[FFmpeg-user] How to extract 1 frame as JPEG per minute

[Ulf Zibis]

Hi again,

Am 20.12.18 um 01:20 schrieb Carl Eugen Hoyos:
> I suspect your video does not start at "0".

You may be right, so I'm wondering why. To find this out, I describe how
I created the video:

The DVD was recorded by a hardware DVD-Recorder from the original VHS
cassette several years ago by somebody unknown. I only have the DVD,
which has several format errors, so it only can be played by a hardware
DVD-Player or with VLC, other players report read errors. So I first
ripped the DVD with dvd::rip. As result I got 23 VOB snippets, which
were a kind of corrupted, as no player could display the snippets
without errors. Then I concatenated them to 1 file with:
ffmpeg -ss 00:03 -t 01:16:20 -i
"concat:001-C001/CYD-001.vob|001-C002/CYD-001.vob|001-C003/CYD-001.vob|001-C004/CYD-001.vob|001-C005/CYD-001.vob|001-C006/CYD-001.vob|001-C007/CYD-001.vob|001-C008/CYD-001.vob|001-C009/CYD-001.vob|001-C010/CYD-001.vob|001-C011/CYD-001.vob|001-C012/CYD-001.vob|001-C013/CYD-001.vob|001-C014/CYD-001.vob|001-C015/CYD-001.vob|001-C016/CYD-001.vob|001-C017/CYD-001.vob|001-C018/CYD-001.vob|001-C019/CYD-001.vob|001-C020/CYD-001.vob|001-C021/CYD-001.vob|001-C022/CYD-001.vob|001-C023/CYD-001.vob"
-movflags +faststart -c copy /media/Sicherung/Filme/CYD/ffmpeg/CYD_copy.vob
The result was playable. In the console I saw a lot of sync and other
errors which seemed to be corrected by ffmpeg.

Then I filtered the video and converted it to MPEG-4 with H.264 and Lame
codecs:
ffmpeg -i CYD_copy.vob -movflags +faststart -vf atadenoise -c:v libx264
-c:a libmp3lame -q:a 4 CYD_atadenoise_H.264_mp3-q4.mp4
In the console I still saw some of sync and other errors.

>From this file I extracted the JPEGs with:
ffmpeg -i CYD_atadenoise_H.264_mp3-q4.mp4 -vf select='not(mod(n\,1500))'
-vsync vfr -q:v 2 CYD_atadenoise_1%03d.jpg

Can you give me some hints, how I can assure, that my files are
error-free and will start at "0"?

Thanks

-Ulf