[vlc-devel] [vlc-commits] commit: mtime: Avoid overflow when using mach_absolute_time(). (Pierre d' Herbemont )

Rémi Denis-Courmont remi at remlab.net
Sun Sep 26 06:52:21 CEST 2010


   Hello,

On Sunday 26 September 2010, git at videolan.org wrote:
> vlc | branch: master | Pierre d'Herbemont <pdherbemont at free.fr> | Sun Aug 
> 1 12:48:49 2010 +0200| [532b014ad9c53a3ef32a74373fdb895726bde516] |
> committer: Pierre d'Herbemont
> 
> mtime: Avoid overflow when using mach_absolute_time().
> 
> Switch to double, do the operations and then convert back.
> This fixes the iPad video freezes.

Double precision operations are probably awfully slow on iPad. I am not aware 
of any ARM core that supports doubles in hardware. This may be neglectible 
because ARM does not support integer division (by a non-constant or non-power 
of two divisor) either. Still, double has less precision than int64_t so this 
seems like a regression to me.

Why don't you use the same (integer) strategy as the Win32 code already does?

-- 
Rémi Denis-Courmont
http://www.remlab.net/



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