Fix mp4 fps without re-encoding?

[TubeBar]

I purchased the entire 1983 & 1984 He-Man Classic Series from iTunes but they are PAL 25fps sped-up, no idea why they used the PAL masters?

I removed the DRM and it's basically just an mp4 container renamed to m4v w/ some unknown subtitle format in there. I was able to repack to mp4 using mp4box but if I change the speed to 24fps or 23.976fps it doesn't seem to work.

Is there anyway of changig the fps w/o having to re-encode all of these? There's 130 episodes no way I am going to re-encode all of those. I don't want to buy the DVD as it is rumored to be a PAL to NTSC conversion so just as bad.

[Baldrick]

What does MediaInfo say aftet you adjusted the fps header with mp4box?

[TubeBar]

It says 23.976 or 24fps but when I play it in Quicktime the video is all green, same with windows media player. I would THINK it's just changing the speed so what's the big deal? But it doesn't like it.

[racer-x]

What do you think will happen when you slow the video to 96%, yet keep the audio at 100%? You can use your imagination...

[mail2tom]

FWIW, a few years ago I read a thread about anime conversion, on web site with a name long forgotten, which described something similar (including recovery of subtitle tracks). The author used TFM Audio Tool to slow down the audio from 25 to 23.976 and converted it from AAC/MP3/WAV to AC-3. To recover the subtitles he used CCextractorGUI on the m4v file and subframerate (Subtitle Framerate Changer) to adjust the subtitles from 25 to 23.976. The final step was to use MKVMerge by loading the original m4v, uncheck the audio stream, add the new AC-3 audio and new subtitles, highlight the video stream and under the "format specific options" tab adjust the FPS to 24000/1001, then "start muxing" to a MKV container.

It's a process that has many "moving parts" but gave satisfactory results in the end. Sometimes the audio pitch needed tweaking (which can be done in TFMAudio), but again, eventually gave satisfactory results. In my experience I found that video which was VFR and not CFR often resulted in audio/video synch issues. YMMV.

[TubeBar]

FWIW, a few years ago I read a thread about anime conversion, on web site with a name long forgotten, which described something similar (including recovery of subtitle tracks). The author used TFM Audio Tool to slow down the audio from 25 to 23.976 and converted it from AAC/MP3/WAV to AC-3. To recover the subtitles he used CCextractorGUI on the m4v file and subframerate (Subtitle Framerate Changer) to adjust the subtitles from 25 to 23.976. The final step was to use MKVMerge by loading the original m4v, uncheck the audio stream, add the new AC-3 audio and new subtitles, highlight the video stream and under the "format specific options" tab adjust the FPS to 24000/1001, then "start muxing" to a MKV container.

It's a process that has many "moving parts" but gave satisfactory results in the end. Sometimes the audio pitch needed tweaking (which can be done in TFMAudio), but again, eventually gave satisfactory results. In my experience I found that video which was VFR and not CFR often resulted in audio/video synch issues. YMMV.

Thanks actually this process worked. Unfortunatly iTunes won't load MKV (I use Apple TV) but at least for my PC this works. I think I will buy a Roku since it's not that much and not having support for MKV has been such a pain.

I didn't need to fix the pitch as far as I can tell they never fixed it to start with but it's hard to know for certain since no NTSC masters exist.

[TubeBar]

What do you think will happen when you slow the video to 96%, yet keep the audio at 100%? You can use your imagination...

Yea that would be a problem, so I used TFM as suggested to fix that. It's easy t use and has a 25fps to 23.976 setting