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

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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
#ifndef MEDIA_FORMATS_MP4_ENCRYPTING_FRAGMENTER_H_
#define MEDIA_FORMATS_MP4_ENCRYPTING_FRAGMENTER_H_
#include "packager/media/formats/mp4/fragmenter.h"
namespace edash_packager {
namespace media {
class AesCtrEncryptor;
struct EncryptionKey;
namespace mp4 {
/// EncryptingFragmenter generates MP4 fragments with sample encrypted.
class EncryptingFragmenter : public Fragmenter {
public:
/// @param traf points to a TrackFragment box.
/// @param encryption_key contains the encryption parameters.
/// @param clear_time specifies clear lead duration in units of the current
/// track's timescale.
/// @param nalu_length_size specifies the size of NAL unit length, in bytes,
/// for subsample encryption.
EncryptingFragmenter(TrackFragment* traf,
scoped_ptr<EncryptionKey> encryption_key,
int64_t clear_time,
uint8_t nalu_length_size);
~EncryptingFragmenter() override;
/// @name Fragmenter implementation overrides.
/// @{
Status AddSample(scoped_refptr<MediaSample> sample) override;
Status InitializeFragment(int64_t first_sample_dts) override;
void FinalizeFragment() override;
/// @}
protected:
/// Prepare current fragment for encryption.
/// @return OK on success, an error status otherwise.
virtual Status PrepareFragmentForEncryption(bool enable_encryption);
/// Finalize current fragment for encryption.
virtual void FinalizeFragmentForEncryption();
/// Create the encryptor for the internal encryption key. The existing
/// encryptor will be reset if it is not NULL.
/// @return OK on success, an error status otherwise.
Status CreateEncryptor();
EncryptionKey* encryption_key() { return encryption_key_.get(); }
AesCtrEncryptor* encryptor() { return encryptor_.get(); }
void set_encryption_key(scoped_ptr<EncryptionKey> encryption_key) {
encryption_key_ = encryption_key.Pass();
}
private:
void EncryptBytes(uint8_t* data, uint32_t size);
Status EncryptSample(scoped_refptr<MediaSample> sample);
// Should we enable subsample encryption?
bool IsSubsampleEncryptionRequired() { return nalu_length_size_ != 0; }
scoped_ptr<EncryptionKey> encryption_key_;
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.
const uint8_t nalu_length_size_;
int64_t clear_time_;
DISALLOW_COPY_AND_ASSIGN(EncryptingFragmenter);
};
} // namespace mp4
} // namespace media
} // namespace edash_packager
#endif // MEDIA_FORMATS_MP4_ENCRYPTING_FRAGMENTER_H_