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TheFluff · 25th January 2012, 03:31

Took a look at the sample file. FFMS2 correctly detects the input as PC range I420 and does no conversions at all. Your ConvertToYV12() line does nothing since the input already is YV12 (I420 is the same thing as YV12 but with the chroma plane order swapped; Avisynth considers the two formats the same for most purposes). I assume that when VirtualDub (or whatever you're screenshotting with) converts the YV12 input to RGB for display, it does so while incorrectly assuming TV range. I added ConvertToRGB32(matrix="PC.709") to the end of the script and then I got mostly the same results as in your 2.16 screenshot (didn't compare exactly but it looks very similar at least). FFVideoSource(..., colorspace="RGB32") gives the same results as well.

If the same script worked in 2.16, what happened there was that you were a victim of that bug I fixed; FFMS2 internally scaled the PC range input to TV range, and by pure chance the rest of your encoding/playback chain happened to assume the input was TV range and thus rescaled it to PC range again for display.

Keep in mind that when you encode with x264 and the input is an Avisynth script, x264 cannot automatically detect the color range. You'll have to tell it to set the fullrange flag appropriately.

25th January 2012, 03:31	#1443 \| Link
TheFluff Excessively jovial fellow Join Date: Jun 2004 Location: rude Posts: 1,100	Took a look at the sample file. FFMS2 correctly detects the input as PC range I420 and does no conversions at all. Your ConvertToYV12() line does nothing since the input already is YV12 (I420 is the same thing as YV12 but with the chroma plane order swapped; Avisynth considers the two formats the same for most purposes). I assume that when VirtualDub (or whatever you're screenshotting with) converts the YV12 input to RGB for display, it does so while incorrectly assuming TV range. I added ConvertToRGB32(matrix="PC.709") to the end of the script and then I got mostly the same results as in your 2.16 screenshot (didn't compare exactly but it looks very similar at least). FFVideoSource(..., colorspace="RGB32") gives the same results as well. If the same script worked in 2.16, what happened there was that you were a victim of that bug I fixed; FFMS2 internally scaled the PC range input to TV range, and by pure chance the rest of your encoding/playback chain happened to assume the input was TV range and thus rescaled it to PC range again for display. Keep in mind that when you encode with x264 and the input is an Avisynth script, x264 cannot automatically detect the color range. You'll have to tell it to set the fullrange flag appropriately.