[FFmpeg-devel] [RFC] GXF Patches - HD

[Reuben Martin]

About 3 yrs ago, I had a set of patches for GXF that fixed some bugs and added 
a few features. Most of the bug fixes made it in, but I really didn't follow 
through with the feature patches. My personal build was enough for my personal 
purposes, so I didn't pursue it very hard.

I recently had a request via email for those patches, but they needed some 
minor re-working to be of any use. I've since been able to relocate the 
patches and update them. They should apply against current head.

At the time, Baptiste Coudurier was maintainer and reviewed GXF related 
patches. I assume that is still the case.

I've added support for 720p and 1080i. I could also support 1080p, but am not 
sure how to differenciate the two. FFmpeg deals with timecode base in frames, 
while in GXF everything is in fields. FFmpeg can handle interlaced fields, but 
that seems to be mostly handled at the codec context level rather than the 
stream context level. I can't see how to determine the difference between 30p 
and 60i for instance. FFmpeg treats both as 30 fps. However GXF makes a 
distinction in the video stream descriptors between the two. Not sure how to 
work around that. 

Also, I don't consider myself to have a good grasp of the ffmpeg code base at 
all, so suggestions on how to deal with the fields/frames issues (or anything 
for that matter) are always welcome.

Patches to be added to this thread shortly...

thanks,
-Reuben