[FFmpeg-user] Screenrecording, audio is sped up when other process starts

[Tarjei Bærland]

Hello!

I have an issue where my audio is sped up when I start certain process
while running ffmpeg. You can hear it after about 13 seconds in this video:
https://www.youtube.com/watch?v=aGr2pDgZ_6k (it's in Norwegian and
informal, as it is meant for fourteen highschool students), where it
happens when I start a python process where pygame is loaded.


Does anyone have any idea what could be the cause, and what I could do to
remedy it?

I have startet ffmpeg by the following command

 ffmpeg \
    -f x11grab \
    -video_size 1920x1080 \
    -i $DISPLAY.0+1920,0 \
    -f alsa \
    -acodec pcm_s32le \
    -ac 4 \
    -ar 44100 \
    -i  sysdefault:CARD=U192k \
    -filter:a "volume=10dB" \
    -preset ultrafast \
    -c:v libx264 \
    -y \
    -ac 1 \
    -threads 4 \
    ${OUTFILE}


My audiocard is a Behringer UMC404HD.

All help is very much appreciated.

Kind regards,
Tarjei Bærland