Add callback in VideoDecoder and AudioDecoder to return decoded frames.

media/filters/ffmpeg_audio_decoder.cc

 // Copyright (c) 2012 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/ffmpeg_audio_decoder.h"
 
 #include "base/callback_helpers.h"
 #include "base/single_thread_task_runner.h"
 #include "media/base/audio_buffer.h"
 #include "media/base/audio_bus.h"
@@ skipping 123 matching lines @@
       log_cb_(log_cb) {
 }
 
 FFmpegAudioDecoder::~FFmpegAudioDecoder() {
   DCHECK_EQ(state_, kUninitialized);
   DCHECK(!codec_context_);
   DCHECK(!av_frame_);
 }
 
 void FFmpegAudioDecoder::Initialize(const AudioDecoderConfig& config,
-                                    const PipelineStatusCB& status_cb) {
+                                    const PipelineStatusCB& status_cb,
+                                    const OutputCB& output_cb) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK(!config.is_encrypted());
 
   FFmpegGlue::InitializeFFmpeg();
 
   config_ = config;
   PipelineStatusCB initialize_cb = BindToCurrentLoop(status_cb);
 
   if (!config.IsValidConfig() || !ConfigureDecoder()) {
     initialize_cb.Run(DECODER_ERROR_NOT_SUPPORTED);
     return;
   }
 
   // Success!
+  output_cb_ = BindToCurrentLoop(output_cb);
   state_ = kNormal;
   initialize_cb.Run(PIPELINE_OK);
 }
 
 void FFmpegAudioDecoder::Decode(const scoped_refptr<DecoderBuffer>& buffer,
                                 const DecodeCB& decode_cb) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK(!decode_cb.is_null());
   CHECK_NE(state_, kUninitialized);
   DecodeCB decode_cb_bound = BindToCurrentLoop(decode_cb);
 
   if (state_ == kError) {
-    decode_cb_bound.Run(kDecodeError, NULL);
+    decode_cb_bound.Run(kDecodeError);
     return;
   }
 
-  // Return empty frames if decoding has finished.
+  // Do nothing if decoding has finished.
   if (state_ == kDecodeFinished) {
-    decode_cb_bound.Run(kOk, AudioBuffer::CreateEOSBuffer());
+    decode_cb_bound.Run(kOk);
     return;
   }
 
   if (!buffer) {

[xhwang, 2014/06/05 21:53:50]

hmm, should this ever happen?

[Sergey Ulanov, 2014/06/06 22:49:40]

Done.

-    decode_cb_bound.Run(kAborted, NULL);
+    decode_cb_bound.Run(kAborted);
     return;
   }
 
   DecodeBuffer(buffer, decode_cb_bound);
 }
 
-scoped_refptr<AudioBuffer> FFmpegAudioDecoder::GetDecodeOutput() {
-  DCHECK(task_runner_->BelongsToCurrentThread());
-  if (queued_audio_.empty())
-    return NULL;
-  scoped_refptr<AudioBuffer> out = queued_audio_.front();
-  queued_audio_.pop_front();
-  return out;
-}
-
 void FFmpegAudioDecoder::Reset(const base::Closure& closure) {
   DCHECK(task_runner_->BelongsToCurrentThread());
 
   avcodec_flush_buffers(codec_context_.get());
   state_ = kNormal;
   ResetTimestampState();
   task_runner_->PostTask(FROM_HERE, closure);
 }
 
 void FFmpegAudioDecoder::Stop() {
@@ skipping 42 matching lines @@
   //     When avcodec_decode_audio4() returns 0 data.
   // kFlushCodec -> kError:
   //     When avcodec_decode_audio4() errors out.
   // (any state) -> kNormal:
   //     Any time Reset() is called.
 
   // Make sure we are notified if http://crbug.com/49709 returns.  Issue also
   // occurs with some damaged files.
   if (!buffer->end_of_stream() && buffer->timestamp() == kNoTimestamp()) {
     DVLOG(1) << "Received a buffer without timestamps!";
-    decode_cb.Run(kDecodeError, NULL);
+    decode_cb.Run(kDecodeError);
     return;
   }
 
   if (!buffer->end_of_stream() && !discard_helper_->initialized() &&
       codec_context_->codec_id == AV_CODEC_ID_VORBIS &&
       buffer->timestamp() < base::TimeDelta()) {
     // Dropping frames for negative timestamps as outlined in section A.2
     // in the Vorbis spec. http://xiph.org/vorbis/doc/Vorbis_I_spec.html
     const int discard_frames =
         discard_helper_->TimeDeltaToFrames(-buffer->timestamp());
     discard_helper_->Reset(discard_frames);
   }
 
   // Transition to kFlushCodec on the first end of stream buffer.
   if (state_ == kNormal && buffer->end_of_stream()) {
     state_ = kFlushCodec;
   }
 
   if (!FFmpegDecode(buffer)) {
     state_ = kError;
-    decode_cb.Run(kDecodeError, NULL);
+    decode_cb.Run(kDecodeError);
     return;
   }
 
-  if (queued_audio_.empty()) {
-    if (state_ == kFlushCodec) {
-      DCHECK(buffer->end_of_stream());
-      state_ = kDecodeFinished;
-      decode_cb.Run(kOk, AudioBuffer::CreateEOSBuffer());
-      return;
-    }
-
-    decode_cb.Run(kNotEnoughData, NULL);
-    return;
+  if (state_ == kFlushCodec) {
+    state_ = kDecodeFinished;
+    output_cb_.Run(AudioBuffer::CreateEOSBuffer());

[xhwang, 2014/06/05 21:53:50]

should we keep calling FFmpegDecode(EOS) until the codec is completely flushed?

[Sergey Ulanov, 2014/06/06 22:49:40]

There is a loop in FFmpegDecode() which should flush all data.

   }
 
-  decode_cb.Run(kOk, queued_audio_.front());
-  queued_audio_.pop_front();
+  decode_cb.Run(kOk);
 }
 
 bool FFmpegAudioDecoder::FFmpegDecode(
     const scoped_refptr<DecoderBuffer>& buffer) {
-  DCHECK(queued_audio_.empty());
-
   AVPacket packet;
   av_init_packet(&packet);
   if (buffer->end_of_stream()) {
     packet.data = NULL;
     packet.size = 0;
   } else {
     packet.data = const_cast<uint8*>(buffer->data());
     packet.size = buffer->data_size();
   }
 
@@ skipping 40 matching lines @@
                     << ", Sample Format: " << av_frame_->format << " vs "
                     << av_sample_format_;
 
         if (config_.codec() == kCodecAAC &&
             av_frame_->sample_rate == 2 * config_.samples_per_second()) {
           MEDIA_LOG(log_cb_) << "Implicit HE-AAC signalling is being used."
                              << " Please use mp4a.40.5 instead of mp4a.40.2 in"
                              << " the mimetype.";
         }
         // This is an unrecoverable error, so bail out.
-        queued_audio_.clear();
         av_frame_unref(av_frame_.get());
         return false;
       }
 
       // Get the AudioBuffer that the data was decoded into. Adjust the number
       // of frames, in case fewer than requested were actually decoded.
       output = reinterpret_cast<AudioBuffer*>(
           av_buffer_get_opaque(av_frame_->buf[0]));
 
       DCHECK_EQ(ChannelLayoutToChannelCount(config_.channel_layout()),
                 output->channel_count());
       const int unread_frames = output->frame_count() - av_frame_->nb_samples;
       DCHECK_GE(unread_frames, 0);
       if (unread_frames > 0)
         output->TrimEnd(unread_frames);
 
       av_frame_unref(av_frame_.get());
     }
 
     // WARNING: |av_frame_| no longer has valid data at this point.
     const int decoded_frames = frame_decoded ? output->frame_count() : 0;
     if (IsEndOfStream(result, decoded_frames, buffer)) {
       DCHECK_EQ(packet.size, 0);
-      queued_audio_.push_back(AudioBuffer::CreateEOSBuffer());
+      output_cb_.Run(AudioBuffer::CreateEOSBuffer());
     } else if (discard_helper_->ProcessBuffers(buffer, output)) {
-      queued_audio_.push_back(output);
+      output_cb_.Run(output);
     }
   } while (packet.size > 0);
 
   return true;
 }
 
 void FFmpegAudioDecoder::ReleaseFFmpegResources() {
   codec_context_.reset();
   av_frame_.reset();
 }
@@ skipping 52 matching lines @@
 
   ResetTimestampState();
   return true;
 }
 
 void FFmpegAudioDecoder::ResetTimestampState() {
   discard_helper_->Reset(config_.codec_delay());
 }
 
 }  // namespace media