media/cdm/ppapi/cdm_wrapper.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_CDM_WRAPPER_H_
   6 #define MEDIA_CDM_PPAPI_CDM_WRAPPER_H_
   7
   8 #include "base/basictypes.h"
   9 #include "media/cdm/ppapi/api/content_decryption_module.h"
  10 #include "media/cdm/ppapi/cdm_helpers.h"
  11 #include "ppapi/cpp/logging.h"
  12
  13 namespace media {
  14
  15 // CdmWrapper wraps different versions of ContentDecryptionModule interfaces and
  16 // exposes a common interface to the caller.
  17 //
  18 // The caller should call CdmWrapper::Create() to create a CDM instance.
  19 // CdmWrapper will first try to create a CDM instance that supports the latest
  20 // CDM interface (ContentDecryptionModule). If such an instance cannot be
  21 // created (e.g. an older CDM was loaded), CdmWrapper will try to create a CDM
  22 // that supports an older version of CDM interface (e.g.
  23 // ContentDecryptionModule_*). Internally CdmWrapper converts the CdmWrapper
  24 // calls to corresponding ContentDecryptionModule calls.
  25 //
  26 // Note that CdmWrapper interface always reflects the latest state of content
  27 // decryption related PPAPI APIs (e.g. pp::ContentDecryptor_Private).
  28 //
  29 // Since this file is highly templated and default implementations are short
  30 // (just a shim layer in most cases), everything is done in this header file.
  31 class CdmWrapper {
  32  public:
  33   static CdmWrapper* Create(const char* key_system,
  34                             uint32_t key_system_size,
  35                             GetCdmHostFunc get_cdm_host_func,
  36                             void* user_data);
  37
  38   virtual ~CdmWrapper() {};
  39
  40   virtual cdm::Status GenerateKeyRequest(const char* type,
  41                                          uint32_t type_size,
  42                                          const uint8_t* init_data,
  43                                          uint32_t init_data_size) = 0;
  44   virtual cdm::Status AddKey(const char* session_id,
  45                              uint32_t session_id_size,
  46                              const uint8_t* key,
  47                              uint32_t key_size,
  48                              const uint8_t* key_id,
  49                              uint32_t key_id_size) = 0;
  50   virtual cdm::Status CancelKeyRequest(const char* session_id,
  51                                        uint32_t session_id_size) = 0;
  52   virtual void TimerExpired(void* context) = 0;
  53   virtual cdm::Status Decrypt(const cdm::InputBuffer& encrypted_buffer,
  54                               cdm::DecryptedBlock* decrypted_buffer) = 0;
  55   virtual cdm::Status InitializeAudioDecoder(
  56       const cdm::AudioDecoderConfig& audio_decoder_config) = 0;
  57   virtual cdm::Status InitializeVideoDecoder(
  58       const cdm::VideoDecoderConfig& video_decoder_config) = 0;
  59   virtual void DeinitializeDecoder(cdm::StreamType decoder_type) = 0;
  60   virtual void ResetDecoder(cdm::StreamType decoder_type) = 0;
  61   virtual cdm::Status DecryptAndDecodeFrame(
  62       const cdm::InputBuffer& encrypted_buffer,
  63       cdm::VideoFrame* video_frame) = 0;
  64   virtual cdm::Status DecryptAndDecodeSamples(
  65       const cdm::InputBuffer& encrypted_buffer,
  66       cdm::AudioFrames* audio_frames) = 0;
  67   virtual void OnPlatformChallengeResponse(
  68       const cdm::PlatformChallengeResponse& response) = 0;
  69   virtual void OnQueryOutputProtectionStatus(
  70       uint32_t link_mask,
  71       uint32_t output_protection_mask) = 0;
  72
  73  protected:
  74   CdmWrapper() {};
  75
  76  private:
  77   DISALLOW_COPY_AND_ASSIGN(CdmWrapper);
  78 };
  79
  80 // Template class that does the CdmWrapper -> CdmInterface conversion. Default
  81 // implementations are provided. Any methods that need special treatment should
  82 // be specialized.
  83 template <class CdmInterface>
  84 class CdmWrapperImpl : public CdmWrapper {
  85  public:
  86   static CdmWrapper* Create(const char* key_system,
  87                             uint32_t key_system_size,
  88                             GetCdmHostFunc get_cdm_host_func,
  89                             void* user_data) {
  90     void* cdm_instance = ::CreateCdmInstance(
  91         CdmInterface::kVersion, key_system, key_system_size, get_cdm_host_func,
  92         user_data);
  93     if (!cdm_instance)
  94       return NULL;
  95
  96     return new CdmWrapperImpl<CdmInterface>(
  97         static_cast<CdmInterface*>(cdm_instance));
  98   }
  99
 100   virtual ~CdmWrapperImpl() {
 101     cdm_->Destroy();
 102   }
 103
 104   virtual cdm::Status GenerateKeyRequest(const char* type,
 105                                          uint32_t type_size,
 106                                          const uint8_t* init_data,
 107                                          uint32_t init_data_size) OVERRIDE {
 108     return cdm_->GenerateKeyRequest(type, type_size, init_data, init_data_size);
 109   }
 110
 111   virtual cdm::Status AddKey(const char* session_id,
 112                              uint32_t session_id_size,
 113                              const uint8_t* key,
 114                              uint32_t key_size,
 115                              const uint8_t* key_id,
 116                              uint32_t key_id_size) OVERRIDE {
 117     return cdm_->AddKey(
 118         session_id, session_id_size, key, key_size, key_id, key_id_size);
 119   }
 120
 121   virtual cdm::Status CancelKeyRequest(const char* session_id,
 122                                        uint32_t session_id_size) OVERRIDE {
 123     return cdm_->CancelKeyRequest(session_id, session_id_size);
 124   }
 125
 126   virtual void TimerExpired(void* context) OVERRIDE {
 127     cdm_->TimerExpired(context);
 128   }
 129
 130   virtual cdm::Status Decrypt(const cdm::InputBuffer& encrypted_buffer,
 131                               cdm::DecryptedBlock* decrypted_buffer) OVERRIDE {
 132     return cdm_->Decrypt(encrypted_buffer, decrypted_buffer);
 133   }
 134
 135   virtual cdm::Status InitializeAudioDecoder(
 136       const cdm::AudioDecoderConfig& audio_decoder_config) OVERRIDE {
 137     return cdm_->InitializeAudioDecoder(audio_decoder_config);
 138   }
 139
 140   virtual cdm::Status InitializeVideoDecoder(
 141       const cdm::VideoDecoderConfig& video_decoder_config) OVERRIDE {
 142     return cdm_->InitializeVideoDecoder(video_decoder_config);
 143   }
 144
 145   virtual void DeinitializeDecoder(cdm::StreamType decoder_type) OVERRIDE {
 146     cdm_->DeinitializeDecoder(decoder_type);
 147   }
 148
 149   virtual void ResetDecoder(cdm::StreamType decoder_type) OVERRIDE {
 150     cdm_->ResetDecoder(decoder_type);
 151   }
 152
 153   virtual cdm::Status DecryptAndDecodeFrame(
 154       const cdm::InputBuffer& encrypted_buffer,
 155       cdm::VideoFrame* video_frame) OVERRIDE {
 156     return cdm_->DecryptAndDecodeFrame(encrypted_buffer, video_frame);
 157   }
 158
 159   virtual cdm::Status DecryptAndDecodeSamples(
 160       const cdm::InputBuffer& encrypted_buffer,
 161       cdm::AudioFrames* audio_frames) OVERRIDE {
 162     return cdm_->DecryptAndDecodeSamples(encrypted_buffer, audio_frames);
 163   }
 164
 165   virtual void OnPlatformChallengeResponse(
 166       const cdm::PlatformChallengeResponse& response) OVERRIDE {
 167     cdm_->OnPlatformChallengeResponse(response);
 168   }
 169
 170   virtual void OnQueryOutputProtectionStatus(
 171       uint32_t link_mask,
 172       uint32_t output_protection_mask) OVERRIDE {
 173     cdm_->OnQueryOutputProtectionStatus(link_mask, output_protection_mask);
 174   }
 175
 176  private:
 177   CdmWrapperImpl(CdmInterface* cdm) : cdm_(cdm) {
 178     PP_DCHECK(cdm_);
 179   }
 180
 181   CdmInterface* cdm_;
 182
 183   DISALLOW_COPY_AND_ASSIGN(CdmWrapperImpl);
 184 };
 185
 186 // Specializations for ContentDecryptionModule_1.
 187
 188 template <> void CdmWrapperImpl<cdm::ContentDecryptionModule_1>::
 189     OnPlatformChallengeResponse(
 190         const cdm::PlatformChallengeResponse& response) {
 191   PP_NOTREACHED();
 192 }
 193
 194 template <> void CdmWrapperImpl<cdm::ContentDecryptionModule_1>::
 195     OnQueryOutputProtectionStatus(uint32_t link_mask,
 196                                   uint32_t output_protection_mask) {
 197   PP_NOTREACHED();
 198 }
 199
 200 template <> cdm::Status CdmWrapperImpl<cdm::ContentDecryptionModule_1>::
 201     DecryptAndDecodeSamples(const cdm::InputBuffer& encrypted_buffer,
 202                             cdm::AudioFrames* audio_frames) {
 203   AudioFramesImpl audio_frames_1;
 204   cdm::Status status =
 205       cdm_->DecryptAndDecodeSamples(encrypted_buffer, &audio_frames_1);
 206   if (status != cdm::kSuccess)
 207     return status;
 208
 209   audio_frames->SetFrameBuffer(audio_frames_1.PassFrameBuffer());
 210   audio_frames->SetFormat(cdm::kAudioFormatS16);
 211   return cdm::kSuccess;
 212 }
 213
 214 CdmWrapper* CdmWrapper::Create(const char* key_system,
 215                                uint32_t key_system_size,
 216                                GetCdmHostFunc get_cdm_host_func,
 217                                void* user_data) {
 218   // Try to create the CDM using the latest CDM interface version.
 219   CdmWrapper* cdm_adapter =
 220       CdmWrapperImpl<cdm::ContentDecryptionModule>::Create(
 221           key_system, key_system_size, get_cdm_host_func, user_data);
 222   if (cdm_adapter)
 223     return cdm_adapter;
 224
 225   // Try to see if the CDM supports older version(s) of CDM interface(s).
 226   cdm_adapter = CdmWrapperImpl<cdm::ContentDecryptionModule_1>::Create(
 227       key_system, key_system_size, get_cdm_host_func, user_data);
 228   return cdm_adapter;
 229 }
 230
 231 // When updating the CdmAdapter, ensure you've updated the CdmWrapper to contain
 232 // stub implementations for new or modified methods that the older CDM interface
 233 // does not have.
 234 COMPILE_ASSERT(cdm::ContentDecryptionModule::kVersion ==
 235                    cdm::ContentDecryptionModule_2::kVersion,
 236                ensure_cdm_wrapper_templates_have_old_version_support);
 237
 238 }  // namespace media
 239
 240 #endif  // MEDIA_CDM_PPAPI_CDM_WRAPPER_H_