xref: /aosp_15_r20/external/skia/src/codec/SkWebpCodec.cpp (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
1 /*
2  * Copyright 2015 Google Inc.
3  *
4  * Use of this source code is governed by a BSD-style license that can be
5  * found in the LICENSE file.
6  */
7 
8 #include "src/codec/SkWebpCodec.h"
9 
10 #include "include/codec/SkCodec.h"
11 #include "include/codec/SkCodecAnimation.h"
12 #include "include/codec/SkWebpDecoder.h"
13 #include "include/core/SkAlphaType.h"
14 #include "include/core/SkBitmap.h"
15 #include "include/core/SkColorType.h"
16 #include "include/core/SkImageInfo.h"
17 #include "include/core/SkRect.h"
18 #include "include/core/SkSize.h"
19 #include "include/core/SkStream.h"
20 #include "include/private/base/SkAlign.h"
21 #include "include/private/base/SkMath.h"
22 #include "include/private/base/SkTFitsIn.h"
23 #include "include/private/base/SkTemplates.h"
24 #include "include/private/base/SkTo.h"
25 #include "modules/skcms/skcms.h"
26 #include "src/codec/SkParseEncodedOrigin.h"
27 #include "src/codec/SkSampler.h"
28 #include "src/core/SkRasterPipeline.h"
29 #include "src/core/SkRasterPipelineOpContexts.h"
30 #include "src/core/SkRasterPipelineOpList.h"
31 #include "src/core/SkStreamPriv.h"
32 
33 #include <algorithm>
34 #include <cstdint>
35 #include <cstring>
36 #include <utility>
37 
38 // A WebP decoder on top of (subset of) libwebp
39 // For more information on WebP image format, and libwebp library, see:
40 //   https://code.google.com/speed/webp/
41 //   http://www.webmproject.org/code/#libwebp-webp-image-library
42 //   https://chromium.googlesource.com/webm/libwebp
43 
44 // If moving libwebp out of skia source tree, path for webp headers must be
45 // updated accordingly. Here, we enforce using local copy in webp sub-directory.
46 #include "webp/decode.h"  // NO_G3_REWRITE
47 #include "webp/demux.h"  // NO_G3_REWRITE
48 #include "webp/mux_types.h"  // NO_G3_REWRITE
49 
IsWebp(const void * buf,size_t bytesRead)50 bool SkWebpCodec::IsWebp(const void* buf, size_t bytesRead) {
51     // WEBP starts with the following:
52     // RIFFXXXXWEBPVP
53     // Where XXXX is unspecified.
54     const char* bytes = static_cast<const char*>(buf);
55     return bytesRead >= 14 && !memcmp(bytes, "RIFF", 4) && !memcmp(&bytes[8], "WEBPVP", 6);
56 }
57 
58 // Parse headers of RIFF container, and check for valid Webp (VP8) content.
59 // Returns an SkWebpCodec on success
MakeFromStream(std::unique_ptr<SkStream> stream,Result * result)60 std::unique_ptr<SkCodec> SkWebpCodec::MakeFromStream(std::unique_ptr<SkStream> stream,
61                                                      Result* result) {
62     SkASSERT(result);
63     if (!stream) {
64         *result = SkCodec::kInvalidInput;
65         return nullptr;
66     }
67     // Webp demux needs a contiguous data buffer.
68     sk_sp<SkData> data = nullptr;
69     if (stream->getMemoryBase()) {
70         // It is safe to make without copy because we'll hold onto the stream.
71         data = SkData::MakeWithoutCopy(stream->getMemoryBase(), stream->getLength());
72     } else {
73         data = SkCopyStreamToData(stream.get());
74 
75         // If we are forced to copy the stream to a data, we can go ahead and delete the stream.
76         stream.reset(nullptr);
77     }
78 
79     // It's a little strange that the |demux| will outlive |webpData|, though it needs the
80     // pointer in |webpData| to remain valid.  This works because the pointer remains valid
81     // until the SkData is freed.
82     WebPData webpData = { data->bytes(), data->size() };
83     WebPDemuxState state;
84     SkAutoTCallVProc<WebPDemuxer, WebPDemuxDelete> demux(WebPDemuxPartial(&webpData, &state));
85     switch (state) {
86         case WEBP_DEMUX_PARSE_ERROR:
87             *result = kInvalidInput;
88             return nullptr;
89         case WEBP_DEMUX_PARSING_HEADER:
90             *result = kIncompleteInput;
91             return nullptr;
92         case WEBP_DEMUX_PARSED_HEADER:
93         case WEBP_DEMUX_DONE:
94             SkASSERT(demux);
95             break;
96     }
97 
98     const int width = WebPDemuxGetI(demux, WEBP_FF_CANVAS_WIDTH);
99     const int height = WebPDemuxGetI(demux, WEBP_FF_CANVAS_HEIGHT);
100 
101     // Validate the image size that's about to be decoded.
102     {
103         const int64_t size = sk_64_mul(width, height);
104         // now check that if we are 4-bytes per pixel, we also don't overflow
105         if (!SkTFitsIn<int32_t>(size) || SkTo<int32_t>(size) > (0x7FFFFFFF >> 2)) {
106             *result = kInvalidInput;
107             return nullptr;
108         }
109     }
110 
111     std::unique_ptr<SkEncodedInfo::ICCProfile> profile = nullptr;
112     {
113         WebPChunkIterator chunkIterator;
114         SkAutoTCallVProc<WebPChunkIterator, WebPDemuxReleaseChunkIterator> autoCI(&chunkIterator);
115         if (WebPDemuxGetChunk(demux, "ICCP", 1, &chunkIterator)) {
116             // FIXME: I think this could be MakeWithoutCopy
117             auto chunk = SkData::MakeWithCopy(chunkIterator.chunk.bytes, chunkIterator.chunk.size);
118             profile = SkEncodedInfo::ICCProfile::Make(std::move(chunk));
119         }
120         if (profile && profile->profile()->data_color_space != skcms_Signature_RGB) {
121             profile = nullptr;
122         }
123     }
124 
125     SkEncodedOrigin origin = kDefault_SkEncodedOrigin;
126     {
127         WebPChunkIterator chunkIterator;
128         SkAutoTCallVProc<WebPChunkIterator, WebPDemuxReleaseChunkIterator> autoCI(&chunkIterator);
129         if (WebPDemuxGetChunk(demux, "EXIF", 1, &chunkIterator)) {
130             SkParseEncodedOrigin(chunkIterator.chunk.bytes, chunkIterator.chunk.size, &origin);
131         }
132     }
133 
134     // Get the first frame and its "features" to determine the color and alpha types.
135     WebPIterator frame;
136     SkAutoTCallVProc<WebPIterator, WebPDemuxReleaseIterator> autoFrame(&frame);
137     if (!WebPDemuxGetFrame(demux, 1, &frame)) {
138         *result = kIncompleteInput;
139         return nullptr;
140     }
141 
142     WebPBitstreamFeatures features;
143     switch (WebPGetFeatures(frame.fragment.bytes, frame.fragment.size, &features)) {
144         case VP8_STATUS_OK:
145             break;
146         case VP8_STATUS_SUSPENDED:
147         case VP8_STATUS_NOT_ENOUGH_DATA:
148             *result = kIncompleteInput;
149             return nullptr;
150         default:
151             *result = kInvalidInput;
152             return nullptr;
153     }
154 
155     const bool hasAlpha = SkToBool(frame.has_alpha)
156             || frame.width != width || frame.height != height;
157     SkEncodedInfo::Color color;
158     SkEncodedInfo::Alpha alpha;
159     switch (features.format) {
160         case 0:
161             // This indicates a "mixed" format.  We could see this for
162             // animated webps (multiple fragments).
163             // We could also guess kYUV here, but I think it makes more
164             // sense to guess kBGRA which is likely closer to the final
165             // output.  Otherwise, we might end up converting
166             // BGRA->YUVA->BGRA.
167             [[fallthrough]];
168         case 2:
169             // This is the lossless format (BGRA).
170             if (hasAlpha) {
171                 color = SkEncodedInfo::kBGRA_Color;
172                 alpha = SkEncodedInfo::kUnpremul_Alpha;
173             } else {
174                 color = SkEncodedInfo::kBGRX_Color;
175                 alpha = SkEncodedInfo::kOpaque_Alpha;
176             }
177             break;
178         case 1:
179             // This is the lossy format (YUV).
180             if (hasAlpha) {
181                 color = SkEncodedInfo::kYUVA_Color;
182                 alpha = SkEncodedInfo::kUnpremul_Alpha;
183             } else {
184                 color = SkEncodedInfo::kYUV_Color;
185                 alpha = SkEncodedInfo::kOpaque_Alpha;
186             }
187             break;
188         default:
189             *result = kInvalidInput;
190             return nullptr;
191     }
192 
193 
194     *result = kSuccess;
195     SkEncodedInfo info = SkEncodedInfo::Make(width, height, color, alpha, 8, std::move(profile));
196     return std::unique_ptr<SkCodec>(new SkWebpCodec(std::move(info), std::move(stream),
197                                                     demux.release(), std::move(data), origin));
198 }
199 
webp_decode_mode(SkColorType dstCT,bool premultiply)200 static WEBP_CSP_MODE webp_decode_mode(SkColorType dstCT, bool premultiply) {
201     switch (dstCT) {
202         case kBGRA_8888_SkColorType:
203             return premultiply ? MODE_bgrA : MODE_BGRA;
204         case kRGBA_8888_SkColorType:
205             return premultiply ? MODE_rgbA : MODE_RGBA;
206         case kRGB_565_SkColorType:
207             return MODE_RGB_565;
208         default:
209             return MODE_LAST;
210     }
211 }
212 
appendNewFrame(bool hasAlpha)213 SkWebpCodec::Frame* SkWebpCodec::FrameHolder::appendNewFrame(bool hasAlpha) {
214     const int i = this->size();
215     fFrames.emplace_back(i, hasAlpha ? SkEncodedInfo::kUnpremul_Alpha
216                                      : SkEncodedInfo::kOpaque_Alpha);
217     return &fFrames[i];
218 }
219 
onGetValidSubset(SkIRect * desiredSubset) const220 bool SkWebpCodec::onGetValidSubset(SkIRect* desiredSubset) const {
221     if (!desiredSubset) {
222         return false;
223     }
224 
225     if (!this->bounds().contains(*desiredSubset)) {
226         return false;
227     }
228 
229     // As stated below, libwebp snaps to even left and top. Make sure top and left are even, so we
230     // decode this exact subset.
231     // Leave right and bottom unmodified, so we suggest a slightly larger subset than requested.
232     desiredSubset->fLeft = (desiredSubset->fLeft >> 1) << 1;
233     desiredSubset->fTop = (desiredSubset->fTop >> 1) << 1;
234     return true;
235 }
236 
onGetRepetitionCount()237 int SkWebpCodec::onGetRepetitionCount() {
238     auto flags = WebPDemuxGetI(fDemux.get(), WEBP_FF_FORMAT_FLAGS);
239     if (!(flags & ANIMATION_FLAG)) {
240         return 0;
241     }
242 
243     int loopCount = WebPDemuxGetI(fDemux.get(), WEBP_FF_LOOP_COUNT);
244     if (0 == loopCount) {
245         return kRepetitionCountInfinite;
246     }
247 
248     loopCount--;
249     return loopCount;
250 }
251 
onGetFrameCount()252 int SkWebpCodec::onGetFrameCount() {
253     auto flags = WebPDemuxGetI(fDemux.get(), WEBP_FF_FORMAT_FLAGS);
254     if (!(flags & ANIMATION_FLAG)) {
255         return 1;
256     }
257 
258     const uint32_t oldFrameCount = fFrameHolder.size();
259     if (fFailed) {
260         return oldFrameCount;
261     }
262 
263     const uint32_t frameCount = WebPDemuxGetI(fDemux, WEBP_FF_FRAME_COUNT);
264     if (oldFrameCount == frameCount) {
265         // We have already parsed this.
266         return frameCount;
267     }
268 
269     fFrameHolder.reserve(frameCount);
270 
271     for (uint32_t i = oldFrameCount; i < frameCount; i++) {
272         WebPIterator iter;
273         SkAutoTCallVProc<WebPIterator, WebPDemuxReleaseIterator> autoIter(&iter);
274 
275         if (!WebPDemuxGetFrame(fDemux.get(), i + 1, &iter)) {
276             fFailed = true;
277             break;
278         }
279 
280         // libwebp only reports complete frames of an animated image.
281         SkASSERT(iter.complete);
282 
283         Frame* frame = fFrameHolder.appendNewFrame(iter.has_alpha);
284         frame->setXYWH(iter.x_offset, iter.y_offset, iter.width, iter.height);
285         frame->setDisposalMethod(iter.dispose_method == WEBP_MUX_DISPOSE_BACKGROUND ?
286                 SkCodecAnimation::DisposalMethod::kRestoreBGColor :
287                 SkCodecAnimation::DisposalMethod::kKeep);
288         frame->setDuration(iter.duration);
289         if (WEBP_MUX_BLEND != iter.blend_method) {
290             frame->setBlend(SkCodecAnimation::Blend::kSrc);
291         }
292         fFrameHolder.setAlphaAndRequiredFrame(frame);
293     }
294 
295     return fFrameHolder.size();
296 
297 }
298 
onGetFrame(int i) const299 const SkFrame* SkWebpCodec::FrameHolder::onGetFrame(int i) const {
300     return static_cast<const SkFrame*>(this->frame(i));
301 }
302 
frame(int i) const303 const SkWebpCodec::Frame* SkWebpCodec::FrameHolder::frame(int i) const {
304     SkASSERT(i >= 0 && i < this->size());
305     return &fFrames[i];
306 }
307 
onGetFrameInfo(int i,FrameInfo * frameInfo) const308 bool SkWebpCodec::onGetFrameInfo(int i, FrameInfo* frameInfo) const {
309     if (i >= fFrameHolder.size()) {
310         return false;
311     }
312 
313     const Frame* frame = fFrameHolder.frame(i);
314     if (!frame) {
315         return false;
316     }
317 
318     if (frameInfo) {
319         // libwebp only reports fully received frames for an
320         // animated image.
321         frame->fillIn(frameInfo, true);
322     }
323 
324     return true;
325 }
326 
is_8888(SkColorType colorType)327 static bool is_8888(SkColorType colorType) {
328     switch (colorType) {
329         case kRGBA_8888_SkColorType:
330         case kBGRA_8888_SkColorType:
331             return true;
332         default:
333             return false;
334     }
335 }
336 
337 // Requires that the src input be unpremultiplied (or opaque).
blend_line(SkColorType dstCT,void * dst,SkColorType srcCT,const void * src,SkAlphaType dstAt,bool srcHasAlpha,int width)338 static void blend_line(SkColorType dstCT, void* dst,
339                        SkColorType srcCT, const void* src,
340                        SkAlphaType dstAt,
341                        bool srcHasAlpha,
342                        int width) {
343     SkRasterPipeline_MemoryCtx dst_ctx = {                   dst,  0 },
344                                src_ctx = { const_cast<void*>(src), 0 };
345 
346     SkRasterPipeline_<256> p;
347 
348     p.appendLoadDst(dstCT, &dst_ctx);
349     if (kUnpremul_SkAlphaType == dstAt) {
350         p.append(SkRasterPipelineOp::premul_dst);
351     }
352 
353     p.appendLoad(srcCT, &src_ctx);
354     if (srcHasAlpha) {
355         p.append(SkRasterPipelineOp::premul);
356     }
357 
358     p.append(SkRasterPipelineOp::srcover);
359 
360     if (kUnpremul_SkAlphaType == dstAt) {
361         p.append(SkRasterPipelineOp::unpremul);
362     }
363     p.appendStore(dstCT, &dst_ctx);
364 
365     p.run(0,0, width,1);
366 }
367 
onGetPixels(const SkImageInfo & dstInfo,void * dst,size_t rowBytes,const Options & options,int * rowsDecodedPtr)368 SkCodec::Result SkWebpCodec::onGetPixels(const SkImageInfo& dstInfo, void* dst, size_t rowBytes,
369                                          const Options& options, int* rowsDecodedPtr) {
370     const int index = options.fFrameIndex;
371     SkASSERT(0 == index || index < fFrameHolder.size());
372     SkASSERT(0 == index || !options.fSubset);
373 
374     WebPDecoderConfig config;
375     if (0 == WebPInitDecoderConfig(&config)) {
376         // ABI mismatch.
377         // FIXME: New enum for this?
378         return kInvalidInput;
379     }
380 
381     // Free any memory associated with the buffer. Must be called last, so we declare it first.
382     SkAutoTCallVProc<WebPDecBuffer, WebPFreeDecBuffer> autoFree(&(config.output));
383 
384     WebPIterator frame;
385     SkAutoTCallVProc<WebPIterator, WebPDemuxReleaseIterator> autoFrame(&frame);
386     // If this succeeded in onGetFrameCount(), it should succeed again here.
387     SkAssertResult(WebPDemuxGetFrame(fDemux, index + 1, &frame));
388 
389     const bool independent = index == 0 ? true :
390             (fFrameHolder.frame(index)->getRequiredFrame() == kNoFrame);
391     // Get the frameRect.  libwebp will have already signaled an error if this is not fully
392     // contained by the canvas.
393     auto frameRect = SkIRect::MakeXYWH(frame.x_offset, frame.y_offset, frame.width, frame.height);
394     SkASSERT(this->bounds().contains(frameRect));
395     const bool frameIsSubset = frameRect != this->bounds();
396     if (independent && frameIsSubset) {
397         SkSampler::Fill(dstInfo, dst, rowBytes, options.fZeroInitialized);
398     }
399 
400     int dstX = frameRect.x();
401     int dstY = frameRect.y();
402     int subsetWidth = frameRect.width();
403     int subsetHeight = frameRect.height();
404     if (options.fSubset) {
405         SkIRect subset = *options.fSubset;
406         SkASSERT(this->bounds().contains(subset));
407         SkASSERT(SkIsAlign2(subset.fLeft) && SkIsAlign2(subset.fTop));
408         SkASSERT(this->getValidSubset(&subset) && subset == *options.fSubset);
409 
410         if (!SkIRect::Intersects(subset, frameRect)) {
411             return kSuccess;
412         }
413 
414         int minXOffset = std::min(dstX, subset.x());
415         int minYOffset = std::min(dstY, subset.y());
416         dstX -= minXOffset;
417         dstY -= minYOffset;
418         frameRect.offset(-minXOffset, -minYOffset);
419         subset.offset(-minXOffset, -minYOffset);
420 
421         // Just like we require that the requested subset x and y offset are even, libwebp
422         // guarantees that the frame x and y offset are even (it's actually impossible to specify
423         // an odd frame offset).  So we can still guarantee that the adjusted offsets are even.
424         SkASSERT(SkIsAlign2(subset.fLeft) && SkIsAlign2(subset.fTop));
425 
426         SkIRect intersection;
427         SkAssertResult(intersection.intersect(frameRect, subset));
428         subsetWidth = intersection.width();
429         subsetHeight = intersection.height();
430 
431         config.options.use_cropping = 1;
432         config.options.crop_left = subset.x();
433         config.options.crop_top = subset.y();
434         config.options.crop_width = subsetWidth;
435         config.options.crop_height = subsetHeight;
436     }
437 
438     // Ignore the frame size and offset when determining if scaling is necessary.
439     int scaledWidth = subsetWidth;
440     int scaledHeight = subsetHeight;
441     SkISize srcSize = options.fSubset ? options.fSubset->size() : this->dimensions();
442     if (srcSize != dstInfo.dimensions()) {
443         config.options.use_scaling = 1;
444 
445         if (frameIsSubset) {
446             float scaleX = ((float) dstInfo.width()) / srcSize.width();
447             float scaleY = ((float) dstInfo.height()) / srcSize.height();
448 
449             // We need to be conservative here and floor rather than round.
450             // Otherwise, we may find ourselves decoding off the end of memory.
451             dstX = scaleX * dstX;
452             scaledWidth = scaleX * scaledWidth;
453             dstY = scaleY * dstY;
454             scaledHeight = scaleY * scaledHeight;
455             if (0 == scaledWidth || 0 == scaledHeight) {
456                 return kSuccess;
457             }
458         } else {
459             scaledWidth = dstInfo.width();
460             scaledHeight = dstInfo.height();
461         }
462 
463         config.options.scaled_width = scaledWidth;
464         config.options.scaled_height = scaledHeight;
465     }
466 
467     const bool blendWithPrevFrame = !independent && frame.blend_method == WEBP_MUX_BLEND
468         && frame.has_alpha;
469 
470     auto webpInfo = dstInfo;
471     if (!frame.has_alpha) {
472         webpInfo = webpInfo.makeAlphaType(kOpaque_SkAlphaType);
473     } else if (this->colorXform() || blendWithPrevFrame) {
474         // the colorXform and blend_line expect unpremul.
475         webpInfo = webpInfo.makeAlphaType(kUnpremul_SkAlphaType);
476     }
477     if (this->colorXform()) {
478         // Swizzling between RGBA and BGRA is zero cost in a color transform.  So when we have a
479         // color transform, we should decode to whatever is easiest for libwebp, and then let the
480         // color transform swizzle if necessary.
481         // Lossy webp is encoded as YUV (so RGBA and BGRA are the same cost).  Lossless webp is
482         // encoded as BGRA. This means decoding to BGRA is either faster or the same cost as RGBA.
483         webpInfo = webpInfo.makeColorType(kBGRA_8888_SkColorType);
484     }
485 
486     SkBitmap webpDst;
487     if ((this->colorXform() && !is_8888(dstInfo.colorType())) || blendWithPrevFrame) {
488         // We will decode the entire image and then perform the color transform.  libwebp
489         // does not provide a row-by-row API.  This is a shame particularly when we do not want
490         // 8888, since we will need to create another image sized buffer.
491         webpDst.allocPixels(webpInfo);
492     } else {
493         // libwebp can decode directly into the output memory.
494         webpDst.installPixels(webpInfo, dst, rowBytes);
495     }
496 
497     config.output.colorspace = webp_decode_mode(webpInfo.colorType(),
498             webpInfo.alphaType() == kPremul_SkAlphaType);
499     config.output.is_external_memory = 1;
500 
501     config.output.u.RGBA.rgba = reinterpret_cast<uint8_t*>(webpDst.getAddr(dstX, dstY));
502     config.output.u.RGBA.stride = static_cast<int>(webpDst.rowBytes());
503     config.output.u.RGBA.size = webpDst.computeByteSize();
504 
505     SkAutoTCallVProc<WebPIDecoder, WebPIDelete> idec(WebPIDecode(nullptr, 0, &config));
506     if (!idec) {
507         return kInvalidInput;
508     }
509 
510     int rowsDecoded = 0;
511     SkCodec::Result result;
512     switch (WebPIUpdate(idec, frame.fragment.bytes, frame.fragment.size)) {
513         case VP8_STATUS_OK:
514             rowsDecoded = scaledHeight;
515             result = kSuccess;
516             break;
517         case VP8_STATUS_SUSPENDED:
518             if (!WebPIDecGetRGB(idec, &rowsDecoded, nullptr, nullptr, nullptr)
519                     || rowsDecoded <= 0) {
520                 return kInvalidInput;
521             }
522             *rowsDecodedPtr = rowsDecoded + dstY;
523             result = kIncompleteInput;
524             break;
525         default:
526             return kInvalidInput;
527     }
528 
529     const size_t dstBpp = dstInfo.bytesPerPixel();
530     dst = SkTAddOffset<void>(dst, dstBpp * dstX + rowBytes * dstY);
531     const size_t srcRowBytes = config.output.u.RGBA.stride;
532 
533     const auto dstCT = dstInfo.colorType();
534     if (this->colorXform()) {
535         uint32_t* xformSrc = (uint32_t*) config.output.u.RGBA.rgba;
536         SkBitmap tmp;
537         void* xformDst;
538 
539         if (blendWithPrevFrame) {
540             // Xform into temporary bitmap big enough for one row.
541             tmp.allocPixels(dstInfo.makeWH(scaledWidth, 1));
542             xformDst = tmp.getPixels();
543         } else {
544             xformDst = dst;
545         }
546 
547         for (int y = 0; y < rowsDecoded; y++) {
548             this->applyColorXform(xformDst, xformSrc, scaledWidth);
549             if (blendWithPrevFrame) {
550                 blend_line(dstCT, dst, dstCT, xformDst,
551                         dstInfo.alphaType(), frame.has_alpha, scaledWidth);
552                 dst = SkTAddOffset<void>(dst, rowBytes);
553             } else {
554                 xformDst = SkTAddOffset<void>(xformDst, rowBytes);
555             }
556             xformSrc = SkTAddOffset<uint32_t>(xformSrc, srcRowBytes);
557         }
558     } else if (blendWithPrevFrame) {
559         const uint8_t* src = config.output.u.RGBA.rgba;
560 
561         for (int y = 0; y < rowsDecoded; y++) {
562             blend_line(dstCT, dst, webpDst.colorType(), src,
563                     dstInfo.alphaType(), frame.has_alpha, scaledWidth);
564             src = SkTAddOffset<const uint8_t>(src, srcRowBytes);
565             dst = SkTAddOffset<void>(dst, rowBytes);
566         }
567     }
568 
569     return result;
570 }
571 
SkWebpCodec(SkEncodedInfo && info,std::unique_ptr<SkStream> stream,WebPDemuxer * demux,sk_sp<SkData> data,SkEncodedOrigin origin)572 SkWebpCodec::SkWebpCodec(SkEncodedInfo&& info, std::unique_ptr<SkStream> stream,
573                          WebPDemuxer* demux, sk_sp<SkData> data, SkEncodedOrigin origin)
574     : INHERITED(std::move(info), skcms_PixelFormat_BGRA_8888, std::move(stream),
575                 origin)
576     , fDemux(demux)
577     , fData(std::move(data))
578     , fFailed(false)
579 {
580     const auto& eInfo = this->getEncodedInfo();
581     fFrameHolder.setScreenSize(eInfo.width(), eInfo.height());
582 }
583 
584 namespace SkWebpDecoder {
IsWebp(const void * data,size_t len)585 bool IsWebp(const void* data, size_t len) {
586     return SkWebpCodec::IsWebp(data, len);
587 }
588 
Decode(std::unique_ptr<SkStream> stream,SkCodec::Result * outResult,SkCodecs::DecodeContext)589 std::unique_ptr<SkCodec> Decode(std::unique_ptr<SkStream> stream,
590                                 SkCodec::Result* outResult,
591                                 SkCodecs::DecodeContext) {
592     SkCodec::Result resultStorage;
593     if (!outResult) {
594         outResult = &resultStorage;
595     }
596     return SkWebpCodec::MakeFromStream(std::move(stream), outResult);
597 }
598 
Decode(sk_sp<SkData> data,SkCodec::Result * outResult,SkCodecs::DecodeContext)599 std::unique_ptr<SkCodec> Decode(sk_sp<SkData> data,
600                                 SkCodec::Result* outResult,
601                                 SkCodecs::DecodeContext) {
602     if (!data) {
603         if (outResult) {
604             *outResult = SkCodec::kInvalidInput;
605         }
606         return nullptr;
607     }
608     return Decode(SkMemoryStream::Make(std::move(data)), outResult, nullptr);
609 }
610 }  // namespace SkWebpDecoder
611