I upgraded the ffmpeg packages to 0.9 which now allows me to play video via subsonic but gives a different error for the flac or m4a transcoding
There's a known issue with the latest Subsonic version not correctly transcoding flac using the default ffmpeg transcoding config. There are some documented ways around this on the subsonic forums where you use a two phase transcode for flac.
I got it to work by doing the following;
On the transcode page there should already be two transcode entries. The first one "mp3 audio", I removed the portion "flac" from the "convert from" section, leaving everything else the same and created a new transcode entry;
ffmpeg -i %s -v 0 -f wav -
lame -V 0 --tt %t --ta %a --tl %l -S --resample 44.1 - -
Seemed to work when I tested it with a few flac files. I think there's some issue with the two step process not working well with the jukebox function(?), but to be honest I don't do much other than use Subsonic via an iPad app and occasional mkv transcode. I'd be interested to know if it works for more people than just me.
Incidentally, I've worked out all the necesary packages for getting 4.6 Subsonic to play audio and video. I didn't want to install too much as I also run AirVideo and so wanted to understand what packages were needed rather than install the full mencoder stuff as in my view there's always a danger of package version mismatches when running too many things that use the same binaries/libs.
All the packages I've installed together with a copy of the 4.6 subsonic tar file and also a script I quickly threw together which I use to install are on my dropbox - https://www.dropbox.com/sh/n3txaphjh79svq3/6X9eVBTSzT
I'm not currently using the plugin, instead I just have all the packages in my /boot/packages directory, manually call the script from my "go" file and if I want to stop/start, I do it via command line in the usual way. eg. /etc/rc.d/rc.subsonic stop|start. My copy of subsonic runs from cache drive, so after first untar'ing the subsonic file and getting things working, I don't worry about things surviving a reboot other than to reinstall the packages. I'm sure it could probably be wrapped into ajax's plugin.