Kdenlive webcams : logitech c310 capture doesn’t work

Why wtf it doesn’t  work  ?

Because of :

-you are not on video and audio group
-canonical uses pulse as default so kubuntu too
-kdenlive is not set well for pulse
-kdenlive uses ffmpeg that doesn’t understand well the situation , ffmpeg can’t capture the audio… and close itself => no video capture on kdenlive. the error on my case it’s this  [oss @ 0x9bff420]/dev/dsp: No such file or directory,

First of all you need to be sure you are on the audio and video groups, that could be not necessary but for example for google talks it is .. you could not get your integrated mic recognized by the browser

sudo adduser $USER video
sudo adduser $USER audio

if you want test your error just copy and paste from  ===> settings , configure kdenlive, recording

you will see something like this :

-f oss -i /dev/dsp -acodec mp2 -f video4linux2 -s 320×240 -r 15 -i /dev/video0 -vcodec mjpeg

well just edit this string and add something :

ffmpeg -f oss -i /dev/dsp -acodec mp2 -f video4linux2 -s 320×240 -r 15 -i /dev/video0 -vcodec mjpeg OUTOU.AVI

and you will get your own error.


now you should understand which audio device  you would use , i use the webcam mic because just simply work well.


cat /proc/asound/pcm | awk -F ':' '/USB/{gsub(/-/," "); print $1 }'

explanation in case code would not work :

cat /proc/asound/pcm

i get

00-00: ALC861-VD Analog : ALC861-VD Analog : playback 1 : capture 1
00-06: Si3054 Modem : Si3054 Modem : playback 1 : capture 1
01-00: USB Audio : USB Audio : capture 1

So if i would like use the usb i should use -i hw:1,0

Testing strings , open a konsole and type

ffmpeg -f alsa -ac 1 -ar 48000  -i hw:1,0  -acodec mp2  -f video4linux2 -s 1280x1080 -r 30 -i /dev/video0 -vcodec mjpeg -sameq test.avi

after a while press “Q” and  play the video with

ffplay test.avi

now lets set kdenlibe better

what i get 🙂


screenrecorder with usb mic from logitech

alias screenrecoderb=" ffmpeg -f alsa -ac 1 -ar 48000  -i hw:1,0  -acodec mp2  -s $(xrandr  | awk '/, current /{print $8}')x$(xrandr  | awk '/, current /{gsub(/\,/,"");print $10}') -f x11grab -r 30  -i :0.0  -vcodec  ljpeg  -y  $HOME/output.avi"

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