[FFmpeg-user] Extracting video levels on the command line

[Robert Krüger]

On Tue, Aug 4, 2015 at 4:11 PM, Dave Rice <dave at dericed.com> wrote:

>
> > On Aug 4, 2015, at 6:22 AM, Robert Krüger <krueger at lesspain.de> wrote:
> >
> > On Mon, Aug 3, 2015 at 10:49 PM, Paul B Mahol <onemda at gmail.com> wrote:
> >
> >> Dana 3. 8. 2015. 22:28 osoba "Moritz Barsnick" <barsnick at gmx.net>
> napisala
> >> je:
> >>>
> >>> On Mon, Aug 03, 2015 at 21:55:59 +0200, Robert Krüger wrote:
> >>>> Is there any other way than looking at each frame's histogram (using
> >> the
> >>>> histogram filter) and counting pixels?
> >>>
> >>> It should probably be easy to write such a filter.
> >>>
> >>> Have you looked at signalstats? It does seem to have the capability to
> >>> identify various statistics on the Y, U, V planes, but reports them
> >>> only in metadata, not in console output (IIUC).
> >>
> >> ffprobe can output any metadata
> >
> >
> > Thanks. I overlooked signalstats. It does not give me quite what I want,
> > because it's per frame but it is a lot better than abusing the histogram
> > filter for that. No idea if this makes sense but maybe this total min/max
> > thing could even be implemented generically in ffprobe for any
> > number-valued metadata but that's just an idea.
>
> A summary section for signalstats would make sense. As a workaround you
> could output from the filter to a csv and then evaluate the csv:
>
> ffprobe -f lavfi movie=file.mov,signalstats -show_entries
> frame_tags=lavfi.signalstats.YMIN,lavfi.signalstats.YMAX -of csv > stats.csv
>
>
yes, scripting that is easy in csv or xml. I will probably do that (and
then hope that someone adds this functionality eventually, I know, patch
welcome :-S)