GNOME Bugzilla – Bug 642669
interlace: Improve and extend field patterns
Last modified: 2013-02-05 12:44:56 UTC
The following attachments are patches that improve the documentation of and extend the possible field patterns offered in the interlace element that are used for creating telecine streams.
Created attachment 181211 [details] [review] interlace: Add more verbose hints about field patterns
Created attachment 181212 [details] [review] interlace: Add support for more telecine patterns These patterns may seem strange and indeed they are. Perhaps some are bogus. They are just what I found on Wikipedia, so I assume that they are perhaps being used somewhere.
I don't think the second patch is interesting. interlace should create a good pulldown pattern automatically for uncommon ratios. I suppose that means there should be an "auto" setting.
So then deinterlace needs to be able to identify a pattern, when it repeats, how many output buffers there will be and use all that to interpolate timestamps. Sounds fun. :)
Aren't we talking about interlace? (For deinterlace, yes I agree that there should be a way of specifically setting uncommon patterns.)
Explicit specification of the patterns in both interlace and deinterlace, when known would be good, I agree. That way third party apps can define and use their own patterns. I was talking about deinterlace in my last comment as I'm considering that whatever one does, the other should be able to undo effectively somehow. Maybe in any real GStreamer usage sense that's irrelevant as no one should produce something and then undo it. But it's certainly useful for testing. My point was that if we allow interlace to create a pattern on-the-fly according to the input and output frame rates, deinterlace needs some way to detect and output something sane. Such patterns could well differ from those in the pattern list so we should implement something extra on top of the pattern locking stuff I've done. I'll elaborate on the relevant ticket what is implemented already to handle this.
Any progress on this bug?
Robert, do you have anything for the upcoming release?
Not unless someone wants to take the second patch into circulation.
While having the auto-mode sounds good, wouldn't it be useful (e.g. for testing to have all modes exposed). Too me the patch won't hurt as it is, but I don't know enough to say how useful it really would be. Anyway would be good to conclude this and either proceed or reject the changes.
I just hacked it together to do the testing. In that sense, it does what it needs to and it could later be adjusted/extended to automatically adjust the pattern according to framerate. Personally I don't consider that essential or worth delaying the possibility of having the functionality. But then I wrote the patch. :)
commit 4513a48e8af2807398983390bd60f59053231ce5 Author: Robert Swain <robert.swain@collabora.co.uk> Date: Mon Dec 27 23:21:10 2010 +0100 interlace: Add support for more telecine patterns commit 0fc9b0b289cb7c886df65c950df56ee1ae27bbff Author: Robert Swain <robert.swain@collabora.co.uk> Date: Mon Jan 10 10:36:43 2011 +0100 interlace: Add more verbose hints about field patterns