[FFmpeg-user] Why are half the frames "duplicate" ?

[Carl Eugen Hoyos]

2018-09-27 4:27 GMT+02:00, sean darcy <seandarcy2 at gmail.com>:
> I'm transcoding mpeg2 -> x264.
>
> Stream #0:0[0x64]: Video: mpeg2video (Main) ([2][0][0][0] / 0x0002),
> yuv420p(tv, progressive), 720x480 [SAR 8:9 DAR 4:3], Closed Captions,
> 29.97 fps, 59.94 tbr, 90k tbn, 59.94 tbc
>
> When I run ffmpeg:
>
> ffmpeg -i in.mpg -map 0:0 -map 0:2 -c:v libx264 -tune film -preset slow
> -crf 22 -c:a copy out.mp4

Please (test current FFmpeg git head and) provide the command line
you used together with the complete, uncut console output.

If your input is progressive and variable frame rate and you want
mp4 output, then the duplicated frames are unavoidable as FFmpeg
is unable to write valid variable frame rate mp4 files.
(vfr mkv is supported)
If your input is mixed telecined and progressive, there are command
lines that help iirc.
If your input is only telecined or soft telecined, the output frame-rate
should be 24000/1001 (this is also true for the case above).
The idet filter can help you detect what your input's properties are,
visual inspection is even better, an alternative is to provide a sample.

Carl Eugen