Detecting Interlaced Video

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Newsgroups: gmane.comp.video.transcode.user
Date: 2005-11-25

0n 05/11/25 <at> 11:06 Jeff Hyche told me:

> There must be 50 ways to deinterlace video but I can't find out how to tell
> if the video is interlaced to start with.

If the video is interlaced and you want to keep it interlaced (my advice, if you encode for CRT-TV) you just have to tell transcode which field is first (—encode_fields).

PAL is normaly (from TV) top-field first, ntsc bottom-field first. In case of DV source both are bottom-field first.

Detecting Interlaced Video

> if the video is interlaced to start with.

I guess Jeff wants to check whether the source is interlaced at all..

If in doubt (both whether interlaced and - if interlaced - what field-order), try the "fieldanalysis" filter.

> If you have a video that is already deinterlaced it is progressive,
> isn't it?

Deinterlacing a non-deinterlaced source-material will degrade quality.

Filter Plugins/Filter Fieldanalysis

http://www.transcoding.org/cgi-bin/transcode?Filter_Plugins/Filter_Fieldanalysis

*Tags*: fieldanalysis — transcode plug-in/plugin/filter to detect progressive/interlaced/telecined video

fieldanalysis scans video for interlacing artifacts and detects progressive / interlaced / telecined video. It also determines the major field for interlaced video.

Usage Examples: No.

documented on: 2006.01.08