+- Selur's Little Message Board (https://forum.selur.net)
+-- Forum: Hybrid - Support (https://forum.selur.net/forum-1.html)
+--- Forum: Problems & Questions (https://forum.selur.net/forum-3.html)
+--- Thread: How to deal with NTSC 99.9% progressive dvd of films shot in 24p? (/thread-3727.html)
How to deal with NTSC 99.9% progressive dvd of films shot in 24p? - remek - 03.06.2024
Is there any way to avoid audio/video desync when removing pulldown tags? I couldn't find that option in Hybrid by the way, is it hidden somewhere?
So I used TSMuxer and eac3to to remove pulldown tags but the audio, especially in the end, becomes about half a second out of sync with the video because the resulted 23.976fps progressive video stream is one second shorter than the original 29.97 mpeg2 container.
TSMuxer reports the source of these issues during pulldown remove process:
at about 30%:
Warning! Source stream contain irregular pulldown marks. Mistiming between original fps and fps/1.25(without pulldown) exceed 100ms.
Warning! Source stream contain irregular pulldown marks. Mistiming between original fps and fps/1.25(without pulldown) exceed 200ms.
then at about 75%:
Warning! Source stream contain irregular pulldown marks. Mistiming between original fps and fps/1.25(without pulldown) exceed 400ms.
I checked the original 29.97fps container with DGIndex analyzer and it reports that the MPEG2 stream is 99,97% progressive, the rest is somehow interlaced.
The funniest thing is that when I play the original video with pulldown tags (dvd remux made with makemkv) in Media Player Classic I can see that it plays the video at progressive frame rate about 24p and has no audio sync issues. Does it mean that there is a way to make this NTSC dvd video 23.976/24p and get rid of pull down tags if Media Player Classic can do that in real time?
According to MediaInfo the original video stream is 23.976 (24000/10001)fps Scan type: Progressive, Scan order: 2:3 Pulldown
RE: How to deal with NTSC 99.9% progressive dvd of films shot in 24p? - Selur - 04.06.2024
That is what is called 'forced' telecine.
I don't think you can simply remove the pulldown flag, reencoding is needed.
(In Hybrid, you couldn't enable 'DGDecNV support' + overwrite scan type to '(soft) telecine', so the DGDecNV source filter would apply handle it, alternatively simply overwrite the content to 'telecine' (assuming Hybrid detected it as 29.97fps interlaced).
RE: How to deal with NTSC 99.9% progressive dvd of films shot in 24p? - remek - 04.06.2024
Hybrid detects it as telecine by default, but it seems to me it applies the filters for hard-telecine content even though my dvds are soft telecine (no visible interlace) which results in 20p frame rate and chopped movements. I can upload one mkv file (1,5gb), perhaps you could take a look to find the best way to encode it to 23.976/24p lossless (ffv1) in Hybrid without audio desync issues if it is not possible to simply remove correctly the pulldown flags from mpeg2?
Maybe I should remove the same amount of time (less than 1 second) from ac3 sound track to make it the same lenght as video to fix the desync issue when I simply remove pulldown tags from mpeg2 stream?
RE: How to deal with NTSC 99.9% progressive dvd of films shot in 24p? - Selur - 04.06.2024
I can look at it if you send me a link.