Integrating GES in Pitivi, weekly report 06 & 07 sorry :/

[Mathieu Duponchelle <mduponchelle1 gmail com>]

Hi everyone !

These last two weeks were pretty busy for me.
First off, last week I reached my mid-term evaluation goal, which was to 
load a GESTimeline with xptv projects thanks to my GESPitiviFormatter, 
then load a GESTimelinePipeline with the timeline, then connect it to 
the viewer in Pitivi, all of this using my python bindings for GES. This 
was a long sentence but quite a short job, and this was still pretty hacky.
Afterwards, I played around a little with projects, only to realize that 
I had a nasty bug with the interaction of effects and transitions, which 
obviously came from my formatter. This was in the middle of last week.

After this discovery, I moved in to another flat, and the end of the 
week was not really filled with working.

I started to tackle this bug by the beginning of this week, and I must 
admit it took me a long time to figure out where it came from (the 
respective priorities of transitions and effects, which determine which 
object is "above" and which is "under" had to be set in the appropriate 
way), and still longer to fix it : once I made out how everything had to 
fit together, I also realized that the calculating of the needs in terms 
of transitions had to be refactored, I needed to compare the sorted 
track objects one after another, and not the track objects belonging to 
the sorted timeline objects one after another. I hope I'm clear enough, 
anyway I had to add a function to the GESTrack API to achieve this, 
which makes me think I'll also have to update the bindings aha.

Also, during this week I broke my scooter, and that didn't help me in 
concentrating on my problems. It now lies in pieces in my yard waiting 
for me to fix it or for someone to steal it xD.

Anyway.

These bugs are now fixed, and I can now attack the rest of the 
integration with a free mind.

I will now explain you how to checkout my work and give it a try, if you 
find bugs don't hesitate to contact me.

This is if you don't use jhbuild :

First, you'll need pitivi. After that, you'll need the latest 
gst-python, then you'll have to get to my GES repository, which is at 
https://github.com/Mathieu69 as usual. You'll want to checkout the 
"integration" branch, autogen it *without* prefix (this is due to the 
CONFIGURED_PYTHON_PATH in pitivi, will fix that when I'll have time), 
make and make install.

To test the bindings : ipython, from gst import ges. If it imports, fine 
! You're nearly done. Otherwise, mail me with the traceback.

Afterwards, all you'll have to do is go to my pitivi repo, and checkout 
the "intcheck" branch. Just switch to it, launch pitivi, and load a 
project *using the start up wizard*. You'll then be able to press play 
and profit :D You can also pause, undock the viewer, and that's pretty 
much all xD.

Anyway, what's interesting is to compare the playback between master and 
my branch, you'll be able to see the difference in smoothness ;) GES 
makes playback nearly smooth, it only lags a little when transitions 
start or if you think that a clip is way cooler with agingtv, chromium, 
color lookup table filter, vertigo TV, and whatever effect *at the same 
time*, where in pitivi and with my computer you can only see one picture 
every 2/3 seconds, with no transitions. When transitions or effects kick 
in, you just want to switch to pause and go ahead by hand, it's nearly 
smoother ;)

If you have issues at any point of the testing, mail me or directly come 
to pitivi's IRC channel, my nick is Mathieu_Du.

Voila !