2015-07-02, 19:34
(2015-07-02, 01:16)noggin Wrote: However whilst luminance heavy content has deinterlaced properly to 50p, saturated, chroma-heavy stuff has appeared to deinterlace to 25p. It's almost as if luminance and chrominance were being deinterlaced separately, and the luma was being deinterlaced to 50p but the chroma to 25p?
Odd. And a tiny bit annoying as a lot of my content originates 4:2:2 and it would be nice to watch it full quality rather than subsampled to 4:2:0 (which is also a pain).
The issue is that the chroma sub-sampling positions for 4:2:0 are different for interlaced and progressive and of course a de-interlacer will expect the interlaced variant.
If you convert from/to 4:2:0 you need to know whether to do interlaced or progressive. By default in the "computer player world" progressive is assumed. Doing this results in interlaced chroma bleeding between fields - which confuses de-interlacers, and can look like you describe - IME what it looks like varies with the de-interlacer and the content/speed/direction etc.
Playing with kodi git from today using gl renderer I can see that ffmpeg is doing a progressive scale - I don't know anything about how kodi calls ffmpeg but from cli ffmpeg experience with interlaced content the words "auto inserted scaler" tend to be bad news.
Code:
16:50:02 T:140492792747776 DEBUG: ffmpeg[7FC707015700]: [src] w:704 h:576 pixfmt:yuv422p tb:1/50 fr:0/1 sar:1/1 sws_param:
16:50:02 T:140492792747776 DEBUG: ffmpeg[7FC707015700]: [auto-inserted scaler 0] w:iw h:ih flags:'bilinear' interl:0
16:50:02 T:140492792747776 DEBUG: ffmpeg[7FC707015700]: [Parsed_yadif_0] auto-inserting filter 'auto-inserted scaler 0' between the filter 'src' and the filter 'Parsed_yadif_0'
16:50:02 T:140492792747776 DEBUG: ffmpeg[7FC707015700]: [auto-inserted scaler 0] w:704 h:576 fmt:yuv422p sar:1/1 -> w:704 h:576 fmt:yuv420p sar:1/1 flags:0x2interl:0 means progressive. As it happens ffmpegs yadif can take 4:2:2 so had the scaler been after it all would have been good. Still 4:2:0 though - I assume kodi gl yuv->rgb doesn't do 4:2:2?
The same happens without de-interlacer enabled.
Random kodi git observations - the preview picture for 422 looks wrong ( I guess it blindly assumes 420). While messing with per vid deint settings they sometimes failed to save - but then maybe I was not always quiing cleanly enough eg.change setting <s> enter on highlighted <exit>
Other thoughts - yadif needs a lot of cpu for HD content fine for SD. I don't know what h/w you use but even though radeonsi vdpau advertises 422 (packed) it doesn't work. It's possible to workaround but not (IIRC) that safe!
