[FFmpeg-devel] Reducing time spent in av_find_stream_info()

[Diego Santa Cruz]

> > For video streams there is still a good deal of time spent updating
duration_error, due to the lack
> of FPU and the large amount of standard timebases tested when updating
duration_error. Is it really
> necessary to have all those standard time bases? There are currently
725. As far as I understand all
> frame rates between 1/1001 and 60/1001, in steps of 1/12, are
included. Can this be reduced to a
> (much) more reduced set so that it does not take that much time to
compute duration_error? As this
> code affects all file formats and broken files I do not know all the
implications by far...
> 
> its surely possible to remove some of frame rates, but the code must
be clean
> if its more complex than currently then it likely will be rejected
> also the floats could be chnaged to integers
> and there are likely many optimizations possible, ive not expected
this code
> to matter speedwise at all
> 

I see, any hints about which framerates should be kept? I will try also
to reduce the complexity of the calculations.

 
> reindentions must be in seperate patches from functional changes (see
the
> docs on ffmpeg.org)
> 

Ooops, sorry. Please see attached patches, first one is the actual
change, second one reindents the code to make it prettier.

--
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Diego Santa Cruz, PhD
Software Architect, SpinetiX S.A.

PSE-C, CH-1015, Lausanne, Switzerland
Tel:    +41 (0) 21 693 89 81
Mail:   Diego.SantaCruz at spinetix.com

Get Information : www.spinetix.com

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