I regularly use Audacity to record audio and I am delighted like millions of people around the world.
I also use VLC to play videos and I am delighted too.
Looking for a software for dubbing I realized that there is no free application that facilitates the task of dubbing movies. Everything I have found is paid and I would like to teach my students without having to buy additional software.
I think the dubbing task would be very simple if you could synchronize the audacity timeline with the vlc timeline.
The video file would open simultaneously in Audacity and VLC.
Audacity to listen and record audio and vlc to see the images that correspond to that position in the file.
My question is if there is any functionality in audacity, or some plugin that allows sending the position of the timeline of my cursor to other programs. In this case it would be to send it to VLC.
Or if VLC is able to read the position of the timeline cursor in Audacity (You will tell me that this question is better to ask in the VLC forum. I try it here first because I am more confident)
All of this could be simplified if Audacity could play the image associated with an audio file that has been loaded. As far as I know it is impossible and there is no plugin that does this either.
I leave it as an idea to the developers.
This would give Audacity a very large dubbing capacity, of course.
If someone can tell me if something of what I quote above can be done I would be very grateful.
I’d recommend a video editor. Most video editors can do some audio editing too and it’s easier to keep the audio & video in-sync (although the “highly compressed” MPEG-4 variations seem to sometimes have A/V sync problems when editing).
Sometimes I extract the audio from A/V file with Audacity and then put them back together with my video editor. The trick is not to make any edits that affect the timing.
You could open the audio in Audacity and then record the new audio in a new track, syncing both audio tracks before combining the new audio & video.
As far as I know VLC can’t replace the audio track in an A/V file, but maybe you know more than me… There may be some free tools that can do that. If you look for a tool/application, combining audio & video into one file is called “audio/video multiplexing”.
I’ve used Corel Video Studio and I’m “currently” using Cyberlink PowerDirector, although my audio/video computer has died and I’ve ordered a new one. Both of these go for about $100 USD and although it’s a “apples to oranges” comparison, I’d say these basic video editors are not as good as Audacity. 
There are some [u]free audio/video editors[/u] but I don’t have any experience with them. (I’ll probably try a few of them next time I work on a video project.)
Hi @dueronet
I bumped onto this thread via an internet search and I noticed it was not all too old and still a relevant question. As my follow-up quest resulted in some nice finding, I thought it would be good to reply here!
One thing I found that looked interesting is this plugin “vidplayvst” [link removed by moderator. Advertising is not permitted] - which should play video in sync with audio. Though, it unfortunately there is no 32-bit version for MacOS (there is for windows…), so it doesn’t work in Audacity on mac, because “On Windows and Mac OS X, Audacity is a 32-bit application so won’t see 64-bit versions of VST plug-ins, even on 64-bit operating systems.” ( https://wiki.audacityteam.org/wiki/VST_Plug-ins ). I also tried the Audio Unit, but that doesn’t even show up in the list…
There are other windows-only (seemingly free) 32/64 bit VSTs that seem to do the same job, “MediaVST” and “VideoVST” - so that might be more your taste if you’re on Windows (I haven’t tried those).
As I was first unsure if the plugin loading issue was a plugin fault or due to Audacity, I tried it in another DAW I have on my computer: Reaper… A commercial DAW, but cheap (and, try the demo… it actually never really expires…) https://www.reaper.fm/
It worked there, but I was quite surprised that actually Reaper already natively has a video player included, so that’s even better!
More info on video playback (and also on exporting video) in Reaper.
This made me realise that this software is really the best free-ish dubbing option around!
Though, I very much like Audacity, and it has better features to edit audio than reaper (which is more focussed on music production), so it would be great if either the vidplayvst would work one day, or, if someone else builds something similar. I think that under the hood, this plugin is using the same powerful library that is being used by VLC (and ffmpeg too for example): libavcodec. I think that’s an easier way to do it. I guess it also may be technically possible to stream the video to VLC via a cast, but it would be more cumbersome and processor intensive and not yielding more benefits.
I realise I’m diverging a bit from the context of this thread though, as it’s posted in the WIndows forum…
Good luck!
“it would be great if either the vidplayvst would work one day, or, if someone else builds something similar”
There is a Windows build of Audacity with video sync using a customized version of VidPlayVST…
[Link removed as AudaVid appears to be in breach of GPL by failing to provide the source code]
“[Link removed as AudaVid appears to be in breach of GPL by failing to provide the source code]”
AudaVid is free to download and use. It conforms to GPL by providing, in the product download file, a license statement with a link to obtain the source code.
Moderator note: link removed - advertising is not permitted on this Forum. If you continue to post such links you will be banned from the Forum.
I’ve found the object code, and the source code for Audacity 2.3.2, but where is the source code for AudaVid?
Please post a link to the source code of AudaVid.