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1 /* | 1 /* |
2 * Copyright (C) 2006 Apple Computer, Inc. All rights reserved. | 2 * Copyright (C) 2006 Apple Computer, Inc. All rights reserved. |
3 * | 3 * |
4 * Redistribution and use in source and binary forms, with or without | 4 * Redistribution and use in source and binary forms, with or without |
5 * modification, are permitted provided that the following conditions | 5 * modification, are permitted provided that the following conditions |
6 * are met: | 6 * are met: |
7 * 1. Redistributions of source code must retain the above copyright | 7 * 1. Redistributions of source code must retain the above copyright |
8 * notice, this list of conditions and the following disclaimer. | 8 * notice, this list of conditions and the following disclaimer. |
9 * 2. Redistributions in binary form must reproduce the above copyright | 9 * 2. Redistributions in binary form must reproduce the above copyright |
10 * notice, this list of conditions and the following disclaimer in the | 10 * notice, this list of conditions and the following disclaimer in the |
(...skipping 10 matching lines...) Expand all Loading... |
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | 21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | 23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
24 */ | 24 */ |
25 | 25 |
26 #ifndef GIFImageDecoder_h | 26 #ifndef GIFImageDecoder_h |
27 #define GIFImageDecoder_h | 27 #define GIFImageDecoder_h |
28 | 28 |
29 #include <memory> | 29 #include <memory> |
30 #include "platform/image-decoders/ImageDecoder.h" | 30 #include "platform/image-decoders/ImageDecoder.h" |
| 31 #include "platform/image-decoders/SegmentStream.h" |
31 #include "platform/wtf/Noncopyable.h" | 32 #include "platform/wtf/Noncopyable.h" |
| 33 #include "platform/wtf/RefPtr.h" |
| 34 #include "third_party/skia/include/codec/SkCodec.h" |
32 | 35 |
33 namespace blink { | 36 namespace blink { |
34 | 37 |
35 class GIFImageReader; | |
36 | |
37 using GIFRow = Vector<unsigned char>; | |
38 | |
39 // This class decodes the GIF image format. | 38 // This class decodes the GIF image format. |
40 class PLATFORM_EXPORT GIFImageDecoder final : public ImageDecoder { | 39 class PLATFORM_EXPORT GIFImageDecoder final : public ImageDecoder { |
41 WTF_MAKE_NONCOPYABLE(GIFImageDecoder); | 40 WTF_MAKE_NONCOPYABLE(GIFImageDecoder); |
42 | 41 |
43 public: | 42 public: |
44 GIFImageDecoder(AlphaOption, const ColorBehavior&, size_t max_decoded_bytes); | 43 GIFImageDecoder(AlphaOption, const ColorBehavior&, size_t max_decoded_bytes); |
45 ~GIFImageDecoder() override; | 44 ~GIFImageDecoder() override; |
46 | 45 |
47 enum GIFParseQuery { kGIFSizeQuery, kGIFFrameCountQuery }; | |
48 | |
49 // ImageDecoder: | 46 // ImageDecoder: |
50 String FilenameExtension() const override { return "gif"; } | 47 String FilenameExtension() const override { return "gif"; } |
51 void OnSetData(SegmentReader* data) override; | 48 void OnSetData(SegmentReader* data) override; |
52 int RepetitionCount() const override; | 49 int RepetitionCount() const override; |
53 bool FrameIsReceivedAtIndex(size_t) const override; | 50 bool FrameIsReceivedAtIndex(size_t) const override; |
54 float FrameDurationAtIndex(size_t) const override; | 51 float FrameDurationAtIndex(size_t) const override; |
55 // CAUTION: SetFailed() deletes |reader_|. Be careful to avoid | 52 // CAUTION: SetFailed() deletes |codec_|. Be careful to avoid |
56 // accessing deleted memory, especially when calling this from inside | 53 // accessing deleted memory. |
57 // GIFImageReader! | |
58 bool SetFailed() override; | 54 bool SetFailed() override; |
59 | 55 |
60 // Callbacks from the GIF reader. | 56 size_t ClearCacheExceptFrame(size_t) override; |
61 bool HaveDecodedRow(size_t frame_index, | |
62 GIFRow::const_iterator row_begin, | |
63 size_t width, | |
64 size_t row_number, | |
65 unsigned repeat_count, | |
66 bool write_transparent_pixels); | |
67 bool FrameComplete(size_t frame_index); | |
68 | |
69 // For testing. | |
70 bool ParseCompleted() const; | |
71 | 57 |
72 private: | 58 private: |
73 // ImageDecoder: | 59 // ImageDecoder: |
74 void ClearFrameBuffer(size_t frame_index) override; | 60 void DecodeSize() override {} |
75 virtual void DecodeSize() { Parse(kGIFSizeQuery); } | |
76 size_t DecodeFrameCount() override; | 61 size_t DecodeFrameCount() override; |
77 void InitializeNewFrame(size_t) override; | 62 void InitializeNewFrame(size_t) override; |
78 void Decode(size_t) override; | 63 void Decode(size_t) override; |
79 | |
80 // Parses as much as is needed to answer the query, ignoring bitmap | |
81 // data. If parsing fails, sets the "decode failure" flag. | |
82 void Parse(GIFParseQuery); | |
83 | |
84 // Reset the alpha tracker for this frame. Before calling this method, the | |
85 // caller must verify that the frame exists. | |
86 void OnInitFrameBuffer(size_t) override; | |
87 | |
88 // When the disposal method of the frame is DisposeOverWritePrevious, the | 64 // When the disposal method of the frame is DisposeOverWritePrevious, the |
89 // next frame will use the previous frame's buffer as its starting state, so | 65 // next frame will use a previous frame's buffer as its starting state, so |
90 // we can't take over the data in that case. Before calling this method, the | 66 // we can't take over the data in that case. Before calling this method, the |
91 // caller must verify that the frame exists. | 67 // caller must verify that the frame exists. |
92 bool CanReusePreviousFrameBuffer(size_t) const override; | 68 bool CanReusePreviousFrameBuffer(size_t) const override; |
93 | 69 |
94 bool current_buffer_saw_alpha_; | 70 // When a frame depends on a previous frames's content, there is a list of |
95 mutable int repetition_count_; | 71 // candidate reference frames. This function will find a previous frame from |
96 std::unique_ptr<GIFImageReader> reader_; | 72 // that list which satisfies the requirements of being a reference frame |
| 73 // (kFrameComplete, not kDisposeOverwritePrevious). |
| 74 // If no frame is found, it returns kNotFound. |
| 75 size_t GetViableReferenceFrameIndex(size_t) const; |
| 76 |
| 77 std::unique_ptr<SkCodec> codec_; |
| 78 // |codec_| owns the SegmentStream, but we need access to it to append more |
| 79 // data as it arrives. |
| 80 SegmentStream* segment_stream_; |
97 }; | 81 }; |
98 | 82 |
99 } // namespace blink | 83 } // namespace blink |
100 | 84 |
101 #endif | 85 #endif |
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