content/common/gpu/media/accelerated_video_decoder.h

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CONTENT_COMMON_GPU_MEDIA_ACCELERATED_VIDEO_DECODER_H_
   6 #define CONTENT_COMMON_GPU_MEDIA_ACCELERATED_VIDEO_DECODER_H_
   7
   8 #include "base/macros.h"
   9 #include "content/common/content_export.h"
  10 #include "ui/gfx/geometry/size.h"
  11
  12 namespace content {
  13
  14 // An AcceleratedVideoDecoder is a video decoder that requires support from an
  15 // external accelerator (typically a hardware accelerator) to partially offload
  16 // the decode process after parsing stream headers, and performing reference
  17 // frame and state management.
  18 class CONTENT_EXPORT AcceleratedVideoDecoder {
  19  public:
  20   AcceleratedVideoDecoder() {}
  21   virtual ~AcceleratedVideoDecoder() {}
  22
  23   virtual void SetStream(const uint8_t* ptr, size_t size) = 0;
  24
  25   // Have the decoder flush its state and trigger output of all previously
  26   // decoded surfaces. Return false on failure.
  27   virtual bool Flush() WARN_UNUSED_RESULT = 0;
  28
  29   // Stop (pause) decoding, discarding all remaining inputs and outputs,
  30   // but do not flush decoder state, so that playback can be resumed later,
  31   // possibly from a different location.
  32   // To be called during decoding.
  33   virtual void Reset() = 0;
  34
  35   enum DecodeResult {
  36     kDecodeError,  // Error while decoding.
  37     // TODO(posciak): unsupported streams are currently treated as error
  38     // in decoding; in future it could perhaps be possible to fall back
  39     // to software decoding instead.
  40     // kStreamError,  // Error in stream.
  41     kAllocateNewSurfaces,  // Need a new set of surfaces to be allocated.
  42     kRanOutOfStreamData,   // Need more stream data to proceed.
  43     kRanOutOfSurfaces,     // Waiting for the client to free up output surfaces.
  44   };
  45
  46   // Try to decode more of the stream, returning decoded frames asynchronously.
  47   // Return when more stream is needed, when we run out of free surfaces, when
  48   // we need a new set of them, or when an error occurs.
  49   virtual DecodeResult Decode() WARN_UNUSED_RESULT = 0;
  50
  51   // Return dimensions/required number of output surfaces that client should
  52   // be ready to provide for the decoder to function properly.
  53   // To be used after Decode() returns kNeedNewSurfaces.
  54   virtual gfx::Size GetPicSize() const = 0;
  55   virtual size_t GetRequiredNumOfPictures() const = 0;
  56
  57  private:
  58   DISALLOW_COPY_AND_ASSIGN(AcceleratedVideoDecoder);
  59 };
  60
  61 }  //  namespace content
  62
  63 #endif  // CONTENT_COMMON_GPU_MEDIA_ACCELERATED_VIDEO_DECODER_H_