Video: When importing video with multiple soundtracks, REAPER only recognize one.
Hi There,
When I import a video with TWO sound tracks (4 channels) into REAPER, it can only recognize ONE.
Like this:
However in Audition (and Video players) we can see that the video has totally 4 audio channels. Many films with multiple Language tracks would use this method to encode sound track.
And when I export the sound from Audition and import it to REAPER, it can recognize all 4 Channels!
So I guess is there anything was missed when importing video? Please support importing multiple sound tracks of a video.
(BTW I wrote it on FR before, but I think it's more like.. sort of a bug or design flaw?)
Reaper imports multi channel but actually not multi tracks. To get around until this feature gets implemented you could just use a demuxer to separate video from audio before importing into Reaper. MKVtoolnix, MP4Muxer and mp4creator are tools which allow in a second to split video from audio.
But of course multi track import would be cool in Reaper. But I'm not sure how often this is needed.
Reaper imports multi channel but actually not multi tracks. To get around until this feature gets implemented you could just use a demuxer to separate video from audio before importing into Reaper. MKVtoolnix, MP4Muxer and mp4creator are tools which allow in a second to split video from audio.
But of course multi track import would be cool in Reaper. But I'm not sure how often this is needed.
Greetings
Eli
Yay, maybe I'm confusing "sound tracks" and "channels".
For now I would just use other software to extract sound tracks, thanks for your recommends!
The ‘-c copy’ part is there so that we’re just taking the video out of one container (MKV) and putting it into another (MP4) without reecoding, which would be slow and lossy.
This time we’re not simply taking the audio out of one container and putting it into another; we’re actually reencoding to WAV. Typically the MKV included audio in AAC and we could use ‘-c copy’ to extract the AAC without reencoding, but I tried to work with AAC in REAPER and it didn’t go well, for example, I’d make edits and the audio would go out of sync. Reencoding isn’t as big a deal with audio as it is with video because it’s super-fast and we don’t lose quality, as we’re going from a more compressed stream (AAC) to a less compressed stream (WAV).
Programs such as OBS may record in stereo even if the source was mono, for example, a microphone. With the command above we’re extracting a single channel and creating a mono WAV. The ‘0.1’ corresponds to the stream (the thing that was ‘0:1’ in the examples above); the final ‘.0’ means channel 0 (that is the left channel in a stereo stream).
The example above is a single command that extracts all the relevant parts of a multitrack recording and produces files that are ready to edit in REAPER.
EDIT: the manual method using ffmpeg worked! still it'd be great to get the reaper script working...
Quote:
Originally Posted by leafac
I developed a better solution: a ReaScript that explodes these multi-track audio files into single-track files right from REAPER:
I also live-streamed the whole development process for those interested in coding, Lua, and so forth.
@Leandro, first off, thanks for all your scripts and videos, they're always super helpful.
Unfortunately, I'm having an issue running this script. I'm attempting to explode the audio an MP4 video as you show in your video. It is encoded withe the following codecs:
Code:
Timecode, Linear PCM, HEVC
There should be 4 tracks of audio (I can verify that in VLC and when opening with adobe audition), but when I run the script, it attempts to make 5 audio streams (the first 4 files are 0 bytes, and the 5th is 20 bytes) and i get the following error:
Thanks for the nice words. I’m happy that my code & videos are helpful to you.
The issue doesn’t seem to be coming from the script, but from ffmpeg. The script is a glue to call ffmpeg from within REAPER, but the actual work of exploding media is done by ffmpeg.
ffmpeg is this command-line tool that can convert between several audio/video formats, and is used under the hood by everything from desktop applications to YouTube.
The error message from ffmpeg seems to indicate that the codecs in your file aren’t supported. See, for example, how it says “Function not implemented”.
I wonder if this is still an issue in the latest versions of ffmpeg. Can you please test this for us?
I developed a better solution: a ReaScript that explodes these multi-track audio files into single-track files right from REAPER:
I also live-streamed the whole development process for those interested in coding, Lua, and so forth.
Wow thanks leafac!
This script is really helping me prepare some screen recordings / tutorials for a Game Audio Talk that I'll have later this week. Great work!
@leafac
How does your script handle mkv with six tracks/streams of WAV 24-bit?
Just want to know if it does any lossy conversion to audio when WAV at 24-bit is already present?
Would like to be sure that there is no conversion happening with original audio while importing to Reaper. It seems as if it is always generating WAV with 16-bit...