shaka-packager/packager/media/formats/mp4/multi_segment_segmenter.cc

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// Copyright 2014 Google Inc. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd
#include "packager/media/formats/mp4/multi_segment_segmenter.h"
#include <algorithm>
#include "packager/base/strings/string_number_conversions.h"
#include "packager/base/strings/string_util.h"
#include "packager/file/file.h"
#include "packager/media/base/buffer_writer.h"
#include "packager/media/base/muxer_options.h"
#include "packager/media/base/muxer_util.h"
#include "packager/media/event/muxer_listener.h"
#include "packager/media/formats/mp4/box_definitions.h"
namespace shaka {
namespace media {
namespace mp4 {
MultiSegmentSegmenter::MultiSegmentSegmenter(const MuxerOptions& options,
std::unique_ptr<FileType> ftyp,
std::unique_ptr<Movie> moov)
: Segmenter(options, std::move(ftyp), std::move(moov)),
styp_(new SegmentType),
num_segments_(0) {
// Use the same brands for styp as ftyp.
styp_->major_brand = Segmenter::ftyp()->major_brand;
styp_->compatible_brands = Segmenter::ftyp()->compatible_brands;
// Replace 'cmfc' with 'cmfs' for CMAF segments compatibility.
std::replace(styp_->compatible_brands.begin(), styp_->compatible_brands.end(),
FOURCC_cmfc, FOURCC_cmfs);
}
MultiSegmentSegmenter::~MultiSegmentSegmenter() {}
bool MultiSegmentSegmenter::GetInitRange(size_t* offset, size_t* size) {
VLOG(1) << "MultiSegmentSegmenter outputs init segment: "
<< options().output_file_name;
return false;
}
bool MultiSegmentSegmenter::GetIndexRange(size_t* offset, size_t* size) {
VLOG(1) << "MultiSegmentSegmenter does not have index range.";
return false;
}
std::vector<Range> MultiSegmentSegmenter::GetSegmentRanges() {
VLOG(1) << "MultiSegmentSegmenter does not have media segment ranges.";
return std::vector<Range>();
}
Status MultiSegmentSegmenter::DoInitialize() {
DCHECK(ftyp());
DCHECK(moov());
// Generate the output file with init segment.
File* file = File::Open(options().output_file_name.c_str(), "w");
if (file == NULL) {
return Status(error::FILE_FAILURE,
"Cannot open file for write " + options().output_file_name);
}
std::unique_ptr<BufferWriter> buffer(new BufferWriter);
ftyp()->Write(buffer.get());
moov()->Write(buffer.get());
Status status = buffer->WriteToFile(file);
if (!file->Close()) {
LOG(WARNING) << "Failed to close the file properly: "
<< options().output_file_name;
}
return status;
}
Status MultiSegmentSegmenter::DoFinalize() {
SetComplete();
return Status::OK;
}
Status MultiSegmentSegmenter::DoFinalizeSegment() {
DCHECK(sidx());
// earliest_presentation_time is the earliest presentation time of any
// access unit in the reference stream in the first subsegment.
// It will be re-calculated later when subsegments are finalized.
sidx()->earliest_presentation_time =
sidx()->references[0].earliest_presentation_time;
if (options().num_subsegments_per_sidx <= 0)
return WriteSegment();
// sidx() contains pre-generated segment references with one reference per
// fragment. Calculate |num_fragments_per_subsegment| and combine
// pre-generated references into final subsegment references.
size_t num_fragments = sidx()->references.size();
size_t num_fragments_per_subsegment =
(num_fragments - 1) / options().num_subsegments_per_sidx + 1;
if (num_fragments_per_subsegment <= 1)
return WriteSegment();
size_t frag_index = 0;
size_t subseg_index = 0;
std::vector<SegmentReference>& refs = sidx()->references;
uint64_t first_sap_time =
refs[0].sap_delta_time + refs[0].earliest_presentation_time;
for (size_t i = 1; i < num_fragments; ++i) {
refs[subseg_index].referenced_size += refs[i].referenced_size;
refs[subseg_index].subsegment_duration += refs[i].subsegment_duration;
refs[subseg_index].earliest_presentation_time =
std::min(refs[subseg_index].earliest_presentation_time,
refs[i].earliest_presentation_time);
if (refs[subseg_index].sap_type == SegmentReference::TypeUnknown &&
refs[i].sap_type != SegmentReference::TypeUnknown) {
refs[subseg_index].sap_type = refs[i].sap_type;
first_sap_time =
refs[i].sap_delta_time + refs[i].earliest_presentation_time;
}
if (++frag_index >= num_fragments_per_subsegment) {
// Calculate sap delta time w.r.t. sidx_->earliest_presentation_time.
if (refs[subseg_index].sap_type != SegmentReference::TypeUnknown) {
refs[subseg_index].sap_delta_time =
first_sap_time - refs[subseg_index].earliest_presentation_time;
}
if (++i >= num_fragments)
break;
refs[++subseg_index] = refs[i];
first_sap_time =
refs[i].sap_delta_time + refs[i].earliest_presentation_time;
frag_index = 1;
}
}
refs.resize(options().num_subsegments_per_sidx);
// earliest_presentation_time is the earliest presentation time of any
// access unit in the reference stream in the first subsegment.
sidx()->earliest_presentation_time = refs[0].earliest_presentation_time;
return WriteSegment();
}
Status MultiSegmentSegmenter::WriteSegment() {
DCHECK(sidx());
DCHECK(fragment_buffer());
DCHECK(styp_);
std::unique_ptr<BufferWriter> buffer(new BufferWriter());
File* file;
std::string file_name;
if (options().segment_template.empty()) {
// Append the segment to output file if segment template is not specified.
file_name = options().output_file_name.c_str();
file = File::Open(file_name.c_str(), "a");
if (file == NULL) {
return Status(
error::FILE_FAILURE,
"Cannot open file for append " + options().output_file_name);
}
} else {
file_name = GetSegmentName(options().segment_template,
sidx()->earliest_presentation_time,
num_segments_++, options().bandwidth);
file = File::Open(file_name.c_str(), "w");
if (file == NULL) {
return Status(error::FILE_FAILURE,
"Cannot open file for write " + file_name);
}
styp_->Write(buffer.get());
}
// If num_subsegments_per_sidx is negative, no SIDX box is generated.
if (options().num_subsegments_per_sidx >= 0)
sidx()->Write(buffer.get());
const size_t segment_size = buffer->Size() + fragment_buffer()->Size();
DCHECK_NE(segment_size, 0u);
Status status = buffer->WriteToFile(file);
if (status.ok())
status = fragment_buffer()->WriteToFile(file);
if (!file->Close())
LOG(WARNING) << "Failed to close the file properly: " << file_name;
if (!status.ok())
return status;
uint64_t segment_duration = 0;
// ISO/IEC 23009-1:2012: the value shall be identical to sum of the the
// values of all Subsegment_duration fields in the first sidx box.
for (size_t i = 0; i < sidx()->references.size(); ++i)
segment_duration += sidx()->references[i].subsegment_duration;
UpdateProgress(segment_duration);
if (muxer_listener()) {
muxer_listener()->OnSampleDurationReady(sample_duration());
muxer_listener()->OnNewSegment(file_name,
sidx()->earliest_presentation_time,
segment_duration, segment_size);
}
return Status::OK;
}
} // namespace mp4
} // namespace media
} // namespace shaka