Add accelerated video decoder interface, VP8 and H.264 implementations and hook up to V4L2SVDA.

content/common/gpu/media/accelerated_video_decoder.h

+// 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.
+
+#ifndef CONTENT_COMMON_GPU_MEDIA_ACCELERATED_VIDEO_DECODER_
+#define CONTENT_COMMON_GPU_MEDIA_ACCELERATED_VIDEO_DECODER_
+
+#include "base/callback_forward.h"
+#include "base/callback_helpers.h"
+#include "base/memory/ref_counted.h"
+#include "content/common/content_export.h"
+#include "ui/gfx/geometry/size.h"
+
+namespace content {
+
+// An AcceleratedVideoDecoder is a video decoder that requires support from an
+// external accelerator (typically a hardware accelerator) to partially offload
+// the decode process after parsing stream headers, and performing reference
+// frame and state management.
+class CONTENT_EXPORT AcceleratedVideoDecoder {
+ public:
+  AcceleratedVideoDecoder() {}
+  virtual ~AcceleratedVideoDecoder() {}
+
+  virtual void SetStream(const uint8* ptr, size_t size) = 0;
+
+  // Have the decoder flush its state and trigger output of all previously
+  // decoded surfaces. Return false on failure.
+  virtual bool Flush() WARN_UNUSED_RESULT = 0;
+
+  // To be called during decoding.
+  // Stop (pause) decoding, discarding all remaining inputs and outputs,
+  // but do not flush decoder state, so that the playback can be resumed later,
+  // possibly from a different location.
+  virtual void Reset() = 0;
+
+  // Decode result codes.
+  enum DecResult {
+    kDecodeError,  // Error while decoding.
+    // TODO posciak: unsupported streams are currently treated as error
+    // in decoding; in future it could perhaps be possible to fall back
+    // to software decoding instead.
+    // kStreamError,  // Error in stream.
+    kAllocateNewSurfaces,  // Need a new set of surfaces to be allocated.
+    kRanOutOfStreamData,   // Need more stream data to proceed.
+    kRanOutOfSurfaces,     // Waiting for the client to free up output surfaces.
+  };
+
+  // Try to decode more of the stream, returning decoded frames asynchronously.
+  // Return when more stream is needed, when we run out of free surfaces, when
+  // we need a new set of them, or when an error occurs.
+  virtual DecResult Decode() WARN_UNUSED_RESULT = 0;
+
+  // Return dimensions/required number of output surfaces that client should
+  // be ready to provide for the decoder to function properly.
+  // To be used after Decode() returns kNeedNewSurfaces.
+  virtual gfx::Size GetPicSize() = 0;
+  virtual size_t GetRequiredNumOfPictures() = 0;
+
+  DISALLOW_COPY_AND_ASSIGN(AcceleratedVideoDecoder);
+};
+
+}  //  namespace content
+
+#endif  // CONTENT_COMMON_GPU_MEDIA_ACCELERATED_VIDEO_DECODER_