shaka-packager/media/formats/mp4/fragmenter.h

114 lines
3.4 KiB
C++

// 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
#ifndef MEDIA_FORMATS_MP4_FRAGMENTER_H_
#define MEDIA_FORMATS_MP4_FRAGMENTER_H_
#include <vector>
#include "base/memory/ref_counted.h"
#include "base/memory/scoped_ptr.h"
#include "media/base/status.h"
namespace media {
class BufferWriter;
class MediaSample;
namespace mp4 {
struct SegmentReference;
struct TrackFragment;
/// Fragmenter is responsible for the generation of MP4 fragments, i.e. 'traf'
/// box and corresponding 'mdat' box.
class Fragmenter {
public:
/// @param traf points to a TrackFragment box.
/// @param normalize_presentation_timestamp defines whether PTS should be
/// normalized to start from zero.
Fragmenter(TrackFragment* traf, bool normalize_presentation_timestamp);
virtual ~Fragmenter();
/// Add a sample to the fragmenter.
/// @param sample points to the sample to be added.
/// @return OK on success, an error status otherwise.
virtual Status AddSample(scoped_refptr<MediaSample> sample);
/// Initialize the fragment with default data.
/// @param first_sample_dts specifies the decoding timestamp for the first
/// sample for this fragment.
/// @return OK on success, an error status otherwise.
virtual Status InitializeFragment(int64 first_sample_dts);
/// Finalize and optimize the fragment.
virtual void FinalizeFragment();
/// Fill @a reference with current fragment information.
void GenerateSegmentReference(SegmentReference* reference);
uint64 fragment_duration() const { return fragment_duration_; }
uint64 first_sap_time() const { return first_sap_time_; }
uint64 earliest_presentation_time() const {
return earliest_presentation_time_;
}
bool fragment_initialized() const { return fragment_initialized_; }
bool fragment_finalized() const { return fragment_finalized_; }
BufferWriter* data() { return data_.get(); }
BufferWriter* aux_data() { return aux_data_.get(); }
protected:
TrackFragment* traf() { return traf_; }
/// Optimize sample entries table. If all values in @a entries are identical,
/// then @a entries is cleared and the value is assigned to @a default_value;
/// otherwise it is a NOP. Return true if the table is optimized.
template <typename T>
bool OptimizeSampleEntries(std::vector<T>* entries, T* default_value);
private:
// Check if the current fragment starts with SAP.
bool StartsWithSAP();
TrackFragment* traf_;
bool fragment_initialized_;
bool fragment_finalized_;
uint64 fragment_duration_;
bool normalize_presentation_timestamp_;
int64 presentation_start_time_;
int64 earliest_presentation_time_;
int64 first_sap_time_;
scoped_ptr<BufferWriter> data_;
scoped_ptr<BufferWriter> aux_data_;
DISALLOW_COPY_AND_ASSIGN(Fragmenter);
};
template <typename T>
bool Fragmenter::OptimizeSampleEntries(std::vector<T>* entries,
T* default_value) {
DCHECK(entries);
DCHECK(default_value);
DCHECK(!entries->empty());
typename std::vector<T>::const_iterator it = entries->begin();
T value = *it;
for (; it < entries->end(); ++it)
if (value != *it)
return false;
// Clear |entries| if it contains only one value.
entries->clear();
*default_value = value;
return true;
}
} // namespace mp4
} // namespace media
#endif // MEDIA_FORMATS_MP4_FRAGMENTER_H_