Add callback in VideoDecoder and AudioDecoder to return decoded frames.

media/filters/decrypting_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/decrypting_audio_decoder.h"
 
 #include <cstdlib>
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
@@ skipping 27 matching lines @@
     const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
     const SetDecryptorReadyCB& set_decryptor_ready_cb)
     : task_runner_(task_runner),
       state_(kUninitialized),
       set_decryptor_ready_cb_(set_decryptor_ready_cb),
       decryptor_(NULL),
       key_added_while_decode_pending_(false),
       weak_factory_(this) {}
 
 void DecryptingAudioDecoder::Initialize(const AudioDecoderConfig& config,
-                                        const PipelineStatusCB& status_cb) {
+                                        const PipelineStatusCB& status_cb,
+                                        const OutputCB& output_cb) {
   DVLOG(2) << "Initialize()";
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK(decode_cb_.is_null());
   DCHECK(reset_cb_.is_null());
 
   weak_this_ = weak_factory_.GetWeakPtr();
   init_cb_ = BindToCurrentLoop(status_cb);
+  output_cb_ = BindToCurrentLoop(output_cb);

[xhwang, 2014/05/29 22:15:14]

nit: BindToCurrentLoop() introduce an extra post. We are probably over-posting
the |output_cb| by doing this. I can see that on l.97, in Decode() call, we
should post the |output_cb|. But in EnqueueSamples (called in DeliverFrames(),
which is always posted), we don't really need to post the |output_cb|. Since I
assume most frames are delivered in EnqueueSamples(), it's worth dropping this
extra post.

I notice that in the original code, we always BindToCurrentLoop(decode_cb). So
this is not introduced by your CL. Feel free to keep it and I'll see whether
it's worth to improve it.

[Sergey Ulanov, 2014/06/03 00:08:11]

VideoDecoder contract says that |decode_cb| is not called before Decode()
returns, so |decode_cb| must be posted. Similarly DecoderStream contract
requires that Read() is completed asynchronously. It should be possible to allow
output_cb to be called from Decode(), but I think it's better to do it later in
a separate CL.

 
   if (!config.IsValidConfig()) {
     DLOG(ERROR) << "Invalid audio stream config.";
     base::ResetAndReturn(&init_cb_).Run(PIPELINE_ERROR_DECODE);
     return;
   }
 
   // DecryptingAudioDecoder only accepts potentially encrypted stream.
   if (!config.is_encrypted()) {
     base::ResetAndReturn(&init_cb_).Run(DECODER_ERROR_NOT_SUPPORTED);
@@ skipping 19 matching lines @@
   DVLOG(3) << "Decode()";
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK(state_ == kIdle || state_ == kDecodeFinished) << state_;
   DCHECK(!decode_cb.is_null());
   CHECK(decode_cb_.is_null()) << "Overlapping decodes are not supported.";
 
   decode_cb_ = BindToCurrentLoop(decode_cb);
 
   // Return empty (end-of-stream) frames if decoding has finished.
   if (state_ == kDecodeFinished) {
-    base::ResetAndReturn(&decode_cb_).Run(kOk, AudioBuffer::CreateEOSBuffer());
+    output_cb_.Run(AudioBuffer::CreateEOSBuffer());
+    base::ResetAndReturn(&decode_cb_).Run(kOk);
     return;
   }
 
-  if (!queued_audio_frames_.empty()) {
-    DCHECK(!buffer);
-    base::ResetAndReturn(&decode_cb_).Run(kOk, queued_audio_frames_.front());
-    queued_audio_frames_.pop_front();
-    return;
-  }
-
   // Initialize the |next_output_timestamp_| to be the timestamp of the first
   // non-EOS buffer.
   if (timestamp_helper_->base_timestamp() == kNoTimestamp() &&
       !buffer->end_of_stream()) {
     timestamp_helper_->SetBaseTimestamp(buffer->timestamp());
   }
 
   pending_buffer_to_decode_ = buffer;
   state_ = kPendingDecode;
   DecodePendingBuffer();
 }
 
-scoped_refptr<AudioBuffer> DecryptingAudioDecoder::GetDecodeOutput() {
-  if (queued_audio_frames_.empty())
-    return NULL;
-  scoped_refptr<AudioBuffer> out = queued_audio_frames_.front();
-  queued_audio_frames_.pop_front();
-  return out;
-}
-
 void DecryptingAudioDecoder::Reset(const base::Closure& closure) {
   DVLOG(2) << "Reset() - state: " << state_;
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK(state_ == kIdle ||
          state_ == kPendingDecode ||
          state_ == kWaitingForKey ||
          state_ == kDecodeFinished) << state_;
   DCHECK(init_cb_.is_null());  // No Reset() during pending initialization.
   DCHECK(reset_cb_.is_null());
 
   reset_cb_ = BindToCurrentLoop(closure);
 
   decryptor_->ResetDecoder(Decryptor::kAudio);
 
   // Reset() cannot complete if the read callback is still pending.
   // Defer the resetting process in this case. The |reset_cb_| will be fired
   // after the read callback is fired - see DecryptAndDecodeBuffer() and
   // DeliverFrame().
   if (state_ == kPendingDecode) {
     DCHECK(!decode_cb_.is_null());
     return;
   }
 
   if (state_ == kWaitingForKey) {
     DCHECK(!decode_cb_.is_null());
     pending_buffer_to_decode_ = NULL;
-    base::ResetAndReturn(&decode_cb_).Run(kAborted, NULL);
+    base::ResetAndReturn(&decode_cb_).Run(kAborted);
   }
 
   DCHECK(decode_cb_.is_null());
   DoReset();
 }
 
 void DecryptingAudioDecoder::Stop() {
   DVLOG(2) << "Stop() - state: " << state_;
   DCHECK(task_runner_->BelongsToCurrentThread());
 
   // Invalidate all weak pointers so that pending callbacks won't be fired into
   // this object.
   weak_factory_.InvalidateWeakPtrs();
 
   if (decryptor_) {
     decryptor_->DeinitializeDecoder(Decryptor::kAudio);
     decryptor_ = NULL;
   }
   if (!set_decryptor_ready_cb_.is_null())
     base::ResetAndReturn(&set_decryptor_ready_cb_).Run(DecryptorReadyCB());
   pending_buffer_to_decode_ = NULL;
   if (!init_cb_.is_null())
     base::ResetAndReturn(&init_cb_).Run(DECODER_ERROR_NOT_SUPPORTED);
   if (!decode_cb_.is_null())
-    base::ResetAndReturn(&decode_cb_).Run(kAborted, NULL);
+    base::ResetAndReturn(&decode_cb_).Run(kAborted);
   if (!reset_cb_.is_null())
     base::ResetAndReturn(&reset_cb_).Run();
 
   state_ = kStopped;
 }
 
 DecryptingAudioDecoder::~DecryptingAudioDecoder() {
   DCHECK(state_ == kUninitialized || state_ == kStopped) << state_;
 }
 
@@ skipping 70 matching lines @@
 
 void DecryptingAudioDecoder::DeliverFrame(
     int buffer_size,
     Decryptor::Status status,
     const Decryptor::AudioBuffers& frames) {
   DVLOG(3) << "DeliverFrame() - status: " << status;
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK_EQ(state_, kPendingDecode) << state_;
   DCHECK(!decode_cb_.is_null());
   DCHECK(pending_buffer_to_decode_.get());
-  DCHECK(queued_audio_frames_.empty());
 
   bool need_to_try_again_if_nokey_is_returned = key_added_while_decode_pending_;
   key_added_while_decode_pending_ = false;
 
   scoped_refptr<DecoderBuffer> scoped_pending_buffer_to_decode =
       pending_buffer_to_decode_;
   pending_buffer_to_decode_ = NULL;
 
   if (!reset_cb_.is_null()) {
-    base::ResetAndReturn(&decode_cb_).Run(kAborted, NULL);
+    base::ResetAndReturn(&decode_cb_).Run(kAborted);
     DoReset();
     return;
   }
 
   DCHECK_EQ(status == Decryptor::kSuccess, !frames.empty());
 
   if (status == Decryptor::kError) {
     DVLOG(2) << "DeliverFrame() - kError";
     state_ = kDecodeFinished; // TODO add kError state
-    base::ResetAndReturn(&decode_cb_).Run(kDecodeError, NULL);
+    base::ResetAndReturn(&decode_cb_).Run(kDecodeError);
     return;
   }
 
   if (status == Decryptor::kNoKey) {
     DVLOG(2) << "DeliverFrame() - kNoKey";
     // Set |pending_buffer_to_decode_| back as we need to try decoding the
     // pending buffer again when new key is added to the decryptor.
     pending_buffer_to_decode_ = scoped_pending_buffer_to_decode;
 
     if (need_to_try_again_if_nokey_is_returned) {
       // The |state_| is still kPendingDecode.
       DecodePendingBuffer();
       return;
     }
 
     state_ = kWaitingForKey;
     return;
   }
 
   if (status == Decryptor::kNeedMoreData) {
     DVLOG(2) << "DeliverFrame() - kNeedMoreData";
     if (scoped_pending_buffer_to_decode->end_of_stream()) {
       state_ = kDecodeFinished;
-      base::ResetAndReturn(&decode_cb_)
-          .Run(kOk, AudioBuffer::CreateEOSBuffer());
+      output_cb_.Run(AudioBuffer::CreateEOSBuffer());
+      base::ResetAndReturn(&decode_cb_).Run(kOk);
       return;
     }
 
     state_ = kIdle;
-    base::ResetAndReturn(&decode_cb_).Run(kNotEnoughData, NULL);
+    base::ResetAndReturn(&decode_cb_).Run(kOk);
     return;
   }
 
   DCHECK_EQ(status, Decryptor::kSuccess);
   DCHECK(!frames.empty());
   EnqueueFrames(frames);
 
   state_ = kIdle;
-  base::ResetAndReturn(&decode_cb_).Run(kOk, queued_audio_frames_.front());
-  queued_audio_frames_.pop_front();
+  base::ResetAndReturn(&decode_cb_).Run(kOk);
 }
 
 void DecryptingAudioDecoder::OnKeyAdded() {
   DCHECK(task_runner_->BelongsToCurrentThread());
 
   if (state_ == kPendingDecode) {
     key_added_while_decode_pending_ = true;
     return;
   }
 
   if (state_ == kWaitingForKey) {
     state_ = kPendingDecode;
     DecodePendingBuffer();
   }
 }
 
 void DecryptingAudioDecoder::DoReset() {
   DCHECK(init_cb_.is_null());
   DCHECK(decode_cb_.is_null());
   timestamp_helper_->SetBaseTimestamp(kNoTimestamp());
   state_ = kIdle;
   base::ResetAndReturn(&reset_cb_).Run();
 }
 
 void DecryptingAudioDecoder::EnqueueFrames(
     const Decryptor::AudioBuffers& frames) {
-  queued_audio_frames_ = frames;
-
-  for (Decryptor::AudioBuffers::iterator iter = queued_audio_frames_.begin();
-       iter != queued_audio_frames_.end();
+  for (Decryptor::AudioBuffers::const_iterator iter = frames.begin();
+       iter != frames.end();
        ++iter) {
-    scoped_refptr<AudioBuffer>& frame = *iter;
+    scoped_refptr<AudioBuffer> frame = *iter;
 
     DCHECK(!frame->end_of_stream()) << "EOS frame returned.";
     DCHECK_GT(frame->frame_count(), 0) << "Empty frame returned.";
 
     base::TimeDelta current_time = timestamp_helper_->GetTimestamp();
     if (IsOutOfSync(current_time, frame->timestamp())) {
       DVLOG(1) << "Timestamp returned by the decoder ("
                << frame->timestamp().InMilliseconds() << " ms)"
                << " does not match the input timestamp and number of samples"
                << " decoded (" << current_time.InMilliseconds() << " ms).";
     }
 
     frame->set_timestamp(current_time);
     timestamp_helper_->AddFrames(frame->frame_count());
+
+    output_cb_.Run(frame);
   }
 }
 
 }  // namespace media