[FFmpeg-user] kmsgrab and audio problem

[Ferdi Scholten]

> With this code:
> sudo ffmpeg -y -device /dev/dri/card0 -r 30 -framerate 30 -f kmsgrab -i -
> -f alsa -i default -vf
> 'hwmap=derive_device=vaapi,scale_vaapi=w=1280:h=720:format=nv12' -c:v
> h264_vaapi -g 60 -b:v 5500k -c:a aac -ac 2 -b:a 320k -f flv output.flv
> record working, no errors in ffmpeg, but no audio.
> With this code:
> sudo ffmpeg -y -device /dev/dri/card0 -r 30 -framerate 30 -f kmsgrab -i -
> -f pulse -i default -vf
> 'hwmap=derive_device=vaapi,scale_vaapi=w=1280:h=720:format=nv12' -c:v
> h264_vaapi -g 60 -b:v 5500k -c:a aac -ac 2 -b:a 320k -f flv output2.flv
> i got:
> [kmsgrab @ 0x55576139cc00] Using plane 48 to locate framebuffers.
> [kmsgrab @ 0x55576139cc00] Template framebuffer is 85: 1920x1080 format
> 34325258 modifier 0 flags 0.
> Input #0, kmsgrab, from 'pipe:':
>    Duration: N/A, start: 1702202199.445880, bitrate: N/A
>    Stream #0:0: Video: wrapped_avframe, drm_prime, 1920x1080, 29.92 tbr,
> 1000k tbn
> default: No such process
>
> вс, 10 дек. 2023 г. в 04:20, Ferdi Scholten<ferdi at sttc-nlp.nl>:
>
>> Cant record desktop video and audio with kmsgrab and pulseaudio/alsa on
>>> debian/arch system with xorg. I got video without audio or ffmpeg fail to
>>> record. If record only video with kmsgrab all works. How i can record
>> video
>>> and audio with kmsgrab and alsa/pulseaudio?
>>> _______________________________________________
>>>
>> kmsgrab only records video, you need to specify an audio source if you
>> also want to record that.
>>
>> But we do not have a clue about what you are doing because you forgot
>> the most important part of your question!
>>
>> In order to be able to start helping you we need to see what you have
>> already tried so please specify your full commandline and the full
>> output of the terminal for that command.
>> _______________________________________________
>>
Maybe you need to add
-flvflags aac_seq_header_detect

Or even better, use another container like MP4 or MKV instead of the 
obsolete FLV