[FFmpeg-user] Warning: VBV buffer size not set

[Carl Eugen Hoyos]

2018-12-13 0:57 GMT+01:00, Hans Carlson <forbyta at gmx.com>:
> On Wed, 12 Dec 2018, Carl Eugen Hoyos wrote:
>
>> 2018-12-08 22:28 GMT+01:00, Ulf Zibis <Ulf.Zibis at gmx.de>:
>>
>>> with:
>>> ffmpeg -i "concat:CYD-001.vob|CYD-002.vob|..." -c copy CYD_copy.vob
>>> I get the warning:
>>> [svcd @ 0x56377151e140] VBV buffer size not set, using default size of
>>> 130KB
>>> If you want the mpeg file to be compliant to some specification
>>> Like DVD, VCD or others, make sure you set the correct buffer size
>>>
>>> How can I aviod the warning?
>>
>> Use the target option.
>
> If the target option is used WITHOUT "-c copy", then it's true you won't
> see this warning.  But then it's doing a re-encode... NOT a copy.  The
> problem comes when trying to do a COPY and the target option doesn't
> help in that case.
>
> So, I'll rephrase Ulf's original question... how do you avoid this warning
> while doing a stream COPY (remux)?

You cannot, as the maximum bit-rate cannot be set when remuxing.
The muxer has to assume that your input confirms to the relevant
specification. Note that command lines without "-f" make it
impossible for ffmpeg to even understand which standard you want.

Carl Eugen