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

content/common/gpu/media/vp8_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_VP8_DECODER_H_
+#define CONTENT_COMMON_GPU_MEDIA_VP8_DECODER_H_
+
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "content/common/gpu/media/accelerated_video_decoder.h"
+#include "content/common/gpu/media/vp8_picture.h"
+#include "media/filters/vp8_parser.h"
+
+namespace content {
+
+// Clients of this class are expected to pass raw VP8 stream and are expected
+// to provide an implementation of VP8Accelerator for offloading final steps
+// of the decoding process.
+//
+// This class must be created, called and destroyed on a single thread, and
+// does nothing internally on any other thread.
+class CONTENT_EXPORT VP8Decoder : public AcceleratedVideoDecoder {
+ public:
+  class CONTENT_EXPORT VP8Accelerator {
+   public:
+    VP8Accelerator();
+    virtual ~VP8Accelerator();
+
+    // Create a new VP8Picture that the decoder client can use for decoding
+    // and pass back to this accelerator for decoding or reference.
+    // When the picture is no longer needed by decoder, it will just drop
+    // its reference to it, and it may do so at any time.
+    // Note that this may return nullptr if accelerator is not able to provide
+    // any new pictures at given time. The decoder is expected to handle
+    // this situation as normal and return from Decode() with kRanOutOfSurfaces.
+    virtual scoped_refptr<VP8Picture> CreateVP8Picture() = 0;
+
+    // Submit decode for |pic|, taking as arguments |frame_hdr| with parsed
+    // VP8 frame header information for current frame, and using |last_frame|,
+    // |golden_frame| and |alt_frame| as references, as per VP8 specification.
+    // Note that this runs the decode in hardware.
+    // Return true if successful.
+    virtual bool SubmitDecode(const scoped_refptr<VP8Picture>& pic,
+                              const media::Vp8FrameHeader* frame_hdr,
+                              const scoped_refptr<VP8Picture>& last_frame,
+                              const scoped_refptr<VP8Picture>& golden_frame,
+                              const scoped_refptr<VP8Picture>& alt_frame) = 0;
+
+    // Schedule output (display) of |pic|. Note that returning from this
+    // method does not mean that |pic| has already been outputted (displayed),
+    // but guarantees that all pictures will be outputted in the same order
+    // as this method was called for them. Decoder may drop its reference
+    // to |pic| after calling this method.
+    // Return true if successful.
+    virtual bool OutputPicture(const scoped_refptr<VP8Picture>& pic) = 0;
+
+   private:
+    DISALLOW_COPY_AND_ASSIGN(VP8Accelerator);
+  };
+
+  VP8Decoder(VP8Accelerator* accelerator);
+  ~VP8Decoder() override;
+
+  // content::AcceleratedVideoDecoder implementation.
+  bool Flush() override WARN_UNUSED_RESULT;
+  void Reset() override;
+  void SetStream(const uint8_t* ptr, size_t size) override;
+  DecodeResult Decode() override WARN_UNUSED_RESULT;
+  gfx::Size GetPicSize() const override { return pic_size_; }
+  size_t GetRequiredNumOfPictures() const override;
+
+ private:
+  bool DecodeAndOutputCurrentFrame();
+  void RefreshReferenceFrames();
+
+  enum State {
+    kNeedStreamMetadata,  // After initialization, need a keyframe.
+    kDecoding,            // Ready to decode from any point.
+    kAfterReset,          // After Reset(), need a resume point.
+    kError,               // Error in decode, can't continue.
+  };
+
+  State state_;
+
+  media::Vp8Parser parser_;
+
+  scoped_ptr<media::Vp8FrameHeader> curr_frame_hdr_;
+  scoped_refptr<VP8Picture> curr_pic_;
+  scoped_refptr<VP8Picture> last_frame_;
+  scoped_refptr<VP8Picture> golden_frame_;
+  scoped_refptr<VP8Picture> alt_frame_;
+
+  const uint8_t* curr_frame_start_;
+  size_t frame_size_;
+
+  gfx::Size pic_size_;
+  int horizontal_scale_;
+  int vertical_scale_;
+
+  VP8Accelerator* accelerator_;
+
+  DISALLOW_COPY_AND_ASSIGN(VP8Decoder);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_COMMON_GPU_MEDIA_VP8_DECODER_H_