Use passthrough decoder for (E)AC3 formats

media/base/audio_buffer.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MEDIA_BASE_AUDIO_BUFFER_H_
 #define MEDIA_BASE_AUDIO_BUFFER_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 46 matching lines @@
   static scoped_refptr<AudioBuffer> CopyFrom(
       SampleFormat sample_format,
       ChannelLayout channel_layout,
       int channel_count,
       int sample_rate,
       int frame_count,
       const uint8_t* const* data,
       const base::TimeDelta timestamp,
       scoped_refptr<AudioBufferMemoryPool> pool = nullptr);
 
+  // Create an AudioBuffer for compressed bitstream. Its channel data is copied
+  // from |data|, and the size is |data_size|. |data| must not be null and
+  // |frame_count| must be >= 0.
+  static scoped_refptr<AudioBuffer> CopyBitstreamFrom(
+      SampleFormat sample_format,
+      ChannelLayout channel_layout,
+      int channel_count,
+      int sample_rate,
+      int frame_count,
+      const uint8_t* const* data,
+      const size_t data_size,
+      const base::TimeDelta timestamp,
+      scoped_refptr<AudioBufferMemoryPool> pool = nullptr);
+
   // Create an AudioBuffer with |frame_count| frames. Buffer is allocated, but
   // not initialized. Timestamp and duration are set to kNoTimestamp. For
   // optimal efficiency when many buffers are being created, a
   // AudioBufferMemoryPool can be provided to avoid thrashing memory.
   static scoped_refptr<AudioBuffer> CreateBuffer(
       SampleFormat sample_format,
       ChannelLayout channel_layout,
       int channel_count,
       int sample_rate,
       int frame_count,
       scoped_refptr<AudioBufferMemoryPool> pool = nullptr);
 
+  // Create an AudioBuffer for compressed bitstream. Buffer is allocated, but
+  // not initialized. Timestamp and duration are set to kNoTimestamp.
+  static scoped_refptr<AudioBuffer> CreateBitstreamBuffer(
+      SampleFormat sample_format,
+      ChannelLayout channel_layout,
+      int channel_count,
+      int sample_rate,
+      int frame_count,
+      size_t data_size,
+      scoped_refptr<AudioBufferMemoryPool> pool = nullptr);
+
   // Create an empty AudioBuffer with |frame_count| frames.
   static scoped_refptr<AudioBuffer> CreateEmptyBuffer(
       ChannelLayout channel_layout,
       int channel_count,
       int sample_rate,
       int frame_count,
       const base::TimeDelta timestamp);
 
   // Create a AudioBuffer indicating we've reached end of stream.
   // Calling any method other than end_of_stream() on the resulting buffer
@@ skipping 32 matching lines @@
 
   // Return the number of channels.
   int channel_count() const { return channel_count_; }
 
   // Return the number of frames held.
   int frame_count() const { return adjusted_frame_count_; }
 
   // Return the sample rate.
   int sample_rate() const { return sample_rate_; }
 
+  // Return the sample format.

[DaleCurtis, 2017/05/04 19:05:44]

Can we drop this? And instead return IsBitstreamFormat()?  I don't want clients
thinking they can know the sample format for AudioBuffers, they are expected to
use Read() irrespective of the format.

[AndyWu, 2017/05/06 01:46:48]

Done, you are right, IsBitstreamFormat() is enough.

+  SampleFormat sample_format() const { return sample_format_; }
+
   // Return the channel layout.
   ChannelLayout channel_layout() const { return channel_layout_; }
 
   base::TimeDelta timestamp() const { return timestamp_; }
   base::TimeDelta duration() const { return duration_; }
   void set_timestamp(base::TimeDelta timestamp) { timestamp_ = timestamp; }
 
   // If there's no data in this buffer, it represents end of stream.
   bool end_of_stream() const { return end_of_stream_; }
 
@@ skipping 20 matching lines @@
   // [data,data+data_size) to the allocated buffer(s). If |data| is null, no
   // data is copied. If |create_buffer| is false, no data buffer is created (or
   // copied to).
   AudioBuffer(SampleFormat sample_format,
               ChannelLayout channel_layout,
               int channel_count,
               int sample_rate,
               int frame_count,
               bool create_buffer,
               const uint8_t* const* data,
+              const size_t data_size,
               const base::TimeDelta timestamp,
               scoped_refptr<AudioBufferMemoryPool> pool);
 
   virtual ~AudioBuffer();
 
   const SampleFormat sample_format_;
   const ChannelLayout channel_layout_;
   const int channel_count_;
   int sample_rate_;
   int adjusted_frame_count_;
@@ skipping 45 matching lines @@
   base::Lock entry_lock_;
   using MemoryEntry = std::pair<AudioMemory, size_t>;
   std::list<MemoryEntry> entries_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioBufferMemoryPool);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_AUDIO_BUFFER_H_