diff options
Diffstat (limited to 'src/codec/SkGifCodec.h')
| -rw-r--r-- | src/codec/SkGifCodec.h | 200 |
1 files changed, 76 insertions, 124 deletions
diff --git a/src/codec/SkGifCodec.h b/src/codec/SkGifCodec.h index c56d3719a9..544ba13695 100644 --- a/src/codec/SkGifCodec.h +++ b/src/codec/SkGifCodec.h @@ -6,13 +6,13 @@ */ #include "SkCodec.h" +#include "SkCodecAnimation.h" #include "SkColorSpace.h" #include "SkColorTable.h" #include "SkImageInfo.h" #include "SkSwizzler.h" -struct GifFileType; -struct SavedImage; +#include "GIFImageReader.h" /* * @@ -30,30 +30,10 @@ public: */ static SkCodec* NewFromStream(SkStream*); + // Callback for GIFImageReader when a row is available. + bool haveDecodedRow(size_t frameIndex, const unsigned char* rowBegin, + size_t rowNumber, unsigned repeatCount, bool writeTransparentPixels); protected: - - /* - * Read enough of the stream to initialize the SkGifCodec. - * Returns a bool representing success or failure. - * - * @param codecOut - * If it returned true, and codecOut was not nullptr, - * codecOut will be set to a new SkGifCodec. - * - * @param gifOut - * If it returned true, and codecOut was nullptr, - * gifOut must be non-nullptr and gifOut will be set to a new - * GifFileType pointer. - * - * @param stream - * Deleted on failure. - * codecOut will take ownership of it in the case where we created a codec. - * Ownership is unchanged when we returned a gifOut. - * - */ - static bool ReadHeader(SkStream* stream, SkCodec** codecOut, - GifFileType** gifOut); - /* * Performs the full gif decode */ @@ -68,55 +48,37 @@ protected: uint64_t onGetFillValue(const SkImageInfo&) const override; - int onOutputScanline(int inputScanline) const override; + std::vector<FrameInfo> onGetFrameInfo() override; -private: + Result onStartIncrementalDecode(const SkImageInfo& /*dstInfo*/, void*, size_t, + const SkCodec::Options&, SkPMColor*, int*) override; - /* - * A gif can contain multiple image frames. We will only decode the first - * frame. This function reads up to the first image frame, processing - * transparency and/or animation information that comes before the image - * data. - * - * @param gif Pointer to the library type that manages the gif decode - * @param transIndex This call will set the transparent index based on the - * extension data. - */ - static Result ReadUpToFirstImage(GifFileType* gif, uint32_t* transIndex); - - /* - * A gif may contain many image frames, all of different sizes. - * This function checks if the gif dimensions are valid, based on the frame - * dimensions, and corrects the gif dimensions if necessary. - * - * @param gif Pointer to the library type that manages the gif decode - * @param size Size of the image that we will decode. - * Will be set by this function if the return value is true. - * @param frameRect Contains the dimenions and offset of the first image frame. - * Will be set by this function if the return value is true. - * - * @return true on success, false otherwise - */ - static bool GetDimensions(GifFileType* gif, SkISize* size, SkIRect* frameRect); + Result onIncrementalDecode(int*) override; + +private: /* * Initializes the color table that we will use for decoding. * * @param dstInfo Contains the requested dst color type. + * @param frameIndex Frame whose color table to use. * @param inputColorPtr Copies the encoded color table to the client's * input color table if the client requests kIndex8. - * @param inputColorCount If the client requests kIndex8, sets - * inputColorCount to 256. Since gifs always - * contain 8-bit indices, we need a 256 entry color - * table to ensure that indexing is always in - * bounds. + * @param inputColorCount If the client requests kIndex8, this will be set + * to the number of colors in the array that + * inputColorPtr now points to. This will typically + * be 256. Since gifs may have up to 8-bit indices, + * using a 256-entry table means a pixel will never + * be out of range. This will be set to 1 if there + * is no color table, since that will be a + * transparent frame. */ - void initializeColorTable(const SkImageInfo& dstInfo, SkPMColor* colorPtr, - int* inputColorCount); + void initializeColorTable(const SkImageInfo& dstInfo, size_t frameIndex, + SkPMColor* colorPtr, int* inputColorCount); /* - * Checks for invalid inputs and calls setFrameDimensions(), and - * initializeColorTable() in the proper sequence. + * Does necessary setup, including setting up the color table and swizzler, + * and reports color info to the client. */ Result prepareToDecode(const SkImageInfo& dstInfo, SkPMColor* inputColorPtr, int* inputColorCount, const Options& opts); @@ -124,82 +86,72 @@ private: /* * Initializes the swizzler. * - * @param dstInfo Output image information. Dimensions may have been - * adjusted if the image frame size does not match the size - * indicated in the header. - * @param options Informs the swizzler if destination memory is zero initialized. - * Contains subset information. + * @param dstInfo Output image information. Dimensions may have been + * adjusted if the image frame size does not match the size + * indicated in the header. + * @param frameIndex Which frame we are decoding. This determines the frameRect + * to use. */ - void initializeSwizzler(const SkImageInfo& dstInfo, - const Options& options); + void initializeSwizzler(const SkImageInfo& dstInfo, size_t frameIndex); SkSampler* getSampler(bool createIfNecessary) override { SkASSERT(fSwizzler); - return fSwizzler; + return fSwizzler.get(); } /* - * @return true if the read is successful and false if the read fails. - */ - bool readRow(); - - Result onStartScanlineDecode(const SkImageInfo& dstInfo, const Options& opts, - SkPMColor inputColorPtr[], int* inputColorCount) override; - - int onGetScanlines(void* dst, int count, size_t rowBytes) override; - - bool onSkipScanlines(int count) override; - - /* - * For a scanline decode of "count" lines, this function indicates how - * many of the "count" lines should be skipped until we reach the top of - * the image frame and how many of the "count" lines are actually inside - * the image frame. + * Recursive function to decode a frame. * - * @param count The number of scanlines requested. - * @param rowsBeforeFrame Output variable. The number of lines before - * we reach the top of the image frame. - * @param rowsInFrame Output variable. The number of lines to decode - * inside the image frame. - */ - void handleScanlineFrame(int count, int* rowsBeforeFrame, int* rowsInFrame); - - SkScanlineOrder onGetScanlineOrder() const override; - - /* - * This function cleans up the gif object after the decode completes - * It is used in a SkAutoTCallIProc template + * @param firstAttempt Whether this is the first call to decodeFrame since + * starting. e.g. true in onGetPixels, and true in the + * first call to onIncrementalDecode after calling + * onStartIncrementalDecode. + * When true, this method may have to initialize the + * frame, for example by filling or decoding the prior + * frame. + * @param opts Options for decoding. May be different from + * this->options() for decoding prior frames. Specifies + * the frame to decode and whether the prior frame has + * already been decoded to fDst. If not, and the frame + * is not independent, this method will recursively + * decode the frame it depends on. + * @param rowsDecoded Out-parameter to report the total number of rows + * that have been decoded (or at least written to, if + * it had to fill), including rows decoded by prior + * calls to onIncrementalDecode. + * @return kSuccess if the frame is complete, kIncompleteInput + * otherwise. */ - static void CloseGif(GifFileType* gif); - - /* - * Frees any extension data used in the decode - * Used in a SkAutoTCallVProc - */ - static void FreeExtension(SavedImage* image); + Result decodeFrame(bool firstAttempt, const Options& opts, int* rowsDecoded); /* * Creates an instance of the decoder * Called only by NewFromStream - * - * @param info contains properties of the encoded data - * @param stream the stream of image data - * @param gif pointer to library type that manages gif decode - * takes ownership - * @param transIndex The transparent index. An invalid value - * indicates that there is no transparent index. + * Takes ownership of the GIFImageReader */ - SkGifCodec(int width, int height, const SkEncodedInfo& info, SkStream* stream, - GifFileType* gif, uint32_t transIndex, const SkIRect& frameRect, bool frameIsSubset); - - SkAutoTCallVProc<GifFileType, CloseGif> fGif; // owned - SkAutoTDeleteArray<uint8_t> fSrcBuffer; - const SkIRect fFrameRect; - const uint32_t fTransIndex; - uint32_t fFillIndex; - const bool fFrameIsSubset; - SkAutoTDelete<SkSwizzler> fSwizzler; - SkAutoTUnref<SkColorTable> fColorTable; + SkGifCodec(const SkEncodedInfo&, const SkImageInfo&, GIFImageReader*); + + std::unique_ptr<GIFImageReader> fReader; + std::unique_ptr<uint8_t[]> fTmpBuffer; + std::unique_ptr<SkSwizzler> fSwizzler; + sk_sp<SkColorTable> fCurrColorTable; + // We may create a dummy table if there is not a Map in the input data. In + // that case, we set this value to false, and we can skip a lot of decoding + // work (which would not be meaningful anyway). We create a "fake"/"dummy" + // one in that case, so the client and the swizzler have something to draw. + bool fCurrColorTableIsReal; + // Whether the background was filled. + bool fFilledBackground; + // True on the first call to onIncrementalDecode. This value is passed to + // decodeFrame. + bool fFirstCallToIncrementalDecode; + + void* fDst; + size_t fDstRowBytes; + + // Updated inside haveDecodedRow when rows are decoded, unless we filled + // the background, in which case it is set once and left alone. + int fRowsDecoded; typedef SkCodec INHERITED; }; |