Support (E)AC3 passthrough

media/filters/android/media_codec_audio_decoder.cc

 // Copyright 2016 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.
 
 #include "media/filters/android/media_codec_audio_decoder.h"
 
+#include <cmath>
+
 #include "base/android/build_info.h"
 #include "base/bind.h"
 #include "base/callback_helpers.h"
 #include "base/logging.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "media/base/android/sdk_media_codec_bridge.h"
 #include "media/base/audio_buffer.h"
 #include "media/base/audio_timestamp_helper.h"
 #include "media/base/bind_to_current_loop.h"
 #include "media/base/timestamp_constants.h"
 
 namespace media {
 
 MediaCodecAudioDecoder::MediaCodecAudioDecoder(
     scoped_refptr<base::SingleThreadTaskRunner> task_runner)
     : task_runner_(task_runner),
       state_(STATE_UNINITIALIZED),
+      is_passthrough_(false),
       channel_count_(0),
       channel_layout_(CHANNEL_LAYOUT_NONE),
       sample_rate_(0),
       media_drm_bridge_cdm_context_(nullptr),
       cdm_registration_id_(0),
       weak_factory_(this) {
   DVLOG(1) << __FUNCTION__;
 }
 
 MediaCodecAudioDecoder::~MediaCodecAudioDecoder() {
@@ skipping 19 matching lines @@
 }
 
 void MediaCodecAudioDecoder::Initialize(const AudioDecoderConfig& config,
                                         CdmContext* cdm_context,
                                         const InitCB& init_cb,
                                         const OutputCB& output_cb) {
   DVLOG(1) << __FUNCTION__ << ": " << config.AsHumanReadableString();
   DCHECK_EQ(state_, STATE_UNINITIALIZED);
 
   InitCB bound_init_cb = BindToCurrentLoop(init_cb);
+  is_passthrough_ = (config.codec() == kCodecRaw);
 
   // We can support only the codecs that AudioCodecBridge can decode.
-  const bool is_codec_supported = config.codec() == kCodecVorbis ||
-                                  config.codec() == kCodecAAC ||
-                                  config.codec() == kCodecOpus;
+  const bool is_codec_supported =
+      config.codec() == kCodecVorbis || config.codec() == kCodecAAC ||
+      config.codec() == kCodecOpus || is_passthrough_;
   if (!is_codec_supported) {
     DVLOG(1) << "Unsuported codec " << GetCodecName(config.codec());
     bound_init_cb.Run(false);
     return;
   }
 
   if (config.is_encrypted() && !cdm_context) {
     NOTREACHED() << "The stream is encrypted but there is no CDM context";
     bound_init_cb.Run(false);
     return;
@@ skipping 212 matching lines @@
 }
 
 void MediaCodecAudioDecoder::OnInputDataQueued(bool success) {
   // If this is an EOS buffer, then wait to call back until we are notified that
   // it has been processed via OnDecodedEos().  If the EOS was not queued
   // successfully, then we do want to signal error now since there is no queued
   // EOS to process later.
   if (input_queue_.front().first->end_of_stream() && success)
     return;
 
+  if (is_passthrough_ && success) {
+    scoped_refptr<DecoderBuffer> decoder_buffer = input_queue_.front().first;
+
+    if (!decoder_buffer->end_of_stream()) {
+      duration_queue_.push_back(std::make_pair(decoder_buffer->timestamp(),
+                                               decoder_buffer->duration()));
+    }
+  }
+
   input_queue_.front().second.Run(success ? DecodeStatus::OK
                                           : DecodeStatus::DECODE_ERROR);
   input_queue_.pop_front();
 }
 
 void MediaCodecAudioDecoder::ClearInputQueue(DecodeStatus decode_status) {
   DVLOG(2) << __FUNCTION__;
 
   for (const auto& entry : input_queue_)
     entry.second.Run(decode_status);
@@ skipping 38 matching lines @@
   DCHECK(codec_loop_);
   MediaCodecBridge* media_codec = codec_loop_->GetCodec();
   DCHECK(media_codec);
 
   // For proper |frame_count| calculation we need to use the actual number
   // of channels which can be different from |config_| value.
   DCHECK_GT(channel_count_, 0);
 
   // Android MediaCodec can only output 16bit PCM audio.
   const int bytes_per_frame = sizeof(uint16_t) * channel_count_;
-  const size_t frame_count = out.size / bytes_per_frame;
+  size_t frame_count = out.size / bytes_per_frame;
+
+  if (is_passthrough_) {

[DaleCurtis, 2016/11/01 23:05:13]

Didn't we determine that this is all CBR? So we know duration, etc without this?

[AndyWu, 2016/11/04 18:04:24]

Could you please advise how to get audio bit rate? Thanks.

+    // Retrieve duratioin information from PTS-duration pair queue.
+    base::TimeDelta duration;
+    while (!duration_queue_.empty()) {
+      PtsDurationPair pts_duration = duration_queue_.front();
+      duration_queue_.pop_front();
+
+      base::TimeDelta diff = pts_duration.first - out.pts;
+      if (diff.magnitude() < base::TimeDelta::FromMicroseconds(1)) {
+        duration = pts_duration.second;
+        break;
+      }
+    }
+
+    // Calculate the frame count of this compressed audio buffer.
+    frame_count =
+        std::round(config_.samples_per_second() * duration.InSecondsF());
+  }
+
+  const SampleFormat sample_format =
+      is_passthrough_ ? kSampleFormatRaw : kSampleFormatS16;
+  const size_t size = is_passthrough_ ? out.size : 0;
 
   // Create AudioOutput buffer based on current parameters.
   scoped_refptr<AudioBuffer> audio_buffer =
-      AudioBuffer::CreateBuffer(kSampleFormatS16, channel_layout_,
-                                channel_count_, sample_rate_, frame_count);
+      AudioBuffer::CreateBuffer(sample_format, channel_layout_, channel_count_,
+                                sample_rate_, frame_count, size);
 
   // Copy data into AudioBuffer.
   CHECK_LE(out.size, audio_buffer->data_size());
 
   MediaCodecStatus status = media_codec->CopyFromOutputBuffer(
       out.index, out.offset, audio_buffer->channel_data()[0], out.size);
 
   // Release MediaCodec output buffer.
   media_codec->ReleaseOutputBuffer(out.index, false);
 
@@ skipping 89 matching lines @@
     RETURN_STRING(STATE_READY);
     RETURN_STRING(STATE_ERROR);
   }
   NOTREACHED() << "Unknown state " << state;
   return nullptr;
 }
 
 #undef RETURN_STRING
 
 }  // namespace media