Encrypted Media: Enforcing the CDM to decode audio into S16 integers.

media/filters/decrypting_audio_decoder.cc

Index: media/filters/decrypting_audio_decoder.cc
diff --git a/media/filters/decrypting_audio_decoder.cc b/media/filters/decrypting_audio_decoder.cc
index 9d635818a925ad9c7ab1a522616bee32779e8ecc..a92fd34bf18c4045c35a3b0d13cc5a5f188d64fd 100644
--- a/media/filters/decrypting_audio_decoder.cc
+++ b/media/filters/decrypting_audio_decoder.cc
@@ -25,6 +25,8 @@ namespace media {
 #define BIND_TO_LOOP(function) \
     media::BindToLoop(message_loop_, base::Bind(function, this))
 
+const int DecryptingAudioDecoder::kSupportedBitsPerChannel = 16;
+
 static inline bool IsOutOfSync(const base::TimeDelta& timestamp_1,
                                const base::TimeDelta& timestamp_2) {
   // Out of sync of 100ms would be pretty noticeable and we should keep any
@@ -170,8 +172,17 @@ void DecryptingAudioDecoder::SetDecryptor(Decryptor* decryptor) {
   set_decryptor_ready_cb_.Reset();
   decryptor_ = decryptor;
 
+  const AudioDecoderConfig& input_config =
+      demuxer_stream_->audio_decoder_config();
   scoped_ptr<AudioDecoderConfig> scoped_config(new AudioDecoderConfig());
-  scoped_config->CopyFrom(demuxer_stream_->audio_decoder_config());
+  scoped_config->Initialize(input_config.codec(),
+                            kSampleFormatS16,
+                            input_config.channel_layout(),
+                            input_config.samples_per_second(),
+                            input_config.extra_data(),
+                            input_config.extra_data_size(),
+                            input_config.is_encrypted(),
+                            false);
 
   state_ = kPendingDecoderInit;
   decryptor_->InitializeAudioDecoder(
@@ -194,13 +205,7 @@ void DecryptingAudioDecoder::FinishInitialization(bool success) {
   }
 
   // Success!
-  const AudioDecoderConfig& config = demuxer_stream_->audio_decoder_config();
-  bits_per_channel_ = config.bits_per_channel();
-  channel_layout_ = config.channel_layout();
-  samples_per_second_ = config.samples_per_second();
-  const int kBitsPerByte = 8;
-  bytes_per_sample_ = ChannelLayoutToChannelCount(channel_layout_) *
-      bits_per_channel_ / kBitsPerByte;
+  SetDecoderConfig();
 
   decryptor_->RegisterNewKeyCB(
       Decryptor::kAudio, BIND_TO_LOOP(&DecryptingAudioDecoder::OnKeyAdded));
@@ -224,6 +229,8 @@ void DecryptingAudioDecoder::FinishConfigChange(bool success) {
   }
 
   // Config change succeeded.
+  SetDecoderConfig();

[DaleCurtis, 2013/01/10 01:24:35]

Is this a bug fix?

[xhwang, 2013/01/10 18:17:23]

Hmm, yes, filed bug and split this change to
https://codereview.chromium.org/11824066/

+
   if (!reset_cb_.is_null()) {
     base::ResetAndReturn(&read_cb_).Run(kAborted, NULL);
     DoReset();
@@ -285,8 +292,17 @@ void DecryptingAudioDecoder::DoDecryptAndDecodeBuffer(
   if (status == DemuxerStream::kConfigChanged) {
     DVLOG(2) << "DoDecryptAndDecodeBuffer() - kConfigChanged";
 
-    scoped_ptr<AudioDecoderConfig> scoped_config(new AudioDecoderConfig());
-    scoped_config->CopyFrom(demuxer_stream_->audio_decoder_config());
+  const AudioDecoderConfig& input_config =
+      demuxer_stream_->audio_decoder_config();
+  scoped_ptr<AudioDecoderConfig> scoped_config(new AudioDecoderConfig());
+  scoped_config->Initialize(input_config.codec(),
+                            kSampleFormatS16,
+                            input_config.channel_layout(),
+                            input_config.samples_per_second(),
+                            input_config.extra_data(),
+                            input_config.extra_data_size(),
+                            input_config.is_encrypted(),
+                            false);
 
     state_ = kPendingConfigChange;
     decryptor_->DeinitializeDecoder(Decryptor::kAudio);
@@ -447,6 +463,18 @@ void DecryptingAudioDecoder::DoReset() {
   base::ResetAndReturn(&reset_cb_).Run();
 }
 
+void DecryptingAudioDecoder::SetDecoderConfig() {
+  const AudioDecoderConfig& config = demuxer_stream_->audio_decoder_config();
+  bits_per_channel_ = kSupportedBitsPerChannel;
+  channel_layout_ = config.channel_layout();
+  samples_per_second_ = config.samples_per_second();
+  const int kBitsPerByte = 8;
+  bytes_per_sample_ = ChannelLayoutToChannelCount(channel_layout_) *
+      bits_per_channel_ / kBitsPerByte;
+  output_timestamp_base_ = kNoTimestamp();
+  total_samples_decoded_ = 0;
+}
+
 void DecryptingAudioDecoder::EnqueueFrames(
     const Decryptor::AudioBuffers& frames) {
   queued_audio_frames_ = frames;