[FFmpeg-devel] [RFC] Runtime-inited versus Hardcoded tables.

Kostya kostya.shishkov
Thu Jan 31 13:38:50 CET 2008


On Thu, Jan 31, 2008 at 01:23:43PM +0100, Reimar D?ffinger wrote:
> Hello,
> On Thu, Jan 31, 2008 at 12:54:16PM +0100, Zdenek Kabelac wrote:
> > But I think that files like rv34vlc.h,indeo3data.h are already quite
> > too much if there exists simple code to generate them at runtime I
> > would prefer rather this version.
> 
> After compression at least the indeo ones are less than 20 kB as well
> though.
> Nevertheless, if they are really big and easy to create, IMO they should
> not just be created at runtime but be part of the codec context - at
> least I consider the usual case that only one codec is open at a time,
> and big tables should not use up memory when the codec is no longer
> used, just because it has been used once.
> Though if there are big tables and they can be easily calculated at
> runtime, there is quite a probability that those tables could be made
> smaller without much of a speed loss.
> 
> > The scenario is simple - you release binary/source package which is
> > then downloaded by thousands of user - which spends time/money waiting
> > for download :)
> 
> Even if we were pessimistic and assumed 20 codecs with as huge tables as
> indeo3, that would be about 400 kB of data to transfer. Even for a modem
> user that is not that much of a deal - at least that is what I think,
> and why I find this a bit constructed.

Alternatively we can consider taking ScummVM path - moving large tables
into binary file and loading data from it when needed.
This will add a bit of user confusion too.




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