[GMG-Devel] GStreamer 1.0

[Boris Bobrov]

Hello,

Today I was happy to find out that my branch with GStreamer 1.x and 
improvements to video and audio processing was merged to Mediagoblin master 
branch! It means that it will be included in the next release, which will 
happen in a couple of weeks.

The features merged include:
 - New GStreamer. Old GStreamer is many years old and not supported; no codecs 
were added there and it didn't work with Python 3;
 - New thumbnail generator. It became more reliable and works always if the 
uploaded video is supported;
 - Early failure on unsupported videos. A lot of complaints were that videos 
uploaded successfully but failed to be processed, without any information why. 
Now the possibility to process the video is determined right on upload and if 
the video is not supported (due to missing packages, lack of codecs), error 
message is printed about the failure and a more verbose message is logged as 
warning;
 - Multiple audio and video streams processing and video without audio 
processing. Common usecase -- a film with audio for several languages or a 
recording of the same event from multiple cameras;
 - Tests of audio and video

Please check out already updates docs about what to install for these 
features:
http://mediagoblin.readthedocs.org/en/latest/siteadmin/media-types.html#video

I would appreciate bug reports or comments.

*But* there is one tiny problem: not all distros support GStreamer 1.x. There 
is Debian with a bug not letting to install all required packages from stable 
and stable backports; Centos 6 doesn't have GStreamer 1.x; Arch on certain 
configurations failes to install required packages.

What is not yet decided is whether to make the new functionality the default 
and remove support of GStreamer0.10, make it the default and leave 
gstreamer0.10 support in "deprecation" state or leave GStreamer0.10 the 
default and make GStreamer1.0 and all the improvements to be a new option.

Supporting gstreamer0.10 might be good for users. It means that we don't push 
users to install packages from repos outside their distros' releases.

On the other hand, I think that every user of MediaGoblin with old video 
plugin has ran into strange problems with transcoding or thumbnails. It is 
also easy to run into the problems for a new user, who usually has his videos 
encoded with some proprietary codec, that usually fails on old GStreamer. The 
user tries uploading, gets weird error, gives up. 

Now I tend towards the second option: Use GStreamer 1.0 by default and provide 
a way to fallback to 0.10. This option might have ugly implementation: a 
script to fallback to 0.10 with sql tables renames and a script to revert the 
fallback in some future when we drop 0.10 completely, again with sql tables 
renames. It also looks error-prone to me.

What do you think?

-- 
С наилучшими пожеланиями,
Boris