[FFmpeg-user] ffprobe -show_frames values

Joel Lopez badassmexican at gmail.com
Tue May 5 00:05:51 CEST 2015


That was definitely easier to read.  I did a grep for "I" for my 4 versions
of the same video at different bitrates.  I can now tell that they
keyframes aren't aligned and under 1 second apart.  All my research says
keyframes must be aligned and a constant separation between 2 - 10 seconds.

Should I re-encode these videos or could they still work?  I saw that it's
be possible to force keyframes on an existing video.

video 1
frame,0.000000,I
frame,1.200000,I
frame,1.266667,I
frame,1.333333,I
frame,3.000000,I
frame,6.000000,I
frame,9.000000,I
frame,12.000000,I
frame,15.000000,I
frame,18.000000,I
frame,21.000000,I
frame,24.000000,I
frame,27.000000,I
frame,30.000000,I
frame,33.000000,I
frame,36.000000,I
frame,39.000000,I
frame,42.000000,I
frame,45.000000,I
frame,48.000000,I
frame,51.000000,I
frame,54.000000,I
frame,57.000000,I
frame,60.000000,I

video 2
frame,0.000000,I
frame,1.200000,I
frame,1.266667,I
frame,4.000000,I
frame,8.000000,I
frame,12.000000,I
frame,16.000000,I
frame,20.000000,I
frame,24.000000,I
frame,28.000000,I
frame,32.000000,I
frame,36.000000,I
frame,40.000000,I
frame,44.000000,I
frame,48.000000,I
frame,52.000000,I
frame,56.000000,I
frame,60.000000,I
frame,64.000000,I
frame,68.000000,I
frame,72.000000,I
frame,76.000000,I
frame,80.000000,I
frame,84.000000,I

video 3
frame,0.000000,I
frame,4.000000,I
frame,8.000000,I
frame,12.000000,I
frame,16.000000,I
frame,20.000000,I
frame,24.000000,I
frame,28.000000,I
frame,32.000000,I
frame,36.000000,I
frame,40.000000,I
frame,44.000000,I
frame,48.000000,I
frame,52.000000,I
frame,56.000000,I
frame,60.000000,I
frame,64.000000,I
frame,68.000000,I
frame,72.000000,I
frame,76.000000,I
frame,80.000000,I
frame,84.000000,I
frame,88.000000,I
frame,92.000000,I

video 4
frame,0.000000,I
frame,1.200000,I
frame,5.200000,I
frame,9.200000,I
frame,13.200000,I
frame,17.200000,I
frame,21.200000,I
frame,25.200000,I
frame,29.200000,I
frame,33.200000,I
frame,37.200000,I
frame,41.200000,I
frame,45.200000,I
frame,49.200000,I
frame,53.200000,I
frame,57.200000,I
frame,61.200000,I
frame,65.200000,I
frame,69.200000,I
frame,73.200000,I
frame,77.200000,I
frame,81.200000,I
frame,85.200000,I
frame,89.200000,I



On Fri, May 1, 2015 at 2:13 AM, Werner Robitza <werner.robitza at gmail.com>
wrote:

> On Thu, Apr 30, 2015 at 5:26 PM, Joel Lopez <badassmexican at gmail.com>
> wrote:
> >
> > Thanks for the help.  It's making a bit of sense now.  It looks like my
> > keyframes are 1/3 of a second.  Is less than 2 seconds apart ok?
>
> For adaptive streaming the keyframes should be at regular intervals.
> That means, for encoding, you'll have to specify a keyframe interval
> and disable scene cut detection, if any.
>
> > In the pict_type field I'm seeing B's and P's with one I.  Does that
> > translate to how far apart they are?
>
> Use this command, which gives you output that's easier to read:
>
> ffprobe -select_streams v -show_frames -of csv -show_entries
> frame=pkt_pts_time, pict_type
>
> Now, assuming the PTS time increases in regular intervals, it'll be
> quite easy to count the distance (in number of frames) between
> I-frames, and the time interval. Just do the subtraction of the PTS
> between two consecutive I-frames.
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