| // 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_ACCELERATED_VIDEO_DECODER_H_ |
| #define MEDIA_GPU_ACCELERATED_VIDEO_DECODER_H_ |
| |
| #include <stddef.h> |
| #include <stdint.h> |
| |
| #include "base/macros.h" |
| #include "media/base/decoder_buffer.h" |
| #include "media/gpu/media_gpu_export.h" |
| #include "ui/gfx/geometry/rect.h" |
| #include "ui/gfx/geometry/size.h" |
| |
| namespace media { |
| |
| // An AcceleratedVideoDecoder is a video decoder that requires support from an |
| // external accelerator (typically a hardware accelerator) to partially offload |
| // the decode process after parsing stream headers, and performing reference |
| // frame and state management. |
| class MEDIA_GPU_EXPORT AcceleratedVideoDecoder { |
| public: |
| AcceleratedVideoDecoder() {} |
| virtual ~AcceleratedVideoDecoder() {} |
| |
| // Set the buffer owned by |decoder_buffer| as the current source of encoded |
| // stream data. AcceleratedVideoDecoder doesn't have an ownership of the |
| // buffer. |decoder_buffer| must be kept alive until Decode() returns |
| // kRanOutOfStreamData. Pictures produced as a result of this call should be |
| // assigned the passed stream |id|. |
| virtual void SetStream(int32_t id, const DecoderBuffer& decoder_buffer) = 0; |
| |
| // Have the decoder flush its state and trigger output of all previously |
| // decoded surfaces. Return false on failure. |
| virtual bool Flush() WARN_UNUSED_RESULT = 0; |
| |
| // Stop (pause) decoding, discarding all remaining inputs and outputs, |
| // but do not flush decoder state, so that playback can be resumed later, |
| // possibly from a different location. |
| // To be called during decoding. |
| virtual void Reset() = 0; |
| |
| enum DecodeResult { |
| kDecodeError, // Error while decoding. |
| // TODO(posciak): unsupported streams are currently treated as error |
| // in decoding; in future it could perhaps be possible to fall back |
| // to software decoding instead. |
| // kStreamError, // Error in stream. |
| kAllocateNewSurfaces, // Need a new set of surfaces to be allocated. |
| kRanOutOfStreamData, // Need more stream data to proceed. |
| kRanOutOfSurfaces, // Waiting for the client to free up output surfaces. |
| kNeedContextUpdate, // Waiting for the client to update decoding context |
| // with data acquired from the accelerator. |
| kTryAgain, // The accelerator needs additional data (independently |
| // provided) in order to proceed. This may be a new key in order to decrypt |
| // encrypted data, or existing hardware resources freed so that they can be |
| // reused. Decoding can resume once the data has been provided. |
| }; |
| |
| // Try to decode more of the stream, returning decoded frames asynchronously. |
| // Return when more stream is needed, when we run out of free surfaces, when |
| // we need a new set of them, or when an error occurs. |
| virtual DecodeResult Decode() WARN_UNUSED_RESULT = 0; |
| |
| // Return dimensions/visible rectangle/required number of pictures that client |
| // should be ready to provide for the decoder to function properly (of which |
| // up to GetNumReferenceFrames() might be needed for internal decoding). To be |
| // used after Decode() returns kAllocateNewSurfaces. |
| virtual gfx::Size GetPicSize() const = 0; |
| virtual gfx::Rect GetVisibleRect() const = 0; |
| virtual size_t GetRequiredNumOfPictures() const = 0; |
| virtual size_t GetNumReferenceFrames() const = 0; |
| |
| // About 3 secs for 30 fps video. When the new sized keyframe is missed, the |
| // decoder cannot decode the frame. The number of frames are skipped until |
| // getting new keyframe. If dropping more than the number of frames, the |
| // decoder reports decode error, which may take longer time to recover it. |
| // The number is the sweet spot which the decoder can tolerate to handle the |
| // missing keyframe by itself. In addition, this situation is exceptional. |
| static constexpr size_t kVPxMaxNumOfSizeChangeFailures = 75; |
| |
| private: |
| DISALLOW_COPY_AND_ASSIGN(AcceleratedVideoDecoder); |
| }; |
| |
| } // namespace media |
| |
| #endif // MEDIA_GPU_ACCELERATED_VIDEO_DECODER_H_ |