subsample_generator.h

// Copyright 2018 Google LLC. 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 PACKAGER_MEDIA_CRYPTO_SUBSAMPLE_GENERATOR_H_
#define PACKAGER_MEDIA_CRYPTO_SUBSAMPLE_GENERATOR_H_
 
#include <memory>
#include <vector>
 
#include <packager/media/base/fourccs.h>
#include <packager/media/base/stream_info.h>
#include <packager/status.h>
 
namespace shaka {
namespace media {
 
class AV1Parser;
class VideoSliceHeaderParser;
class VPxParser;
struct SubsampleEntry;
 
class SubsampleGenerator {
 public:
  explicit SubsampleGenerator(bool vp9_subsample_encryption);
 
  virtual ~SubsampleGenerator();
 
  virtual Status Initialize(FourCC protection_scheme,
                            const StreamInfo& stream_info);
 
  virtual Status GenerateSubsamples(const uint8_t* frame,
                                    size_t frame_size,
                                    std::vector<SubsampleEntry>* subsamples);
 
  // Testing injections.
  void InjectVpxParserForTesting(std::unique_ptr<VPxParser> vpx_parser);
  void InjectVideoSliceHeaderParserForTesting(
      std::unique_ptr<VideoSliceHeaderParser> header_parser);
  void InjectAV1ParserForTesting(std::unique_ptr<AV1Parser> av1_parser);
 
 private:
  SubsampleGenerator(const SubsampleGenerator&) = delete;
  SubsampleGenerator& operator=(const SubsampleGenerator&) = delete;
 
  Status GenerateSubsamplesFromVPxFrame(
      const uint8_t* frame,
      size_t frame_size,
      std::vector<SubsampleEntry>* subsamples);
  Status GenerateSubsamplesFromH26xFrame(
      const uint8_t* frame,
      size_t frame_size,
      std::vector<SubsampleEntry>* subsamples);
  Status GenerateSubsamplesFromAV1Frame(
      const uint8_t* frame,
      size_t frame_size,
      std::vector<SubsampleEntry>* subsamples);
 
  const bool vp9_subsample_encryption_ = false;
  // Whether the protected portion should be AES block (16 bytes) aligned.
  bool align_protected_data_ = false;
  Codec codec_ = kUnknownCodec;
  // For NAL structured video only, the size of NAL unit length in bytes. Can be
  // 1, 2 or 4 bytes.
  uint8_t nalu_length_size_ = 0;
  // For SAMPLE AES only, 32 bytes for Video and 16 bytes for audio.
  size_t leading_clear_bytes_size_ = 0;
  // For SAMPLE AES only, if the data size is less than this value, none of the
  // bytes are encrypted. The size is 48+1 bytes for video NAL and 32 bytes for
  // audio according to MPEG-2 Stream Encryption Format for HTTP Live Streaming.
  size_t min_protected_data_size_ = 0;
 
  // VPx parser for VPx streams.
  std::unique_ptr<VPxParser> vpx_parser_;
  // Video slice header parser for NAL strucutred streams.
  std::unique_ptr<VideoSliceHeaderParser> header_parser_;
  // AV1 parser for AV1 streams.
  std::unique_ptr<AV1Parser> av1_parser_;
};
 
}  // namespace media
}  // namespace shaka
 
#endif  // PACKAGER_MEDIA_CRYPTO_SUBSAMPLE_GENERATOR_H_