MediaCodecPlayer implementation (stage 4 - preroll)

media/base/android/media_codec_audio_decoder.cc

 // Copyright 2015 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/base/android/media_codec_audio_decoder.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "media/base/android/media_codec_bridge.h"
 #include "media/base/audio_timestamp_helper.h"
 #include "media/base/demuxer_stream.h"
 
 namespace {
 
 // Use 16bit PCM for audio output. Keep this value in sync with the output
 // format we passed to AudioTrack in MediaCodecBridge.
 const int kBytesPerAudioOutputSample = 2;
+
+// Fake buffer index that refers to pending buffer.
+const int kPendingBufferIndex = -1;
 }
 
 namespace media {
 
 MediaCodecAudioDecoder::MediaCodecAudioDecoder(
     const scoped_refptr<base::SingleThreadTaskRunner>& media_task_runner,
     const base::Closure& request_data_cb,
     const base::Closure& starvation_cb,
+    const base::Closure& preroll_done_cb,
     const base::Closure& stop_done_cb,
     const base::Closure& error_cb,
     const SetTimeCallback& update_current_time_cb)
     : MediaCodecDecoder(media_task_runner,
                         request_data_cb,
                         starvation_cb,
+                        preroll_done_cb,
                         stop_done_cb,
                         error_cb,
                         "AudioDecoder"),
       volume_(-1.0),
       bytes_per_frame_(0),
       output_sampling_rate_(0),
       frame_count_(0),
       update_current_time_cb_(update_current_time_cb) {
 }
 
@@ skipping 20 matching lines @@
   configs_ = configs;
   if (!media_codec_bridge_)
     output_sampling_rate_ = configs.audio_sampling_rate;
 }
 
 void MediaCodecAudioDecoder::Flush() {
   DCHECK(media_task_runner_->BelongsToCurrentThread());
 
   MediaCodecDecoder::Flush();
   frame_count_ = 0;
+  pending_buffer_.Invalidate();
+}
+
+void MediaCodecAudioDecoder::ReleaseMediaCodec() {
+  DCHECK(media_task_runner_->BelongsToCurrentThread());
+
+  DVLOG(1) << class_name() << "::" << __FUNCTION__;
+
+  MediaCodecDecoder::ReleaseMediaCodec();
+  pending_buffer_.Invalidate();
 }
 
 void MediaCodecAudioDecoder::SetVolume(double volume) {
   DCHECK(media_task_runner_->BelongsToCurrentThread());
 
   DVLOG(1) << class_name() << "::" << __FUNCTION__ << " " << volume;
 
   volume_ = volume;
   SetVolumeInternal();
 }
@@ skipping 69 matching lines @@
   DCHECK(media_codec_bridge_);
 
   int old_sampling_rate = output_sampling_rate_;
   output_sampling_rate_ = media_codec_bridge_->GetOutputSamplingRate();
   if (output_sampling_rate_ != old_sampling_rate)
     ResetTimestampHelper();
 }
 
 void MediaCodecAudioDecoder::Render(int buffer_index,
                                     size_t size,
-                                    bool render_output,
+                                    RenderMode render_mode,
                                     base::TimeDelta pts,
                                     bool eos_encountered) {
   DCHECK(decoder_thread_.task_runner()->BelongsToCurrentThread());
 
-  DVLOG(2) << class_name() << "::" << __FUNCTION__ << " pts:" << pts;
+  DVLOG(2) << class_name() << "::" << __FUNCTION__ << " pts:" << pts << " "
+           << AsString(render_mode);
 
-  render_output = render_output && (size != 0u);
+  bool do_render = false;
 
-  if (render_output) {
-    int64 head_position =
-        (static_cast<AudioCodecBridge*>(media_codec_bridge_.get()))
-            ->PlayOutputBuffer(buffer_index, size);
+  switch (render_mode) {
+    case kRenderSkip:
+      break;
 
-    size_t new_frames_count = size / bytes_per_frame_;
-    frame_count_ += new_frames_count;
-    audio_timestamp_helper_->AddFrames(new_frames_count);
-    int64 frames_to_play = frame_count_ - head_position;
-    DCHECK_GE(frames_to_play, 0);
+    case kRenderAfterPreroll:
+      // Do not bother to play a single last frame after preroll
+      if (!eos_encountered && size != 0u)
+        CreatePendingBuffer(buffer_index, size, pts);

[qinmin, 2015/07/31 18:43:10]

I prefer we just move the pending buffer to java side. Let mediaCodecBridge hold
the buffer instead. In that case, we just need to change the
MediaCodecBridge::PlayerOutputBuffer() to take a new param to buffer the data.

+      break;
 
-    base::TimeDelta last_buffered = audio_timestamp_helper_->GetTimestamp();
-    base::TimeDelta now_playing =
-        last_buffered -
-        audio_timestamp_helper_->GetFrameDuration(frames_to_play);
+    case kRenderNow:
+      do_render = (size != 0u);
+      break;
+  }
 
-    DVLOG(2) << class_name() << "::" << __FUNCTION__ << " pts:" << pts
-             << " will play: [" << now_playing << "," << last_buffered << "]";
+  if (do_render) {
+    if (pending_buffer_.IsValid()) {
+      PlayOutputBuffer(kPendingBufferIndex, pending_buffer_.data.size(),
+                       pending_buffer_.pts);
+      pending_buffer_.Invalidate();
+    }
 
-    media_task_runner_->PostTask(
-        FROM_HERE,
-        base::Bind(update_current_time_cb_, now_playing, last_buffered));
+    PlayOutputBuffer(buffer_index, size, pts);
   }
 
   media_codec_bridge_->ReleaseOutputBuffer(buffer_index, false);
 
   CheckLastFrame(eos_encountered, false);  // no delayed tasks
 }
 
+void MediaCodecAudioDecoder::CreatePendingBuffer(int buffer_index,
+                                                 size_t size,
+                                                 base::TimeDelta pts) {
+  DCHECK(decoder_thread_.task_runner()->BelongsToCurrentThread());
+  DVLOG(1) << class_name() << "::" << __FUNCTION__ << " pts:" << pts
+           << " size:" << size;
+
+  pending_buffer_.pts = pts;
+  pending_buffer_.data.resize(size);  // capacity should only increase
+
+  DCHECK(media_codec_bridge_);
+  if (!media_codec_bridge_->CopyFromOutputBuffer(
+          buffer_index, 0, &pending_buffer_.data[0], size)) {
+    DVLOG(0) << class_name() << "::" << __FUNCTION__ << ": cannot copy"
+             << " from buffer index:" << buffer_index << " size:" << size;
+    pending_buffer_.Invalidate();
+  }
+}
+
+void MediaCodecAudioDecoder::PlayOutputBuffer(int buffer_index,
+                                              size_t size,
+                                              base::TimeDelta pts) {
+  DCHECK(decoder_thread_.task_runner()->BelongsToCurrentThread());
+
+  AudioCodecBridge* audio_codec =
+      static_cast<AudioCodecBridge*>(media_codec_bridge_.get());
+
+  DCHECK(audio_codec);
+
+  int64 head_position =
+      (buffer_index == kPendingBufferIndex)
+          ? audio_codec->PlayOutputBuffer(&pending_buffer_.data[0], size)
+          : audio_codec->PlayOutputBuffer(buffer_index, size);
+
+  DVLOG(2) << class_name() << "::" << __FUNCTION__ << " pts:" << pts
+           << " head_position:" << head_position;
+
+  size_t new_frames_count = size / bytes_per_frame_;
+  frame_count_ += new_frames_count;
+  audio_timestamp_helper_->AddFrames(new_frames_count);
+
+  int64 frames_to_play = frame_count_ - head_position;
+
+  // TODO(timav): remove this DVLOG after more testing.
+  if (frames_to_play < 0) {
+    DVLOG(0) << class_name() << "::" << __FUNCTION__ << " pts:" << pts
+             << " frame_count_ < head_position (" << frame_count_ << " < "
+             << head_position << ")"
+             << " new_frames_count:" << new_frames_count;
+  }
+  DCHECK_GE(frames_to_play, 0);
+
+  base::TimeDelta last_buffered = audio_timestamp_helper_->GetTimestamp();
+  base::TimeDelta now_playing =
+      last_buffered - audio_timestamp_helper_->GetFrameDuration(frames_to_play);
+
+  DVLOG(2) << class_name() << "::" << __FUNCTION__ << " pts:" << pts
+           << " will play: [" << now_playing << "," << last_buffered << "]";
+
+  media_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(update_current_time_cb_, now_playing, last_buffered));
+}
+
 void MediaCodecAudioDecoder::SetVolumeInternal() {
   DCHECK(media_task_runner_->BelongsToCurrentThread());
 
   if (media_codec_bridge_) {
     static_cast<AudioCodecBridge*>(media_codec_bridge_.get())
         ->SetVolume(volume_);
   }
 }
 
 void MediaCodecAudioDecoder::ResetTimestampHelper() {
   // Media thread or Decoder thread
   // When this method is called on Media thread, decoder thread
   // should not be running.
 
   if (audio_timestamp_helper_)
     base_timestamp_ = audio_timestamp_helper_->GetTimestamp();
 
   audio_timestamp_helper_.reset(
       new AudioTimestampHelper(configs_.audio_sampling_rate));
 
   audio_timestamp_helper_->SetBaseTimestamp(base_timestamp_);
 }
 
 }  // namespace media