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IMAGE: Improved dithering support for QuickTime RLE

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This commit is contained in:
Cameron Cawley
2024-12-07 17:25:46 +00:00
committed by Eugene Sandulenko
parent 0a84ffe3d7
commit 1e62c54dcd
2 changed files with 149 additions and 9 deletions
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image/codecs/qtrle.cpp
+147 -9
View File
@@ -260,6 +260,68 @@ void QTRLEDecoder::decode16(Common::SeekableReadStream &stream, uint32 rowPtr, u
}
}
namespace {
inline uint16 readDitherColor16(Common::ReadStream &stream) {
return stream.readUint16BE() >> 1;
}
} // End of anonymous namespace
void QTRLEDecoder::dither16(Common::SeekableReadStream &stream, uint32 rowPtr, uint32 linesToChange) {
uint32 pixelPtr = 0;
byte *output = (byte *)_surface->getPixels();
static const uint16 colorTableOffsets[] = { 0x0000, 0xC000, 0x4000, 0x8000 };
// clone2727 thinks this should be startLine & 3, but the original definitely
// isn't doing this. Unless startLine & 3 is always 0? Kinda defeats the
// purpose of the compression then.
byte curColorTableOffset = 0;
while (linesToChange--) {
CHECK_STREAM_PTR(2);
byte rowOffset = stream.readByte() - 1;
pixelPtr = rowPtr + rowOffset;
uint16 colorTableOffset = colorTableOffsets[curColorTableOffset] + (rowOffset << 14);
for (int rleCode = stream.readSByte(); rleCode != -1; rleCode = stream.readSByte()) {
if (rleCode == 0) {
// there's another skip code in the stream
CHECK_STREAM_PTR(1);
pixelPtr += stream.readByte() - 1;
} else if (rleCode < 0) {
// decode the run length code
rleCode = -rleCode;
CHECK_STREAM_PTR(2);
uint16 color = readDitherColor16(stream);
CHECK_PIXEL_PTR(rleCode);
while (rleCode--) {
output[pixelPtr++] = _colorMap[colorTableOffset + color];
colorTableOffset += 0x4000;
}
} else {
CHECK_STREAM_PTR(rleCode * 2);
CHECK_PIXEL_PTR(rleCode);
// copy pixels directly to output
while (rleCode--) {
uint16 color = readDitherColor16(stream);
output[pixelPtr++] = _colorMap[colorTableOffset + color];
colorTableOffset += 0x4000;
}
}
}
rowPtr += _paddedWidth;
curColorTableOffset = (curColorTableOffset + 1) & 3;
}
}
void QTRLEDecoder::decode24(Common::SeekableReadStream &stream, uint32 rowPtr, uint32 linesToChange) {
uint32 pixelPtr = 0;
uint32 *rgb = (uint32 *)_surface->getPixels();
@@ -309,9 +371,12 @@ void QTRLEDecoder::decode24(Common::SeekableReadStream &stream, uint32 rowPtr, u
namespace {
inline uint16 readDitherColor24(Common::ReadStream &stream) {
uint16 color = (stream.readByte() & 0xF8) << 6;
color |= (stream.readByte() & 0xF8) << 1;
color |= stream.readByte() >> 4;
uint8 rgb[3];
stream.read(rgb, 3);
uint16 color = (rgb[0] & 0xF8) << 6;
color |= (rgb[1] & 0xF8) << 1;
color |= rgb[2] >> 4;
return color;
}
@@ -343,12 +408,12 @@ void QTRLEDecoder::dither24(Common::SeekableReadStream &stream, uint32 rowPtr, u
} else if (rleCode < 0) {
// decode the run length code
rleCode = -rleCode;
CHECK_STREAM_PTR(3);
CHECK_PIXEL_PTR(rleCode);
uint16 color = readDitherColor24(stream);
CHECK_PIXEL_PTR(rleCode);
while (rleCode--) {
output[pixelPtr++] = _colorMap[colorTableOffset + color];
colorTableOffset += 0x4000;
@@ -419,6 +484,74 @@ void QTRLEDecoder::decode32(Common::SeekableReadStream &stream, uint32 rowPtr, u
}
}
namespace {
inline uint16 readDitherColor32(Common::ReadStream &stream) {
uint8 argb[4];
stream.read(argb, 4);
uint16 color = (argb[1] & 0xF8) << 6;
color |= (argb[2] & 0xF8) << 1;
color |= argb[3] >> 4;
return color;
}
} // End of anonymous namespace
void QTRLEDecoder::dither32(Common::SeekableReadStream &stream, uint32 rowPtr, uint32 linesToChange) {
uint32 pixelPtr = 0;
byte *output = (byte *)_surface->getPixels();
static const uint16 colorTableOffsets[] = { 0x0000, 0xC000, 0x4000, 0x8000 };
// clone2727 thinks this should be startLine & 3, but the original definitely
// isn't doing this. Unless startLine & 3 is always 0? Kinda defeats the
// purpose of the compression then.
byte curColorTableOffset = 0;
while (linesToChange--) {
CHECK_STREAM_PTR(2);
byte rowOffset = stream.readByte() - 1;
pixelPtr = rowPtr + rowOffset;
uint16 colorTableOffset = colorTableOffsets[curColorTableOffset] + (rowOffset << 14);
for (int rleCode = stream.readSByte(); rleCode != -1; rleCode = stream.readSByte()) {
if (rleCode == 0) {
// there's another skip code in the stream
CHECK_STREAM_PTR(1);
pixelPtr += stream.readByte() - 1;
} else if (rleCode < 0) {
// decode the run length code
rleCode = -rleCode;
CHECK_STREAM_PTR(4);
uint16 color = readDitherColor32(stream);
CHECK_PIXEL_PTR(rleCode);
while (rleCode--) {
output[pixelPtr++] = _colorMap[colorTableOffset + color];
colorTableOffset += 0x4000;
}
} else {
CHECK_STREAM_PTR(rleCode * 4);
CHECK_PIXEL_PTR(rleCode);
// copy pixels directly to output
while (rleCode--) {
uint16 color = readDitherColor32(stream);
output[pixelPtr++] = _colorMap[colorTableOffset + color];
colorTableOffset += 0x4000;
}
}
}
rowPtr += _paddedWidth;
curColorTableOffset = (curColorTableOffset + 1) & 3;
}
}
const Graphics::Surface *QTRLEDecoder::decodeFrame(Common::SeekableReadStream &stream) {
if (!_surface)
createSurface();
@@ -467,7 +600,10 @@ const Graphics::Surface *QTRLEDecoder::decodeFrame(Common::SeekableReadStream &s
decode8(stream, rowPtr, height);
break;
case 16:
decode16(stream, rowPtr, height);
if (_ditherPalette.size() > 0)
dither16(stream, rowPtr, height);
else
decode16(stream, rowPtr, height);
break;
case 24:
if (_ditherPalette.size() > 0)
@@ -476,7 +612,10 @@ const Graphics::Surface *QTRLEDecoder::decodeFrame(Common::SeekableReadStream &s
decode24(stream, rowPtr, height);
break;
case 32:
decode32(stream, rowPtr, height);
if (_ditherPalette.size() > 0)
dither32(stream, rowPtr, height);
else
decode32(stream, rowPtr, height);
break;
default:
error("Unsupported QTRLE bits per pixel %d", _bitsPerPixel);
@@ -512,8 +651,7 @@ Graphics::PixelFormat QTRLEDecoder::getPixelFormat() const {
}
bool QTRLEDecoder::canDither(DitherType type) const {
// Only 24-bit dithering is implemented at the moment
return type == kDitherTypeQT && _bitsPerPixel == 24;
return type == kDitherTypeQT && (_bitsPerPixel == 16 || _bitsPerPixel == 24 || _bitsPerPixel == 32);
}
void QTRLEDecoder::setDither(DitherType type, const byte *palette) {
image/codecs/qtrle.h
+2
View File
@@ -62,9 +62,11 @@ private:
void decode2_4(Common::SeekableReadStream &stream, uint32 rowPtr, uint32 linesToChange, byte bpp);
void decode8(Common::SeekableReadStream &stream, uint32 rowPtr, uint32 linesToChange);
void decode16(Common::SeekableReadStream &stream, uint32 rowPtr, uint32 linesToChange);
void dither16(Common::SeekableReadStream &stream, uint32 rowPtr, uint32 linesToChange);
void decode24(Common::SeekableReadStream &stream, uint32 rowPtr, uint32 linesToChange);
void dither24(Common::SeekableReadStream &stream, uint32 rowPtr, uint32 linesToChange);
void decode32(Common::SeekableReadStream &stream, uint32 rowPtr, uint32 linesToChange);
void dither32(Common::SeekableReadStream &stream, uint32 rowPtr, uint32 linesToChange);
};
} // End of namespace Image