Quote:
Originally Posted by kwag
If your source is DVD, the KVCD you make has exactly the same color space/brightness/contrast.
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It does end up the same colourspace (YV12), but goes through numerous transformations on the way. Usually this is:
YV12 stored on DVD
MPEG2DEC reads YV12 from DVD, converts to YUY2
Avisynth processes in YUY2
VFAPI plugin reads YUY2 from Avisynth, converts to RGB
TMPGEnc reads RGB from VFAPI plugin, converts to YV12
YV12 stored on VCD
Each conversion introduces errors, except for the initial YV12->YUY2 if it's done right. This is one of the reasons people are excited about Avisynth 2.5, which has native support for YV12. With it, the process would look like:
YV12 stored on DVD
MPEG2DEC reads YV12 from DVD
Avisynth processes in YV12
VFAPI plugin reads YV12 from Avisynth, converts to RGB
TMPGEnc reads RGB from VFAPI plugin, converts to YV12
YV12 stored on VCD
Which of course is better but still not perfect. This is the ideal process, as used by most 2.5 testers right now:
YV12 stored on DVD
MPEG2DEC reads YV12 from DVD
Avisynth processes in YV12
VDub mod reads YV12 from Avisynth
XViD reads YV12 from VDub, compresses
YV12 stored in MPEG-4 file
Perfect colour fidelity. Time for us to petition for support for YV12 source material in TMPGEnc
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