I have been trying to create MP3 files using a Thunar custom action under Xubuntu. The command that I was using in the custom action was as follows.
xfce4-terminal -x  ffmpeg -i %f -acodec libmp3lame -v 8 New/%n.mp3
This has the obvious issue of I haven't figured out the sed command to strip the various file types that I might have selected. Much less obvious and much more important is that when I transfered the files to my MP3 player the player essentially locked up and died. So after some irritation and blaming the MP3 manufacturer I found out that some files worked and other didn't. Depending on what software I use I get different answers. Rythmbox tells me that nothing is wrong that they files are whatever kbps similar to my conversion software. Thunar tells me that every file that is crashing is 32 KBit/s. VLC has confused answer. Under media information codec tab it says that
codec: MPEG Audio Layer 1/2/3 (mpga)
Channels: Stereo
Sample Rate: 44100 Hz
Bitrate: 32 kb/s
but on the statistics tab
it says under input/read that the content bitrate is whatever it is supposed to be. Also for reference under the metadata tab on files that don't work it says among other things
major_brand: mp42
compatible_brands: mp42isom3gp63g2a3gp4
minor_version: 0
On ones that work it says nothing on that tab or Software: Lavf52.64.2

Using WinFF or ffmpeg result in the same issue. If I use VLC to convert/save I get a good file. However it seems like using that to convert every file in my library would take a little bit of time. I am hoping to be able to select files and send them to a new folder with a simple right click.