[FFmpeg-user] Archlinux update breaks kmsgrab: Failed to get plane resources: Permission denied

[Kai Hendry]

Hi there,

For sometime I've been happily using kmsgrab to make screencasts on my Archlinux Xorg desktop.

https://github.com/kaihendry/recordmydesktop2.0/blob/9825a44d886318d78463c0a602681c0c7931cf83/x11capture#L71

But then it broke after a reboot as described here:
https://www.reddit.com/r/ffmpeg/comments/ez4u5z/failed_to_get_plane_resources_permission_denied/

Downgrading ffmpeg or linux didn't appear to solve the problem. Perhaps it was some Intel driver update? I'm not sure what package to try downgrade or to bisect this breaking dist-upgrade and reboot, since there has been so many updates...



After some frustration I revisited the ffmpeg wiki to find the "Capture the screen from the first active KMS plane" (using -device /dev/dri/card0 instead of -vaapi_device /dev/dri/renderD128) which does work... for a few *minutes* and then bombs out:

[AVHWFramesContext @ 0x559c5137c400] Failed to create surface from DRM object: 2 (resource allocation failed).
[Parsed_hwmap_0 @ 0x559c513653c0] Failed to map frame: -5.
Error while filtering: Input/output error
Failed to inject frame into filter network: Input/output error
Error while processing the decoded data for stream #1:0
[AVIOContext @ 0x559c51361500] Statistics: 0 seeks, 15 writeouts
[h264_vaapi @ 0x559c513492c0] Freed output buffer 0
[aac @ 0x559c51360580] Qavg: 227.062
[aac @ 0x559c51360580] 2 frames left in the queue on closing
Conversion failed!

Full log is here:
https://s.natalian.org/2020-02-06/1580968072.mp4.log

The output file appears unrecoverable: "moov atom not found" :( 

So any tips to get kmsgrab working on my system again? 
Btw I found kmsgrab *much better* than x11grab since with VAAPI it doesn't appear to make my T480s overheat. So I really want to restore the gloriously efficient kmsgrab UX I was using until some package update broke it.


Kind regards,