webkit/media/crypto/ppapi/clear_key_cdm.h

   1 // Copyright (c) 2012 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 WEBKIT_MEDIA_CRYPTO_PPAPI_CLEAR_KEY_CDM_H_
   6 #define WEBKIT_MEDIA_CRYPTO_PPAPI_CLEAR_KEY_CDM_H_
   7
   8 #include <string>
   9
  10 #include "base/basictypes.h"
  11 #include "base/compiler_specific.h"
  12 #include "base/memory/ref_counted.h"
  13 #include "base/memory/scoped_ptr.h"
  14 #include "base/synchronization/lock.h"
  15 #include "media/crypto/aes_decryptor.h"
  16 #include "webkit/media/crypto/ppapi/cdm/content_decryption_module.h"
  17
  18 // Enable this to use the fake decoder for testing.
  19 // TODO(tomfinegan): Move fake audio decoder into a separate class.
  20 #if 0
  21 #define CLEAR_KEY_CDM_USE_FAKE_AUDIO_DECODER
  22 #endif
  23
  24 namespace media {
  25 class DecoderBuffer;
  26 }
  27
  28 namespace webkit_media {
  29
  30 class CdmVideoDecoder;
  31 class FFmpegCdmAudioDecoder;
  32
  33 // Clear key implementation of the cdm::ContentDecryptionModule interface.
  34 class ClearKeyCdm : public cdm::ContentDecryptionModule {
  35  public:
  36   explicit ClearKeyCdm(cdm::Host* host);
  37   virtual ~ClearKeyCdm();
  38
  39   // ContentDecryptionModule implementation.
  40   virtual cdm::Status GenerateKeyRequest(
  41       const char* type, int type_size,
  42       const uint8_t* init_data, int init_data_size) OVERRIDE;
  43   virtual cdm::Status AddKey(const char* session_id, int session_id_size,
  44                              const uint8_t* key, int key_size,
  45                              const uint8_t* key_id, int key_id_size) OVERRIDE;
  46   virtual cdm::Status CancelKeyRequest(const char* session_id,
  47                                        int 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
  65  private:
  66   // TODO(xhwang): After we removed DecryptorClient. We probably can also remove
  67   // this Client class as well. Investigate this possibility.
  68   class Client {
  69    public:
  70     enum Status {
  71       kKeyAdded,
  72       kKeyError,
  73       kKeyMessage,
  74       kNeedKey
  75     };
  76
  77     Client();
  78     virtual ~Client();
  79
  80     Status status() { return status_; }
  81     const std::string& session_id() { return session_id_; }
  82     const std::string& key_message() { return key_message_; }
  83     const std::string& default_url() { return default_url_; }
  84
  85     // Resets the Client to a clean state.
  86     void Reset();
  87
  88     void KeyAdded(const std::string& key_system, const std::string& session_id);
  89     void KeyError(const std::string& key_system,
  90                   const std::string& session_id,
  91                   media::Decryptor::KeyError error_code,
  92                   int system_code);
  93     void KeyMessage(const std::string& key_system,
  94                     const std::string& session_id,
  95                     const std::string& message,
  96                     const std::string& default_url);
  97     void NeedKey(const std::string& key_system,
  98                  const std::string& session_id,
  99                  const std::string& type,
 100                  scoped_ptr<uint8[]> init_data, int init_data_length);
 101
 102    private:
 103     Status status_;
 104     std::string session_id_;
 105     std::string key_message_;
 106     std::string default_url_;
 107   };
 108
 109   // Prepares next heartbeat message and sets a timer for it.
 110   void ScheduleNextHeartBeat();
 111
 112   // Decrypts the |encrypted_buffer| and puts the result in |decrypted_buffer|.
 113   // Returns cdm::kSuccess if decryption succeeded. The decrypted result is
 114   // put in |decrypted_buffer|. If |encrypted_buffer| is empty, the
 115   // |decrypted_buffer| is set to an empty (EOS) buffer.
 116   // Returns cdm::kNoKey if no decryption key was available. In this case
 117   // |decrypted_buffer| should be ignored by the caller.
 118   // Returns cdm::kDecryptError if any decryption error occurred. In this case
 119   // |decrypted_buffer| should be ignored by the caller.
 120   cdm::Status DecryptToMediaDecoderBuffer(
 121       const cdm::InputBuffer& encrypted_buffer,
 122       scoped_refptr<media::DecoderBuffer>* decrypted_buffer);
 123
 124 #if defined(CLEAR_KEY_CDM_USE_FAKE_AUDIO_DECODER)
 125   int64 CurrentTimeStampInMicroseconds() const;
 126
 127   // Generates fake video frames with |duration_in_microseconds|.
 128   // Returns the number of samples generated in the |audio_frames|.
 129   int GenerateFakeAudioFramesFromDuration(int64 duration_in_microseconds,
 130                                           cdm::AudioFrames* audio_frames) const;
 131
 132   // Generates fake video frames given |input_timestamp|.
 133   // Returns cdm::kSuccess if any audio frame is successfully generated.
 134   cdm::Status GenerateFakeAudioFrames(int64 timestamp_in_microseconds,
 135                                       cdm::AudioFrames* audio_frames);
 136 #endif  // CLEAR_KEY_CDM_USE_FAKE_AUDIO_DECODER
 137
 138   Client client_;
 139   media::AesDecryptor decryptor_;
 140
 141   // Protects the |client_| from being accessed by the |decryptor_|
 142   // simultaneously.
 143   base::Lock client_lock_;
 144
 145   cdm::Host* host_;
 146
 147   std::string heartbeat_session_id_;
 148   std::string next_heartbeat_message_;
 149
 150   // Timer delay in milliseconds for the next host_->SetTimer() call.
 151   int64 timer_delay_ms_;
 152
 153   // Indicates whether a timer has been set to prevent multiple timers from
 154   // running.
 155   bool timer_set_;
 156
 157 #if defined(CLEAR_KEY_CDM_USE_FAKE_AUDIO_DECODER)
 158   int channel_count_;
 159   int bits_per_channel_;
 160   int samples_per_second_;
 161   int64 output_timestamp_base_in_microseconds_;
 162   int total_samples_generated_;
 163 #endif  // CLEAR_KEY_CDM_USE_FAKE_AUDIO_DECODER
 164
 165 #if defined(CLEAR_KEY_CDM_USE_FFMPEG_DECODER)
 166   scoped_ptr<FFmpegCdmAudioDecoder> audio_decoder_;
 167 #endif  // CLEAR_KEY_CDM_USE_FFMPEG_DECODER
 168
 169   scoped_ptr<CdmVideoDecoder> video_decoder_;
 170
 171   DISALLOW_COPY_AND_ASSIGN(ClearKeyCdm);
 172 };
 173
 174 }  // namespace webkit_media
 175
 176 #endif  // WEBKIT_MEDIA_CRYPTO_PPAPI_CLEAR_KEY_CDM_H_