shaka-packager/packager/media/formats/mp2t/es_parser_h26x.cc

297 lines
10 KiB
C++

// Copyright 2014 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 "packager/media/formats/mp2t/es_parser_h26x.h"
#include <stdint.h>
#include "packager/base/logging.h"
#include "packager/base/numerics/safe_conversions.h"
#include "packager/media/base/media_sample.h"
#include "packager/media/base/offset_byte_queue.h"
#include "packager/media/base/timestamp.h"
#include "packager/media/base/video_stream_info.h"
#include "packager/media/filters/h264_byte_to_unit_stream_converter.h"
#include "packager/media/filters/h265_byte_to_unit_stream_converter.h"
#include "packager/media/formats/mp2t/mp2t_common.h"
namespace edash_packager {
namespace media {
namespace mp2t {
namespace {
H26xByteToUnitStreamConverter* CreateStreamConverter(Nalu::CodecType type) {
if (type == Nalu::kH264) {
return new H264ByteToUnitStreamConverter();
} else {
DCHECK_EQ(Nalu::kH265, type);
return new H265ByteToUnitStreamConverter();
}
}
} // anonymous namespace
EsParserH26x::EsParserH26x(Nalu::CodecType type,
uint32_t pid,
const EmitSampleCB& emit_sample_cb)
: EsParser(pid),
emit_sample_cb_(emit_sample_cb),
type_(type),
es_queue_(new media::OffsetByteQueue()),
current_access_unit_pos_(0),
found_access_unit_(false),
stream_converter_(CreateStreamConverter(type)),
pending_sample_duration_(0),
waiting_for_key_frame_(true) {
}
EsParserH26x::~EsParserH26x() {}
bool EsParserH26x::Parse(const uint8_t* buf,
int size,
int64_t pts,
int64_t dts) {
// Note: Parse is invoked each time a PES packet has been reassembled.
// Unfortunately, a PES packet does not necessarily map
// to an h264/h265 access unit, although the HLS recommendation is to use one
// PES for each access unit (but this is just a recommendation and some
// streams do not comply with this recommendation).
// HLS recommendation: "In AVC video, you should have both a DTS and a
// PTS in each PES header".
// However, some streams do not comply with this recommendation.
DVLOG_IF(1, pts == kNoTimestamp) << "Each video PES should have a PTS";
if (pts != kNoTimestamp) {
TimingDesc timing_desc;
timing_desc.pts = pts;
timing_desc.dts = (dts != kNoTimestamp) ? dts : pts;
// Link the end of the byte queue with the incoming timing descriptor.
timing_desc_list_.push_back(
std::pair<int64_t, TimingDesc>(es_queue_->tail(), timing_desc));
}
// Add the incoming bytes to the ES queue.
es_queue_->Push(buf, size);
// Skip to the first access unit.
if (!found_access_unit_) {
if (!FindNextAccessUnit(current_access_unit_pos_,
&current_access_unit_pos_)) {
return true;
}
es_queue_->Trim(current_access_unit_pos_);
found_access_unit_ = true;
}
return ParseInternal();
}
void EsParserH26x::Flush() {
DVLOG(1) << "EsParserH26x::Flush";
// Simulate an additional AUD to force emitting the last access unit
// which is assumed to be complete at this point.
if (type_ == Nalu::kH264) {
uint8_t aud[] = {0x00, 0x00, 0x01, 0x09};
es_queue_->Push(aud, sizeof(aud));
} else {
DCHECK_EQ(Nalu::kH265, type_);
uint8_t aud[] = {0x00, 0x00, 0x01, 0x46, 0x01};
es_queue_->Push(aud, sizeof(aud));
}
ParseInternal();
if (pending_sample_) {
// Flush pending sample.
DCHECK(pending_sample_duration_);
pending_sample_->set_duration(pending_sample_duration_);
emit_sample_cb_.Run(pid(), pending_sample_);
pending_sample_ = scoped_refptr<MediaSample>();
}
}
void EsParserH26x::Reset() {
es_queue_.reset(new media::OffsetByteQueue());
current_access_unit_pos_ = 0;
found_access_unit_ = false;
timing_desc_list_.clear();
pending_sample_ = scoped_refptr<MediaSample>();
pending_sample_duration_ = 0;
waiting_for_key_frame_ = true;
}
bool EsParserH26x::FindNextAccessUnit(int64_t stream_pos,
int64_t* next_unit_pos) {
// TODO(modmaker): Avoid re-parsing by saving old position.
// Every access unit must have a VCL entry and defines the end of the access
// unit. Track it to return on the element after it so we get the whole
// access unit.
bool seen_vcl_nalu = false;
while (true) {
const uint8_t* es;
int size;
es_queue_->PeekAt(stream_pos, &es, &size);
// Find a start code.
uint64_t start_code_offset;
uint8_t start_code_size;
bool start_code_found = NaluReader::FindStartCode(
es, size, &start_code_offset, &start_code_size);
stream_pos += start_code_offset;
// No start code found or NALU type not available yet.
if (!start_code_found ||
start_code_offset + start_code_size >= static_cast<uint64_t>(size)) {
return false;
}
Nalu nalu;
const uint8_t* nalu_ptr = es + start_code_offset + start_code_size;
size_t nalu_size = size - (start_code_offset + start_code_size);
if (nalu.Initialize(type_, nalu_ptr, nalu_size)) {
// ITU H.264 sec. 7.4.1.2.3
// H264: The first of the NAL units with |can_start_access_unit() == true|
// after the last VCL NAL unit of a primary coded picture specifies the
// start of a new access unit. |nuh_layer_id()| is for H265 only; it is
// included below for ease of computation (the value is always 0).
// ITU H.265 sec. 7.4.2.4.4
// H265: The first of the NAL units with |can_start_access_unit() == true|
// after the last VCL NAL unit preceding firstBlPicNalUnit (the first
// VCL NAL unit of a coded picture with nuh_layer_id equal to 0), if
// any, specifies the start of a new access unit.
// TODO(modmaker): This does not handle nuh_layer_id != 0 correctly.
// AUD VCL SEI VCL* VPS VCL
// | Current method splits here.
// | Should split here.
// If we are searching for the first access unit, then stop at the first
// NAL unit that can start an access unit.
if ((seen_vcl_nalu || !found_access_unit_) &&
nalu.can_start_access_unit()) {
break;
}
bool is_vcl_nalu = nalu.is_video_slice() && nalu.nuh_layer_id() == 0;
seen_vcl_nalu |= is_vcl_nalu;
}
// The current NALU is not an AUD, skip the start code
// and continue parsing the stream.
stream_pos += start_code_size;
}
*next_unit_pos = stream_pos;
return true;
}
bool EsParserH26x::ParseInternal() {
DCHECK_LE(es_queue_->head(), current_access_unit_pos_);
DCHECK_LE(current_access_unit_pos_, es_queue_->tail());
// Resume parsing later if no AUD was found.
int64_t access_unit_end;
if (!FindNextAccessUnit(current_access_unit_pos_, &access_unit_end))
return true;
// At this point, we know we have a full access unit.
bool is_key_frame = false;
int pps_id_for_access_unit = -1;
const uint8_t* es;
int size;
es_queue_->PeekAt(current_access_unit_pos_, &es, &size);
int access_unit_size = base::checked_cast<int, int64_t>(
access_unit_end - current_access_unit_pos_);
DCHECK_LE(access_unit_size, size);
NaluReader reader(type_, kIsAnnexbByteStream, es, access_unit_size);
// TODO(modmaker): Consider combining with FindNextAccessUnit to avoid
// scanning the data twice.
while (true) {
Nalu nalu;
bool is_eos = false;
switch (reader.Advance(&nalu)) {
case NaluReader::kOk:
break;
case NaluReader::kEOStream:
is_eos = true;
break;
default:
return false;
}
if (is_eos)
break;
if (!ProcessNalu(nalu, &is_key_frame, &pps_id_for_access_unit))
return false;
}
if (waiting_for_key_frame_) {
waiting_for_key_frame_ = !is_key_frame;
}
if (!waiting_for_key_frame_) {
// Emit a frame and move the stream to the next AUD position.
RCHECK(EmitFrame(current_access_unit_pos_, access_unit_size,
is_key_frame, pps_id_for_access_unit));
}
current_access_unit_pos_ = access_unit_end;
es_queue_->Trim(current_access_unit_pos_);
return true;
}
bool EsParserH26x::EmitFrame(int64_t access_unit_pos,
int access_unit_size,
bool is_key_frame,
int pps_id) {
// Get the access unit timing info.
TimingDesc current_timing_desc = {kNoTimestamp, kNoTimestamp};
while (!timing_desc_list_.empty() &&
timing_desc_list_.front().first <= access_unit_pos) {
current_timing_desc = timing_desc_list_.front().second;
timing_desc_list_.pop_front();
}
if (current_timing_desc.pts == kNoTimestamp)
return false;
// Emit a frame.
DVLOG(LOG_LEVEL_ES) << "Emit frame: stream_pos=" << current_access_unit_pos_
<< " size=" << access_unit_size;
int es_size;
const uint8_t* es;
es_queue_->PeekAt(current_access_unit_pos_, &es, &es_size);
CHECK_GE(es_size, access_unit_size);
// Convert frame to unit stream format.
std::vector<uint8_t> converted_frame;
if (!stream_converter_->ConvertByteStreamToNalUnitStream(
es, access_unit_size, &converted_frame)) {
DLOG(ERROR) << "Failure to convert video frame to unit stream format.";
return false;
}
// Update the video decoder configuration if needed.
RCHECK(UpdateVideoDecoderConfig(pps_id));
// Create the media sample, emitting always the previous sample after
// calculating its duration.
scoped_refptr<MediaSample> media_sample = MediaSample::CopyFrom(
converted_frame.data(), converted_frame.size(), is_key_frame);
media_sample->set_dts(current_timing_desc.dts);
media_sample->set_pts(current_timing_desc.pts);
if (pending_sample_) {
DCHECK_GT(media_sample->dts(), pending_sample_->dts());
pending_sample_duration_ = media_sample->dts() - pending_sample_->dts();
pending_sample_->set_duration(pending_sample_duration_);
emit_sample_cb_.Run(pid(), pending_sample_);
}
pending_sample_ = media_sample;
return true;
}
} // namespace mp2t
} // namespace media
} // namespace edash_packager