[FFmpeg-user] Possible ffmpeg regression in encoding interlaced h264 video

[Paul Gardiner]

I use this command to archive TV recordings:

/usr/bin/ffmpeg -f ac3 -i <audio-in> -f rawvideo -top 1 -pix_fmt yuv420p 
-s 1440x1088 -r 25 -i <video-in> -threads 2 -vf crop=1440:1080:0:0 
-vcodec libx264 -preset medium -profile high -flags +ilme+ildct -crf 
20.0 -aspect 16:9 -acodec copy -ar 48000 -f mp4 <encoded-file-out>.mp4

It used to work perfectly, giving a smoothly playing 50Hz interlaced
file. Something has changed recently, and now it still mostly works,
but the file produced is somehow marked as bottom-field-first,
rather than top-field-first. The system I use to playback has a
setting for reversing the interlace, so I can play these back and
see that in every other way the encoding is still correct.

Anyone know of changes that may have broken this? Should I be looking
at x264 rather than ffmpeg fort he cause, perhaps?

Cheers,
	Paul.