video_decoder.h revision 5821806d5e7f356e8fa4b058a389a808ea183019
1// Copyright (c) 2012 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 REMOTING_CODEC_VIDEO_DECODER_H_ 6#define REMOTING_CODEC_VIDEO_DECODER_H_ 7 8#include "base/basictypes.h" 9#include "remoting/proto/video.pb.h" 10#include "third_party/skia/include/core/SkRect.h" 11#include "third_party/skia/include/core/SkRegion.h" 12#include "third_party/skia/include/core/SkSize.h" 13 14namespace remoting { 15 16// Interface for a decoder that takes a stream of bytes from the network and 17// outputs frames of data. 18// 19// TODO(ajwong): Beef up this documentation once the API stablizes. 20class VideoDecoder { 21 public: 22 // DecodeResult is returned from DecodePacket() and indicates current state 23 // of the decoder. DECODE_DONE means that last packet for the frame was 24 // processed, and the frame can be displayed now. DECODE_IN_PROGRESS 25 // indicates that the decoder must receive more data before the frame can be 26 // displayed. DECODE_ERROR is returned if there was an error in the stream. 27 enum DecodeResult { 28 DECODE_ERROR = -1, 29 DECODE_IN_PROGRESS, 30 DECODE_DONE, 31 }; 32 33 VideoDecoder() {} 34 virtual ~VideoDecoder() {} 35 36 // Initializes the decoder and sets the output dimensions. 37 // |screen size| must not be empty. 38 virtual void Initialize(const SkISize& screen_size) = 0; 39 40 // Feeds more data into the decoder. 41 virtual DecodeResult DecodePacket(const VideoPacket* packet) = 0; 42 43 // Returns true if decoder is ready to accept data via DecodePacket. 44 virtual bool IsReadyForData() = 0; 45 46 virtual VideoPacketFormat::Encoding Encoding() = 0; 47 48 // Marks the specified |region| of the view for update the next time 49 // RenderFrame() is called. |region| is expressed in |view_size| coordinates. 50 // |view_size| must not be empty. 51 virtual void Invalidate(const SkISize& view_size, 52 const SkRegion& region) = 0; 53 54 // Copies invalidated pixels within |clip_area| to |image_buffer|. Pixels are 55 // invalidated either by new data received in DecodePacket(), or by explicit 56 // calls to Invalidate(). |clip_area| is specified in |view_size| coordinates. 57 // If |view_size| differs from the source size then the copied pixels will be 58 // scaled accordingly. |view_size| cannot be empty. 59 // 60 // |image_buffer|'s origin must correspond to the top-left of |clip_area|, 61 // and the buffer must be large enough to hold |clip_area| RGBA32 pixels. 62 // |image_stride| gives the output buffer's stride in pixels. 63 // 64 // On return, |output_region| contains the updated area, in |view_size| 65 // coordinates. 66 virtual void RenderFrame(const SkISize& view_size, 67 const SkIRect& clip_area, 68 uint8* image_buffer, 69 int image_stride, 70 SkRegion* output_region) = 0; 71}; 72 73} // namespace remoting 74 75#endif // REMOTING_CODEC_VIDEO_DECODER_H_ 76