View Full Version : Fixing pitch and speed on video

2009-10-08, 09:12 AM
I obtained a video and the pitch on it was clearly flat. How does one go about changing the speed on VOB files? What software do I need?

2009-10-08, 10:04 AM
you'd need to demux the vob files into video & audio streams, then import the audio stream into yer audio production prog to adjust the pitch...then import the corrected audio back into a DVD authoring prog to mux/create dvd menu/etc

i usually use ffmpegx or MPEGStreamclip to demux, and then Ableton Live or Logic for audio post work

honestly tho, its a LOT more work than you'd think...unless yer an audio engineer and have the knowledge/gear to do it, i wouldn't waste my time...just my .02

2009-10-08, 10:14 AM
I thought it would be a lot of work. How do you change the speed of the video to keep it in sych?

2009-10-08, 11:01 AM
i wouldn't change the speed of the video, yer gonna have to then re-render which will cause some degradation in quality...you'd want to change the pitch of the audio w/o changing the speed or length, then it'll still sync up with the vid from start to finish

like i said, if you don't have the knowledge/progs to do it, i wouldn't waste my time...to do this *properly*, the pitch will have to be adjusted constantly thruout, as the fluctuations in tape speed are not a set xx amount...not to mention a good bit of $ for the progs, & the time to learn how to do this properly

if this is that rare of a show and you can confirm there's no proper transfer out there, i'd find someone with the equipment/knowledge who's willing to do the work...no offense to you or any other noobs out there, but the art of restoring old audio or video, mixing/mastering/re-mastering, etc is something that takes years of training & practice -- its not something you teach yerself in one month with a couple hundred dollars worth of software ;)

2009-10-09, 12:40 AM
Thank you for your help. The recording in question is Robin Trower at Winterland 11/25/75.

Here is my reason for not wanting to change the pitch of the music without changing the speed (of the video):
I already have software that will change pitch along with speed (which approximates the speeding up or slowing down of the analog tape on wich the recording was certainly done) as well as changing the pitch or speed alone. For the purpose of music, I do not believe in changing either of these factors alone without the other, as the intent is to make the recording represent, to the best that it can, the actual music that was made on that night. To change the pitch without the speed would make the recording sound in line with the key in which I know and have heard the songs done, on record and in live performance. However, the tempo would not fit and would prove to be an inncurate representation of the performance, however slight and (to most), unnoticable, it may be. Authenticity is a great concern of mine, and it is for this reason that I would endeavour to learn the steps (and, though a "noob", have the discipline to learn them) for such an arduous process in order to create the document that is proper for hearing and seeing the closest representation of the show as it was performed in real time.

I know, I'm a bit anal. But I think it goes with the territory in this community. We all want the best documents that we can get of something that occurred. I think we all want to get it just right, you know? I am simply new to trading video. Trading audio, I was always able to respeed things without worrying about it matching a separate video track, and always had good results. I wish to achive the same, authentic result in video.

Again, thank you for your advice, and any more is welcome.