View Single Post
Old 10th June 2010, 13:09   #4  |  Link
nm
Registered User
 
Join Date: Mar 2005
Location: Finland
Posts: 2,641
Quote:
Originally Posted by bernd_b View Post
As far as I understood ffmpeg is of no help because it is build to change the frame rate without altering the length (deinterlace, pull-up/down or simply dropping frames).
Ffmpeg can change the framerate and alter length when the user forces an input framerate, but that only works with input formats which don't have timestamps. That's probably not what you have, so you'd need to use the setpts filter.

MEncoder or some actual muxer tool is probably an easier option. For example, if you're muxing to Matroska, mkvmerge can change the framerate for you.

Quote:
2. I found out that sox has a promising option called "stretch" which claims to alter the lenght of an audio file without changing the pitch
You should first determine how the audio was treated in the Film->PAL conversion. I'd guess that usually audio is stretched simply by speeding up and resampling, so that pitch is altered too. In that case you'll want to do the same in reverse by simply slowing down and resampling back to 48 kHz. Along the encoder, resampling filter is a critical component, so pick it wisely.
nm is offline   Reply With Quote