V4L2SVDA: Add a VP9Accelerator implementation utilizing the V4L2 VP9 frame API.

media/gpu/vp9_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 MEDIA_GPU_VP9_DECODER_H_
 #define MEDIA_GPU_VP9_DECODER_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <memory>
 #include <vector>
 
+#include "base/callback_forward.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "media/filters/vp9_parser.h"
 #include "media/gpu/accelerated_video_decoder.h"
 #include "media/gpu/vp9_picture.h"
 
 namespace media {
 
 // This class implements an AcceleratedVideoDecoder for VP9 decoding.
 // Clients of this class are expected to pass raw VP9 stream and are expected
@@ skipping 17 matching lines @@
     // When a picture is no longer needed by the decoder, it will just drop
     // its reference to it, and it may do so at any time.
     //
     // Note that this may return nullptr if the accelerator is not able to
     // provide any new pictures at the given time. The decoder must handle this
     // case and treat it as normal, returning kRanOutOfSurfaces from Decode().
     virtual scoped_refptr<VP9Picture> CreateVP9Picture() = 0;
 
     // Submit decode for |pic| to be run in accelerator, taking as arguments
     // information contained in it, as well as current segmentation and loop
-    // filter state in |seg| and |lf|, respectively, and using pictures in
-    // |ref_pictures| for reference.
+    // filter state in |segm_params| and |lf_params|, respectively, and using
+    // pictures in |ref_pictures| for reference.
+    // If done_cb_ is not null, it will be run once decode is done in hardware.
     //
     // Note that returning from this method does not mean that the decode
     // process is finished, but the caller may drop its references to |pic|
-    // and |ref_pictures| immediately, and the data in |seg| and |lf| does not
-    // need to remain valid after this method returns.
+    // and |ref_pictures| immediately, and the data in |segm_params| and
+    // |lf_params| does not need to remain valid after this method returns.
     //
     // Return true when successful, false otherwise.
     virtual bool SubmitDecode(
         const scoped_refptr<VP9Picture>& pic,
-        const Vp9SegmentationParams& seg,
-        const Vp9LoopFilterParams& lf,
-        const std::vector<scoped_refptr<VP9Picture>>& ref_pictures) = 0;
+        const Vp9SegmentationParams& segm_params,
+        const Vp9LoopFilterParams& lf_params,
+        const std::vector<scoped_refptr<VP9Picture>>& ref_pictures,
+        const base::Closure& done_cb) = 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, and that
     // they are decoded before outputting (assuming SubmitDecode() has been
     // called for them beforehand). Decoder may drop its references to |pic|
     // immediately after calling this method.
     //
     // Return true when successful, false otherwise.
     virtual bool OutputPicture(const scoped_refptr<VP9Picture>& pic) = 0;
 
+    // Return true if the accelerator requires the client to provide frame
+    // context in order to decode. If so, the Vp9FrameHeader provided by the
+    // client must contain a valid compressed header and frame context data.
+    virtual bool IsFrameContextRequired() const = 0;
+
+    // Set |frame_ctx| to the state after decoding |pic|, returning true on
+    // success, false otherwise.
+    virtual bool GetFrameContext(const scoped_refptr<VP9Picture>& pic,
+                                 Vp9FrameContext* frame_ctx) = 0;
+
    private:
     DISALLOW_COPY_AND_ASSIGN(VP9Accelerator);
   };
 
-  VP9Decoder(VP9Accelerator* accelerator);
+  explicit VP9Decoder(VP9Accelerator* accelerator);
   ~VP9Decoder() override;
 
   // AcceleratedVideoDecoder implementation.
   void SetStream(const uint8_t* ptr, size_t size) override;
   bool Flush() override WARN_UNUSED_RESULT;
   void Reset() override;
   DecodeResult Decode() override WARN_UNUSED_RESULT;
   gfx::Size GetPicSize() const override;
   size_t GetRequiredNumOfPictures() const override;
 
  private:
   // Update ref_frames_ based on the information in current frame header.
   void RefreshReferenceFrames(const scoped_refptr<VP9Picture>& pic);
 
   // Decode and possibly output |pic| (if the picture is to be shown).
   // Return true on success, false otherwise.
   bool DecodeAndOutputPicture(scoped_refptr<VP9Picture> pic);
 
+  // Get frame context state after decoding |pic| from the accelerator, and call
+  // |context_refresh_cb| with the acquired state.
+  void UpdateFrameContext(
+      const scoped_refptr<VP9Picture>& pic,
+      const base::Callback<void(const Vp9FrameContext&)>& context_refresh_cb);
+
   // Called on error, when decoding cannot continue. Sets state_ to kError and
   // releases current state.
   void SetError();
 
   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.
   };
 
   // Current decoder state.
   State state_;
 
   // Current frame header to be used in decoding the next picture.
   std::unique_ptr<Vp9FrameHeader> curr_frame_hdr_;
 
   // Reference frames currently in use.
   std::vector<scoped_refptr<VP9Picture>> ref_frames_;
 
   // Current coded resolution.
   gfx::Size pic_size_;
 
-  Vp9Parser parser_;
-
   // VP9Accelerator instance owned by the client.
   VP9Accelerator* accelerator_;
 
+  Vp9Parser parser_;
+
   DISALLOW_COPY_AND_ASSIGN(VP9Decoder);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_GPU_VP9_DECODER_H_