Author Topic: 12 panels on Octo outputs, support for BTRFS (compressed filesystem)  (Read 730 times)

Offline dkulp

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I just uploaded yet another image.   


I updated the ledscape/octo code to support 12 panels on each output.   With 8 outputs, thats 96 panels.  Doing the math on this, if you use the 1/16 scan panels (32x32), that's 295K channels.  At 25ms timing (40fps), thats 12MB/sec.   There's no way your going to get that much data to the BBB via the network and even pulling that much off the SD card could be an issue.   Also, the SIZE of the files will be huge.   (that said, refresh rate on 96 panels of the 32x32 variety will not be great..... that's a lot of pixels push out)


Thus, I added support for BTRFS to the mount detection for the media filesystem.   If you flash the FPP to the eMMC and then reformat the SD card (or USB stick) to BTRFS ( sudo mkfs.btrfs /dev/mmcblk0p1 )and then select that for the media device, then it will mount that with the LZO compression turned on.   This has a few benefits (with a minor drawback).   The drawback is of course CPU usage.  The processor has to compress the files on write (rare) and decompress on read.  That said, LZO is very quick so impact is minimal.  The main advantage though is we can get the sequence data off the slower SD/USB card quicker.      The other advantage is space savings.  I just copied 6GB of sequences over to the card, but only 520 MB of the space is "used".    :)



Dan Kulp

Offline JonB256

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Re: 12 panels on Octo outputs, support for BTRFS (compressed filesystem)
« Reply #1 on: June 30, 2017, 08:51:29 AM »
The newest image (0629) - to fully implement the 12 panel and BTRFS changes, do I need to install from that image or just use the GitHub update?

(i.e., I did the update and it now shows 12 panels per output - just haven't tested)

Offline dkulp

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Re: 12 panels on Octo outputs, support for BTRFS (compressed filesystem)
« Reply #2 on: June 30, 2017, 09:12:07 AM »
The newest image (0629) - to fully implement the 12 panel and BTRFS changes, do I need to install from that image or just use the GitHub update?

(i.e., I did the update and it now shows 12 panels per output - just haven't tested)


Depends.....  if you use the normal 1/8 scan (16x32) panels, you can just use the git update thing.  If you need to use the 1/16 scan panels, you'll need a full image update.   Either that or create a file name /etc/modprobe.d/uio_pruss.conf that contains:


Code: [Select]
# allocate 384K instead of the default 256K
options uio_pruss extram_pool_sz=393216


By default, the uio_pruss driver doesn't allocate enough memory for 96 panels of 32x32 size so we need that setting to get a bit more memory.   






 

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