[Ffmpeg-devel] (minor) performance improvement suggestions

Robert Lippmann rlippmann
Sat Jun 4 06:22:56 CEST 2005

hi all,

been looking at some minor optimizations during some of the initialization
functions.  due to the sheer number of format/codecs, i think some
improvements can be made.  not on the scale of improving a couple
milliseconds on a decoder loop, but every little bit counts, right?

anyway, here's my suggestions:
1) in av_probe_input_format, it does an exhaustive search over a large
number of input format types.  some probes return AVPROBE_SCORE_MAX.
shouldn't the loop just break there?
2) in a similar vein, perhaps some of the lesser used formats (ie westwood,
sierra, etc) shouldn't be enabled (and registered ) by default.
3) similarly, avcodec_find_encoder and avcodec_find_decoder look through a
long linked list.  seems like there's a natural hash key using the codec id
and encode/decode.  but, finding a minimal perfect hash function generator
in a friday night is making my head hurt :)


-- rob

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