[FFmpeg-trac] #3678(avcodec:new): Regressions in the video duration/bitrate report
FFmpeg
trac at avcodec.org
Wed May 28 11:59:44 CEST 2014
#3678: Regressions in the video duration/bitrate report
------------------------------------+-----------------------------------
Reporter: Malizor | Owner:
Type: defect | Status: new
Priority: normal | Component: avcodec
Version: git-master | Resolution:
Keywords: | Blocked By:
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
------------------------------------+-----------------------------------
Comment (by cehoyos):
Replying to [comment:4 Malizor]:
> Replying to [comment:3 cehoyos]:
> > Replying to [comment:2 Malizor]:
> >
> > > The full video file is 40G and is 1h 26mn long.
>
> Sorry, in fact it is truly 1:48:31 long (as verified by playing the
video in VLC 2.0.8)
Could you add the exact file size?
{{{ffmpeg -i input -f null -}}} tells you the exact length.
> > > I understand what you say about the bitrate, but it's sure that it
is truly higher than the detected 9118 kb/s.
> >
> > Of course.
> > The bitrate of the file is unknown / wrong because the video stream
doesn't store a bitrate.
>
> Apparently somthing changed in the way ffmpeg try to guess the bitrate,
and it has regressed for some videos like this one.
No. (Or at least I find this wording misleading.)
The value written in mpegvideo streams is not the actual bitrate but the
maximum bitrate.
For your (mxf) file, the values are nearly identical, for (more typical)
dvb streams, the value is completely wrong. It was therefore decided not
to use the (possibly wrong) maximum bitrate value as actual video bitrate.
--
Ticket URL: <https://trac.ffmpeg.org/ticket/3678#comment:5>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker
More information about the FFmpeg-trac
mailing list