() || !audio_cb_.Run(*audio_buffers));
audio_buffers->clear();
}
if (!video_buffers->empty()) {
err |= (video_cb_.is_null() || !video_cb_.Run(*video_buffers));
video_buffers->clear();
}
return !err;
}
bool MP4StreamParser::ReadAndDiscardMDATsUntil(const int64 offset) {
bool err = false;
while (mdat_tail_ < offset) {
const uint8* buf;
int size;
queue_.PeekAt(mdat_tail_, &buf, &size);
FourCC type;
int box_sz;
if (!BoxReader::StartTopLevelBox(buf, size, log_cb_,
&type, &box_sz, &err))
break;
if (type != FOURCC_MDAT) {
MEDIA_LOG(log_cb_) << "Unexpected box type while parsing MDATs: "
<< FourCCToString(type);
}
mdat_tail_ += box_sz;
}
queue_.Trim(std::min(mdat_tail_, offset));
return !err;
}
void MP4StreamParser::ChangeState(State new_state) {
DVLOG(2) << "Changing state: " << new_state;
state_ = new_state;
}
} // namespace mp4
} // namespace media
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