Is H264 mp4 readable on Trisquel?
If not, can I at least convert it without trouble (to WebM for example)?
Well, I see that the license isn't libre.
VLC seems to be able to play that, but not always: http://www.h264info.com/playh264.html
What's your experience?
Yes, if you have installed "trisquel-codecs" package, it should play
well (the package depends on other packages that allow this).
The packages included here are all free/libre, the issue with H.264 is
another one. Although there *are* non-[free/libre] packages that also
allow society to play/decode videos made with such video encoder (and
this cannot be included in free/libre distributions like Trisquel), the
main issue is that H.264 is patented in some countries.
The GNU Free System Distribution Guidelines *does-not* impose that
free/libre distributions "should" or "shouldn't" support usage of such
patented formats, see:
https://www.gnu.org/distros/free-system-distribution-guidelines.html
Of course, we can also make occasional mistakes, and you can help
spotting the mistakes if you want, see:
https://trisquel.info/en/project/issues
https://trisquel.info/en/wiki/how-help
Make sure that the codec used to make the video is really H.264, if you
have "libav-tools" package installed, do:
avprobe "[Path to file]" |& grep 'Stream.*h264'
It works just fine.
Thanks to you both.