| /* |
| * Copyright 2015 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "src/codec/SkWebpCodec.h" |
| |
| #include "include/codec/SkCodecAnimation.h" |
| #include "include/core/SkAlphaType.h" |
| #include "include/core/SkBitmap.h" |
| #include "include/core/SkColorType.h" |
| #include "include/core/SkImageInfo.h" |
| #include "include/core/SkMath.h" |
| #include "include/core/SkRect.h" |
| #include "include/core/SkSize.h" |
| #include "include/core/SkStream.h" |
| #include "include/private/SkTFitsIn.h" |
| #include "include/private/SkTemplates.h" |
| #include "include/private/SkTo.h" |
| #include "modules/skcms/skcms.h" |
| #include "src/codec/SkParseEncodedOrigin.h" |
| #include "src/codec/SkSampler.h" |
| #include "src/core/SkRasterPipeline.h" |
| #include "src/core/SkStreamPriv.h" |
| |
| #include <algorithm> |
| #include <cstdint> |
| #include <cstring> |
| #include <utility> |
| |
| // A WebP decoder on top of (subset of) libwebp |
| // For more information on WebP image format, and libwebp library, see: |
| // https://code.google.com/speed/webp/ |
| // http://www.webmproject.org/code/#libwebp-webp-image-library |
| // https://chromium.googlesource.com/webm/libwebp |
| |
| // If moving libwebp out of skia source tree, path for webp headers must be |
| // updated accordingly. Here, we enforce using local copy in webp sub-directory. |
| #include "webp/decode.h" |
| #include "webp/demux.h" |
| #include "webp/mux_types.h" |
| |
| bool SkWebpCodec::IsWebp(const void* buf, size_t bytesRead) { |
| // WEBP starts with the following: |
| // RIFFXXXXWEBPVP |
| // Where XXXX is unspecified. |
| const char* bytes = static_cast<const char*>(buf); |
| return bytesRead >= 14 && !memcmp(bytes, "RIFF", 4) && !memcmp(&bytes[8], "WEBPVP", 6); |
| } |
| |
| // Parse headers of RIFF container, and check for valid Webp (VP8) content. |
| // Returns an SkWebpCodec on success |
| std::unique_ptr<SkCodec> SkWebpCodec::MakeFromStream(std::unique_ptr<SkStream> stream, |
| Result* result) { |
| // Webp demux needs a contiguous data buffer. |
| sk_sp<SkData> data = nullptr; |
| if (stream->getMemoryBase()) { |
| // It is safe to make without copy because we'll hold onto the stream. |
| data = SkData::MakeWithoutCopy(stream->getMemoryBase(), stream->getLength()); |
| } else { |
| data = SkCopyStreamToData(stream.get()); |
| |
| // If we are forced to copy the stream to a data, we can go ahead and delete the stream. |
| stream.reset(nullptr); |
| } |
| |
| // It's a little strange that the |demux| will outlive |webpData|, though it needs the |
| // pointer in |webpData| to remain valid. This works because the pointer remains valid |
| // until the SkData is freed. |
| WebPData webpData = { data->bytes(), data->size() }; |
| WebPDemuxState state; |
| SkAutoTCallVProc<WebPDemuxer, WebPDemuxDelete> demux(WebPDemuxPartial(&webpData, &state)); |
| switch (state) { |
| case WEBP_DEMUX_PARSE_ERROR: |
| *result = kInvalidInput; |
| return nullptr; |
| case WEBP_DEMUX_PARSING_HEADER: |
| *result = kIncompleteInput; |
| return nullptr; |
| case WEBP_DEMUX_PARSED_HEADER: |
| case WEBP_DEMUX_DONE: |
| SkASSERT(demux); |
| break; |
| } |
| |
| const int width = WebPDemuxGetI(demux, WEBP_FF_CANVAS_WIDTH); |
| const int height = WebPDemuxGetI(demux, WEBP_FF_CANVAS_HEIGHT); |
| |
| // Validate the image size that's about to be decoded. |
| { |
| const int64_t size = sk_64_mul(width, height); |
| // now check that if we are 4-bytes per pixel, we also don't overflow |
| if (!SkTFitsIn<int32_t>(size) || SkTo<int32_t>(size) > (0x7FFFFFFF >> 2)) { |
| *result = kInvalidInput; |
| return nullptr; |
| } |
| } |
| |
| std::unique_ptr<SkEncodedInfo::ICCProfile> profile = nullptr; |
| { |
| WebPChunkIterator chunkIterator; |
| SkAutoTCallVProc<WebPChunkIterator, WebPDemuxReleaseChunkIterator> autoCI(&chunkIterator); |
| if (WebPDemuxGetChunk(demux, "ICCP", 1, &chunkIterator)) { |
| // FIXME: I think this could be MakeWithoutCopy |
| auto chunk = SkData::MakeWithCopy(chunkIterator.chunk.bytes, chunkIterator.chunk.size); |
| profile = SkEncodedInfo::ICCProfile::Make(std::move(chunk)); |
| } |
| if (profile && profile->profile()->data_color_space != skcms_Signature_RGB) { |
| profile = nullptr; |
| } |
| } |
| |
| SkEncodedOrigin origin = kDefault_SkEncodedOrigin; |
| { |
| WebPChunkIterator chunkIterator; |
| SkAutoTCallVProc<WebPChunkIterator, WebPDemuxReleaseChunkIterator> autoCI(&chunkIterator); |
| if (WebPDemuxGetChunk(demux, "EXIF", 1, &chunkIterator)) { |
| SkParseEncodedOrigin(chunkIterator.chunk.bytes, chunkIterator.chunk.size, &origin); |
| } |
| } |
| |
| // Get the first frame and its "features" to determine the color and alpha types. |
| WebPIterator frame; |
| SkAutoTCallVProc<WebPIterator, WebPDemuxReleaseIterator> autoFrame(&frame); |
| if (!WebPDemuxGetFrame(demux, 1, &frame)) { |
| *result = kIncompleteInput; |
| return nullptr; |
| } |
| |
| WebPBitstreamFeatures features; |
| switch (WebPGetFeatures(frame.fragment.bytes, frame.fragment.size, &features)) { |
| case VP8_STATUS_OK: |
| break; |
| case VP8_STATUS_SUSPENDED: |
| case VP8_STATUS_NOT_ENOUGH_DATA: |
| *result = kIncompleteInput; |
| return nullptr; |
| default: |
| *result = kInvalidInput; |
| return nullptr; |
| } |
| |
| const bool hasAlpha = SkToBool(frame.has_alpha) |
| || frame.width != width || frame.height != height; |
| SkEncodedInfo::Color color; |
| SkEncodedInfo::Alpha alpha; |
| switch (features.format) { |
| case 0: |
| // This indicates a "mixed" format. We could see this for |
| // animated webps (multiple fragments). |
| // We could also guess kYUV here, but I think it makes more |
| // sense to guess kBGRA which is likely closer to the final |
| // output. Otherwise, we might end up converting |
| // BGRA->YUVA->BGRA. |
| [[fallthrough]]; |
| case 2: |
| // This is the lossless format (BGRA). |
| if (hasAlpha) { |
| color = SkEncodedInfo::kBGRA_Color; |
| alpha = SkEncodedInfo::kUnpremul_Alpha; |
| } else { |
| color = SkEncodedInfo::kBGRX_Color; |
| alpha = SkEncodedInfo::kOpaque_Alpha; |
| } |
| break; |
| case 1: |
| // This is the lossy format (YUV). |
| if (hasAlpha) { |
| color = SkEncodedInfo::kYUVA_Color; |
| alpha = SkEncodedInfo::kUnpremul_Alpha; |
| } else { |
| color = SkEncodedInfo::kYUV_Color; |
| alpha = SkEncodedInfo::kOpaque_Alpha; |
| } |
| break; |
| default: |
| *result = kInvalidInput; |
| return nullptr; |
| } |
| |
| |
| *result = kSuccess; |
| SkEncodedInfo info = SkEncodedInfo::Make(width, height, color, alpha, 8, std::move(profile)); |
| return std::unique_ptr<SkCodec>(new SkWebpCodec(std::move(info), std::move(stream), |
| demux.release(), std::move(data), origin)); |
| } |
| |
| static WEBP_CSP_MODE webp_decode_mode(SkColorType dstCT, bool premultiply) { |
| switch (dstCT) { |
| case kBGRA_8888_SkColorType: |
| return premultiply ? MODE_bgrA : MODE_BGRA; |
| case kRGBA_8888_SkColorType: |
| return premultiply ? MODE_rgbA : MODE_RGBA; |
| case kRGB_565_SkColorType: |
| return MODE_RGB_565; |
| default: |
| return MODE_LAST; |
| } |
| } |
| |
| SkWebpCodec::Frame* SkWebpCodec::FrameHolder::appendNewFrame(bool hasAlpha) { |
| const int i = this->size(); |
| fFrames.emplace_back(i, hasAlpha ? SkEncodedInfo::kUnpremul_Alpha |
| : SkEncodedInfo::kOpaque_Alpha); |
| return &fFrames[i]; |
| } |
| |
| bool SkWebpCodec::onGetValidSubset(SkIRect* desiredSubset) const { |
| if (!desiredSubset) { |
| return false; |
| } |
| |
| if (!this->bounds().contains(*desiredSubset)) { |
| return false; |
| } |
| |
| // As stated below, libwebp snaps to even left and top. Make sure top and left are even, so we |
| // decode this exact subset. |
| // Leave right and bottom unmodified, so we suggest a slightly larger subset than requested. |
| desiredSubset->fLeft = (desiredSubset->fLeft >> 1) << 1; |
| desiredSubset->fTop = (desiredSubset->fTop >> 1) << 1; |
| return true; |
| } |
| |
| int SkWebpCodec::onGetRepetitionCount() { |
| auto flags = WebPDemuxGetI(fDemux.get(), WEBP_FF_FORMAT_FLAGS); |
| if (!(flags & ANIMATION_FLAG)) { |
| return 0; |
| } |
| |
| int loopCount = WebPDemuxGetI(fDemux.get(), WEBP_FF_LOOP_COUNT); |
| if (0 == loopCount) { |
| return kRepetitionCountInfinite; |
| } |
| |
| loopCount--; |
| return loopCount; |
| } |
| |
| int SkWebpCodec::onGetFrameCount() { |
| auto flags = WebPDemuxGetI(fDemux.get(), WEBP_FF_FORMAT_FLAGS); |
| if (!(flags & ANIMATION_FLAG)) { |
| return 1; |
| } |
| |
| const uint32_t oldFrameCount = fFrameHolder.size(); |
| if (fFailed) { |
| return oldFrameCount; |
| } |
| |
| const uint32_t frameCount = WebPDemuxGetI(fDemux, WEBP_FF_FRAME_COUNT); |
| if (oldFrameCount == frameCount) { |
| // We have already parsed this. |
| return frameCount; |
| } |
| |
| fFrameHolder.reserve(frameCount); |
| |
| for (uint32_t i = oldFrameCount; i < frameCount; i++) { |
| WebPIterator iter; |
| SkAutoTCallVProc<WebPIterator, WebPDemuxReleaseIterator> autoIter(&iter); |
| |
| if (!WebPDemuxGetFrame(fDemux.get(), i + 1, &iter)) { |
| fFailed = true; |
| break; |
| } |
| |
| // libwebp only reports complete frames of an animated image. |
| SkASSERT(iter.complete); |
| |
| Frame* frame = fFrameHolder.appendNewFrame(iter.has_alpha); |
| frame->setXYWH(iter.x_offset, iter.y_offset, iter.width, iter.height); |
| frame->setDisposalMethod(iter.dispose_method == WEBP_MUX_DISPOSE_BACKGROUND ? |
| SkCodecAnimation::DisposalMethod::kRestoreBGColor : |
| SkCodecAnimation::DisposalMethod::kKeep); |
| frame->setDuration(iter.duration); |
| if (WEBP_MUX_BLEND != iter.blend_method) { |
| frame->setBlend(SkCodecAnimation::Blend::kSrc); |
| } |
| fFrameHolder.setAlphaAndRequiredFrame(frame); |
| } |
| |
| return fFrameHolder.size(); |
| |
| } |
| |
| const SkFrame* SkWebpCodec::FrameHolder::onGetFrame(int i) const { |
| return static_cast<const SkFrame*>(this->frame(i)); |
| } |
| |
| const SkWebpCodec::Frame* SkWebpCodec::FrameHolder::frame(int i) const { |
| SkASSERT(i >= 0 && i < this->size()); |
| return &fFrames[i]; |
| } |
| |
| bool SkWebpCodec::onGetFrameInfo(int i, FrameInfo* frameInfo) const { |
| if (i >= fFrameHolder.size()) { |
| return false; |
| } |
| |
| const Frame* frame = fFrameHolder.frame(i); |
| if (!frame) { |
| return false; |
| } |
| |
| if (frameInfo) { |
| // libwebp only reports fully received frames for an |
| // animated image. |
| frame->fillIn(frameInfo, true); |
| } |
| |
| return true; |
| } |
| |
| static bool is_8888(SkColorType colorType) { |
| switch (colorType) { |
| case kRGBA_8888_SkColorType: |
| case kBGRA_8888_SkColorType: |
| return true; |
| default: |
| return false; |
| } |
| } |
| |
| // Requires that the src input be unpremultiplied (or opaque). |
| static void blend_line(SkColorType dstCT, void* dst, |
| SkColorType srcCT, const void* src, |
| SkAlphaType dstAt, |
| bool srcHasAlpha, |
| int width) { |
| SkRasterPipeline_MemoryCtx dst_ctx = { (void*)dst, 0 }, |
| src_ctx = { (void*)src, 0 }; |
| |
| SkRasterPipeline_<256> p; |
| |
| p.append_load_dst(dstCT, &dst_ctx); |
| if (kUnpremul_SkAlphaType == dstAt) { |
| p.append(SkRasterPipeline::premul_dst); |
| } |
| |
| p.append_load(srcCT, &src_ctx); |
| if (srcHasAlpha) { |
| p.append(SkRasterPipeline::premul); |
| } |
| |
| p.append(SkRasterPipeline::srcover); |
| |
| if (kUnpremul_SkAlphaType == dstAt) { |
| p.append(SkRasterPipeline::unpremul); |
| } |
| p.append_store(dstCT, &dst_ctx); |
| |
| p.run(0,0, width,1); |
| } |
| |
| SkCodec::Result SkWebpCodec::onGetPixels(const SkImageInfo& dstInfo, void* dst, size_t rowBytes, |
| const Options& options, int* rowsDecodedPtr) { |
| const int index = options.fFrameIndex; |
| SkASSERT(0 == index || index < fFrameHolder.size()); |
| SkASSERT(0 == index || !options.fSubset); |
| |
| WebPDecoderConfig config; |
| if (0 == WebPInitDecoderConfig(&config)) { |
| // ABI mismatch. |
| // FIXME: New enum for this? |
| return kInvalidInput; |
| } |
| |
| // Free any memory associated with the buffer. Must be called last, so we declare it first. |
| SkAutoTCallVProc<WebPDecBuffer, WebPFreeDecBuffer> autoFree(&(config.output)); |
| |
| WebPIterator frame; |
| SkAutoTCallVProc<WebPIterator, WebPDemuxReleaseIterator> autoFrame(&frame); |
| // If this succeeded in onGetFrameCount(), it should succeed again here. |
| SkAssertResult(WebPDemuxGetFrame(fDemux, index + 1, &frame)); |
| |
| const bool independent = index == 0 ? true : |
| (fFrameHolder.frame(index)->getRequiredFrame() == kNoFrame); |
| // Get the frameRect. libwebp will have already signaled an error if this is not fully |
| // contained by the canvas. |
| auto frameRect = SkIRect::MakeXYWH(frame.x_offset, frame.y_offset, frame.width, frame.height); |
| SkASSERT(this->bounds().contains(frameRect)); |
| const bool frameIsSubset = frameRect != this->bounds(); |
| if (independent && frameIsSubset) { |
| SkSampler::Fill(dstInfo, dst, rowBytes, options.fZeroInitialized); |
| } |
| |
| int dstX = frameRect.x(); |
| int dstY = frameRect.y(); |
| int subsetWidth = frameRect.width(); |
| int subsetHeight = frameRect.height(); |
| if (options.fSubset) { |
| SkIRect subset = *options.fSubset; |
| SkASSERT(this->bounds().contains(subset)); |
| SkASSERT(SkIsAlign2(subset.fLeft) && SkIsAlign2(subset.fTop)); |
| SkASSERT(this->getValidSubset(&subset) && subset == *options.fSubset); |
| |
| if (!SkIRect::Intersects(subset, frameRect)) { |
| return kSuccess; |
| } |
| |
| int minXOffset = std::min(dstX, subset.x()); |
| int minYOffset = std::min(dstY, subset.y()); |
| dstX -= minXOffset; |
| dstY -= minYOffset; |
| frameRect.offset(-minXOffset, -minYOffset); |
| subset.offset(-minXOffset, -minYOffset); |
| |
| // Just like we require that the requested subset x and y offset are even, libwebp |
| // guarantees that the frame x and y offset are even (it's actually impossible to specify |
| // an odd frame offset). So we can still guarantee that the adjusted offsets are even. |
| SkASSERT(SkIsAlign2(subset.fLeft) && SkIsAlign2(subset.fTop)); |
| |
| SkIRect intersection; |
| SkAssertResult(intersection.intersect(frameRect, subset)); |
| subsetWidth = intersection.width(); |
| subsetHeight = intersection.height(); |
| |
| config.options.use_cropping = 1; |
| config.options.crop_left = subset.x(); |
| config.options.crop_top = subset.y(); |
| config.options.crop_width = subsetWidth; |
| config.options.crop_height = subsetHeight; |
| } |
| |
| // Ignore the frame size and offset when determining if scaling is necessary. |
| int scaledWidth = subsetWidth; |
| int scaledHeight = subsetHeight; |
| SkISize srcSize = options.fSubset ? options.fSubset->size() : this->dimensions(); |
| if (srcSize != dstInfo.dimensions()) { |
| config.options.use_scaling = 1; |
| |
| if (frameIsSubset) { |
| float scaleX = ((float) dstInfo.width()) / srcSize.width(); |
| float scaleY = ((float) dstInfo.height()) / srcSize.height(); |
| |
| // We need to be conservative here and floor rather than round. |
| // Otherwise, we may find ourselves decoding off the end of memory. |
| dstX = scaleX * dstX; |
| scaledWidth = scaleX * scaledWidth; |
| dstY = scaleY * dstY; |
| scaledHeight = scaleY * scaledHeight; |
| if (0 == scaledWidth || 0 == scaledHeight) { |
| return kSuccess; |
| } |
| } else { |
| scaledWidth = dstInfo.width(); |
| scaledHeight = dstInfo.height(); |
| } |
| |
| config.options.scaled_width = scaledWidth; |
| config.options.scaled_height = scaledHeight; |
| } |
| |
| const bool blendWithPrevFrame = !independent && frame.blend_method == WEBP_MUX_BLEND |
| && frame.has_alpha; |
| |
| auto webpInfo = dstInfo; |
| if (!frame.has_alpha) { |
| webpInfo = webpInfo.makeAlphaType(kOpaque_SkAlphaType); |
| } else if (this->colorXform() || blendWithPrevFrame) { |
| // the colorXform and blend_line expect unpremul. |
| webpInfo = webpInfo.makeAlphaType(kUnpremul_SkAlphaType); |
| } |
| if (this->colorXform()) { |
| // Swizzling between RGBA and BGRA is zero cost in a color transform. So when we have a |
| // color transform, we should decode to whatever is easiest for libwebp, and then let the |
| // color transform swizzle if necessary. |
| // Lossy webp is encoded as YUV (so RGBA and BGRA are the same cost). Lossless webp is |
| // encoded as BGRA. This means decoding to BGRA is either faster or the same cost as RGBA. |
| webpInfo = webpInfo.makeColorType(kBGRA_8888_SkColorType); |
| } |
| |
| SkBitmap webpDst; |
| if ((this->colorXform() && !is_8888(dstInfo.colorType())) || blendWithPrevFrame) { |
| // We will decode the entire image and then perform the color transform. libwebp |
| // does not provide a row-by-row API. This is a shame particularly when we do not want |
| // 8888, since we will need to create another image sized buffer. |
| webpDst.allocPixels(webpInfo); |
| } else { |
| // libwebp can decode directly into the output memory. |
| webpDst.installPixels(webpInfo, dst, rowBytes); |
| } |
| |
| config.output.colorspace = webp_decode_mode(webpInfo.colorType(), |
| webpInfo.alphaType() == kPremul_SkAlphaType); |
| config.output.is_external_memory = 1; |
| |
| config.output.u.RGBA.rgba = reinterpret_cast<uint8_t*>(webpDst.getAddr(dstX, dstY)); |
| config.output.u.RGBA.stride = static_cast<int>(webpDst.rowBytes()); |
| config.output.u.RGBA.size = webpDst.computeByteSize(); |
| |
| SkAutoTCallVProc<WebPIDecoder, WebPIDelete> idec(WebPIDecode(nullptr, 0, &config)); |
| if (!idec) { |
| return kInvalidInput; |
| } |
| |
| int rowsDecoded = 0; |
| SkCodec::Result result; |
| switch (WebPIUpdate(idec, frame.fragment.bytes, frame.fragment.size)) { |
| case VP8_STATUS_OK: |
| rowsDecoded = scaledHeight; |
| result = kSuccess; |
| break; |
| case VP8_STATUS_SUSPENDED: |
| if (!WebPIDecGetRGB(idec, &rowsDecoded, nullptr, nullptr, nullptr) |
| || rowsDecoded <= 0) { |
| return kInvalidInput; |
| } |
| *rowsDecodedPtr = rowsDecoded + dstY; |
| result = kIncompleteInput; |
| break; |
| default: |
| return kInvalidInput; |
| } |
| |
| const size_t dstBpp = dstInfo.bytesPerPixel(); |
| dst = SkTAddOffset<void>(dst, dstBpp * dstX + rowBytes * dstY); |
| const size_t srcRowBytes = config.output.u.RGBA.stride; |
| |
| const auto dstCT = dstInfo.colorType(); |
| if (this->colorXform()) { |
| uint32_t* xformSrc = (uint32_t*) config.output.u.RGBA.rgba; |
| SkBitmap tmp; |
| void* xformDst; |
| |
| if (blendWithPrevFrame) { |
| // Xform into temporary bitmap big enough for one row. |
| tmp.allocPixels(dstInfo.makeWH(scaledWidth, 1)); |
| xformDst = tmp.getPixels(); |
| } else { |
| xformDst = dst; |
| } |
| |
| for (int y = 0; y < rowsDecoded; y++) { |
| this->applyColorXform(xformDst, xformSrc, scaledWidth); |
| if (blendWithPrevFrame) { |
| blend_line(dstCT, dst, dstCT, xformDst, |
| dstInfo.alphaType(), frame.has_alpha, scaledWidth); |
| dst = SkTAddOffset<void>(dst, rowBytes); |
| } else { |
| xformDst = SkTAddOffset<void>(xformDst, rowBytes); |
| } |
| xformSrc = SkTAddOffset<uint32_t>(xformSrc, srcRowBytes); |
| } |
| } else if (blendWithPrevFrame) { |
| const uint8_t* src = config.output.u.RGBA.rgba; |
| |
| for (int y = 0; y < rowsDecoded; y++) { |
| blend_line(dstCT, dst, webpDst.colorType(), src, |
| dstInfo.alphaType(), frame.has_alpha, scaledWidth); |
| src = SkTAddOffset<const uint8_t>(src, srcRowBytes); |
| dst = SkTAddOffset<void>(dst, rowBytes); |
| } |
| } |
| |
| return result; |
| } |
| |
| SkWebpCodec::SkWebpCodec(SkEncodedInfo&& info, std::unique_ptr<SkStream> stream, |
| WebPDemuxer* demux, sk_sp<SkData> data, SkEncodedOrigin origin) |
| : INHERITED(std::move(info), skcms_PixelFormat_BGRA_8888, std::move(stream), |
| origin) |
| , fDemux(demux) |
| , fData(std::move(data)) |
| , fFailed(false) |
| { |
| const auto& eInfo = this->getEncodedInfo(); |
| fFrameHolder.setScreenSize(eInfo.width(), eInfo.height()); |
| } |