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hzeller / flaschen-taschen

Noisebridge Flaschen Taschen display
GNU General Public License v3.0
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VLC: possibility to reduce color depth? #74

Open beta-tester opened 1 week ago

beta-tester commented 1 week ago

hi, i am very new to VLC for Flaschen-Taschen. i am using VLC 3.0.21 that is shipped with Raspberry Pi OS (bookworm) 64bit. i have the ft-server running for a 256x128 LED-Matrix (two chains with 4x 64x64 outdoor panels). so on the server i am running the ft-server with:

sudo ~/git/flaschen-taschen/server/ft-server --led-rows=64 --led-cols=64 --led-chain=4 --led-parallel=2 --led-multiplexing=1 --led-pwm-bits=5 --led-pixel-mapper=Rotate:180 --led-show-refresh

on the other raspberry pi with Raspberry Pi OS (bookworm) 64bit, i tried to run:

vlc --vout=flaschen --flaschen-display=matrix.local --flaschen-width=256 --flaschen-height=128 video.mp4
...
[0000007f440013f0] flaschen vout display error: sendmsg: error Message too long in vout display flaschen
[0000007f440013f0] flaschen vout display error: sendmsg: error Message too long in vout display flaschen
...

i know, a single UDP frame can only hold up to 65536 bytes and my display size with 98304 bytes does not fit to a single UDP frame. that's why i get the error messages error Message too long in vout display flaschen.

i am wondering if there is a possibility to reduce the color depth vlc is sending to the ft-server. e.g. if i can set the color depth down to 5bit per color => rrrrrgggggbbbbb => 2 byte per pixel, then a image of 256x128x2byte has 65536 bytes, what would fit to a single UDP frame.

hzeller commented 1 week ago

Color depth reduction is not possible, but it is possible to send in multiple packets.

I once actually had a fix for that to patch into VLC https://mailman.videolan.org/pipermail/vlc-devel/2020-March/132387.html ... but that was at the beginning of the pandemic and then I was getting busy making PPE and did not finish that patch.

hzeller commented 1 week ago

(If you are just interested in the video, no sound, then https://github.com/hzeller/flaschen-taschen/tree/master/client#send-video might be sufficient)

beta-tester commented 1 week ago

so the patch for multiple packages is not implemented in the stock vlc 3.0.21 of the Raspberry pi repository? is it maybe in the windows version?

i am not interest in sound. does 'send-video' also downscale videos to the required size of the display and can it open youtube videos? EDIT: and can i compile send-video for windows?