GNOME Bugzilla – Bug 651806
Implement Video compositing and Audio Mixing
Last modified: 2013-09-24 16:03:38 UTC
Until now, there is no way to mix audios/videos from various layers. We need to get something with a similar behavior as what now have in pitivi. The solution in pitivi is: * Have mixer elements smartVideomixerBin and SmartAdderBin (in pitivi/elements/mixer.py) * All tracks add this mixer in a gnloperation with a priority of 0 and which is expandable so it is in the whole duration of the track so any trackobject added to track is plugged on the mixer in pitivi/timeline/track.py This result in: + layers (audio/video from different layer) are mixed when the alpha channel of objects on higher layers are < 100 We also currently have an optimization that take advantage of the alpha passthrough capabilities of the videomixer, we should try to keep it. If we want to reproduce something similar, we re-implement those custom GstElement-s and modify ges/ges-track.c to handle it. In GES, we should use the new video mixer: videomixer2 Also I guess this is something we might want to handle directly in GnlComposition, passing a videomixer or adder to it?
Looking into it/Working on it :)
Currently, this is one of the key regressions in Pitivi. As nobody is working on it at the moment, unassigning.
This bug has been fix between commit 9e0632e353cfbd2301f8d74a7398c4276371a5a3 Author: Mathieu Duponchelle <mathieu.duponchelle@epitech.eu> Date: Mon Jun 3 23:02:15 2013 +0200 ges: Add a framepositionner element used in ges-smart-mixer and ges-uri-source It adds metadata on the buffers and the mixer parses them. This is done because we want to keep positionning properties and set them on the dynamic mixer pad. and ... commit 7e25aaeccc6334343ea5b179a3347d32444b5b8c Author: Thibault Saunier <thibault.saunier@collabora.com> Date: Sat Mar 30 19:02:52 2013 +0100 track: Implement infrastructure for mixing