Add callback in VideoDecoder and AudioDecoder to return decoded frames.

media/filters/gpu_video_decoder.cc

Index: media/filters/gpu_video_decoder.cc
diff --git a/media/filters/gpu_video_decoder.cc b/media/filters/gpu_video_decoder.cc
index 4bb30ba8820b9cb73610a32e1924c4ea0029e452..e2b4f7fa4dd43267fffb426c2c2160b1101db116 100644
--- a/media/filters/gpu_video_decoder.cc
+++ b/media/filters/gpu_video_decoder.cc
@@ -43,12 +43,14 @@ GpuVideoDecoder::SHMBuffer::SHMBuffer(base::SharedMemory* m, size_t s)
 
 GpuVideoDecoder::SHMBuffer::~SHMBuffer() {}
 
-GpuVideoDecoder::BufferPair::BufferPair(
-    SHMBuffer* s, const scoped_refptr<DecoderBuffer>& b)
-    : shm_buffer(s), buffer(b) {
+GpuVideoDecoder::PendingDecoderBuffer::PendingDecoderBuffer(
+    SHMBuffer* s,
+    const scoped_refptr<DecoderBuffer>& b,
+    const DecodeCB& done_cb)
+    : shm_buffer(s), buffer(b), done_cb(done_cb) {
 }
 
-GpuVideoDecoder::BufferPair::~BufferPair() {}
+GpuVideoDecoder::PendingDecoderBuffer::~PendingDecoderBuffer() {}
 
 GpuVideoDecoder::BufferData::BufferData(
     int32 bbid, base::TimeDelta ts, const gfx::Rect& vr, const gfx::Size& ns)
@@ -82,24 +84,14 @@ void GpuVideoDecoder::Reset(const base::Closure& closure)  {
         FROM_HERE,
         base::Bind(
             &GpuVideoDecoder::Reset, weak_factory_.GetWeakPtr(), closure));
-    // NOTE: if we're deferring Reset() until a Flush() completes, return
-    // queued pictures to the VDA so they can be used to finish that Flush().
-    if (pending_decode_cb_.is_null())
-      ready_video_frames_.clear();
     return;
   }
 
-  // Throw away any already-decoded, not-yet-delivered frames.
-  ready_video_frames_.clear();
-
   if (!vda_) {
     base::MessageLoop::current()->PostTask(FROM_HERE, closure);
     return;
   }
 
-  if (!pending_decode_cb_.is_null())
-    EnqueueFrameAndTriggerFrameDelivery(VideoFrame::CreateEOSFrame());
-
   DCHECK(pending_reset_cb_.is_null());
   pending_reset_cb_ = BindToCurrentLoop(closure);
 
@@ -110,8 +102,7 @@ void GpuVideoDecoder::Stop() {
   DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent();
   if (vda_)
     DestroyVDA();
-  if (!pending_decode_cb_.is_null())
-    EnqueueFrameAndTriggerFrameDelivery(VideoFrame::CreateEOSFrame());
+  DCHECK(bitstream_buffers_in_decoder_.empty());
   if (!pending_reset_cb_.is_null())
     base::ResetAndReturn(&pending_reset_cb_).Run();
 }
@@ -158,7 +149,8 @@ static void ReportGpuVideoDecoderInitializeStatusToUMAAndRunCB(
 
 void GpuVideoDecoder::Initialize(const VideoDecoderConfig& config,
                                  bool live_mode,
-                                 const PipelineStatusCB& orig_status_cb) {
+                                 const PipelineStatusCB& orig_status_cb,
+                                 const OutputCB& output_cb) {
   DVLOG(3) << "Initialize()";
   DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent();
   DCHECK(config.IsValidConfig());
@@ -187,6 +179,7 @@ void GpuVideoDecoder::Initialize(const VideoDecoderConfig& config,
 
   config_ = config;
   needs_bitstream_conversion_ = (config.codec() == kCodecH264);
+  output_cb_ = BindToCurrentLoop(output_cb);
 
   if (previously_initialized) {
     // Reinitialization with a different config (but same codec and profile).
@@ -237,52 +230,39 @@ void GpuVideoDecoder::Decode(const scoped_refptr<DecoderBuffer>& buffer,
                              const DecodeCB& decode_cb) {
   DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent();
   DCHECK(pending_reset_cb_.is_null());
-  DCHECK(pending_decode_cb_.is_null());
 
-  pending_decode_cb_ = BindToCurrentLoop(decode_cb);
+  DecodeCB bound_decode_cb = BindToCurrentLoop(decode_cb);
 
   if (state_ == kError || !vda_) {
-    base::ResetAndReturn(&pending_decode_cb_).Run(kDecodeError, NULL);
+    bound_decode_cb.Run(kDecodeError);
     return;
   }
 
   switch (state_) {
     case kDecoderDrained:
-      if (!ready_video_frames_.empty()) {
-        EnqueueFrameAndTriggerFrameDelivery(NULL);
-        return;
-      }
       state_ = kNormal;
       // Fall-through.
     case kNormal:
       break;
     case kDrainingDecoder:
-      DCHECK(buffer->end_of_stream());
-      // Do nothing.  Will be satisfied either by a PictureReady or
-      // NotifyFlushDone below.
-      return;
     case kError:
       NOTREACHED();
       return;
   }
 
+  DCHECK_EQ(state_, kNormal);
+
   if (buffer->end_of_stream()) {
-    if (state_ == kNormal) {
-      state_ = kDrainingDecoder;
-      vda_->Flush();
-      // If we have ready frames, go ahead and process them to ensure that the
-      // Flush operation does not block in the VDA due to lack of picture
-      // buffers.
-      if (!ready_video_frames_.empty())
-        EnqueueFrameAndTriggerFrameDelivery(NULL);
-    }
+    state_ = kDrainingDecoder;
+    eos_decode_cb_ = bound_decode_cb;
+    vda_->Flush();
     return;
   }
 
   size_t size = buffer->data_size();
   SHMBuffer* shm_buffer = GetSHM(size);
   if (!shm_buffer) {
-    base::ResetAndReturn(&pending_decode_cb_).Run(kDecodeError, NULL);
+    bound_decode_cb.Run(kDecodeError);
     return;
   }
 
@@ -291,24 +271,15 @@ void GpuVideoDecoder::Decode(const scoped_refptr<DecoderBuffer>& buffer,
       next_bitstream_buffer_id_, shm_buffer->shm->handle(), size);
   // Mask against 30 bits, to avoid (undefined) wraparound on signed integer.
   next_bitstream_buffer_id_ = (next_bitstream_buffer_id_ + 1) & 0x3FFFFFFF;
-  bool inserted = bitstream_buffers_in_decoder_.insert(std::make_pair(
-      bitstream_buffer.id(), BufferPair(shm_buffer, buffer))).second;
-  DCHECK(inserted);
+  DCHECK(!ContainsKey(bitstream_buffers_in_decoder_, bitstream_buffer.id()));
+  bitstream_buffers_in_decoder_.insert(
+      std::make_pair(bitstream_buffer.id(),
+                     PendingDecoderBuffer(shm_buffer, buffer, decode_cb)));
+  DCHECK_LE(static_cast<int>(bitstream_buffers_in_decoder_.size()),
+            kMaxInFlightDecodes);
   RecordBufferData(bitstream_buffer, *buffer.get());
 
   vda_->Decode(bitstream_buffer);
-
-  if (!ready_video_frames_.empty()) {
-    EnqueueFrameAndTriggerFrameDelivery(NULL);
-    return;
-  }
-
-  if (CanMoreDecodeWorkBeDone())
-    base::ResetAndReturn(&pending_decode_cb_).Run(kNotEnoughData, NULL);
-}
-
-bool GpuVideoDecoder::CanMoreDecodeWorkBeDone() {
-  return bitstream_buffers_in_decoder_.size() < kMaxInFlightDecodes;
 }
 
 void GpuVideoDecoder::RecordBufferData(const BitstreamBuffer& bitstream_buffer,
@@ -352,7 +323,11 @@ bool GpuVideoDecoder::CanReadWithoutStalling() const {
   DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent();
   return
       next_picture_buffer_id_ == 0 ||  // Decode() will ProvidePictureBuffers().
-      available_pictures_ > 0 || !ready_video_frames_.empty();
+      available_pictures_ > 0;
+}
+
+int GpuVideoDecoder::GetMaxDecodeRequests() const {
+  return kMaxInFlightDecodes;
 }
 
 void GpuVideoDecoder::ProvidePictureBuffers(uint32 count,
@@ -485,10 +460,10 @@ void GpuVideoDecoder::PictureReady(const media::Picture& picture) {
                                              pb.texture_id())).second;
   DCHECK(inserted);
 
-  EnqueueFrameAndTriggerFrameDelivery(frame);
+  DeliverFrame(frame);
 }
 
-void GpuVideoDecoder::EnqueueFrameAndTriggerFrameDelivery(
+void GpuVideoDecoder::DeliverFrame(
     const scoped_refptr<VideoFrame>& frame) {
   DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent();
 
@@ -497,17 +472,7 @@ void GpuVideoDecoder::EnqueueFrameAndTriggerFrameDelivery(
   if (!pending_reset_cb_.is_null())
     return;
 
-  if (frame.get())
-    ready_video_frames_.push_back(frame);
-  else
-    DCHECK(!ready_video_frames_.empty());
-
-  if (pending_decode_cb_.is_null())
-    return;
-
-  base::ResetAndReturn(&pending_decode_cb_)
-      .Run(kOk, ready_video_frames_.front());
-  ready_video_frames_.pop_front();
+  output_cb_.Run(frame);
 }
 
 // static
@@ -580,7 +545,7 @@ void GpuVideoDecoder::NotifyEndOfBitstreamBuffer(int32 id) {
   DVLOG(3) << "NotifyEndOfBitstreamBuffer(" << id << ")";
   DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent();
 
-  std::map<int32, BufferPair>::iterator it =
+  std::map<int32, PendingDecoderBuffer>::iterator it =
       bitstream_buffers_in_decoder_.find(id);
   if (it == bitstream_buffers_in_decoder_.end()) {
     NotifyError(VideoDecodeAccelerator::PLATFORM_FAILURE);
@@ -589,25 +554,21 @@ void GpuVideoDecoder::NotifyEndOfBitstreamBuffer(int32 id) {
   }
 
   PutSHM(it->second.shm_buffer);
+  it->second.done_cb.Run(state_ == kError ? kDecodeError : kOk);
   bitstream_buffers_in_decoder_.erase(it);
-
-  if (pending_reset_cb_.is_null() && state_ != kDrainingDecoder &&
-      CanMoreDecodeWorkBeDone() && !pending_decode_cb_.is_null()) {
-    base::ResetAndReturn(&pending_decode_cb_).Run(kNotEnoughData, NULL);
-  }
 }
 
 GpuVideoDecoder::~GpuVideoDecoder() {
   DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent();
   // Stop should have been already called.
   DCHECK(!vda_.get() && assigned_picture_buffers_.empty());
-  DCHECK(pending_decode_cb_.is_null());
+  DCHECK(bitstream_buffers_in_decoder_.empty());
   for (size_t i = 0; i < available_shm_segments_.size(); ++i) {
     available_shm_segments_[i]->shm->Close();
     delete available_shm_segments_[i];
   }
   available_shm_segments_.clear();
-  for (std::map<int32, BufferPair>::iterator it =
+  for (std::map<int32, PendingDecoderBuffer>::iterator it =
            bitstream_buffers_in_decoder_.begin();
        it != bitstream_buffers_in_decoder_.end(); ++it) {
     it->second.shm_buffer->shm->Close();
@@ -620,13 +581,14 @@ void GpuVideoDecoder::NotifyFlushDone() {
   DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent();
   DCHECK_EQ(state_, kDrainingDecoder);
   state_ = kDecoderDrained;
-  EnqueueFrameAndTriggerFrameDelivery(VideoFrame::CreateEOSFrame());
+  DeliverFrame(VideoFrame::CreateEOSFrame());
+  base::ResetAndReturn(&eos_decode_cb_).Run(kOk);
 }
 
 void GpuVideoDecoder::NotifyResetDone() {
   DVLOG(3) << "NotifyResetDone()";
   DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent();
-  DCHECK(ready_video_frames_.empty());
+  DCHECK(bitstream_buffers_in_decoder_.empty());
 
   // This needs to happen after the Reset() on vda_ is done to ensure pictures
   // delivered during the reset can find their time data.
@@ -634,9 +596,6 @@ void GpuVideoDecoder::NotifyResetDone() {
 
   if (!pending_reset_cb_.is_null())
     base::ResetAndReturn(&pending_reset_cb_).Run();
-
-  if (!pending_decode_cb_.is_null())
-    EnqueueFrameAndTriggerFrameDelivery(VideoFrame::CreateEOSFrame());
 }
 
 void GpuVideoDecoder::NotifyError(media::VideoDecodeAccelerator::Error error) {
@@ -644,15 +603,10 @@ void GpuVideoDecoder::NotifyError(media::VideoDecodeAccelerator::Error error) {
   if (!vda_)
     return;
 
-  DLOG(ERROR) << "VDA Error: " << error;
-  DestroyVDA();
-
   state_ = kError;
 
-  if (!pending_decode_cb_.is_null()) {
-    base::ResetAndReturn(&pending_decode_cb_).Run(kDecodeError, NULL);
-    return;
-  }
+  DLOG(ERROR) << "VDA Error: " << error;
+  DestroyVDA();
 }
 
 void GpuVideoDecoder::DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent()