[FFmpeg-devel] [PATCH 2/2] doc/filters: add a signalstats example

Dave Rice dave at dericed.com
Wed Jul 2 05:52:54 CEST 2014


On Jul 1, 2014, at 11:36 PM, Timothy Gu <timothygu99 at gmail.com> wrote:
> On Tue, Jul 1, 2014 at 7:44 PM, Dave Rice <dave at dericed.com> wrote:
>> +ffplay example.mov -vf signalstats=stat=brng+vrep+tout,
>> drawtext=fontfile=FreeSerif.ttf:x=8:y=8:fontcolor=yellow:shadowx=3:
>> shadowy=2:fontsize=20:tabsize=8:textfile=signalstat_drawtext.txt'
> The x, y, fontcolor, shadow*, fontsize options are all optional.
> Putting them here will only confuse the reader. You can keep the
> tabsize but an explanation would be helpful.

I removed the options and expanded the description to say that this draws the metadata in a table (via tabs).

> Another problem is that there is an extra ' at the end of the command.
> Also, can you do an 80-column wrap? This will look terrible on man pages.

Both fixed locally.

>> + at end example
>> +
>> +when the contents of signalstat_drawtext.txt are:
> Drop the "when":
> The contents of signalstat_drawtext.txt used in the command are:

 Fixed locally.

>> + at example
>> +time (sec) %@{pts@}    pts %@{pts:hms@}        pict_type %@{pict_type@}
>> +
>> +       min     low     avg     high    max     diff
>> +Y      %@{metadata:lavfi.signalstats.YMIN@}    %@{metadata:lavfi.signalstats.YLOW@}    %@{metadata:lavfi.signalstats.YAVG@}    %@{metadata:lavfi.signalstats.YHIGH@}   %@{metadata:lavfi.signalstats.YMAX@}    %@{metadata:lavfi.signalstats.YDIF@}
>> +U      %@{metadata:lavfi.signalstats.UMIN@}    %@{metadata:lavfi.signalstats.ULOW@}    %@{metadata:lavfi.signalstats.UAVG@}    %@{metadata:lavfi.signalstats.UHIGH@}   %@{metadata:lavfi.signalstats.UMAX@}    %@{metadata:lavfi.signalstats.UDIF@}
>> +V      %@{metadata:lavfi.signalstats.VMIN@}    %@{metadata:lavfi.signalstats.VLOW@}    %@{metadata:lavfi.signalstats.VAVG@}    %@{metadata:lavfi.signalstats.VHIGH@}   %@{metadata:lavfi.signalstats.VMAX@}    %@{metadata:lavfi.signalstats.VDIF@}
>> +SAT    %@{metadata:lavfi.signalstats.SATMIN@}  %@{metadata:lavfi.signalstats.SATLOW@}  %@{metadata:lavfi.signalstats.SATAVG@}  %@{metadata:lavfi.signalstats.SATHIGH@} %@{metadata:lavfi.signalstats.SATMAX@}
>> +
>> +HUE (median)   %@{metadata:lavfi.signalstats.HUEMED@}
>> +HUE (average)  %@{metadata:lavfi.signalstats.HUEAVG@}
>> +TOUT           %@{metadata:lavfi.signalstats.TOUT@}
>> +VREP           %@{metadata:lavfi.signalstats.VREP@}
>> +BRNG           %@{metadata:lavfi.signalstats.BRNG@}
>> +
>> + at end example
>> @end itemize
>> @anchor{smartblur}
> Theoretically no tabs are allowed in FFmpeg. But I get why you decided
> to use it, and personally I'm OK with that. I'll leave final decision
> to somebody else.

I'll wait to see if anyone supports this use of tabs, else will rewrite a more simple and tab-free example.
Dave Rice

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