diff options
author | msarett <msarett@google.com> | 2016-04-20 11:53:35 -0700 |
---|---|---|
committer | Commit bot <commit-bot@chromium.org> | 2016-04-20 11:53:35 -0700 |
commit | c30c418f4eb75f365c7d7a32d5419b41ca780ba8 (patch) | |
tree | d9e5a2dacd55f32f51319fbc22fa3335081e6940 /src/codec/SkBmpCodec.cpp | |
parent | 3e302275b324172c845627cbd00cee8a06571baf (diff) |
Add SkEncodedInfo to report properties of encoded image data
All this does is build an SkEncodedInfo for each codec, and
then convert it to an SkImageInfo.
In future steps I intend to:
(1) Use SkEncodedInfo in place of SrcConfig in SkSwizzler.
(2) Support more conversions in SkSwizzler (non-native
BGRA/RGBA, 16-bit components, float, fixed point)
(3) Investigate optimizing conversions from encoded data
to linear color spaces.
BUG=skia:4133
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1820073002
Committed: https://skia.googlesource.com/skia/+/f682d9ad70d690a343bc15e26ef321d86770be41
Review URL: https://codereview.chromium.org/1820073002
Diffstat (limited to 'src/codec/SkBmpCodec.cpp')
-rw-r--r-- | src/codec/SkBmpCodec.cpp | 82 |
1 files changed, 52 insertions, 30 deletions
diff --git a/src/codec/SkBmpCodec.cpp b/src/codec/SkBmpCodec.cpp index ad6f0ddc4d..680436ab91 100644 --- a/src/codec/SkBmpCodec.cpp +++ b/src/codec/SkBmpCodec.cpp @@ -415,33 +415,47 @@ bool SkBmpCodec::ReadHeader(SkStream* stream, bool inIco, SkCodec** codecOut) { switch (inputFormat) { case kStandard_BmpInputFormat: { - // BMPs-in-ICOs often contain an alpha mask after the image, which - // means we cannot guarantee that an image is opaque, even if the - // embedded bmp is opaque. - // We use |isOpaque| to indicate if the BMP itself is opaque, but - // still need to recommend kUnpremul when it is contained in an ICO. - SkColorType colorType = kN32_SkColorType; - SkAlphaType alphaType = inIco ? kUnpremul_SkAlphaType : kOpaque_SkAlphaType; + // BMPs are generally opaque, however BMPs-in-ICOs may contain + // a transparency mask after the image. Therefore, we mark the + // alpha as kBinary if the BMP is contained in an ICO. + // We use |isOpaque| to indicate if the BMP itself is opaque. + SkEncodedInfo::Alpha alpha = inIco ? SkEncodedInfo::kBinary_Alpha : + SkEncodedInfo::kOpaque_Alpha; bool isOpaque = true; + + SkEncodedInfo::Color color; + uint8_t bitsPerComponent; switch (bitsPerPixel) { // Palette formats case 1: case 2: case 4: case 8: - // We cannot recommend a palette color type for ICOs because they - // may contain a transparency mask. - if (!inIco) { - colorType = kIndex_8_SkColorType; + // In the case of ICO, kBGRA is actually the closest match, + // since we will need to apply a transparency mask. + if (inIco) { + color = SkEncodedInfo::kBGRA_Color; + bitsPerComponent = 8; + } else { + color = SkEncodedInfo::kPalette_Color; + bitsPerComponent = (uint8_t) bitsPerPixel; } break; case 24: + color = SkEncodedInfo::kBGR_Color; + bitsPerComponent = 8; + break; case 32: // 32-bit BMP-in-ICOs actually use the alpha channel in place of a // transparency mask. if (inIco) { isOpaque = false; + alpha = SkEncodedInfo::kUnpremul_Alpha; + color = SkEncodedInfo::kBGRA_Color; + } else { + color = SkEncodedInfo::kBGRX_Color; } + bitsPerComponent = 8; break; default: SkCodecPrintf("Error: invalid input value for bits per pixel.\n"); @@ -453,11 +467,9 @@ bool SkBmpCodec::ReadHeader(SkStream* stream, bool inIco, SkCodec** codecOut) { SkASSERT(!inIco || nullptr != stream->getMemoryBase()); // Set the image info and create a codec. - const SkImageInfo imageInfo = SkImageInfo::Make(width, height, colorType, - alphaType); - *codecOut = new SkBmpStandardCodec(imageInfo, stream, bitsPerPixel, numColors, - bytesPerColor, offset - bytesRead, rowOrder, isOpaque, inIco); - + const SkEncodedInfo info = SkEncodedInfo::Make(color, alpha, bitsPerComponent); + *codecOut = new SkBmpStandardCodec(width, height, info, stream, bitsPerPixel, + numColors, bytesPerColor, offset - bytesRead, rowOrder, isOpaque, inIco); } return true; } @@ -495,13 +507,22 @@ bool SkBmpCodec::ReadHeader(SkStream* stream, bool inIco, SkCodec** codecOut) { return false; } - // Set the image info - SkAlphaType alphaType = masks->getAlphaMask() ? kUnpremul_SkAlphaType : - kOpaque_SkAlphaType; - const SkImageInfo imageInfo = SkImageInfo::Make(width, height, kN32_SkColorType, - alphaType); - *codecOut = new SkBmpMaskCodec(imageInfo, stream, bitsPerPixel, masks.release(), - rowOrder); + // Masked bmps are not a great fit for SkEncodedInfo, since they have + // arbitrary component orderings and bits per component. Here we choose + // somewhat reasonable values - it's ok that we don't match exactly + // because SkBmpMaskCodec has its own mask swizzler anyway. + SkEncodedInfo::Color color; + SkEncodedInfo::Alpha alpha; + if (masks->getAlphaMask()) { + color = SkEncodedInfo::kBGRA_Color; + alpha = SkEncodedInfo::kUnpremul_Alpha; + } else { + color = SkEncodedInfo::kBGR_Color; + alpha = SkEncodedInfo::kOpaque_Alpha; + } + const SkEncodedInfo info = SkEncodedInfo::Make(color, alpha, 8); + *codecOut = new SkBmpMaskCodec(width, height, info, stream, bitsPerPixel, + masks.release(), rowOrder); } return true; } @@ -526,10 +547,11 @@ bool SkBmpCodec::ReadHeader(SkStream* stream, bool inIco, SkCodec** codecOut) { if (codecOut) { // RLE inputs may skip pixels, leaving them as transparent. This // is uncommon, but we cannot be certain that an RLE bmp will be - // opaque. - const SkImageInfo imageInfo = SkImageInfo::Make(width, height, kN32_SkColorType, - kUnpremul_SkAlphaType); - *codecOut = new SkBmpRLECodec(imageInfo, stream, bitsPerPixel, numColors, + // opaque or that we will be able to represent it with a palette. + // For that reason, we always indicate that we are kBGRA. + const SkEncodedInfo info = SkEncodedInfo::Make(SkEncodedInfo::kBGRA_Color, + SkEncodedInfo::kBinary_Alpha, 8); + *codecOut = new SkBmpRLECodec(width, height, info, stream, bitsPerPixel, numColors, bytesPerColor, offset - bytesRead, rowOrder, RLEBytes); } return true; @@ -557,12 +579,12 @@ SkCodec* SkBmpCodec::NewFromStream(SkStream* stream, bool inIco) { return nullptr; } -SkBmpCodec::SkBmpCodec(const SkImageInfo& info, SkStream* stream, +SkBmpCodec::SkBmpCodec(int width, int height, const SkEncodedInfo& info, SkStream* stream, uint16_t bitsPerPixel, SkCodec::SkScanlineOrder rowOrder) - : INHERITED(info, stream) + : INHERITED(width, height, info, stream) , fBitsPerPixel(bitsPerPixel) , fRowOrder(rowOrder) - , fSrcRowBytes(SkAlign4(compute_row_bytes(info.width(), fBitsPerPixel))) + , fSrcRowBytes(SkAlign4(compute_row_bytes(width, fBitsPerPixel))) {} bool SkBmpCodec::onRewind() { |