decrypt_config.h

// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
 
#ifndef PACKAGER_MEDIA_BASE_DECRYPT_CONFIG_H_
#define PACKAGER_MEDIA_BASE_DECRYPT_CONFIG_H_
 
#include <cstdint>
#include <string>
#include <vector>
 
#include <packager/macros/classes.h>
#include <packager/media/base/fourccs.h>
 
namespace shaka {
namespace media {
 
struct SubsampleEntry {
  SubsampleEntry()
    : clear_bytes(0), cipher_bytes(0) {}
  SubsampleEntry(uint16_t clear_bytes, uint32_t cipher_bytes)
    : clear_bytes(clear_bytes), cipher_bytes(cipher_bytes) {}
 
  uint16_t clear_bytes;
  uint32_t cipher_bytes;
};
 
class DecryptConfig {
 public:
  static const size_t kDecryptionKeySize = 16;
 
  DecryptConfig(const std::vector<uint8_t>& key_id,
                const std::vector<uint8_t>& iv,
                const std::vector<SubsampleEntry>& subsamples);
 
  DecryptConfig(const std::vector<uint8_t>& key_id,
                const std::vector<uint8_t>& iv,
                const std::vector<SubsampleEntry>& subsamples,
                FourCC protection_scheme,
                uint8_t crypt_byte_block,
                uint8_t skip_byte_block);
 
  ~DecryptConfig();
 
  void AddSubsample(uint16_t clear_bytes, uint32_t cipher_bytes) {
    subsamples_.emplace_back(clear_bytes, cipher_bytes);
  }
 
  size_t GetTotalSizeOfSubsamples() const;
 
  const std::vector<uint8_t>& key_id() const { return key_id_; }
  const std::vector<uint8_t>& iv() const { return iv_; }
  const std::vector<SubsampleEntry>& subsamples() const { return subsamples_; }
  FourCC protection_scheme() const { return protection_scheme_; }
  uint8_t crypt_byte_block() const { return crypt_byte_block_; }
  uint8_t skip_byte_block() const { return skip_byte_block_; }
 
 private:
  const std::vector<uint8_t> key_id_;
 
  // Initialization vector.
  const std::vector<uint8_t> iv_;
 
  // Subsample information. May be empty for some formats, meaning entire frame
  // (less data ignored by data_offset_) is encrypted.
  std::vector<SubsampleEntry> subsamples_;
 
  const FourCC protection_scheme_;
  // For pattern-based protection schemes, like CENS and CBCS.
  const uint8_t crypt_byte_block_;
  const uint8_t skip_byte_block_;
 
  DISALLOW_COPY_AND_ASSIGN(DecryptConfig);
};
 
}  // namespace media
}  // namespace shaka
 
#endif  // PACKAGER_MEDIA_BASE_DECRYPT_CONFIG_H_