[FFmpeg-user] Meaning of ffprobe output

Ulf Zibis Ulf.Zibis at gmx.de
Fri Jan 18 16:58:15 EET 2019

Hi again,

Am 15.01.19 um 12:54 schrieb Carl Eugen Hoyos:
>>>>>> tbn
>>>>> This is the container timebase, 90k for mpeg streams.
>>>> For what stands 90k? For 90,000 milli seconds?
>>> It stands for a timebase of 1/90000
>> Is it 1/90000 second?
> I suspect timebase is a fraction and has no unit but I may be wrong.

Timebase without unit? What does it serve for?
If it's 1/90000 h, then it would be equal to 1/25 s, which would
perfectly align with the fps 25 of the file.

>>> which is the timebase for all mpeg streams (and cannot be changed afaik).
>> Do you mean MPEG-2 with "mpeg"?
> MPEG program and MPEG transport streams are (also)
> defined in the MPEG-2 standard (that also defines
> several other things).
>> My MPEG-4 stream has 12800 tbn
> Command line and complete, uncut console output missing.

I here refer to the output in my post from 2019-01-12 22:32 GMT+01:00

>> i.e. then the video player is able to write 50 half-frames per
>> second to the output display, which provides better quality
>> than 25 merged progressive frames per second.
> Only (old!) CRTs can do this, so I assume this has no
> relevance here.

You may be right. Technically I don't see an obstacle for a software
player to feed the video display buffer with 50 half-frames per second,
as most displays refresh rate is at least 50 per sec.

> The "idet" filter can do this. 

I have tried that with:
$ ffmpeg -i CYD_atadenoise_H.264_mp3-q4.mp4 -vf idet
and get:
Trailing options were found on the commandline.
At least one output file must be specified.

Now I'm confused what to do, as I don't want to create another big file.
How is the correct syntax?


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