[FFmpeg-user] Meaning of ffprobe output

[Ulf Zibis]

Thanks Carl Eugen ...

Am 11.01.19 um 01:47 schrieb Carl Eugen Hoyos:
> 2019-01-11 0:39 GMT+01:00, Ulf Zibis <Ulf.Zibis at gmx.de>:
>
>> tbn
> This is the container timebase, 90k for mpeg streams.

For what stands 90k? For 90,000 milli seconds?

>> -movflags +faststart -c copy CYD_copy.vob
> Sadly, output option cannot (easily) be checked for correctness.
> Using options that cannot have an effect may reduce your
> chance to get good help here (consider the increased time it
> needs to understand what's going on / what your intentions are).

The probably wrong '+' was taken from the example in the Wiki:
https://trac.ffmpeg.org/wiki/Encode/H.264#AdditionalInformationTips
Maybe this is an error?
Because VOB also is coded with MPEG, I thought this flag may have a
positive effect.
Anyway, without the flag I get the same ffprobe data.


*From:*
$ ffprobe CYD_copy.vob
Input #0, mpeg, from 'CYD_copy.vob':
  Duration: 01:16:20.74, start: 0.500000, bitrate: 7068 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
*I transcoded with:*
$ ffmpeg -i CYD_copy.vob -movflags +faststart -vf atadenoise -c:v
libx264 -c:a libmp3lame -q:a 4 CYD_atadenoise_H.264.mp4
*and get:*
$ ffprobe CYD_atadenoise_H.264.mp4
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'CYD_atadenoise_H.264_mp3-q4.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf57.83.100
  Duration: 01:16:20.42, start: 0.000000, bitrate: 1403 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p,
704x576 [SAR 12:11 DAR 4:3], 1276 kb/s, 25 fps, 25 tbr, 12800 tbn, 50
tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: mp3 (mp4a / 0x6134706D), 48000 Hz, stereo,
fltp, 119 kb/s (default)
    Metadata:
      handler_name    : SoundHandler

Does 50 tbc mean, that I still have 50 interlaced half-frames per
second, or why is the codecs timebase 50?

Thanks for your comments

-Ulf


> Not necessarily related: "-c copy" cannot change anything
> about fields ("half-frames"),

I didn't expect that, the question was about: -c:v libx264

>  libx264 does not support PAFF
> encoding.

What is PAFF?

Thanks in advance

-Ulf