[FFmpeg-user] [HELP]how to avoid "ALSA buffer xrun."

[Soho Soho123]

Hi All,


When I use ffmpeg to capture video and sound (USB device), I can see the
message from alsa-audio-common.c "ALSA buffer xrun."

the command line I use :

ffmpeg -loglevel debug -f video4linux2 -r 30 -s 640x480 -input_format h264
-i /dev/video1 -f alsa -ar 48000 -ac 2 -i hw:0 -vcodec copy -acodec copy
http://localhost:8090/feed1.ffm


In record case, it seems ffmpeg get audio slower than usb device capture
the sound, such that the buffer overflow, right?
Does anyone have idea how to avoid the issue about "ALSA buffer xrun" when
ffmpeg capture sound from usb sound card?


thanks!