How to change the dimensions of the overlay camera?

[oren]

Both commands record with the same dimensions so I am probably passing something wrong in the arguments:

ffscreencast -a1 -c --cargs="-video_size 320x180" --oargs='-c:a flac'
ffscreencast -a1 -c --cargs="-video_size 160x90" --oargs='-c:a flac'

Thanks!

[cytopia]

Could you add --dry to the command and paste the output back in here please.

[oren]

/usr/bin/ffmpeg -hide_banner -loglevel info -thread_queue_size 512 -f x11grab -video_size 1600x900  -i ":0.0" -thread_queue_size 512 -f v4l2  -video_size 320x180 -i "/dev/video0" -thread_queue_size 512 -f alsa -ac 2 -i "hw:0,0" -c:a libfaac -c:v libx264 -c:a flac -filter_complex 'overlay=main_w-overlay_w-10:main_h-overlay_h-10' -threads 0 "/home/oren/Desktop/Screencast 2017-03-18 at 12.21.30.mkv"

And:

/usr/bin/ffmpeg -hide_banner -loglevel info -thread_queue_size 512 -f x11grab -video_size 1600x900  -i ":0.0" -thread_queue_size 512 -f v4l2  -video_size 160x90 -i "/dev/video0" -thread_queue_size 512 -f alsa -ac 2 -i "hw:0,0" -c:a libfaac -c:v libx264 -c:a flac -filter_complex 'overlay=main_w-overlay_w-10:main_h-overlay_h-10' -threads 0 "/home/oren/Desktop/Screencast 2017-03-18 at 12.21.39.mkv"

[oren]

it looks like the video_size was not changes.

[cytopia]

Could you enter the command manually and adjust the overlay=main_w-overlay_w-10:main_h-overlay_h-10 part to scale=1000:1000,overlay=main_w-overlay_w-10:main_h-overlay_h-10

Note the added scale=1000:1000,

[oren]

i did that and the recording's width got smaller.

[cytopia]

I am also not too sure about this command. Could you play around with it a bit. Maybe trying:

scale=100:100,

and

scale=10:10,

[oren]

thanks for your help. I tried it but it look pretty bad (:

[cytopia]

Did the camera overlay get bigger/smaller by adjusting these values?

Btw, what should be your expected result. How big do you want to have the camera overlay (1/4 of the screen or 1/8 ...)? I will play around and see to find a solution

[oren]

i want it to be a bit smaller. the recent experiment/command made it huge. i can't even describe what i saw (:

[cytopia]

Hi @oren

I got something to work.

ffmpeg -f alsa -i pulse -f x11grab -s 1600x900 -r 30 -i :0.0+0,0 -vf "movie=/dev/video0:f=video4linux2, scale=480:-1, fps, setpts=PTS-STARTPTS [movie]; [in][movie] overlay=main_w-overlay_w-2:main_h-overlay_h-2 [out]" -vcodec libx264 -crf 20 -preset veryfast -threads 0 ~/Desktop/video1.mkv

• -f x11grab -s 1600x900: change this to your display resolution
• scale=480:-1: here you can adjust the width of your camera (-1 means the height will scale automatically)

Please let me know how it works

[oren]

the size of the overlay camera changes as expected. but now I noticed two issues:

1. the audio is behind the video (a second late).
2. the video recording is cut off a second or two earlier

[cytopia]

Apart from the audio, Is the camera and the desktop recording in sync?

[oren]

yeah

[cytopia]

Please open up a separate issue for the audio problem so we can keep things organised I will close this ticket for now, as the camera problem is solvable (at least via raw ffmpeg commands).

Changing the camera size easily will be integrated in ffscreencast 2.0

[oren]

is there a plan to add your workaround for the video size issue into the API of ffscreencast? so i can do something like this:

ffscreencast -a1 -c --cargs="-video_size 160x90" --oargs='-c:a flac'