[FFmpeg-user] 2 pass CBR or VBR not really fixing the bitrate?

Nicolas George george at nsup.org
Mon Jul 31 21:29:45 EEST 2017


Le tridi 13 thermidor, an CCXXV, Manuel Tiglio a écrit :
> 1.23. For VOD content the peak bit rate SHOULD be no more than 200% of the average bit rate.

Without a proper definition of "peak bit rate", this sentence is
meaningless. A bit rate is a quantity of information divided by a time.
Since it is discrete, there is no way of doing calculus, and therefore
there is no notion of instantaneous bit rate. Thus, without saying the
period of time on which the bit rate is computed, it does not mean
anything.

> Two pass encoding is used for CBR and constrained VBR.

No, not for CBR. For CBR, you use all bits allowed, period.

Regards,

-- 
  Nicolas George
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: Digital signature
URL: <http://ffmpeg.org/pipermail/ffmpeg-user/attachments/20170731/45cd518a/attachment.sig>


More information about the ffmpeg-user mailing list