thirdparty/scummvm
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IMAGE: Added sanity checks to SMC video decoder

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This commit is contained in:
Eugene Sandulenko 2020-08-19 14:54:47 +02:00
parent cc14dede0f
commit 6fb49b6595
1 changed files with 34 additions and 4 deletions
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38
image/codecs/smc.cpp
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@ -83,6 +83,8 @@ const Graphics::Surface *SMCDecoder::decodeFrame(Common::SeekableReadStream &str
int32 totalBlocks = ((_surface->w + 3) / 4) * ((_surface->h + 3) / 4);
uint32 pixelSize = _surface->w * _surface->h;
// traverse through the blocks
while (totalBlocks != 0) {
// sanity checks
@ -132,8 +134,12 @@ const Graphics::Surface *SMCDecoder::decodeFrame(Common::SeekableReadStream &str
blockPtr = rowPtr + pixelPtr;
prevBlockPtr = prevBlockPtr1;
for (byte y = 0; y < 4; y++) {
for (byte x = 0; x < 4; x++)
for (byte x = 0; x < 4; x++) {
if (blockPtr >= pixelSize)
break;
pixels[blockPtr++] = pixels[prevBlockPtr++];
}
blockPtr += rowInc;
prevBlockPtr += rowInc;
}
@ -178,8 +184,12 @@ const Graphics::Surface *SMCDecoder::decodeFrame(Common::SeekableReadStream &str
prevBlockFlag = !prevBlockFlag;
for (byte y = 0; y < 4; y++) {
for (byte x = 0; x < 4; x++)
for (byte x = 0; x < 4; x++) {
if (blockPtr >= pixelSize)
break;
pixels[blockPtr++] = pixels[prevBlockPtr++];
}
blockPtr += rowInc;
prevBlockPtr += rowInc;
@ -197,8 +207,12 @@ const Graphics::Surface *SMCDecoder::decodeFrame(Common::SeekableReadStream &str
while (numBlocks--) {
blockPtr = rowPtr + pixelPtr;
for (byte y = 0; y < 4; y++) {
for (byte x = 0; x < 4; x++)
for (byte x = 0; x < 4; x++) {
if (blockPtr >= pixelSize)
break;
pixels[blockPtr++] = pixel;
}
blockPtr += rowInc;
}
@ -243,6 +257,10 @@ const Graphics::Surface *SMCDecoder::decodeFrame(Common::SeekableReadStream &str
pixel = colorTableIndex;
flagMask >>= 1;
if (blockPtr >= pixelSize)
break;
pixels[blockPtr++] = _colorPairs[pixel];
}
@ -288,6 +306,10 @@ const Graphics::Surface *SMCDecoder::decodeFrame(Common::SeekableReadStream &str
for (byte x = 0; x < 4; x++) {
pixel = colorTableIndex + ((colorFlags >> flagMask) & 0x03);
flagMask -= 2;
if (blockPtr >= pixelSize)
break;
pixels[blockPtr++] = _colorQuads[pixel];
}
blockPtr += rowInc;
@ -352,6 +374,10 @@ const Graphics::Surface *SMCDecoder::decodeFrame(Common::SeekableReadStream &str
for (byte x = 0; x < 4; x++) {
pixel = colorTableIndex + ((colorFlags >> flagMask) & 0x07);
flagMask -= 3;
if (blockPtr >= pixelSize)
break;
pixels[blockPtr++] = _colorOctets[pixel];
}
@ -368,8 +394,12 @@ const Graphics::Surface *SMCDecoder::decodeFrame(Common::SeekableReadStream &str
while (numBlocks--) {
blockPtr = rowPtr + pixelPtr;
for (byte y = 0; y < 4; y++) {
for (byte x = 0; x < 4; x++)
for (byte x = 0; x < 4; x++) {
if (blockPtr >= pixelSize)
break;
pixels[blockPtr++] = stream.readByte();
}
blockPtr += rowInc;
}