[FFmpeg-user] Meaning of ffprobe output

[Ulf Zibis]

Hi,

again to my initial question ...

Am 31.01.19 um 13:48 schrieb Carl Eugen Hoyos:
> DVD recorders can only produce interlaced files if the input
> was interlaced, in this specific case, a file with progressive
> content was produced (from progressive original).
>
> (Above of course only applies to the content of the file,
> not the encoding. But when talking about de-interlacing
> and the idet filter, only the content is relevant.)
So now I understand (hopefully). My main interest was is to know, if my
video is _encoded_ interlaced or not, and I still don't know it :-(
If it is encoded interlaced, I can understand, that only a pair of lines
can be cropped.

I tried to crop a single line, but got an error:
$ ffmpeg -i CYD_6m_copy.vob -movflags faststart -vf
"split[in1][in2];[in1]crop=in_w:1:0:1[top];[in2]crop=in_w:in_h-1:0:1[main];[top][main]
vstack" -c:v libx264 -c:a copy CYD_6m_crop+copy-1l_H.264.mp4
ffmpeg version 4.1-static https://johnvansickle.com/ffmpeg/  Copyright
(c) 2000-2018 the FFmpeg developers
  built with gcc 6.3.0 (Debian 6.3.0-18+deb9u1) 20170516
[....]
Input #0, mpeg, from 'CYD_6m_copy.vob':
  Duration: 00:06:00.62, start: 0.500000, bitrate: 7022 kb/s
    Stream #0:0[0x80]: Audio: ac3, 48000 Hz, stereo, fltp, 256 kb/s
    Stream #0:1[0x1e0]: Video: mpeg2video (Main), yuv420p(tv, bt470bg,
top first), 704x576 [SAR 12:11 DAR 4:3], 25 fps, 25 tbr, 90k tbn, 50 tbc
Stream mapping:
  Stream #0:1 -> #0:0 (mpeg2video (native) -> h264 (libx264))
  Stream #0:0 -> #0:1 (copy)
Press [q] to stop, [?] for help
[Parsed_crop_1 @ 0x714df40] Invalid too big or non positive size for
width '704' or height '0'
[Parsed_crop_1 @ 0x714df40] Failed to configure input pad on Parsed_crop_1
Error reinitializing filters!
Failed to inject frame into filter network: Invalid argument
Error while processing the decoded data for stream #0:1

What does it mean, that ffmpeg (ffprobe as same) says "top first"? Does
it mean, that my video is encoded interlaced?

If the content of my video is progressive, IHMO it would not harm to
re-encode it progressive, so I can crop single lines.

How can I do this?

-Ulf