Home | History | Annotate | Download | only in vda 
      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 
     15 namespace 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.
     21 class 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