V4L2VDA: do not allocate input buffers in GPU child thread.

media/gpu/v4l2_video_decode_accelerator.h

 // Copyright 2014 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.
 //
 // This file contains an implementation of VideoDecodeAccelerator
 // that utilizes hardware video decoders, which expose Video4Linux 2 API
 // (http://linuxtv.org/downloads/v4l-dvb-apis/).
 
 #ifndef MEDIA_GPU_V4L2_VIDEO_DECODE_ACCELERATOR_H_
 #define MEDIA_GPU_V4L2_VIDEO_DECODE_ACCELERATOR_H_
@@ skipping 118 matching lines @@
     // limits::kMaxVideoFrames to fill up the GpuVideoDecode pipeline,
     // and +1 for a frame in transit.
     kDpbOutputBufferExtraCount = limits::kMaxVideoFrames + 1,
     // Number of extra output buffers if image processor is used.
     kDpbOutputBufferExtraCountForImageProcessor = 1,
   };
 
   // Internal state of the decoder.
   enum State {
     kUninitialized,  // Initialize() not yet called.
-    kInitialized,    // Initialize() returned true; ready to start decoding.
+    kInitialized,    // InitializeTask() succeeds; ready to start decoding.

[kcwu, 2016/11/29 03:51:46]

this is still "Initialize() returned true"

[wuchengli, 2016/11/29 05:18:22]

Done.

     kDecoding,       // DecodeBufferInitial() successful; decoding frames.
     kResetting,      // Presently resetting.
     // Performing resolution change and waiting for image processor to return
     // all frames.
     kChangingResolution,
     // Requested new PictureBuffers via ProvidePictureBuffers(), awaiting
     // AssignPictureBuffers().
     kAwaitingPictureBuffers,
     kError,  // Error in kDecoding state.
   };
@@ skipping 45 matching lines @@
     // Input fds of the processor. Exported from the decoder.
     std::vector<base::ScopedFD> processor_input_fds;
     // Output fds of the processor. Used only when OutputMode is IMPORT.
     std::vector<base::ScopedFD> processor_output_fds;
   };
 
   //
   // Decoding tasks, to be run on decode_thread_.
   //
 
+  // Task to finish initialization on decoder_thread_.
+  void InitializeTask();
+
   // Enqueue a BitstreamBuffer to decode.  This will enqueue a buffer to the
   // decoder_input_queue_, then queue a DecodeBufferTask() to actually decode
   // the buffer.
   void DecodeTask(const BitstreamBuffer& bitstream_buffer);
 
   // Decode from the buffers queued in decoder_input_queue_.  Calls
   // DecodeBufferInitial() or DecodeBufferContinue() as appropriate.
   void DecodeBufferTask();
   // Advance to the next fragment that begins a frame.
   bool AdvanceFrameFragment(const uint8_t* data, size_t size, size_t* endpos);
@@ skipping 361 matching lines @@
 
   // The WeakPtrFactory for |weak_this_|.
   base::WeakPtrFactory<V4L2VideoDecodeAccelerator> weak_this_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(V4L2VideoDecodeAccelerator);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_GPU_V4L2_VIDEO_DECODE_ACCELERATOR_H_