How to play interlaced video, where even lines at top half of picture, and odd lines at bottom half?

Question

I have some device which streams h264 video in following format: top half of picture is even lines of video, and bottom half of picture is odd lines of video. So the question is - how can I play this video in normal visibility, using standart players, ffplay for example. I know about "tinterlace:merge" plugin in ffmpeg, but it combines video from two pictures following one by one. So my task is make a correct video from single frame. Regards, Alexey.

Answer 1

It would be good if you could provide a sample video file. You describe very well what the picture looks like, but the file may contain other information that is helpful for playback.

Furthermore, the format you describe doesn't sound like a standard format, so it's unlikely you will get a regular player to play it the way you want, out-of-the-box. If you're using ffplay, it's likely that you will have to write your own plugin to re-order the scanlines prior to displaying them.

Alternatively, you could re-encode the video into a standard format (interlaced or deinterlaced) using ffmpeg. You could then play it back in any regular player, like ffplay or VLC.

Finally, I recommend asking your question on the ffmpeg mailing list.

Answer 2

I recently had to deal with the exact same problem.

there are many different methods and the optimum solution completely depends on your situation,

the simplest fastest method is weaving two fields together which is perfect for immobile parts but create comb effect in moving object.

more complicated methods use motion detection methods.

what I did was merging two fields then applying Edge-Line averaging (ELA) for moving segments to reduce comb effect.

check this link for a detailed explanation of the problem