shaka-packager/media/mp4/mp4_fragmenter.h

97 lines
2.9 KiB
C++

// Copyright (c) 2013 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.
//
// MP4Fragmenter is responsible for the generation of MP4 fragments, i.e. traf
// and the corresponding mdat. The samples are also encrypted if encryption is
// requested.
#ifndef MEDIA_MP4_MP4_FRAGMENTER_H_
#define MEDIA_MP4_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 AesCtrEncryptor;
class BufferWriter;
class MediaSample;
namespace mp4 {
class SegmentReference;
class TrackFragment;
class MP4Fragmenter {
public:
// Caller retains the ownership of |traf| and transfers ownership of
// |encryptor|. |clear_time| specifies clear time in the current track
// timescale. |nalu_length_size| specifies NAL unit length size, for
// subsample encryption.
MP4Fragmenter(TrackFragment* traf,
scoped_ptr<AesCtrEncryptor> encryptor,
int64 clear_time,
uint8 nalu_length_size);
~MP4Fragmenter();
virtual Status AddSample(scoped_refptr<MediaSample> sample);
// Initialize the fragment with default data.
void InitializeFragment();
// Finalize and optimize the fragment.
void FinalizeFragment();
// Fill in |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_finalized() const { return fragment_finalized_; }
BufferWriter* data() { return data_.get(); }
BufferWriter* aux_data() { return aux_data_.get(); }
private:
void EncryptBytes(uint8* data, uint32 size);
Status EncryptSample(scoped_refptr<MediaSample> sample);
// Should we enable encrytion for the current fragment?
bool ShouldEncryptFragment() {
return (encryptor_ != NULL && clear_time_ <= 0);
}
// Should we enable subsample encryption?
bool IsSubsampleEncryptionRequired() { return nalu_length_size_ != 0; }
// Check if the current fragment starts with SAP.
bool StartsWithSAP();
scoped_ptr<AesCtrEncryptor> encryptor_;
// If this stream contains AVC, subsample encryption specifies that the size
// and type of NAL units remain unencrypted. This field specifies the size of
// the size field. Can be 1, 2 or 4 bytes.
uint8 nalu_length_size_;
TrackFragment* traf_;
bool fragment_finalized_;
uint64 fragment_duration_;
uint64 earliest_presentation_time_;
uint64 first_sap_time_;
int64 clear_time_;
scoped_ptr<BufferWriter> data_;
scoped_ptr<BufferWriter> aux_data_;
DISALLOW_COPY_AND_ASSIGN(MP4Fragmenter);
};
} // namespace mp4
} // namespace media
#endif // MEDIA_MP4_MP4_FRAGMENTER_H_