GRAPHICS: Make YUV410 conversion code use bilinear interpolation

SVQ1 no longer looks blocky and now looks a lot closer to what QuickTime outputs
This commit is contained in:
Matthew Hoops 2012-04-14 17:06:31 -04:00
parent 870ab35f5b
commit 473a09786d
3 changed files with 47 additions and 31 deletions

View File

@ -300,19 +300,8 @@ void convertYUV420ToRGB(Graphics::Surface *dst, const byte *ySrc, const byte *uS
convertYUV420ToRGB<uint32>((byte *)dst->pixels, dst->pitch, lookup, ySrc, uSrc, vSrc, yWidth, yHeight, yPitch, uvPitch);
}
#define OUTPUT_4_PIXEL_COLUMN() \
PUT_PIXEL(*ySrc, dstPtr); \
PUT_PIXEL(*(ySrc + yPitch), dstPtr + dstPitch); \
PUT_PIXEL(*(ySrc + (yPitch << 1)), dstPtr + dstPitch * 2); \
PUT_PIXEL(*(ySrc + (yPitch * 3)), dstPtr + dstPitch * 3); \
ySrc++; \
dstPtr += sizeof(PixelInt)
template<typename PixelInt>
void convertYUV410ToRGB(byte *dstPtr, int dstPitch, const YUVToRGBLookup *lookup, const byte *ySrc, const byte *uSrc, const byte *vSrc, int yWidth, int yHeight, int yPitch, int uvPitch) {
int quarterHeight = yHeight >> 2;
int quarterWidth = yWidth >> 2;
// Keep the tables in pointers here to avoid a dereference on each pixel
const int16 *Cr_r_tab = lookup->_colorTab;
const int16 *Cr_g_tab = Cr_r_tab + 256;
@ -320,26 +309,44 @@ void convertYUV410ToRGB(byte *dstPtr, int dstPitch, const YUVToRGBLookup *lookup
const int16 *Cb_b_tab = Cb_g_tab + 256;
const uint32 *rgbToPix = lookup->_rgbToPix;
for (int h = 0; h < quarterHeight; h++) {
for (int w = 0; w < quarterWidth; w++) {
register const uint32 *L;
for (int y = 0; y < yHeight; y++) {
for (int x = 0; x < yWidth; x++) {
// Perform bilinear interpolation on the the chroma values
// Based on the algorithm found here: http://tech-algorithm.com/articles/bilinear-image-scaling/
// Feel free to optimize further
int targetX = x >> 2;
int targetY = y >> 2;
int xDiff = x & 3;
int yDiff = y & 3;
int index = targetY * uvPitch + targetX;
int16 cr_r = Cr_r_tab[*vSrc];
int16 crb_g = Cr_g_tab[*vSrc] + Cb_g_tab[*uSrc];
int16 cb_b = Cb_b_tab[*uSrc];
++uSrc;
++vSrc;
byte a = uSrc[index];
byte b = uSrc[index + 1];
byte c = uSrc[index + uvPitch];
byte d = uSrc[index + uvPitch + 1];
OUTPUT_4_PIXEL_COLUMN();
OUTPUT_4_PIXEL_COLUMN();
OUTPUT_4_PIXEL_COLUMN();
OUTPUT_4_PIXEL_COLUMN();
byte u = (a * (4 - xDiff) * (4 - yDiff) + b * xDiff * (4 - yDiff) +
c * yDiff * (4 - xDiff) + d * xDiff * yDiff) >> 4;
a = vSrc[index];
b = vSrc[index + 1];
c = vSrc[index + uvPitch];
d = vSrc[index + uvPitch + 1];
byte v = (a * (4 - xDiff) * (4 - yDiff) + b * xDiff * (4 - yDiff) +
c * yDiff * (4 - xDiff) + d * xDiff * yDiff) >> 4;
int16 cr_r = Cr_r_tab[v];
int16 crb_g = Cr_g_tab[v] + Cb_g_tab[u];
int16 cb_b = Cb_b_tab[u];
const uint32 *L;
PUT_PIXEL(ySrc[x], dstPtr);
dstPtr += sizeof(PixelInt);
}
dstPtr += dstPitch * 3;
ySrc += (yPitch << 2) - yWidth;
uSrc += uvPitch - quarterWidth;
vSrc += uvPitch - quarterWidth;
dstPtr += dstPitch - yWidth * sizeof(PixelInt);
ySrc += yPitch;
}
}

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@ -67,6 +67,11 @@ void convertYUV420ToRGB(Graphics::Surface *dst, const byte *ySrc, const byte *uS
/**
* Convert a YUV410 image to an RGB surface
*
* Since the chroma has a very low resolution in 410, we perform bilinear scaling
* on the two chroma planes to produce the image. The chroma planes must have
* at least one extra row that can be read from in order to produce a proper
* image (filled with 0x80). This is required in order to speed up this function.
*
* @param dst the destination surface
* @param ySrc the source of the y component
* @param uSrc the source of the u component

View File

@ -191,14 +191,18 @@ const Graphics::Surface *SVQ1Decoder::decodeImage(Common::SeekableReadStream *st
for (int i = 0; i < 3; i++) {
int width, height;
if (i == 0) {
width = yWidth;
width = yWidth;
height = yHeight;
current[i] = new byte[width * height];
} else {
width = uvWidth;
width = uvWidth;
height = uvHeight;
}
current[i] = new byte[width * height];
// Add an extra row's worth of data to not go out-of-bounds in the
// color conversion. Then fill that with "empty" data.
current[i] = new byte[width * (height + 1)];
memset(current[i] + width * height, 0x80, width);
}
if (frameType == 0) { // I Frame
// Keyframe (I)