24fps file

[carlmart]

In the past, when I used Procoder, it was easier. It made all my conversions to what I needed back then: 29.97 fps.

Now I can choose 25fps and 29.97fps for my DVDs, which has saved me from artifacts when going from PAL to NTSC. It has allowed me using Avisynth in more transparent conversions.

At the moment I have an MKV file that is 24fps according to Mediainfo. What should I convert it to in order to have less visible artifacts? 25 or 29.97? How should I do it through Avisynth? What about the audio?

[guns1inger]

I would posit that your process so far has been flawed, and has not produced optimal results.

I would encode the MKV file to NTSC resolutions at 23.976 fps, then apply pulldown to get 29.970 fps playback. Encoding at either 25 fps or 29.970 fps will not give you the best result (unless, by chance, the source was originally a PAL video shot at 25 fps - unlikely, but possible)

[manono]

At the moment I have an MKV file that is 24fps according to Mediainfo. What should I convert it to in order to have less visible artifacts? 25 or 29.97?

Neither. If it's really 24fps, encode it at 24fps and then run the result through DGPulldown set for 24->29.97fps. That way you don't have to stretch the audio. If it's already AC3 audio, you can author with it as-is.

That's for an NTSC DVD. If you want to make it PAL, encode at 24fps and apply DGIndex afterwards for 24->25fps.

And I pretty much agree with guns1inger - if you allow Procoder to change the framerate, the results are most likely sub-optimal.

Edited later to remove DGIndex because I meant to say DGPulldown.

[guns1inger]

I have seen quite a few mkv files that report being 24fps but that are actually 23.976 fps. I have little faith in the accuracy of the MKV format details.

[carlmart]

I would posit that your process so far has been flawed, and has not produced optimal results.

Guess you mean they were flawed when I converted from 25 to 29.97, right? As I said, since having a dual-system DVD player and TV I don't do that anymore.

I would encode the MKV file to NTSC resolutions at 23.976 fps, then apply pulldown to get 29.970 fps playback. Encoding at either 25 fps or 29.970 fps will not give you the best result (unless, by chance, the source was originally a PAL video shot at 25 fps - unlikely, but possible)

OK. Although what is suggested by Manono looks interesting too. What do you think?

I have seen quite a few mkv files that report being 24fps but that are actually 23.976 fps. I have little faith in the accuracy of the MKV format details.

In this case it does seem to be 24fps, because by distraction I did convert it to m2v with avisynth and DVD Lab Pro is saying it's 24 fps and won't process it.

My concern is to have very little or none conversion artifacts.

[carlmart]

[quote="manono"]

Neither. If it's really 24fps, encode it at 24fps and then run the result through DGIndex set for 24->29.97fps. That way you don't have to stretch the audio. If it's already AC3 audio, you can author with it as-is.

Thanks, I'm already doing that as we speak.

That's for an NTSC DVD. If you want to make it PAL, encode at 24fps and apply DGIndex afterwards for 24->25fps.

I want to avoid such PAL<>NTSC conversions in the future, if I can.

And I pretty much agree with guns1inger - if you allow Procoder to change the framerate, the results are most likely sub-optimal.

I am not using Procoder anymore. Avisynth processing is much cleaner and transparent, with close to none conversion artifacts. Now I have a 42" plasma screen, and I can see problems much better.

[jagabo]

[quote="manono"]

If it's really 24fps, encode it at 24fps and then run the result through DGIndex set for 24->29.97fps.

I think he meant to say DgPulldown, not DgIndex. Encode progressive at the source's frame rate (be it 23.976 of 24) then use DgPulldown to add pulldown flags for the DVD player.

[manono]

In this case it does seem to be 24fps, because by distraction I did convert it to m2v with avisynth and DVD Lab Pro is saying it's 24 fps and won't process it.

I wouldn't really call that hard evidence. It'll be whatever framerate you set in the encoder and/or the script. Why would you give any authoring app a non-compliant video to author anyway, whether 23.976fps or 24fps?

I have seen quite a few mkv files that report being 24fps but that are actually 23.976 fps. I have little faith in the accuracy of the MKV format details.

Yeah, that's why I emphasized the 'really'. If the original source of the thing was DVD or TV broadcast, then almost by definition it can't be 24fps. I was leaving open the possibility of it being someone's home movies or something like that.

I think he meant to say DgPulldown, not DgIndex. Encode progressive at the source's frame rate (be it 23.976 of 24) then use DgPulldown to add pulldown flags for the DVD player.

Oops, thanks for the correction. I'll edit the original post.

[carlmart]

Yes, of course I got it was DGPulldown that I would have to use. And I did.

Results look in sync, though sound appear to be a bit delayed. I will try correcting that and see if it's total or gradual. I think it's the former.

[guns1inger]

If you have encoded at the original framerate and then used DGPulldown correctly there should be no sync issues, as the actual running time has not changed.

[carlmart]

If you have encoded at the original framerate and then used DGPulldown correctly there should be no sync issues, as the actual running time has not changed.

You're right. Running time is exactly the same. I also tested delaying or advancing the sound and seeing how it looked, and it does sync better in some places and worst in others. The original looks fine.