Forum Archive Home -> Video Conversion -> YV12 to RGB color problem
YV12 to RGB color problem |
| wydesenej posted 2009 Oct 30 03:39 |
| Hi,
iam using unix avifile lib to convert YV12 Divx frame to RGB. I attach image of my outup. Left image is real frame from video and right image is my output. If you have any suggestions to solve this problem please post. Thx, wydesenej colors.png |
| pandy posted 2009 Oct 30 04:44 |
| arithmetic without saturation - enable clamp, choose different color space coefficients
more on this http://en.wikipedia.org/wiki/Saturation_arithmetic also problem with chroma planes (swapped Cb with Cr? looks like NOT or XOR values) |
| jagabo posted 2009 Oct 30 08:42 |
It looks like your luma channel is being multiplied by 2 and isn't being clamped -- ie, when values go above 255 they are wrapping back down to 0. It also looks like the chroma channels are reversed. Here's your left image with the chroma channels reversed, converted to RGB, then all primaries multiplied by 2 (with clamping):
Notice how all the dark areas are the same as your right image. The light areas are clamped here so they don't wrap around to black, they're just full out white. |
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