media/filters/decrypting_audio_decoder.cc

   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 #include "media/filters/decrypting_audio_decoder.h"
   6
   7 #include <cstdlib>
   8
   9 #include "base/bind.h"
  10 #include "base/callback_helpers.h"
  11 #include "base/location.h"
  12 #include "base/logging.h"
  13 #include "base/single_thread_task_runner.h"
  14 #include "media/base/audio_buffer.h"
  15 #include "media/base/audio_decoder_config.h"
  16 #include "media/base/audio_timestamp_helper.h"
  17 #include "media/base/bind_to_current_loop.h"
  18 #include "media/base/decoder_buffer.h"
  19 #include "media/base/media_log.h"
  20 #include "media/base/pipeline.h"
  21 #include "media/base/timestamp_constants.h"
  22
  23 namespace media {
  24
  25 static inline bool IsOutOfSync(const base::TimeDelta& timestamp_1,
  26                                const base::TimeDelta& timestamp_2) {
  27   // Out of sync of 100ms would be pretty noticeable and we should keep any
  28   // drift below that.
  29   const int64 kOutOfSyncThresholdInMilliseconds = 100;
  30   return std::abs(timestamp_1.InMilliseconds() - timestamp_2.InMilliseconds()) >
  31          kOutOfSyncThresholdInMilliseconds;
  32 }
  33
  34 DecryptingAudioDecoder::DecryptingAudioDecoder(
  35     const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
  36     const scoped_refptr<MediaLog>& media_log,
  37     const SetDecryptorReadyCB& set_decryptor_ready_cb,
  38     const base::Closure& waiting_for_decryption_key_cb)
  39     : task_runner_(task_runner),
  40       media_log_(media_log),
  41       state_(kUninitialized),
  42       waiting_for_decryption_key_cb_(waiting_for_decryption_key_cb),
  43       set_decryptor_ready_cb_(set_decryptor_ready_cb),
  44       decryptor_(NULL),
  45       key_added_while_decode_pending_(false),
  46       weak_factory_(this) {
  47 }
  48
  49 std::string DecryptingAudioDecoder::GetDisplayName() const {
  50   return "DecryptingAudioDecoder";
  51 }
  52
  53 void DecryptingAudioDecoder::Initialize(const AudioDecoderConfig& config,
  54                                         const InitCB& init_cb,
  55                                         const OutputCB& output_cb) {
  56   DVLOG(2) << "Initialize()";
  57   DCHECK(task_runner_->BelongsToCurrentThread());
  58   DCHECK(decode_cb_.is_null());
  59   DCHECK(reset_cb_.is_null());
  60
  61   weak_this_ = weak_factory_.GetWeakPtr();
  62   init_cb_ = BindToCurrentLoop(init_cb);
  63   output_cb_ = BindToCurrentLoop(output_cb);
  64
  65   if (!config.IsValidConfig()) {
  66     DLOG(ERROR) << "Invalid audio stream config.";
  67     base::ResetAndReturn(&init_cb_).Run(false);
  68     return;
  69   }
  70
  71   // DecryptingAudioDecoder only accepts potentially encrypted stream.
  72   if (!config.is_encrypted()) {
  73     base::ResetAndReturn(&init_cb_).Run(false);
  74     return;
  75   }
  76
  77   config_ = config;
  78
  79   if (state_ == kUninitialized) {
  80     state_ = kDecryptorRequested;
  81     set_decryptor_ready_cb_.Run(BindToCurrentLoop(
  82         base::Bind(&DecryptingAudioDecoder::SetDecryptor, weak_this_)));
  83     return;
  84   }
  85
  86   // Reinitialization (i.e. upon a config change)
  87   decryptor_->DeinitializeDecoder(Decryptor::kAudio);
  88   InitializeDecoder();
  89 }
  90
  91 void DecryptingAudioDecoder::Decode(const scoped_refptr<DecoderBuffer>& buffer,
  92                                     const DecodeCB& decode_cb) {
  93   DVLOG(3) << "Decode()";
  94   DCHECK(task_runner_->BelongsToCurrentThread());
  95   DCHECK(state_ == kIdle || state_ == kDecodeFinished) << state_;
  96   DCHECK(!decode_cb.is_null());
  97   CHECK(decode_cb_.is_null()) << "Overlapping decodes are not supported.";
  98
  99   decode_cb_ = BindToCurrentLoop(decode_cb);
 100
 101   // Return empty (end-of-stream) frames if decoding has finished.
 102   if (state_ == kDecodeFinished) {
 103     output_cb_.Run(AudioBuffer::CreateEOSBuffer());
 104     base::ResetAndReturn(&decode_cb_).Run(kOk);
 105     return;
 106   }
 107
 108   // Initialize the |next_output_timestamp_| to be the timestamp of the first
 109   // non-EOS buffer.
 110   if (timestamp_helper_->base_timestamp() == kNoTimestamp() &&
 111       !buffer->end_of_stream()) {
 112     timestamp_helper_->SetBaseTimestamp(buffer->timestamp());
 113   }
 114
 115   pending_buffer_to_decode_ = buffer;
 116   state_ = kPendingDecode;
 117   DecodePendingBuffer();
 118 }
 119
 120 void DecryptingAudioDecoder::Reset(const base::Closure& closure) {
 121   DVLOG(2) << "Reset() - state: " << state_;
 122   DCHECK(task_runner_->BelongsToCurrentThread());
 123   DCHECK(state_ == kIdle ||
 124          state_ == kPendingDecode ||
 125          state_ == kWaitingForKey ||
 126          state_ == kDecodeFinished) << state_;
 127   DCHECK(init_cb_.is_null());  // No Reset() during pending initialization.
 128   DCHECK(reset_cb_.is_null());
 129
 130   reset_cb_ = BindToCurrentLoop(closure);
 131
 132   decryptor_->ResetDecoder(Decryptor::kAudio);
 133
 134   // Reset() cannot complete if the read callback is still pending.
 135   // Defer the resetting process in this case. The |reset_cb_| will be fired
 136   // after the read callback is fired - see DecryptAndDecodeBuffer() and
 137   // DeliverFrame().
 138   if (state_ == kPendingDecode) {
 139     DCHECK(!decode_cb_.is_null());
 140     return;
 141   }
 142
 143   if (state_ == kWaitingForKey) {
 144     DCHECK(!decode_cb_.is_null());
 145     pending_buffer_to_decode_ = NULL;
 146     base::ResetAndReturn(&decode_cb_).Run(kAborted);
 147   }
 148
 149   DCHECK(decode_cb_.is_null());
 150   DoReset();
 151 }
 152
 153 DecryptingAudioDecoder::~DecryptingAudioDecoder() {
 154   DVLOG(2) << __FUNCTION__;
 155   DCHECK(task_runner_->BelongsToCurrentThread());
 156
 157   if (state_ == kUninitialized)
 158     return;
 159
 160   if (decryptor_) {
 161     decryptor_->DeinitializeDecoder(Decryptor::kAudio);
 162     decryptor_ = NULL;
 163   }
 164   if (!set_decryptor_ready_cb_.is_null())
 165     base::ResetAndReturn(&set_decryptor_ready_cb_).Run(DecryptorReadyCB());
 166   pending_buffer_to_decode_ = NULL;
 167   if (!init_cb_.is_null())
 168     base::ResetAndReturn(&init_cb_).Run(false);
 169   if (!decode_cb_.is_null())
 170     base::ResetAndReturn(&decode_cb_).Run(kAborted);
 171   if (!reset_cb_.is_null())
 172     base::ResetAndReturn(&reset_cb_).Run();
 173 }
 174
 175 void DecryptingAudioDecoder::SetDecryptor(
 176     Decryptor* decryptor,
 177     const DecryptorAttachedCB& decryptor_attached_cb) {
 178   DVLOG(2) << "SetDecryptor()";
 179   DCHECK(task_runner_->BelongsToCurrentThread());
 180   DCHECK_EQ(state_, kDecryptorRequested) << state_;
 181   DCHECK(!init_cb_.is_null());
 182   DCHECK(!set_decryptor_ready_cb_.is_null());
 183
 184   set_decryptor_ready_cb_.Reset();
 185
 186   if (!decryptor) {
 187     MEDIA_LOG(DEBUG, media_log_) << GetDisplayName() << ": no decryptor set";
 188     base::ResetAndReturn(&init_cb_).Run(false);
 189     state_ = kError;
 190     decryptor_attached_cb.Run(false);
 191     return;
 192   }
 193
 194   decryptor_ = decryptor;
 195
 196   InitializeDecoder();
 197   decryptor_attached_cb.Run(true);
 198 }
 199
 200 void DecryptingAudioDecoder::InitializeDecoder() {
 201   state_ = kPendingDecoderInit;
 202   decryptor_->InitializeAudioDecoder(
 203       config_,
 204       BindToCurrentLoop(base::Bind(
 205           &DecryptingAudioDecoder::FinishInitialization, weak_this_)));
 206 }
 207
 208 void DecryptingAudioDecoder::FinishInitialization(bool success) {
 209   DVLOG(2) << "FinishInitialization()";
 210   DCHECK(task_runner_->BelongsToCurrentThread());
 211   DCHECK(state_ == kPendingDecoderInit) << state_;
 212   DCHECK(!init_cb_.is_null());
 213   DCHECK(reset_cb_.is_null());  // No Reset() before initialization finished.
 214   DCHECK(decode_cb_.is_null());  // No Decode() before initialization finished.
 215
 216   if (!success) {
 217     MEDIA_LOG(DEBUG, media_log_) << GetDisplayName()
 218                                  << ": failed to init decoder on decryptor";
 219     base::ResetAndReturn(&init_cb_).Run(false);
 220     decryptor_ = NULL;
 221     state_ = kError;
 222     return;
 223   }
 224
 225   // Success!
 226   timestamp_helper_.reset(
 227       new AudioTimestampHelper(config_.samples_per_second()));
 228
 229   decryptor_->RegisterNewKeyCB(
 230       Decryptor::kAudio,
 231       BindToCurrentLoop(
 232           base::Bind(&DecryptingAudioDecoder::OnKeyAdded, weak_this_)));
 233
 234   state_ = kIdle;
 235   base::ResetAndReturn(&init_cb_).Run(true);
 236 }
 237
 238 void DecryptingAudioDecoder::DecodePendingBuffer() {
 239   DCHECK(task_runner_->BelongsToCurrentThread());
 240   DCHECK_EQ(state_, kPendingDecode) << state_;
 241
 242   int buffer_size = 0;
 243   if (!pending_buffer_to_decode_->end_of_stream()) {
 244     buffer_size = pending_buffer_to_decode_->data_size();
 245   }
 246
 247   decryptor_->DecryptAndDecodeAudio(
 248       pending_buffer_to_decode_,
 249       BindToCurrentLoop(base::Bind(
 250           &DecryptingAudioDecoder::DeliverFrame, weak_this_, buffer_size)));
 251 }
 252
 253 void DecryptingAudioDecoder::DeliverFrame(
 254     int buffer_size,
 255     Decryptor::Status status,
 256     const Decryptor::AudioFrames& frames) {
 257   DVLOG(3) << "DeliverFrame() - status: " << status;
 258   DCHECK(task_runner_->BelongsToCurrentThread());
 259   DCHECK_EQ(state_, kPendingDecode) << state_;
 260   DCHECK(!decode_cb_.is_null());
 261   DCHECK(pending_buffer_to_decode_.get());
 262
 263   bool need_to_try_again_if_nokey_is_returned = key_added_while_decode_pending_;
 264   key_added_while_decode_pending_ = false;
 265
 266   scoped_refptr<DecoderBuffer> scoped_pending_buffer_to_decode =
 267       pending_buffer_to_decode_;
 268   pending_buffer_to_decode_ = NULL;
 269
 270   if (!reset_cb_.is_null()) {
 271     base::ResetAndReturn(&decode_cb_).Run(kAborted);
 272     DoReset();
 273     return;
 274   }
 275
 276   DCHECK_EQ(status == Decryptor::kSuccess, !frames.empty());
 277
 278   if (status == Decryptor::kError) {
 279     DVLOG(2) << "DeliverFrame() - kError";
 280     MEDIA_LOG(ERROR, media_log_) << GetDisplayName() << ": decode error";
 281     state_ = kDecodeFinished; // TODO add kError state
 282     base::ResetAndReturn(&decode_cb_).Run(kDecodeError);
 283     return;
 284   }
 285
 286   if (status == Decryptor::kNoKey) {
 287     DVLOG(2) << "DeliverFrame() - kNoKey";
 288     MEDIA_LOG(DEBUG, media_log_) << GetDisplayName() << ": no key";
 289
 290     // Set |pending_buffer_to_decode_| back as we need to try decoding the
 291     // pending buffer again when new key is added to the decryptor.
 292     pending_buffer_to_decode_ = scoped_pending_buffer_to_decode;
 293
 294     if (need_to_try_again_if_nokey_is_returned) {
 295       // The |state_| is still kPendingDecode.
 296       DecodePendingBuffer();
 297       return;
 298     }
 299
 300     state_ = kWaitingForKey;
 301     waiting_for_decryption_key_cb_.Run();
 302     return;
 303   }
 304
 305   if (status == Decryptor::kNeedMoreData) {
 306     DVLOG(2) << "DeliverFrame() - kNeedMoreData";
 307     state_ = scoped_pending_buffer_to_decode->end_of_stream() ? kDecodeFinished
 308                                                               : kIdle;
 309     base::ResetAndReturn(&decode_cb_).Run(kOk);
 310     return;
 311   }
 312
 313   DCHECK_EQ(status, Decryptor::kSuccess);
 314   DCHECK(!frames.empty());
 315   ProcessDecodedFrames(frames);
 316
 317   if (scoped_pending_buffer_to_decode->end_of_stream()) {
 318     // Set |pending_buffer_to_decode_| back as we need to keep flushing the
 319     // decryptor until kNeedMoreData is returned.
 320     pending_buffer_to_decode_ = scoped_pending_buffer_to_decode;
 321     DecodePendingBuffer();
 322     return;
 323   }
 324
 325   state_ = kIdle;
 326   base::ResetAndReturn(&decode_cb_).Run(kOk);
 327 }
 328
 329 void DecryptingAudioDecoder::OnKeyAdded() {
 330   DCHECK(task_runner_->BelongsToCurrentThread());
 331
 332   if (state_ == kPendingDecode) {
 333     key_added_while_decode_pending_ = true;
 334     return;
 335   }
 336
 337   if (state_ == kWaitingForKey) {
 338     state_ = kPendingDecode;
 339     DecodePendingBuffer();
 340   }
 341 }
 342
 343 void DecryptingAudioDecoder::DoReset() {
 344   DCHECK(init_cb_.is_null());
 345   DCHECK(decode_cb_.is_null());
 346   timestamp_helper_->SetBaseTimestamp(kNoTimestamp());
 347   state_ = kIdle;
 348   base::ResetAndReturn(&reset_cb_).Run();
 349 }
 350
 351 void DecryptingAudioDecoder::ProcessDecodedFrames(
 352     const Decryptor::AudioFrames& frames) {
 353   for (Decryptor::AudioFrames::const_iterator iter = frames.begin();
 354        iter != frames.end();
 355        ++iter) {
 356     scoped_refptr<AudioBuffer> frame = *iter;
 357
 358     DCHECK(!frame->end_of_stream()) << "EOS frame returned.";
 359     DCHECK_GT(frame->frame_count(), 0) << "Empty frame returned.";
 360
 361     base::TimeDelta current_time = timestamp_helper_->GetTimestamp();
 362     if (IsOutOfSync(current_time, frame->timestamp())) {
 363       DVLOG(1) << "Timestamp returned by the decoder ("
 364                << frame->timestamp().InMilliseconds() << " ms)"
 365                << " does not match the input timestamp and number of samples"
 366                << " decoded (" << current_time.InMilliseconds() << " ms).";
 367     }
 368
 369     frame->set_timestamp(current_time);
 370     timestamp_helper_->AddFrames(frame->frame_count());
 371
 372     output_cb_.Run(frame);
 373   }
 374 }
 375
 376 }  // namespace media