Screen capture from VideoCore?

[dgrubb]

I need to capture video of an application I've built using Kivy, which renders using the gl provider without an X session. Consequently, I can't just record /dev/fb0 with something like avconv -f fbdev -i /dev/fb0 as (I think) the gl backend uses the VideoCore directly. I can take screenshots with Andrew's raspi2png, is it also possible to extract video?

N.B: I'm using the official Raspberry Pi Touchscreen, rather than HDMI output.

Cheers,
Dave.

[dgrubb]

Found a solution, courtesy of uv4l: https://www.linux-projects.org/document ... raspidisp/

[CCx266]

Hello @dgrubb,
I find myself in the very same situation (I build an openFrameworks app using openGL)
and I'm trying to record with uv4l-raspidisp when I found out about it.
If someone has an other option to record on card the hdmi output I'm also interested of course.

Could you elaborate on the command lines you use ? I'm trying this without success:

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 uv4l --auto-video_nr --driver raspidisp --framerate 24 --resolution 3

and then to record a 10s video :

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dd if=/dev/uv4l of=video.h264 bs=1M & pid=$! ; sleep 10; kill $pid

all I get for now is a non valid .h264 file, unreadable.

I would gladly appreciate any help,
Thanks

[jamesh]

Google for dispmanx_snapshot, orcsimilar. That should snapshot the output.

[CCx266]

Hello,
thanks for your reply, but I need to capture video and not just a snapshot, also X is not implied

[CCx266]

I found a working solution for now, with 720p resolution (raspi-config)
When 1080p ffmpeg is complaining, and downscaling is neither a good idea. better have same resolution screen/capture

install uv4l:
https://www.linux-projects.org/uv4l/installation/

create virtual input (see options https://www.linux-projects.org/document ... raspidisp/):

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uv4l --auto-video_nr --driver raspidisp  --resolution 7

record with ffmpeg:

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ffmpeg -f video4linux2 -video_size 1280x720 -i /dev/video0 -c:v copy -strict experimental -y -pix_fmt yuv420p out.mp4

works pretty good.