need help for 23.976 to 25 pal and vice versia

[inferno6a]

I converted a 23.976fps video file into 25fps dvd Pal by using "Assumefps(25,true) which cause the show to paly faster(shorter duration) including audio and a shift in pitch. Now I want to try converting the 25fps dvd video file back to the 23.976 fps avi using perhaps virtualdubmod and avisynth which will result in a avi file with the original video and audio speed(with "assumefps" again).

I tried using nic's mpegdecoder.dll but it only retrieve the video part for me in virtualdub mod. Can someone give me some direction on how to get both the audio and video into virtualdub through avisynth ?(cause i need to use the "assumefps"function ) Or is it impossible?

[Guest]

Please read and follow forum rules, specifically, rule 9: use a proper thread title. Thank you.

http://forum.doom9.org/forum-rules.htm

[foxyshadis]

You should be able to use dgdecode, mpeg2source returns audio and video. You can then resample the audio in your script, no need to save it off and remux it.

[Guest]

mpeg2source returns audio and videoYou need a separate audio source call, e.g.:

vid=mpeg2source()
aud=WAVSource()
audiodub(vid,aud)

[Chainmax]

Why not just encode the video as 23.976 NTSC FILM and then use DGPulldown to flag it to 29.97fps?

[inferno6a]

Sorry about the improper title. And thanks for the help. I manage to reverse what i had done by following the suggestions given above.

And is it possible to flag a 23.976 film to 25 pal using dgpulldown and play it fine? And in the future if I am going to reconvert it back into avi, can I get back to 23.976 ? [ converting videos for relatives to watch on dvd players but maybe considering archiving them back into avi or mkv in future when too much pile up]

[Kika]

And is it possible to flag a 23.976 film to 25 pal using dgpulldown and play it fine?

Not really, the playback signal will be interlaced because of the fill in fields. On a CRT-TV, this isn't important, but on a LCD- or Plasma-TV - that's a different story. This type of TVs has to deinterlace such videos, and this can result in jerkyness and blendings.

[Chainmax]

Why is it so important to have 25fps?

[inferno6a]

cause people around me mainly have a pal tv set. so encoding videos file to dvd pal mode for them. But thinking about problems I am going to face if I decide to archive them back as avi in future

Not really, the playback signal will be interlaced because of the fill in fields. On a CRT-TV, this isn't important, but on a LCD- or Plasma-TV - that's a different story. This type of TVs has to deinterlace such videos, and this can result in jerkyness and blendings.

So dgpulldown will totally interlace a progressive show ? or only those fields that it added during playback.

[Kika]

or only those fields that it added during playback.

Only during playback extra fields will be added. For a playback device (TV) this looks exactly like interlaced Video.

[inferno6a]

Only during playback extra fields will be added. For a playback device (TV) this looks exactly like interlaced Video.

Sorry but I still do not understand. The techique use by dgpulldown is similar to what commercial NTSC DVD used right?(or maybe i misunderstood) If I play a commercial Ntsc dvd or a dvd i burnt on my own that uses pulldown flags to acheive the correct framerates, are you saving I am not getting progressive output on my LCD tv using component cables?
Or is it only commercial ones give progressive output while output by dgpulldown are interlace , they are different totally?

[foxyshadis]

NTSC and PAL are not progressive, they live and die interlaced so everything's still displayed one field at a time. But if the TV and the DVD player both support 24p playback, they can quietly ignore the pulldown. It's not really NTSC input then. (Presumably, a TV could decode pulled-down input into progressive display, but I don't know whether any do.) I don't have one myself so I don't know the mechanics, maybe it only works over s-vhs or optical.

[manono]

Hi-

but on a LCD- or Plasma-TV - that's a different story. This type of TVs has to deinterlace such videos, and this can result in jerkyness and blendings.

For a playback device (TV) this looks exactly like interlaced Video.

Depends on the player, Kika. If you have a progressive display and a progressive scan DVD player, and you're outputting 480p or 576p from the player, then the "IVTC" or deinterlacing takes place in the player, and whether it outputs non-deinterlaced progressive frames, or deinterlaced progressive frames depends on the quality of the player. Most will deinterlace, you're right. It can still look good, without any blending, depending on the quality of the player's deinterlacer. My player outputs non-deinterlaced progressive frames, with no stutter or blending. That is, it reassembles the progressive frames from the fields and drops the dupe frames. And if you output 480i or 576i, then it's up to the IVTC or deinterlacing capabilities of the TV, but in general, this is best left up to a good progressive scan DVD player.

Presumably, a TV could decode pulled-down input into progressive display, but I don't know whether any do

More and more of them these days have 3:2 pulldown detection capabilities. Mine does, but I let the player do it, because it also outputs 720p to the TV set, foxyshadis.

As Kika said earlier, interlaced displays don't have any problems at all with the DGPulldown output. If you have a progressive display, you'd also best have a good DVD player to output with the best quality. But this is true for a lot of DVDs around, and not just the ones that were run through DGPulldown with 23.976->25fps. If you like to watch anime or TV series DVDs on your nice new HDTV, you'd better have a good DVD player (not the crappy Philips DVP-642 or similar), because so much of it is hard telecined, or slips back and forth between film and hard telecine. A lousy player will just deinterlace it, with varying results.

[Kika]

Depends on the player, Kika.

Agreed...

I have two players with progressive scan capability and the results are very different. My Denon 2910 does not have problems with 23.976->25 via DGPulldown, but that NeuNeu-thing has. If i use a player without progressive scan my TV (Loewe Xelos A37) also has no problems with videos like that - as long as i don't use it's vector based motion interpolation. On Pulldown videos i have to deactivate this feature to get good results.