Guide to re-encode your video under Windows to get exceptional quality, runs seamlessly on PiWall

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Viktor Forgács

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Jan 26, 2017, 4:04:49 AM1/26/17
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This post is about my solution to produce an exceptional quality full HD video runs on PiWall without choking. The video tested on a 3x1 setup for more than 40 hours and ran 30 hours in production environment. My source video was 30fps but you can use different fps.

Download ffmpeg for windows from https://www.ffmpeg.org/download.html#build-windows

Export your video to a hight quality standard mp4 file, you can easily convert it to the proper format with ffmpeg. I've re-encoded my video under windows with the following command, and never ever got issues playing on PiWall.

ffmpeg -hwaccel dxva2 -i "path to source.avi" -vcodec libx264 -crf 17 -r 30 -acodec copy "path to destination.avi"

The parameter -crf set to 17 renders a good quality video runs seamlessly on PiWall, the framerate can be forced with the -r parameter.

With hardware acceleration (if your system is supported) you can get fast encoding speed.

Feel free to comment.

Christophe Machtelinckx

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Feb 6, 2017, 5:33:57 AM2/6/17
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Hi,

Thanks for this information but this does not work for me.
I'm rendering the Video witch works perfectly. Streaming an Master also works fine but the Clients do not display the Video. Using the suggested demo Video i get the wall working. I'm Using Raspberry PI B2

Command on Client is:
pwomxplayer - A udp://239.0.1.23:1234?buffer_size=1200000B

Any help how I could encode a file to get it working on piwall?
I used before the webservice from new.cloudfile.co/transfer
This is still working for using a Youtube video, but I can no more upload files.

Viktor Forgács

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Feb 6, 2017, 3:53:31 PM2/6/17
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You have to add a route on the master and on the slaves:

route add -net 224.0.0.0 netmask 240.0.0.0 eth0


Start the slaves to listen:

pwomxplayer --tile-code=41 udp://239.0.1.23:1234?buffer_size=1200000B

Then start the master. Voila!

Use the tile code 40 41 42 43 for 2x2 setup (top left, top right, bottom left, bottom right)

Christophe Machtelinckx

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Feb 7, 2017, 5:52:50 AM2/7/17
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My piwall is working, but I do not get it to encode video properly.
With some downloaded Video files it works perfectly
The route is included in the -A

Viktor Forgács

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Feb 7, 2017, 6:04:36 AM2/7/17
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What problem are you experiencing? Strange artifacts? Choppy playback?

With the solution explained above should work properly.

Christophe Machtelinckx

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Feb 7, 2017, 7:54:58 AM2/7/17
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Every downloaded video shows no problem, but a video i tried to create simply does not display.
Master process the file and shows the streamed frames but on Clients nothing happens.

To try, could you give me a video file you rendered and I try to send it to my piwall?

Viktor Forgács

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Feb 7, 2017, 9:30:52 AM2/7/17
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If it plays on the master it is definetely not a video issue, it is network related.

Here is a video converted to the proper format:

Christophe Machtelinckx

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Feb 9, 2017, 2:44:11 AM2/9/17
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Thanks,

This file does not work on my Piwall :-(
Same stuff, Master does rendering but Clients just show nothing up but with other video files it works.

Any idea?

Viktor Forgács

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Feb 9, 2017, 4:13:41 AM2/9/17
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Could you please write me more details about your setup?

How many Pi-s you using, how are they connected, network settings, what is the command you start the video on the master, what is the command you run on slaves.

Are you running the commands in the right order?


Christophe Machtelinckx

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Feb 9, 2017, 6:27:56 AM2/9/17
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I'm using a 3x3 Piwall, which means 10 Raspberry (1 Master, 9 Clients)

Wall is running nicely since 3 months (24/24) with a lot of different video files (.avi files downloaded with http://new.cloudfile.co/transfer from Youtube)
My own generated Powerpoint saved as a movie and converted with:

ffmpeg -hwaccel dxva2 -i "path to source.avi" -vcodec libx264 -crf 17 -r 30 -acodec copy "path to destination.avi"
Does not work.

All the Raspberry's are connected to the same Switch over LAN Cat 6

Im' using a central .piwall file definition content:

# wall definition for 3x3 screens with bezel compensation
[9bez]
width=5760
height=3240
x=0
y=0

[11]
wall=9bez
width=5760
height=3240
x=0
y=0

# corresponding tile definitions
[91]
wall=9bez
width=1920
height=1080
x=0
y=0

[92]
wall=9bez
width=1920
height=1080
x=1910
y=0

[93]
wall=9bez
width=1920
height=1080
x=3820
y=0

[94]
wall=9bez
width=1920
height=1080
x=0
y=1070

[95]
wall=9bez
width=1920
height=1080
x=1910
y=1070

[96]
wall=9bez
width=1920
height=1080
x=3820
y=1070

[97]
wall=9bez
width=1920
height=1080
x=0
y=2140

[98]
wall=9bez
width=1920
height=1080
x=1910
y=2140

[99]
wall=9bez
width=1920
height=1080
x=3820
y=2140

# config
[9bez]
91=91
92=92
93=93
94=94
95=95
96=96
97=97
98=98
99=99
11=11


and every Client a .pitile
with content:
[tile]
id=9x (x = screen number)

Starting order is correct (as it works with other videos)
Command on Clients: pwomxplayer -A udp://239.0.1.23:1234?buffer_size=1200000B
Command on Master: avonv -re -i finame.avi -vcodec copy -f avi -an udp://239.0.1.23:1234

THX for Help

Viktor Forgács

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Feb 9, 2017, 6:35:29 AM2/9/17
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If you can share your powerpoint video, I can analyze the original, and convert it for you. Then I can tell you what was the issue. Pop me a drive, dropbox link to sonw...@gmail.com.

Christophe Machtelinckx

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Feb 9, 2017, 10:57:52 AM2/9/17
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Hi,

As your file S2 does also not work it could be a setting thing in my setup, but with other movies it works....strange

I have 2 Files for you, one working on my piwall : https://www.dropbox.com/s/jjwku5anp866jgu/BigScreen_Working.avi?dl=0
and the same one created with ffmpeg and not working on my piwall:https://www.dropbox.com/s/6ncyn8v0ikvioo6/BigScreen_NotWorking.avi?dl=0

Thanks for taking a look at the files.

Viktor Forgács

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Feb 9, 2017, 12:26:13 PM2/9/17
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The 'not working ' plays choppy, the frames are reappearing in some part of the video under windows in VLC and Media Player.

Christophe Machtelinckx

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Feb 10, 2017, 2:21:21 AM2/10/17
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ok, but except of that, does it plays on your wall?

Christophe Machtelinckx

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Feb 10, 2017, 6:16:23 AM2/10/17
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Have you done special settings in the Network Switch?
Enabled Spanning Tree?

kamran s

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Nov 26, 2017, 10:42:18 AM11/26/17
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Works for me. Thanks

Gregoire Simonnet

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Mar 25, 2018, 11:27:49 AM3/25/18
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Hello Viktor,

When you say you display a HD video on a 3x1 screens :  do you mean
- the source is an HD file  (1920x1080) ?
- or the source is 3 time bigger and you display an HD file on each Pi

Thanks a lot,

Greg
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