Transforming interlaced to progressive...?


I have a bunch of home videos, captured in AVCHD format, 50 fps interlaced. This gives them a slightly "striped" look, when there is movement in the picture. I belive this is a consequence of the interlacing - right? If so - is there a way to "de-interlace" them, to get rid of or minimize this "striping" effect? (I have read somewhere about convertint go progressive, but did not get it and cannot find it again)


I'd suggest leaving them interlaced, you stand to loose half the vertical resolution and the 50fps is rather 25fps with two fields which have a temporal difference between them.

Best to just let the media player deinterlace at playback if necessary and to a quality depending on media player hardware.

If you want to deinterlace then a decent way to do it with motion analysis and frame doubling to give you 50fps would be with Avisynth + Wine + QTGMC

Best to just let the media player deinterlace at playback if necessary and to a quality depending on media player hardware.

Unfortunately this is not always desirable, as the interlace artefacts may remain yet the player does not bother to deinterlace, or may reverse the fields, wich is even worse. Uploading to the internet could also be a problem as again interlace artefacts would remain and look particularly bad when scaled. You already lose vertical resolution in most cases with interlacing as both fields are not meant to be shown at the same time anyway.

However you right that the best way to do it would be to output to an interlace file and deinterlace there. More convenient than Wine would be to use Avidemux which has a variety of de-interlace filters, including the option to de-interlace to 50FPS. However you would want to minimise conpression and if possible create an uncompressed (or visually lossless compression) - which might be tough in terms of space and time.

Alternatively you could create an export profile which de-interlaces in ffmpeg or avcon when exporting if you want a basic field drop, which would skip the step of exporting to another file, but likely offer fewer options and less control.


Thanks for your replies!!

So, the Avidemux-solution seems attractive to me - but just so I understand: does this mean FIRST rendering a film, and THEN de-interlacing it, or is there a way to de-interlace the .mts-clips?


@dylanpank, If you're going to use YADIF in Avidemux then you might as well use YADIF in MLT via kdenlive as that's how kdenlive deinterlaces. QTGMC offers more but expects more effort. Horses for coarses.

@magnusl, if you want to use Yadif outside of kdenlive then yes first edit, then export as via one of the 'lossless' formats, I frame mpeg2 would be decent for your source, then import into Avidemux, deinterlace and encode to h264 or whatever.

You could also use yadif within ffmpeg. Just check it out!

For conversion of m2ts files from a 1080i Sony Camera I used:

ffmpeg -i "$filename" -vf yadif=1 -acodec ac3 -ab 192k -vcodec libx264 -s 1920x1080 -f mp4 -y -sameq "$deinterlaced"

(Just mind that sameq parameter is no longer used in more recent ffmpeg versions!)