ffmpeg open webcam using YUYV but i want MJPEG
You can list additional information about what your webcam can output with v4l2-ctl --list-formats-ext
. You can also show webcam information with ffmpeg using the -list_formats
input option:
$ ffmpeg -f video4linux2 -list_formats all -i /dev/video0
[...]
[video4linux2,v4l2 @ 0x1fb7660] Raw : yuyv422 : YUV 4:2:2 (YUYV) : 640x480 160x120 176x144 320x176 320x240 352x288 432x240 544x288 640x360
[video4linux2,v4l2 @ 0x1fb7660] Compressed: mjpeg : MJPEG : 640x480 160x120 176x144 320x176 320x240 352x288 432x240 544x288 640x360
This webcam from my example can support both raw (yuyv422
) and compressed (mjpeg
) formats, and you can tell ffmpeg
which one you want with the -input_format
input option.
Examples
Stream copy the MJPEG video stream (no re-encoding):
ffmpeg -f v4l2 -input_format mjpeg -i /dev/video0 -c:v copy output.mkv
Re-encode the raw webcam video to H.264:
ffmpeg -f v4l2 -input_format yuyv422 -i /dev/video0 -c:v libx264 -vf format=yuv420p output.mp4
Same as above but manually choose frame rate and video size (v4l2-ctl --list-formats-ext
for available frame rate and video sizes):
ffmpeg -f v4l2 -input_format yuyv422 -framerate 30 -video_size 640x480 -i /dev/video0 -c:v libx264 -vf format=yuv420p output.mp4
See the video4linux2 input device documentation for more options.
If the frame rate being output is lower than expected then add more light: the webcam may be lowering the frame rate to get longer exposures in a dim environment.