media/cdm/ppapi/clear_key_cdm.h

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef MEDIA_CDM_PPAPI_CLEAR_KEY_CDM_H_
   6 #define MEDIA_CDM_PPAPI_CLEAR_KEY_CDM_H_
   7
   8 #include <string>
   9 #include <vector>
  10
  11 #include "base/basictypes.h"
  12 #include "base/compiler_specific.h"
  13 #include "base/memory/ref_counted.h"
  14 #include "base/memory/scoped_ptr.h"
  15 #include "base/synchronization/lock.h"
  16 #include "media/cdm/aes_decryptor.h"
  17 #include "media/cdm/ppapi/api/content_decryption_module.h"
  18
  19 // Enable this to use the fake decoder for testing.
  20 // TODO(tomfinegan): Move fake audio decoder into a separate class.
  21 #if 0
  22 #define CLEAR_KEY_CDM_USE_FAKE_AUDIO_DECODER
  23 #endif
  24
  25 namespace media {
  26 class CdmVideoDecoder;
  27 class DecoderBuffer;
  28 class FFmpegCdmAudioDecoder;
  29
  30 // Clear key implementation of the cdm::ContentDecryptionModule interface.
  31 class ClearKeyCdm : public cdm::ContentDecryptionModule_2 {
  32  public:
  33   explicit ClearKeyCdm(cdm::Host* host);
  34   virtual ~ClearKeyCdm();
  35
  36   // ContentDecryptionModule implementation.
  37   virtual cdm::Status GenerateKeyRequest(
  38       const char* type, uint32_t type_size,
  39       const uint8_t* init_data, uint32_t init_data_size) OVERRIDE;
  40   virtual cdm::Status AddKey(const char* session_id,
  41                              uint32_t session_id_size,
  42                              const uint8_t* key,
  43                              uint32_t key_size,
  44                              const uint8_t* key_id,
  45                              uint32_t key_id_size) OVERRIDE;
  46   virtual cdm::Status CancelKeyRequest(const char* session_id,
  47                                        uint32_t session_id_size) OVERRIDE;
  48   virtual void TimerExpired(void* context) OVERRIDE;
  49   virtual cdm::Status Decrypt(const cdm::InputBuffer& encrypted_buffer,
  50                               cdm::DecryptedBlock* decrypted_block) OVERRIDE;
  51   virtual cdm::Status InitializeAudioDecoder(
  52       const cdm::AudioDecoderConfig& audio_decoder_config) OVERRIDE;
  53   virtual cdm::Status InitializeVideoDecoder(
  54       const cdm::VideoDecoderConfig& video_decoder_config) OVERRIDE;
  55   virtual void DeinitializeDecoder(cdm::StreamType decoder_type) OVERRIDE;
  56   virtual void ResetDecoder(cdm::StreamType decoder_type) OVERRIDE;
  57   virtual cdm::Status DecryptAndDecodeFrame(
  58       const cdm::InputBuffer& encrypted_buffer,
  59       cdm::VideoFrame* video_frame) OVERRIDE;
  60   virtual cdm::Status DecryptAndDecodeSamples(
  61       const cdm::InputBuffer& encrypted_buffer,
  62       cdm::AudioFrames* audio_frames) OVERRIDE;
  63   virtual void Destroy() OVERRIDE;
  64   virtual void OnPlatformChallengeResponse(
  65       const cdm::PlatformChallengeResponse& response) OVERRIDE;
  66   virtual void OnQueryOutputProtectionStatus(
  67       uint32_t link_mask, uint32_t output_protection_mask) OVERRIDE;
  68
  69  private:
  70   // TODO(xhwang): After we removed DecryptorClient. We probably can also remove
  71   // this Client class as well. Investigate this possibility.
  72   class Client {
  73    public:
  74     enum Status {
  75       kKeyAdded,
  76       kKeyError,
  77       kKeyMessage
  78     };
  79
  80     Client();
  81     virtual ~Client();
  82
  83     Status status() { return status_; }
  84     const std::string& session_id() { return session_id_; }
  85     const std::vector<uint8>& key_message() { return key_message_; }
  86     const std::string& default_url() { return default_url_; }
  87
  88     // Resets the Client to a clean state.
  89     void Reset();
  90
  91     void KeyAdded(const std::string& session_id);
  92     void KeyError(const std::string& session_id,
  93                   MediaKeys::KeyError error_code,
  94                   int system_code);
  95     void KeyMessage(const std::string& session_id,
  96                     const std::vector<uint8>& message,
  97                     const std::string& default_url);
  98
  99    private:
 100     Status status_;
 101     std::string session_id_;
 102     std::vector<uint8> key_message_;
 103     std::string default_url_;
 104   };
 105
 106   // Prepares next heartbeat message and sets a timer for it.
 107   void ScheduleNextHeartBeat();
 108
 109   // Decrypts the |encrypted_buffer| and puts the result in |decrypted_buffer|.
 110   // Returns cdm::kSuccess if decryption succeeded. The decrypted result is
 111   // put in |decrypted_buffer|. If |encrypted_buffer| is empty, the
 112   // |decrypted_buffer| is set to an empty (EOS) buffer.
 113   // Returns cdm::kNoKey if no decryption key was available. In this case
 114   // |decrypted_buffer| should be ignored by the caller.
 115   // Returns cdm::kDecryptError if any decryption error occurred. In this case
 116   // |decrypted_buffer| should be ignored by the caller.
 117   cdm::Status DecryptToMediaDecoderBuffer(
 118       const cdm::InputBuffer& encrypted_buffer,
 119       scoped_refptr<DecoderBuffer>* decrypted_buffer);
 120
 121 #if defined(CLEAR_KEY_CDM_USE_FAKE_AUDIO_DECODER)
 122   int64 CurrentTimeStampInMicroseconds() const;
 123
 124   // Generates fake video frames with |duration_in_microseconds|.
 125   // Returns the number of samples generated in the |audio_frames|.
 126   int GenerateFakeAudioFramesFromDuration(int64 duration_in_microseconds,
 127                                           cdm::AudioFrames* audio_frames) const;
 128
 129   // Generates fake video frames given |input_timestamp|.
 130   // Returns cdm::kSuccess if any audio frame is successfully generated.
 131   cdm::Status GenerateFakeAudioFrames(int64 timestamp_in_microseconds,
 132                                       cdm::AudioFrames* audio_frames);
 133 #endif  // CLEAR_KEY_CDM_USE_FAKE_AUDIO_DECODER
 134
 135   Client client_;
 136   AesDecryptor decryptor_;
 137
 138   // Protects the |client_| from being accessed by the |decryptor_|
 139   // simultaneously.
 140   base::Lock client_lock_;
 141
 142   cdm::Host* host_;
 143
 144   std::string heartbeat_session_id_;
 145   std::string next_heartbeat_message_;
 146
 147   // Timer delay in milliseconds for the next host_->SetTimer() call.
 148   int64 timer_delay_ms_;
 149
 150   // Indicates whether a timer has been set to prevent multiple timers from
 151   // running.
 152   bool timer_set_;
 153
 154 #if defined(CLEAR_KEY_CDM_USE_FAKE_AUDIO_DECODER)
 155   int channel_count_;
 156   int bits_per_channel_;
 157   int samples_per_second_;
 158   int64 output_timestamp_base_in_microseconds_;
 159   int total_samples_generated_;
 160 #endif  // CLEAR_KEY_CDM_USE_FAKE_AUDIO_DECODER
 161
 162 #if defined(CLEAR_KEY_CDM_USE_FFMPEG_DECODER)
 163   scoped_ptr<FFmpegCdmAudioDecoder> audio_decoder_;
 164 #endif  // CLEAR_KEY_CDM_USE_FFMPEG_DECODER
 165
 166   scoped_ptr<CdmVideoDecoder> video_decoder_;
 167
 168   DISALLOW_COPY_AND_ASSIGN(ClearKeyCdm);
 169 };
 170
 171 }  // namespace media
 172
 173 #endif  // MEDIA_CDM_PPAPI_CLEAR_KEY_CDM_H_