| /* |
| * 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/SkSampledCodec.h" |
| |
| #include "include/codec/SkCodec.h" |
| #include "include/core/SkEncodedImageFormat.h" |
| #include "include/core/SkImageInfo.h" |
| #include "include/core/SkRect.h" |
| #include "include/core/SkTypes.h" |
| #include "include/private/SkTemplates.h" |
| #include "src/codec/SkCodecPriv.h" |
| #include "src/codec/SkSampler.h" |
| #include "src/core/SkMathPriv.h" |
| |
| SkSampledCodec::SkSampledCodec(SkCodec* codec) |
| : INHERITED(codec) |
| {} |
| |
| SkISize SkSampledCodec::accountForNativeScaling(int* sampleSizePtr, int* nativeSampleSize) const { |
| SkISize preSampledSize = this->codec()->dimensions(); |
| int sampleSize = *sampleSizePtr; |
| SkASSERT(sampleSize > 1); |
| |
| if (nativeSampleSize) { |
| *nativeSampleSize = 1; |
| } |
| |
| // Only JPEG supports native downsampling. |
| if (this->codec()->getEncodedFormat() == SkEncodedImageFormat::kJPEG) { |
| // See if libjpeg supports this scale directly |
| switch (sampleSize) { |
| case 2: |
| case 4: |
| case 8: |
| // This class does not need to do any sampling. |
| *sampleSizePtr = 1; |
| return this->codec()->getScaledDimensions(get_scale_from_sample_size(sampleSize)); |
| default: |
| break; |
| } |
| |
| // Check if sampleSize is a multiple of something libjpeg can support. |
| int remainder; |
| const int sampleSizes[] = { 8, 4, 2 }; |
| for (int supportedSampleSize : sampleSizes) { |
| int actualSampleSize; |
| SkTDivMod(sampleSize, supportedSampleSize, &actualSampleSize, &remainder); |
| if (0 == remainder) { |
| float scale = get_scale_from_sample_size(supportedSampleSize); |
| |
| // this->codec() will scale to this size. |
| preSampledSize = this->codec()->getScaledDimensions(scale); |
| |
| // And then this class will sample it. |
| *sampleSizePtr = actualSampleSize; |
| if (nativeSampleSize) { |
| *nativeSampleSize = supportedSampleSize; |
| } |
| break; |
| } |
| } |
| } |
| |
| return preSampledSize; |
| } |
| |
| SkISize SkSampledCodec::onGetSampledDimensions(int sampleSize) const { |
| const SkISize size = this->accountForNativeScaling(&sampleSize); |
| return SkISize::Make(get_scaled_dimension(size.width(), sampleSize), |
| get_scaled_dimension(size.height(), sampleSize)); |
| } |
| |
| SkCodec::Result SkSampledCodec::onGetAndroidPixels(const SkImageInfo& info, void* pixels, |
| size_t rowBytes, const AndroidOptions& options) { |
| const SkIRect* subset = options.fSubset; |
| if (!subset || subset->size() == this->codec()->dimensions()) { |
| if (this->codec()->dimensionsSupported(info.dimensions())) { |
| return this->codec()->getPixels(info, pixels, rowBytes, &options); |
| } |
| |
| // If the native codec does not support the requested scale, scale by sampling. |
| return this->sampledDecode(info, pixels, rowBytes, options); |
| } |
| |
| // We are performing a subset decode. |
| int sampleSize = options.fSampleSize; |
| SkISize scaledSize = this->getSampledDimensions(sampleSize); |
| if (!this->codec()->dimensionsSupported(scaledSize)) { |
| // If the native codec does not support the requested scale, scale by sampling. |
| return this->sampledDecode(info, pixels, rowBytes, options); |
| } |
| |
| // Calculate the scaled subset bounds. |
| int scaledSubsetX = subset->x() / sampleSize; |
| int scaledSubsetY = subset->y() / sampleSize; |
| int scaledSubsetWidth = info.width(); |
| int scaledSubsetHeight = info.height(); |
| |
| const SkImageInfo scaledInfo = info.makeDimensions(scaledSize); |
| |
| // Copy so we can use a different fSubset. |
| AndroidOptions subsetOptions = options; |
| { |
| // Although startScanlineDecode expects the bottom and top to match the |
| // SkImageInfo, startIncrementalDecode uses them to determine which rows to |
| // decode. |
| SkIRect incrementalSubset = SkIRect::MakeXYWH(scaledSubsetX, scaledSubsetY, |
| scaledSubsetWidth, scaledSubsetHeight); |
| subsetOptions.fSubset = &incrementalSubset; |
| const SkCodec::Result startResult = this->codec()->startIncrementalDecode( |
| scaledInfo, pixels, rowBytes, &subsetOptions); |
| if (SkCodec::kSuccess == startResult) { |
| int rowsDecoded = 0; |
| const SkCodec::Result incResult = this->codec()->incrementalDecode(&rowsDecoded); |
| if (incResult == SkCodec::kSuccess) { |
| return SkCodec::kSuccess; |
| } |
| SkASSERT(incResult == SkCodec::kIncompleteInput || incResult == SkCodec::kErrorInInput); |
| |
| // FIXME: Can zero initialized be read from SkCodec::fOptions? |
| this->codec()->fillIncompleteImage(scaledInfo, pixels, rowBytes, |
| options.fZeroInitialized, scaledSubsetHeight, rowsDecoded); |
| return incResult; |
| } else if (startResult != SkCodec::kUnimplemented) { |
| return startResult; |
| } |
| // Otherwise fall down to use the old scanline decoder. |
| // subsetOptions.fSubset will be reset below, so it will not continue to |
| // point to the object that is no longer on the stack. |
| } |
| |
| // Start the scanline decode. |
| SkIRect scanlineSubset = SkIRect::MakeXYWH(scaledSubsetX, 0, scaledSubsetWidth, |
| scaledSize.height()); |
| subsetOptions.fSubset = &scanlineSubset; |
| |
| SkCodec::Result result = this->codec()->startScanlineDecode(scaledInfo, |
| &subsetOptions); |
| if (SkCodec::kSuccess != result) { |
| return result; |
| } |
| |
| // At this point, we are only concerned with subsetting. Either no scale was |
| // requested, or the this->codec() is handling the scale. |
| // Note that subsetting is only supported for kTopDown, so this code will not be |
| // reached for other orders. |
| SkASSERT(this->codec()->getScanlineOrder() == SkCodec::kTopDown_SkScanlineOrder); |
| if (!this->codec()->skipScanlines(scaledSubsetY)) { |
| this->codec()->fillIncompleteImage(info, pixels, rowBytes, options.fZeroInitialized, |
| scaledSubsetHeight, 0); |
| return SkCodec::kIncompleteInput; |
| } |
| |
| int decodedLines = this->codec()->getScanlines(pixels, scaledSubsetHeight, rowBytes); |
| if (decodedLines != scaledSubsetHeight) { |
| return SkCodec::kIncompleteInput; |
| } |
| return SkCodec::kSuccess; |
| } |
| |
| |
| SkCodec::Result SkSampledCodec::sampledDecode(const SkImageInfo& info, void* pixels, |
| size_t rowBytes, const AndroidOptions& options) { |
| // We should only call this function when sampling. |
| SkASSERT(options.fSampleSize > 1); |
| |
| // FIXME: This was already called by onGetAndroidPixels. Can we reduce that? |
| int sampleSize = options.fSampleSize; |
| int nativeSampleSize; |
| SkISize nativeSize = this->accountForNativeScaling(&sampleSize, &nativeSampleSize); |
| |
| // Check if there is a subset. |
| SkIRect subset; |
| int subsetY = 0; |
| int subsetWidth = nativeSize.width(); |
| int subsetHeight = nativeSize.height(); |
| if (options.fSubset) { |
| // We will need to know about subsetting in the y-dimension in order to use the |
| // scanline decoder. |
| // Update the subset to account for scaling done by this->codec(). |
| const SkIRect* subsetPtr = options.fSubset; |
| |
| // Do the divide ourselves, instead of calling get_scaled_dimension. If |
| // X and Y are 0, they should remain 0, rather than being upgraded to 1 |
| // due to being smaller than the sampleSize. |
| const int subsetX = subsetPtr->x() / nativeSampleSize; |
| subsetY = subsetPtr->y() / nativeSampleSize; |
| |
| subsetWidth = get_scaled_dimension(subsetPtr->width(), nativeSampleSize); |
| subsetHeight = get_scaled_dimension(subsetPtr->height(), nativeSampleSize); |
| |
| // The scanline decoder only needs to be aware of subsetting in the x-dimension. |
| subset.setXYWH(subsetX, 0, subsetWidth, nativeSize.height()); |
| } |
| |
| // Since we guarantee that output dimensions are always at least one (even if the sampleSize |
| // is greater than a given dimension), the input sampleSize is not always the sampleSize that |
| // we use in practice. |
| const int sampleX = subsetWidth / info.width(); |
| const int sampleY = subsetHeight / info.height(); |
| |
| const int samplingOffsetY = get_start_coord(sampleY); |
| const int startY = samplingOffsetY + subsetY; |
| const int dstHeight = info.height(); |
| |
| const SkImageInfo nativeInfo = info.makeDimensions(nativeSize); |
| |
| { |
| // Although startScanlineDecode expects the bottom and top to match the |
| // SkImageInfo, startIncrementalDecode uses them to determine which rows to |
| // decode. |
| AndroidOptions incrementalOptions = options; |
| SkIRect incrementalSubset; |
| if (options.fSubset) { |
| incrementalSubset.fTop = subsetY; |
| incrementalSubset.fBottom = subsetY + subsetHeight; |
| incrementalSubset.fLeft = subset.fLeft; |
| incrementalSubset.fRight = subset.fRight; |
| incrementalOptions.fSubset = &incrementalSubset; |
| } |
| const SkCodec::Result startResult = this->codec()->startIncrementalDecode(nativeInfo, |
| pixels, rowBytes, &incrementalOptions); |
| if (SkCodec::kSuccess == startResult) { |
| SkSampler* sampler = this->codec()->getSampler(true); |
| if (!sampler) { |
| return SkCodec::kUnimplemented; |
| } |
| |
| if (sampler->setSampleX(sampleX) != info.width()) { |
| return SkCodec::kInvalidScale; |
| } |
| if (get_scaled_dimension(subsetHeight, sampleY) != info.height()) { |
| return SkCodec::kInvalidScale; |
| } |
| |
| sampler->setSampleY(sampleY); |
| |
| int rowsDecoded = 0; |
| const SkCodec::Result incResult = this->codec()->incrementalDecode(&rowsDecoded); |
| if (incResult == SkCodec::kSuccess) { |
| return SkCodec::kSuccess; |
| } |
| SkASSERT(incResult == SkCodec::kIncompleteInput || incResult == SkCodec::kErrorInInput); |
| |
| SkASSERT(rowsDecoded <= info.height()); |
| this->codec()->fillIncompleteImage(info, pixels, rowBytes, options.fZeroInitialized, |
| info.height(), rowsDecoded); |
| return incResult; |
| } else if (startResult == SkCodec::kIncompleteInput |
| || startResult == SkCodec::kErrorInInput) { |
| return SkCodec::kInvalidInput; |
| } else if (startResult != SkCodec::kUnimplemented) { |
| return startResult; |
| } // kUnimplemented means use the old method. |
| } |
| |
| // Start the scanline decode. |
| AndroidOptions sampledOptions = options; |
| if (options.fSubset) { |
| sampledOptions.fSubset = ⊂ |
| } |
| SkCodec::Result result = this->codec()->startScanlineDecode(nativeInfo, |
| &sampledOptions); |
| if (SkCodec::kIncompleteInput == result || SkCodec::kErrorInInput == result) { |
| return SkCodec::kInvalidInput; |
| } else if (SkCodec::kSuccess != result) { |
| return result; |
| } |
| |
| SkSampler* sampler = this->codec()->getSampler(true); |
| if (!sampler) { |
| return SkCodec::kInternalError; |
| } |
| |
| if (sampler->setSampleX(sampleX) != info.width()) { |
| return SkCodec::kInvalidScale; |
| } |
| if (get_scaled_dimension(subsetHeight, sampleY) != info.height()) { |
| return SkCodec::kInvalidScale; |
| } |
| |
| switch(this->codec()->getScanlineOrder()) { |
| case SkCodec::kTopDown_SkScanlineOrder: { |
| if (!this->codec()->skipScanlines(startY)) { |
| this->codec()->fillIncompleteImage(info, pixels, rowBytes, options.fZeroInitialized, |
| dstHeight, 0); |
| return SkCodec::kIncompleteInput; |
| } |
| void* pixelPtr = pixels; |
| for (int y = 0; y < dstHeight; y++) { |
| if (1 != this->codec()->getScanlines(pixelPtr, 1, rowBytes)) { |
| this->codec()->fillIncompleteImage(info, pixels, rowBytes, |
| options.fZeroInitialized, dstHeight, y + 1); |
| return SkCodec::kIncompleteInput; |
| } |
| if (y < dstHeight - 1) { |
| if (!this->codec()->skipScanlines(sampleY - 1)) { |
| this->codec()->fillIncompleteImage(info, pixels, rowBytes, |
| options.fZeroInitialized, dstHeight, y + 1); |
| return SkCodec::kIncompleteInput; |
| } |
| } |
| pixelPtr = SkTAddOffset<void>(pixelPtr, rowBytes); |
| } |
| return SkCodec::kSuccess; |
| } |
| case SkCodec::kBottomUp_SkScanlineOrder: { |
| // Note that these modes do not support subsetting. |
| SkASSERT(0 == subsetY && nativeSize.height() == subsetHeight); |
| int y; |
| for (y = 0; y < nativeSize.height(); y++) { |
| int srcY = this->codec()->nextScanline(); |
| if (is_coord_necessary(srcY, sampleY, dstHeight)) { |
| void* pixelPtr = SkTAddOffset<void>(pixels, |
| rowBytes * get_dst_coord(srcY, sampleY)); |
| if (1 != this->codec()->getScanlines(pixelPtr, 1, rowBytes)) { |
| break; |
| } |
| } else { |
| if (!this->codec()->skipScanlines(1)) { |
| break; |
| } |
| } |
| } |
| |
| if (nativeSize.height() == y) { |
| return SkCodec::kSuccess; |
| } |
| |
| // We handle filling uninitialized memory here instead of using this->codec(). |
| // this->codec() does not know that we are sampling. |
| const SkImageInfo fillInfo = info.makeWH(info.width(), 1); |
| for (; y < nativeSize.height(); y++) { |
| int srcY = this->codec()->outputScanline(y); |
| if (!is_coord_necessary(srcY, sampleY, dstHeight)) { |
| continue; |
| } |
| |
| void* rowPtr = SkTAddOffset<void>(pixels, rowBytes * get_dst_coord(srcY, sampleY)); |
| SkSampler::Fill(fillInfo, rowPtr, rowBytes, options.fZeroInitialized); |
| } |
| return SkCodec::kIncompleteInput; |
| } |
| default: |
| SkASSERT(false); |
| return SkCodec::kUnimplemented; |
| } |
| } |