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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 
getWidth()34     virtual int getWidth() const {
35         if (!mDemux) {
36             return 0;
37         }
38         return WebPDemuxGetI(mDemux, WEBP_FF_CANVAS_WIDTH);
39     }
40 
getHeight()41     virtual int getHeight() const {
42         if (!mDemux) {
43             return 0;
44         }
45         return WebPDemuxGetI(mDemux, WEBP_FF_CANVAS_HEIGHT);
46     }
47 
isOpaque()48     virtual bool isOpaque() const {
49         return !(mFormatFlags & ALPHA_FLAG);
50     }
51 
getFrameCount()52     virtual int getFrameCount() const {
53         if (!mDemux) {
54             return 0;
55         }
56         return WebPDemuxGetI(mDemux, WEBP_FF_FRAME_COUNT);
57     }
58 
getDefaultLoopCount()59     virtual int getDefaultLoopCount() const {
60         return mLoopCount;
61     }
62 
getRawByteBuffer()63     virtual jobject getRawByteBuffer() const {
64         return mRawByteBuffer;
65     }
66 
67     virtual FrameSequenceState* createState() const;
68 
getDemuxer()69     WebPDemuxer* getDemuxer() const { return mDemux; }
70 
isKeyFrame(size_t frameNr)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