MediaWiki-Vagrant/TimedMediaHandler

Enabling TMH
vagrant enable-role timedmediahandler vagrant provision

Fixing .ogv transcodes
ffmpeg2theora is broken in Ubuntu 14.04 Trusty and above, leading to broken transcodes with no audio or that don't play at all.

As of August 2015, a patched version of ffmpeg2theora is included which should work. If upgrading an existing VM you may need to run 'apt-get dist-upgrade'.

Fixing .webm transcodes
Two-pass webm encoding appears to be broken in avconv in Ubuntu 14.04 Trusty and above, and in Debian Jessie, leading to unexpectedly low-quality output for streamable WebM transcodes.

MediaWiki-Vagrant now (August 2015) includes an ffmpeg backport that should fix this and other issues; make sure your vagrant setup and packages in the VM are up to date.

Fixing thumbnails
If thumbnail generation runs out of memory, try adding in LocalSettings.php:

and if the 404 thumb handler never works right, try manually disabling it in LocalSettings.php:

(not sure if that's all needed ;)