OBS Only Exporting 1 Audio Track

[Professor Dabs]

Hey guys, I'm trying to use obs studio to record for a podcast, and exporting my desktop audio and microphone in separate tracks so I can edit my voice without touching the audio. However, only one track is being captured and exported. I have advanced settings on and both tracks are selected for exporting, as well as having the devices set to capture to those specific tracks. Of course, both sources are added in my scene too. Does anyone have an idea of what the issue is?

When I convert the video to mp3 using vlc player and import into audacity for editing I only see the one track, and it is my microphone only. No desktop audio to be found. There is also only one track to be selected inside vlc player.

 

[koala]

Post a log that contains a recording session that created a video with only one track. You posted screenshots of your configuration, and they all look fine, but the log file will contain information about what actually happened during recording.

 

[Professor Dabs]

Post a log that contains a recording session that created a video with only one track. You posted screenshots of your configuration, and they all look fine, but the log file will contain information about what actually happened during recording.

Here is my most recent log for my test recordings. Hopefully something can be found in there.

 

[koala]

According to your logs, you configured your audio sources twice. First is in Settings->Audio as global source, and you added them another time as audio input capture and audio output capture directly in the scene. Configure them only once, either global or in the scene, but not in both. Recommended is as global audio source. Then again check the sources-to-track matrix in advanced audio properties.

But you really write 2 audio tracks to the video file:

08:13:51.801: ---------------------------------
08:13:51.802: [FFmpeg aac encoder: 'Mic'] bitrate: 160, channels: 2, channel_layout: 3
08:13:51.802:
08:13:51.805: ---------------------------------
08:13:51.805: [FFmpeg aac encoder: 'Desktop Audio'] bitrate: 160, channels: 2, channel_layout: 3
08:13:51.805:
08:13:51.831: ==== Recording Start ===============================================
08:13:51.831: [ffmpeg muxer: 'adv_file_output'] Writing file 'C:/Users/Anthony Austin/Videos/2022-01-29 08-13-51.mp4'...

Check with MediaInfo or with ffprobe (comes with ffmpeg) which tracks are actually contained in the video file.

 

[Professor Dabs]

According to your logs, you configured your audio sources twice. First is in Settings->Audio as global source, and you added them another time as audio input capture and audio output capture directly in the scene. Configure them only once, either global or in the scene, but not in both. Recommended is as global audio source. Then again check the sources-to-track matrix in advanced audio properties.

But you really write 2 audio tracks to the video file:

08:13:51.801: ---------------------------------
08:13:51.802: [FFmpeg aac encoder: 'Mic'] bitrate: 160, channels: 2, channel_layout: 3
08:13:51.802:
08:13:51.805: ---------------------------------
08:13:51.805: [FFmpeg aac encoder: 'Desktop Audio'] bitrate: 160, channels: 2, channel_layout: 3
08:13:51.805:
08:13:51.831: ==== Recording Start ===============================================
08:13:51.831: [ffmpeg muxer: 'adv_file_output'] Writing file 'C:/Users/Anthony Austin/Videos/2022-01-29 08-13-51.mp4'...

Check with MediaInfo or with ffprobe (comes with ffmpeg) which tracks are actually contained in the video file.

I deleted the scene and made a new one since I figured that would 'refresh' the sources, but it still didn't work. I'm not sure what to do.

 

[WBE]

Within OBS Studio one can set Global Audio Devices. These will capture audio and stream/record it regardless of which scenes are used.

That can be useful when having a lot of scenes that all need the sound of a microphone, usb connected external sound board, gameplay sound etc. so you don't have to insert things repeatedly into all you scenes.

OBS also provides the possibility to add audio sources to your individual scenes. That might be useful when you don't want specific audio in every scene i.e. when showing fullscreen videoclips. This way you have direct control (and it it visible) which audio sources go into which specific scene.

Of course when using global audio devices one can set a hotkey to mute the microphone, but by using the per scene audio souces one does not need to remember to mute and unmute every time. Downside: you might have to add them over 30 times...

You should not use both, as koala explained. That way the net result is that you stream/record your microphone and other sounds twice. So delete one of them. Based on your use case of using only one scene all the time, it does not matter which one to choose. My personal taste/preference would be to have everything visible in the scene (so all global audio devices set to Disabled) but you can as well have it the other way around.

After this adjustment please recheck your Advanced Audio Properties for setting everything to the correct channels.
Then do a retest and post the new log file please.

 

[FerretBomb]

It's when you convert from video to MP3 in VLC that it's only taking the 'active' audio track. MP3 does not support multitrack audio. Importing the original video into an NLE suite SHOULD show both audio tracks.

Another side note, NEVER RECORD TO MP4 DIRECTLY. There's a warning that pops up when you select it for a REASON. It is NOT a recording-safe format.

 

[Professor Dabs]

I disabled my global audio devices and did another test record. I still have the same problem but here is a log.

 

[koala]

According to the log, there are again 2 audio tracks written to the video file. You will find them if you use the video file directly. As @FerretBomb wrote: if you extract audio from the video file, make sure the format you're exporting to supports multiple tracks. Mp3 doesn't. In this case you have to export the tracks to multiple mp3 files and use them separately. Many audio postprocessing tools allow using audio from video files directly, without using an intermediate file, so this intermediate step may not be required.

 

[Professor Dabs]

According to the log, there are again 2 audio tracks written to the video file. You will find them if you use the video file directly. As @FerretBomb wrote: if you extract audio from the video file, make sure the format you're exporting to supports multiple tracks. Mp3 doesn't. In this case you have to export the tracks to multiple mp3 files and use them separately. Many audio postprocessing tools allow using audio from video files directly, without using an intermediate file, so this intermediate step may not be required.

I couldn't see many audio options for conversion on vlc player other than mp3, but I did find two plugins for audacity called ffmpeg & LAME. Using these I was able to directly import the mp4 to audacity like you said, and it recognizes both audio tracks! Thanks guys.