[Libav-user] FFmpeg components needed to extract audio/video metadata

Carl Eugen Hoyos cehoyos at ag.or.at
Thu Oct 11 16:42:40 CEST 2012


William Seemann <wseemann at ...> writes:

>      FLAGS="$FLAGS --enable-shared --disable-symver"

(You could add --disable-debug although it is not 
default for shared anyway iirc.)

>      FLAGS="$FLAGS --enable-small --optimization-flags=-O2"

There are two possibilities:
Either "-O2" is good (be it for all use cases, or only for 
--enable-small), then it should be made default (either in 
all cases, or if --enable-small was selected) = please 
report that it should be made default (and why), so other 
users profit from your experience!
Or it is bad, then don't use it ;-)

>      FLAGS="$FLAGS --disable-doc"

>      FLAGS="$FLAGS --disable-ffmpeg"
>      FLAGS="$FLAGS --disable-ffplay"
>      FLAGS="$FLAGS --disable-ffprobe"
>      FLAGS="$FLAGS --disable-ffserver"

>      FLAGS="$FLAGS --disable-avdevice"
>      FLAGS="$FLAGS --disable-swresample"
>      FLAGS="$FLAGS --disable-swscale"
>      FLAGS="$FLAGS --disable-postproc"
>      FLAGS="$FLAGS --disable-avfilter"
>      FLAGS="$FLAGS --disable-everything"

Doesn't --disable-everything make the others 
unneeded (at least some of them)?

>      FLAGS="$FLAGS --disable-gpl"

This is unneded (disable-gpl is the default).

>      FLAGS="$FLAGS --enable-parsers"

I suspect this enables a very large part of the 
software you disabled above. Try to enable 
only the parsers you need.

>      FLAGS="$FLAGS --enable-protocol=http"

>      FLAGS="$FLAGS --enable-demuxers"
> 
> For instance, if I only need to extract metadata 
> for mp3, ogg, and flac what specifically needs to 
> be enabled?

Did you try --enable-demuxer=mp3,ogg,flac instead of 
--enable-demuxers?

Carl Eugen



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