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      1 /*
      2  * Copyright (C) 2013 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #ifndef RASTERMILL_FRAMESQUENCE_WEBP_H
     18 #define RASTERMILL_FRAMESQUENCE_WEBP_H
     19 
     20 #include "config.h"
     21 #include "webp/decode.h"
     22 #include "webp/demux.h"
     23 
     24 #include "Stream.h"
     25 #include "Color.h"
     26 #include "FrameSequence.h"
     27 
     28 // Parser for a possibly-animated WebP bitstream.
     29 class FrameSequence_webp : public FrameSequence {
     30 public:
     31     FrameSequence_webp(Stream* stream);
     32     virtual ~FrameSequence_webp();
     33 
     34     virtual int getWidth() const {
     35         if (!mDemux) {
     36             return 0;
     37         }
     38         return WebPDemuxGetI(mDemux, WEBP_FF_CANVAS_WIDTH);
     39     }
     40 
     41     virtual int getHeight() const {
     42         if (!mDemux) {
     43             return 0;
     44         }
     45         return WebPDemuxGetI(mDemux, WEBP_FF_CANVAS_HEIGHT);
     46     }
     47 
     48     virtual bool isOpaque() const {
     49         return !(mFormatFlags & ALPHA_FLAG);
     50     }
     51 
     52     virtual int getFrameCount() const {
     53         if (!mDemux) {
     54             return 0;
     55         }
     56         return WebPDemuxGetI(mDemux, WEBP_FF_FRAME_COUNT);
     57     }
     58 
     59     virtual int getDefaultLoopCount() const {
     60         return mLoopCount;
     61     }
     62 
     63     virtual jobject getRawByteBuffer() const {
     64         return mRawByteBuffer;
     65     }
     66 
     67     virtual FrameSequenceState* createState() const;
     68 
     69     WebPDemuxer* getDemuxer() const { return mDemux; }
     70 
     71     bool isKeyFrame(size_t frameNr) const { return mIsKeyFrame[frameNr]; }
     72 
     73 private:
     74     void constructDependencyChain();
     75 
     76     WebPData mData;
     77     WebPDemuxer* mDemux;
     78     int mLoopCount;
     79     uint32_t mFormatFlags;
     80     // mIsKeyFrame[i] is true if ith canvas can be constructed without decoding any prior frames.
     81     bool* mIsKeyFrame;
     82     jobject mRawByteBuffer = nullptr;
     83 };
     84 
     85 // Produces frames of a possibly-animated WebP file for display.
     86 class FrameSequenceState_webp : public FrameSequenceState {
     87 public:
     88     FrameSequenceState_webp(const FrameSequence_webp& frameSequence);
     89     virtual ~FrameSequenceState_webp();
     90 
     91     // Returns frame's delay time in milliseconds.
     92     virtual long drawFrame(int frameNr,
     93             Color8888* outputPtr, int outputPixelStride, int previousFrameNr);
     94 
     95 private:
     96     void initializeFrame(const WebPIterator& currIter, Color8888* currBuffer, int currStride,
     97             const WebPIterator& prevIter, const Color8888* prevBuffer, int prevStride);
     98     bool decodeFrame(const WebPIterator& iter, Color8888* currBuffer, int currStride,
     99             const WebPIterator& prevIter, const Color8888* prevBuffer, int prevStride);
    100 
    101     const FrameSequence_webp& mFrameSequence;
    102     WebPDecoderConfig mDecoderConfig;
    103     Color8888* mPreservedBuffer;
    104 };
    105 
    106 #endif //RASTERMILL_FRAMESQUENCE_WEBP_H
    107