…one more thing

With respect to Tina’s 13 Lunas project


and http://waw.w3.uvm.edu/lunas.php

Which uses Flash to record video, I present Video capture via WebRTC


A work in progress. No Safaris allowed.

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I have pretty much either finished or abandoned all projects and duties, an I am prepared to vacate the premises.

Thank you very much

“Elvis has left the building.”

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Free Books from my Bookshelf

Math, physics, computer science. And a signed copy of  The Art of Computer Programming Volume 1: Fundamental Algorithms (Donald E.Knuth).


Free for the taking, available only in Lafayette 407

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ffmpeg barfs on .AVI file

Entered on 08/31/2017 at 10:54 by juli@med.uvm.edu:

Hi Wesley,
I’ve uploaded 2 movies to the streaming.uvm.edu server, which are not going through. 1 is an avi file, the other a mp4 file. Are there issues with the server?

Issues with ffmpeg.

Exploratory steps

Look up client by NEtID in CTL_cumulusclips/users table, get user_id

Look up by user_id videos in videos table, status=new, get filename. Be an ugly thing like oJAFxvqygTeeeJihlkIT

Fetch /var/www/html/media/cc-core/logs/oJAFxvqygTeeeJihlkIT.log


Look for ffmpeg errors/warnings. In this case, I see

Input #0, avi, from ‘/wowza/users/j/l/jlovelet/temp/oJAFxvqygTeeeJihlkIT.avi’:

Duration: 00:00:03.00, start: 0.000000, bitrate: 52594 kb/s

Stream #0:0: Video: mjpeg (MJPG / 0x47504A4D), yuvj420p(pc, bt470bg/unknown/unknown), 1139×616 [SAR 1:1 DAR 1139:616], 52926 kb/s, 50 fps, 50 tbr, 50 tbn, 50 tbc


title           : ImageJ AVI

Codec AVOption b (set bitrate (in bits/s)) specified for output file #0 (/wowza/users/j/l/jlovelet/HD720/oJAFxvqygTeeeJihlkIT_temp.mp4) has not been used for any stream. The most likely reason is either wrong type (e.g. a video option with no video streams) or that it is a private option of some encoder which was not actually used for any stream.

[swscaler @ 0x22d8420] deprecated pixel format used, make sure you did set range correctly

[libx264 @ 0x22c4880] width not divisible by 2 (1139×616)

Output #0, mp4, to ‘/wowza/users/j/l/jlovelet/HD720/oJAFxvqygTeeeJihlkIT_temp.mp4’:

So which is the error? Much googling suggested this:

[libx264 @ 0x22c4880] width not divisible by 2 (1139×616)

OK, so what’s the fix? ffmpeg command was

/usr/bin/ffmpeg -i oJAFxvqygTeeeJihlkIT.avi -acodec aac -b:a 128k -ac 2 -ar 44100  -af "aresample=first_pts=0" -pix_fmt yuv420p -vsync -1 -sn -vcodec libx264 -r 30 -vf "scale=min(1280\,iw):trunc(ow/a/2)*2" -threads 0 -maxrate 3000k -bufsize 3000k -preset slower -profile:v high -tune film  -x264opts keyint=60:min-keyint=60:no-scenecut -map_metadata -1 -f mp4 -y oJAFxvqygTeeeJihlkIT_temp.mp4

The offending option

-vf "scale=min(1280\,iw):trunc(ow/a/2)*2"

The Fix

-vf "scale=min(1280\,trunc(iw/2)*2):trunc(ow/a/2)*2"

The How? lots of googling, some dumb luck, trial and error. What exactly does this mean? There are many cookbook recipes that say “use this” but finding a guide to the syntax was tricky. I eventually found this article which said,

“The expression trunc(ow/a/2)*2 as vertical resolution means: use as output height the output width (ow = in this case 1280) divided for input aspect ratio and approximated to the nearest multiple of 2
“This command line uses as width the minimum between 1280 and the input width (iw), and then scales the height to maintain the original aspect ratio. Notice that “,” may require to be escaped to “\,” in some shells.”

I tries the same with width, but it didn’t like that divide by a bit, but it did like


Which is self explanatory.

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YoUVM admin tool: move ownership

Figured out how to move ownership of a video from NetID1 to NetID2. Added it to Admin Panel => browse Videos => popup menu ‘Move’

Still some clean-up work to do before sending to production


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Been a long time gone

Last post way back in May. Surely I’ve done something since then. Early May to June…

  • announced my retirement
  • prepared a list of streaming server users
  • prepared a list of adjunct faculty
  • Ticket from Sara Solnick. There is — or was, or may be — a bug in the media manager download function. The files she thought she downloaded were 200 byte text files, not big honking .MOV files. I think I have fixed the bug — I just tried it with a 1.6 GB file. I’m afraid she’ll  have to try again downloading and uploading the 3 videos from Module 4
  • Updated Tina’s web page
  • 303 imaging
  • streaming reports see http://www.uvm.edu/ctl/?Page=resources-teaching/mediamanager/streaming.php#count
  • On leave  until August
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BBB keeps rolling along

Upgraded from 1.1ßeta to 1.1-RC

from BBB:

It’s been almost four months of testing since we announced the availability of 1.1-beta on Jan 12, 2017.  See: https://bigbluebutton.org/2017/01/12/1-1-beta/.
A big thanks to everyone who reported issues with the beta and helped us track down and fix them.  
As our beta releases tend to be quite stable, and we estimate that some companies have run over 100,000 meetings on 1.1-beta.  This heavy usage, along with our community, has enabled us to find and fix many edge cases and harden the product.  If you are interested, here’s a list of all the issues found and fixed since the beta release.
The above list shows the effort we put forward to ensure each release of BigBlueButton is more solid than the previous.  
The result is a 1.1 release that is a stable, documented, localized, and thoroughly tested.  This release should provide you with a platform that you can deploy and build upon for your organization and, for your users, it should provide an easy-to-use interface to hold online classes. 
In short, as product manager, I believe this is our best release to date. 
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WiFi laptops

Spent way too long getting 303 laptops to speak to the wireless network post radius certificate update. Fixed a lot of issues with caspar and munki along the way.

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Guide on the side

Helped Daisy, Graham, and Lyman get updated GOS installed on library servers. They were very happy, but not so happy as to let us use their SpringShare software.

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Data begets data

Created more graphs; moved jpgraph library into cumulusclips library (was on ctl.w3.uvm.edu); refactored code to use cc-core DB  objects for mySQl queries; added tabular (HTML table or Excel CSV download)  custom user reports. Incorporated all of this into Admin Panel.


Wrote a lot of high-level documentation


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