Mihai201818
Posts: 1
Joined: Wed Dec 05, 2018 9:58 pm

Compact flash card media players

Wed Dec 05, 2018 10:17 pm

hey guys,

i'm trying to create some media players:
i have different content(.m2v) on 10 different Compact Flash(cf) cards. i'd like to build 10 players that play in sync and in a continous loop. when pushing a play button.

ideally, each player will have a play and stop button.

i assume we would need a MASTER raspberry PI to act as the main controller. this master should have a play button and when you hit PLAY, it should play all 10 videos synchronized.

videos are ussually synced with a sync generator(bnc input). can i have a BNC input and BNC output to each raspberry PI?

thank you for your help in advance,

m

User avatar
Joel_Mckay
Posts: 177
Joined: Mon Nov 12, 2012 10:22 pm
Contact: Website

Re: Compact flash card media players

Fri Dec 07, 2018 1:32 am

Depends what you are doing, and how accurate the timing needs to be.
You might be able to do live parallel steams from a VLC rtsp server, and hope the buffers stay relatively well matched.
Due to networking and gpu-decoder Latency, the playback mismatch will be difficult to sync up.

There are also scripts people have tried to do a "play all" on remote interfaces for cvlc
https://github.com/Syncplay/syncplay/
https://sourceforge.net/projects/vlcvideowallcon/
Don't know anyone who tried this (I also tend to avoid macro embedded stuff), so YMMV

I would personally look at running a concurrent cluster administration shell like Pssh, and statically assign the dhcp ipv4 leases on your router:

Code: Select all

sudo apt-get install python-pip
sudo pip install pssh

cat > ~/host_worker_list.ipv4
192.168.0.10:22
192.168.0.11:22
192.168.0.12:22
192.168.0.13:22
192.168.0.14:22

pssh --hosts ~/host_worker_list.ipv4 -t 30 --user pi -A  -i "vlc -I http --fullscreen --no-video-title --http-password testing --http-user guest "
Then write a simple Lua scripting tool if you want more from local file playback:
https://forum.videolan.org/viewforum.php?f=29

External sync inputs allow frame timing accuracy to avoid camera banding in the analog signal days, but many people now just use multi-port video cards in high-refresh rate modes (NVIDIA 4 port pci cards with hardware media decoders is $180.)

Cheers,
J

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