[FFmpeg-devel] [PATCH]Mention in the documentation that fieldmatch needs cfr input

[Nicholas Robbins]

> On Wednesday, October 29, 2014 12:25 PM, Carl Eugen Hoyos <cehoyos at ag.or.at> wrote:

> > Calvin Walton <calvin.walton <at> kepstin.ca> writes:
> 
>>  For content that was in mpeg2 with field flags set 
>>  appropriate for display on an interlaced TV 
> 
> This is unrelated to this issue:
> FFmpeg simply ignores the flag and interprets the 
> input as progressive.
> 
>>  which basically accounts for all DVD content
> 
> I live in PAL-country but from user reports and 
> samples (like the one in question) I know that 
> this unfortunately isn't true;-(
> 
> This whole issue is about vob files that contain 
> both progressive 24000/1001 and (hard-) telecined 
> 30000/1001 video in the same stream (with actual 
> switching frame rates).
> It appears to me that decimate should detect the 
> frame rate changes and not drop anything for the 
> progressive content.
> 
> Carl Eugen


I've also seen mixed hard telecined (24->29.97) and interlaced (29.97) in the same stream, or hard telecined and 29.97 progressive. This whole thing makes me wish we used PAL here. Also metric paper, but that is a different gripe.

Not now, but later, I would be interested in helping to adapt decimate to do what we want.
A detectfps filter might be useful too, and would be a subset of the work.

Nick