Video and audio capture while playing Sunvox on Raspberry Pi

Multi-platform modular music creation studio
Post Reply
narF
Posts: 6
Joined: Tue Oct 06, 2020 5:46 am

Video and audio capture while playing Sunvox on Raspberry Pi

Post by narF »

Hi

I would like to record videos (with audio) of Sunvox played in real time, to make tutorials, etc. on a Raspberry Pi 4. I want to be able to hear what Sunvox is playing while my screen recorder app also capture audio and video. I know it's possible because I managed to do it a few months ago and it worked perfectly, but... I forgot how, or something in my setup changed, but now it doesn't work.

My current problem is that the videos I record have no audio. It seems that Sunvox grabs control of the soundcard and my video capture software receives no audio. Sunvox also seems to prevent other apps from playing audio (ex: Firefox or VLC can't play audio if Sunvox is open).

My setup:
- Raspberry Pi 4B, which runs Sunvox very well
- I use an external USB audio device, which is much better audio quality and allow smaller buffer for faster response when playing notes. It works perfectly. It's the same device I used when I was able to do my screen recordings a few months ago.
- For video capture, I use Simple Screen Recorder

Sunvox Audio Preference:
- Driver: Alsa
- Output: hw:1,0 USB Audio Device, USB Audio
- Input: hw:1,0 USB Audio Device, USB Audio
- Buffer: 512; 10ms
- Sample rate = 48000 Hz
Image

I tried all different audio drivers in Sunvox (ALSA, Jack, SDL, OSS) with various settings (auto or not, etc) and the only on that seems to works is the one above↑

That being said, I seem to remember that, when I managed to record audio in my video captures, I was using the SDL driver. But maybe i'm misremembering. When I try it now, I notice that I cannot select an output other than "Auto". (see screenshot) Maybe that's the problem?
Image
narF
Posts: 6
Joined: Tue Oct 06, 2020 5:46 am

Re: Video and audio capture while playing Sunvox on Raspberry Pi

Post by narF »

I did some more searching online... Raspbian (Debian on Raspberry Pi) uses PulseAudio. How do I tell Sunvox to output in PulseAudio?
User avatar
NightRadio
Site Admin
Posts: 3941
Joined: Fri Jan 23, 2004 12:28 am
Location: Ekaterinburg. Russia
Contact:

Re: Video and audio capture while playing Sunvox on Raspberry Pi

Post by NightRadio »

How do I tell Sunvox to output in PulseAudio?
It should output to PulseAudio if the output device is set to default (auto).
Then you can open pavucontrol and set the default intput and output devices
narF
Posts: 6
Joined: Tue Oct 06, 2020 5:46 am

Re: Video and audio capture while playing Sunvox on Raspberry Pi

Post by narF »

If I select Auto and relaunch Sunvox, it says it selected ALSA. Is that normal?
User avatar
NightRadio
Site Admin
Posts: 3941
Joined: Fri Jan 23, 2004 12:28 am
Location: Ekaterinburg. Russia
Contact:

Re: Video and audio capture while playing Sunvox on Raspberry Pi

Post by NightRadio »

Yes, it's ok. SunVox can't work directly with PulseAudio. But default ALSA device is emulated by PulseAudio.
Post Reply