Changing soundtrack on Video.

[Will Martin]

Hi newbie here.
I have ripped an old VHS concert to mpeg2. The sound is of very low quality but I have an MP3 of the concert which is in perfect sync with the video and a flac version which is the best sounding of the two but runs at a slightly different speed. I was wondering if there is a way to get the flac in sync with the video and possibly combine the MP3 and flac into one file to then dub the video. The MP3 whilst not as good as the flac has a lot of detail missing from the flac. Adding the two together could make it the best soundtrack to use. I also don't want to lose the quality of the video. Any advice would be very much appreciated.

Computer spec. Windows 7, Intel Core i5, 6GB RAM and 750GB ram.

[hello_hello]

I have no idea how to replace the audio in an mpeg file, assuming that's what you have, but if you open it with MKVMergeGUI you should be able to add the MP3 audio, deselect the original audio, then save that as an MKV.
MKVMergeGUI should also let you change the video frame rate. If you repeat the above process for the flac file, changing the frame rate slightly might be the easiest way to match it to the audio. Trial and error, maybe. You can also apply a delay to the audio if need be (positive or negative).

You'd need to try to combine the two audio files as a single file using an audio editor such as Audacity first, if you want to combine them, but I'd guess the odds of doing that successfully are something so close to zero they'd effectively be zero. You'd no doubt end up with phasing problems even if you managed to somehow match them up.

MKVMergeGUI should make it fairly easy to experiment with swapping the audio, but I'm not sure what final format you'd prefer.

[Will Martin]

Hi, thanks for the feedback. The tape was recorded to DVD using a Panasonic dmr-es10. The vobs were converted using Mpg2cut2 and cut into clips to preserve video quality for editing. I have changed the tempo of the flac in Audacity matching it with the Mp3. Not sure what phasing is but I think you may be right. Looks like I may have to just use the flac files. The flac files are individual tracks for the songs so will have to alter tempo in each track. I have used Avidemux to join flac and video in one song to test it and it seems to work well. I want to preserve the quality of the original DVD recording with the added benefit of the better sound. This will have to be done using freeware software as I don't have any budget for purchasing software. The finished video will be going back on to DVD. Any further suggestions would be greatly appreciated. Thanks again.