| /* |
| * 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 "SkBmpCodec.h" |
| #include "SkCodecPriv.h" |
| #include "SkColorData.h" |
| #include "SkData.h" |
| #include "SkIcoCodec.h" |
| #include "SkPngCodec.h" |
| #include "SkStream.h" |
| #include "SkTDArray.h" |
| #include "SkTSort.h" |
| |
| /* |
| * Checks the start of the stream to see if the image is an Ico or Cur |
| */ |
| bool SkIcoCodec::IsIco(const void* buffer, size_t bytesRead) { |
| const char icoSig[] = { '\x00', '\x00', '\x01', '\x00' }; |
| const char curSig[] = { '\x00', '\x00', '\x02', '\x00' }; |
| return bytesRead >= sizeof(icoSig) && |
| (!memcmp(buffer, icoSig, sizeof(icoSig)) || |
| !memcmp(buffer, curSig, sizeof(curSig))); |
| } |
| |
| std::unique_ptr<SkCodec> SkIcoCodec::MakeFromStream(std::unique_ptr<SkStream> stream, |
| Result* result) { |
| // Header size constants |
| constexpr uint32_t kIcoDirectoryBytes = 6; |
| constexpr uint32_t kIcoDirEntryBytes = 16; |
| |
| // Read the directory header |
| std::unique_ptr<uint8_t[]> dirBuffer(new uint8_t[kIcoDirectoryBytes]); |
| if (stream->read(dirBuffer.get(), kIcoDirectoryBytes) != kIcoDirectoryBytes) { |
| SkCodecPrintf("Error: unable to read ico directory header.\n"); |
| *result = kIncompleteInput; |
| return nullptr; |
| } |
| |
| // Process the directory header |
| const uint16_t numImages = get_short(dirBuffer.get(), 4); |
| if (0 == numImages) { |
| SkCodecPrintf("Error: No images embedded in ico.\n"); |
| *result = kInvalidInput; |
| return nullptr; |
| } |
| |
| // This structure is used to represent the vital information about entries |
| // in the directory header. We will obtain this information for each |
| // directory entry. |
| struct Entry { |
| uint32_t offset; |
| uint32_t size; |
| }; |
| SkAutoFree dirEntryBuffer(sk_malloc_canfail(sizeof(Entry) * numImages)); |
| if (!dirEntryBuffer) { |
| SkCodecPrintf("Error: OOM allocating ICO directory for %i images.\n", |
| numImages); |
| *result = kInternalError; |
| return nullptr; |
| } |
| auto* directoryEntries = reinterpret_cast<Entry*>(dirEntryBuffer.get()); |
| |
| // Iterate over directory entries |
| for (uint32_t i = 0; i < numImages; i++) { |
| uint8_t entryBuffer[kIcoDirEntryBytes]; |
| if (stream->read(entryBuffer, kIcoDirEntryBytes) != kIcoDirEntryBytes) { |
| SkCodecPrintf("Error: Dir entries truncated in ico.\n"); |
| *result = kIncompleteInput; |
| return nullptr; |
| } |
| |
| // The directory entry contains information such as width, height, |
| // bits per pixel, and number of colors in the color palette. We will |
| // ignore these fields since they are repeated in the header of the |
| // embedded image. In the event of an inconsistency, we would always |
| // defer to the value in the embedded header anyway. |
| |
| // Specifies the size of the embedded image, including the header |
| uint32_t size = get_int(entryBuffer, 8); |
| |
| // Specifies the offset of the embedded image from the start of file. |
| // It does not indicate the start of the pixel data, but rather the |
| // start of the embedded image header. |
| uint32_t offset = get_int(entryBuffer, 12); |
| |
| // Save the vital fields |
| directoryEntries[i].offset = offset; |
| directoryEntries[i].size = size; |
| } |
| |
| // Default Result, if no valid embedded codecs are found. |
| *result = kInvalidInput; |
| |
| // It is "customary" that the embedded images will be stored in order of |
| // increasing offset. However, the specification does not indicate that |
| // they must be stored in this order, so we will not trust that this is the |
| // case. Here we sort the embedded images by increasing offset. |
| struct EntryLessThan { |
| bool operator() (Entry a, Entry b) const { |
| return a.offset < b.offset; |
| } |
| }; |
| EntryLessThan lessThan; |
| SkTQSort(directoryEntries, &directoryEntries[numImages - 1], lessThan); |
| |
| // Now will construct a candidate codec for each of the embedded images |
| uint32_t bytesRead = kIcoDirectoryBytes + numImages * kIcoDirEntryBytes; |
| std::unique_ptr<SkTArray<std::unique_ptr<SkCodec>, true>> codecs( |
| new SkTArray<std::unique_ptr<SkCodec>, true>(numImages)); |
| for (uint32_t i = 0; i < numImages; i++) { |
| uint32_t offset = directoryEntries[i].offset; |
| uint32_t size = directoryEntries[i].size; |
| |
| // Ensure that the offset is valid |
| if (offset < bytesRead) { |
| SkCodecPrintf("Warning: invalid ico offset.\n"); |
| continue; |
| } |
| |
| // If we cannot skip, assume we have reached the end of the stream and |
| // stop trying to make codecs |
| if (stream->skip(offset - bytesRead) != offset - bytesRead) { |
| SkCodecPrintf("Warning: could not skip to ico offset.\n"); |
| break; |
| } |
| bytesRead = offset; |
| |
| // Create a new stream for the embedded codec |
| SkAutoFree buffer(sk_malloc_canfail(size)); |
| if (!buffer) { |
| SkCodecPrintf("Warning: OOM trying to create embedded stream.\n"); |
| break; |
| } |
| |
| if (stream->read(buffer.get(), size) != size) { |
| SkCodecPrintf("Warning: could not create embedded stream.\n"); |
| *result = kIncompleteInput; |
| break; |
| } |
| |
| sk_sp<SkData> data(SkData::MakeFromMalloc(buffer.release(), size)); |
| auto embeddedStream = SkMemoryStream::Make(data); |
| bytesRead += size; |
| |
| // Check if the embedded codec is bmp or png and create the codec |
| std::unique_ptr<SkCodec> codec; |
| Result dummyResult; |
| if (SkPngCodec::IsPng((const char*) data->bytes(), data->size())) { |
| codec = SkPngCodec::MakeFromStream(std::move(embeddedStream), &dummyResult); |
| } else { |
| codec = SkBmpCodec::MakeFromIco(std::move(embeddedStream), &dummyResult); |
| } |
| |
| // Save a valid codec |
| if (nullptr != codec) { |
| codecs->push_back().reset(codec.release()); |
| } |
| } |
| |
| // Recognize if there are no valid codecs |
| if (0 == codecs->count()) { |
| SkCodecPrintf("Error: could not find any valid embedded ico codecs.\n"); |
| return nullptr; |
| } |
| |
| // Use the largest codec as a "suggestion" for image info |
| size_t maxSize = 0; |
| int maxIndex = 0; |
| for (int i = 0; i < codecs->count(); i++) { |
| SkImageInfo info = codecs->operator[](i)->getInfo(); |
| size_t size = info.computeMinByteSize(); |
| |
| if (size > maxSize) { |
| maxSize = size; |
| maxIndex = i; |
| } |
| } |
| |
| auto maxInfo = codecs->operator[](maxIndex)->getEncodedInfo().copy(); |
| |
| *result = kSuccess; |
| // The original stream is no longer needed, because the embedded codecs own their |
| // own streams. |
| return std::unique_ptr<SkCodec>(new SkIcoCodec(std::move(maxInfo), codecs.release())); |
| } |
| |
| SkIcoCodec::SkIcoCodec(SkEncodedInfo&& info, SkTArray<std::unique_ptr<SkCodec>, true>* codecs) |
| // The source skcms_PixelFormat will not be used. The embedded |
| // codec's will be used instead. |
| : INHERITED(std::move(info), skcms_PixelFormat(), nullptr) |
| , fEmbeddedCodecs(codecs) |
| , fCurrCodec(nullptr) |
| {} |
| |
| /* |
| * Chooses the best dimensions given the desired scale |
| */ |
| SkISize SkIcoCodec::onGetScaledDimensions(float desiredScale) const { |
| // We set the dimensions to the largest candidate image by default. |
| // Regardless of the scale request, this is the largest image that we |
| // will decode. |
| int origWidth = this->getInfo().width(); |
| int origHeight = this->getInfo().height(); |
| float desiredSize = desiredScale * origWidth * origHeight; |
| // At least one image will have smaller error than this initial value |
| float minError = ((float) (origWidth * origHeight)) - desiredSize + 1.0f; |
| int32_t minIndex = -1; |
| for (int32_t i = 0; i < fEmbeddedCodecs->count(); i++) { |
| int width = fEmbeddedCodecs->operator[](i)->getInfo().width(); |
| int height = fEmbeddedCodecs->operator[](i)->getInfo().height(); |
| float error = SkTAbs(((float) (width * height)) - desiredSize); |
| if (error < minError) { |
| minError = error; |
| minIndex = i; |
| } |
| } |
| SkASSERT(minIndex >= 0); |
| |
| return fEmbeddedCodecs->operator[](minIndex)->getInfo().dimensions(); |
| } |
| |
| int SkIcoCodec::chooseCodec(const SkISize& requestedSize, int startIndex) { |
| SkASSERT(startIndex >= 0); |
| |
| // FIXME: Cache the index from onGetScaledDimensions? |
| for (int i = startIndex; i < fEmbeddedCodecs->count(); i++) { |
| if (fEmbeddedCodecs->operator[](i)->getInfo().dimensions() == requestedSize) { |
| return i; |
| } |
| } |
| |
| return -1; |
| } |
| |
| bool SkIcoCodec::onDimensionsSupported(const SkISize& dim) { |
| return this->chooseCodec(dim, 0) >= 0; |
| } |
| |
| /* |
| * Initiates the Ico decode |
| */ |
| SkCodec::Result SkIcoCodec::onGetPixels(const SkImageInfo& dstInfo, |
| void* dst, size_t dstRowBytes, |
| const Options& opts, |
| int* rowsDecoded) { |
| if (opts.fSubset) { |
| // Subsets are not supported. |
| return kUnimplemented; |
| } |
| |
| int index = 0; |
| SkCodec::Result result = kInvalidScale; |
| while (true) { |
| index = this->chooseCodec(dstInfo.dimensions(), index); |
| if (index < 0) { |
| break; |
| } |
| |
| SkCodec* embeddedCodec = fEmbeddedCodecs->operator[](index).get(); |
| result = embeddedCodec->getPixels(dstInfo, dst, dstRowBytes, &opts); |
| switch (result) { |
| case kSuccess: |
| case kIncompleteInput: |
| // The embedded codec will handle filling incomplete images, so we will indicate |
| // that all of the rows are initialized. |
| *rowsDecoded = dstInfo.height(); |
| return result; |
| default: |
| // Continue trying to find a valid embedded codec on a failed decode. |
| break; |
| } |
| |
| index++; |
| } |
| |
| SkCodecPrintf("Error: No matching candidate image in ico.\n"); |
| return result; |
| } |
| |
| SkCodec::Result SkIcoCodec::onStartScanlineDecode(const SkImageInfo& dstInfo, |
| const SkCodec::Options& options) { |
| int index = 0; |
| SkCodec::Result result = kInvalidScale; |
| while (true) { |
| index = this->chooseCodec(dstInfo.dimensions(), index); |
| if (index < 0) { |
| break; |
| } |
| |
| SkCodec* embeddedCodec = fEmbeddedCodecs->operator[](index).get(); |
| result = embeddedCodec->startScanlineDecode(dstInfo, &options); |
| if (kSuccess == result) { |
| fCurrCodec = embeddedCodec; |
| return result; |
| } |
| |
| index++; |
| } |
| |
| SkCodecPrintf("Error: No matching candidate image in ico.\n"); |
| return result; |
| } |
| |
| int SkIcoCodec::onGetScanlines(void* dst, int count, size_t rowBytes) { |
| SkASSERT(fCurrCodec); |
| return fCurrCodec->getScanlines(dst, count, rowBytes); |
| } |
| |
| bool SkIcoCodec::onSkipScanlines(int count) { |
| SkASSERT(fCurrCodec); |
| return fCurrCodec->skipScanlines(count); |
| } |
| |
| SkCodec::Result SkIcoCodec::onStartIncrementalDecode(const SkImageInfo& dstInfo, |
| void* pixels, size_t rowBytes, const SkCodec::Options& options) { |
| int index = 0; |
| while (true) { |
| index = this->chooseCodec(dstInfo.dimensions(), index); |
| if (index < 0) { |
| break; |
| } |
| |
| SkCodec* embeddedCodec = fEmbeddedCodecs->operator[](index).get(); |
| switch (embeddedCodec->startIncrementalDecode(dstInfo, |
| pixels, rowBytes, &options)) { |
| case kSuccess: |
| fCurrCodec = embeddedCodec; |
| return kSuccess; |
| case kUnimplemented: |
| // FIXME: embeddedCodec is a BMP. If scanline decoding would work, |
| // return kUnimplemented so that SkSampledCodec will fall through |
| // to use the scanline decoder. |
| // Note that calling startScanlineDecode will require an extra |
| // rewind. The embedded codec has an SkMemoryStream, which is |
| // cheap to rewind, though it will do extra work re-reading the |
| // header. |
| // Also note that we pass nullptr for Options. This is because |
| // Options that are valid for incremental decoding may not be |
| // valid for scanline decoding. |
| // Once BMP supports incremental decoding this workaround can go |
| // away. |
| if (embeddedCodec->startScanlineDecode(dstInfo) == kSuccess) { |
| return kUnimplemented; |
| } |
| // Move on to the next embedded codec. |
| break; |
| default: |
| break; |
| } |
| |
| index++; |
| } |
| |
| SkCodecPrintf("Error: No matching candidate image in ico.\n"); |
| return kInvalidScale; |
| } |
| |
| SkCodec::Result SkIcoCodec::onIncrementalDecode(int* rowsDecoded) { |
| SkASSERT(fCurrCodec); |
| return fCurrCodec->incrementalDecode(rowsDecoded); |
| } |
| |
| SkCodec::SkScanlineOrder SkIcoCodec::onGetScanlineOrder() const { |
| // FIXME: This function will possibly return the wrong value if it is called |
| // before startScanlineDecode()/startIncrementalDecode(). |
| if (fCurrCodec) { |
| return fCurrCodec->getScanlineOrder(); |
| } |
| |
| return INHERITED::onGetScanlineOrder(); |
| } |
| |
| SkSampler* SkIcoCodec::getSampler(bool createIfNecessary) { |
| if (fCurrCodec) { |
| return fCurrCodec->getSampler(createIfNecessary); |
| } |
| |
| return nullptr; |
| } |