25fps to 24fps software that fixes pitch shift

[zoidberg]

Audacity doesn't include the ac3 decoder, you have to install it.

Edit: What spoRv said.

[Stamper]

Yes it does, you have to download additional stuff and install.

I think my problem has to do with drop frames or something. There is/was another framerate beside NTSC which is what make it hard to conform.

[SpaceBlackKnight]

Using Audacity for correcting PAL sped up audio back to 23.97/24 fps rate is easy peasy lemon squeezy, its converting 25fps video (non ghosted, don't start me on field blended shit as I haven't figured that out yet) back to 23.97/24 that's much harder for a novice like me, until I found a secret sauce I came up with.

If the video is at 1080i 50hz (usually sped up and not a field blended shit fest), 1st thing to do would be to use an external converter program to convert it's audio to WAV then use the speed and pitch tab to decrease the rate by -4,096, which brings it back to 24fps then export. For the video content, I deinterlace (BOB) and detelecine using Vidcoder at 25fps to get clean, progressive frames, then take that file into Tsmuxer, tick the change frame rate box and select 24000/1001, then drop in the WAV file you corrected in Audacity and mux. This is what I did to correct the 25fps transfer for Umbrella's Razorback BD back to 24fps and it's perfect with no dropped frames plus the sound runs proper and in sync (despite being in wave 5.1 PCM instead of DTS-MA which has no free conversion alternative).

[deleted user]

Stupid question but why would the pitch need to be corrected? Do movie studios adjust the pitch for 25fps material? I would have thought they just play the tape/film faster which would of course also create a pitch shift - but that pitch shift would simply vanish when you change the speed/sampling rate back to the 24 fps base - all you would need to do to be standards compliant then is to resample the result with a quality SRC

[Feallan]

Stupid question but why would the pitch need to be corrected? Do movie studios adjust the pitch for 25fps material? I would have thought they just play the tape/film faster which would of course also create a pitch shift - but that pitch shift would simply vanish when you change the speed/sampling rate back to the 24 fps base - all you would need to do to be standards compliant then is to resample the result with a quality SRC

I have audio captures of Polish PAL VHS Star Wars tapes, which appear to have had the pitch corrected, so correcting the pitch is needed at least sometimes.

By the way, are this settings correct for adjusting the pitch from 25 to 23.976 fps (Audition, iZotope Radius algorithm):

Stretch 104,27%
Pitch shift 0,72 semitones

Pitch coherence left at 1
Vocoder mode and Preserve speech characteristics checked

[Booshman]

Similar thing with the making of Superman 2 on the bluray. They pitched down the already correct audio.

[zoidberg]

The AAWIL remix was pitch shifted as well, but that was literally the least of its worries.

[Stamper]

Is there a different % when you go from Pal to 24fps? Because I have a Pal DTS track i want to sync to a blu ray that is 24fps and not 23.976. I tried already at -4.096 and it's sightly out of sync.

[Falcon]

Audacity doesn't switch channel order, as long as you don't want to...

Advice: of course importing a lossy file (AC3, DTS) will be, well... lossy? so it's futile to use an higher bitrate than the input file... when I do a frame rate conversion, the bitrate of the converted file is always the same as the bitrate of the source one.

Hi, I was wondering about this.
If I slow down my AC3 track without correcting the pitch, can a higher rate better maintain quality?
During the slowdown, the sound becomes low-pitched, so the track no longer has the same quality and effect.
New curves on the sound spectrum must appear I think, and add more bitrate than before would keep these "improvements" in theory

[Stamper]

I agree what I do is I recode to DTS half bitrate when working from a lossy track. DD+ 640kbps also can do the trick.