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// Note: ported from Chromium commit head: 77118c9
5
6#ifndef ACCELERATED_VIDEO_DECODER_H_
7#define ACCELERATED_VIDEO_DECODER_H_
8
9#include <stddef.h>
10#include <stdint.h>
11
12#include "base/macros.h"
13#include "size.h"
14
15namespace media {
16
17// An AcceleratedVideoDecoder is a video decoder that requires support from an
18// external accelerator (typically a hardware accelerator) to partially offload
19// the decode process after parsing stream headers, and performing reference
20// frame and state management.
21class AcceleratedVideoDecoder {
22 public:
23  AcceleratedVideoDecoder() {}
24  virtual ~AcceleratedVideoDecoder() {}
25
26  virtual void SetStream(const uint8_t* ptr, size_t size) = 0;
27
28  // Have the decoder flush its state and trigger output of all previously
29  // decoded surfaces. Return false on failure.
30  virtual bool Flush() WARN_UNUSED_RESULT = 0;
31
32  // Stop (pause) decoding, discarding all remaining inputs and outputs,
33  // but do not flush decoder state, so that playback can be resumed later,
34  // possibly from a different location.
35  // To be called during decoding.
36  virtual void Reset() = 0;
37
38  enum DecodeResult {
39    kDecodeError,  // Error while decoding.
40    // TODO(posciak): unsupported streams are currently treated as error
41    // in decoding; in future it could perhaps be possible to fall back
42    // to software decoding instead.
43    // kStreamError,  // Error in stream.
44    kAllocateNewSurfaces,  // Need a new set of surfaces to be allocated.
45    kRanOutOfStreamData,   // Need more stream data to proceed.
46    kRanOutOfSurfaces,     // Waiting for the client to free up output surfaces.
47    kNeedContextUpdate,    // Waiting for the client to update decoding context
48                           // with data acquired from the accelerator.
49  };
50
51  // Try to decode more of the stream, returning decoded frames asynchronously.
52  // Return when more stream is needed, when we run out of free surfaces, when
53  // we need a new set of them, or when an error occurs.
54  virtual DecodeResult Decode() WARN_UNUSED_RESULT = 0;
55
56  // Return dimensions/required number of output surfaces that client should
57  // be ready to provide for the decoder to function properly.
58  // To be used after Decode() returns kAllocateNewSurfaces.
59  virtual Size GetPicSize() const = 0;
60  virtual size_t GetRequiredNumOfPictures() const = 0;
61
62 private:
63  DISALLOW_COPY_AND_ASSIGN(AcceleratedVideoDecoder);
64};
65
66}  //  namespace media
67
68#endif  // ACCELERATED_VIDEO_DECODER_H_
69