[FFmpeg-devel] [PATCH] Use hi-res timer under win32 builds
Alexander Chemeris
ipse.ffmpeg
Mon Oct 15 11:57:27 CEST 2007
On 10/15/07, Fred Rothganger <fred at rothganger.org> wrote:
> @@ -2579,9 +2583,21 @@
> */
> int64_t av_gettime(void)
> {
> +# if defined(WIN32) || defined(__CYGWIN__)
> +
> + LARGE_INTEGER count;
> + LARGE_INTEGER frequency;
> + QueryPerformanceCounter (&count);
> + QueryPerformanceFrequency (&frequency);
> + return count.QuadPart * 1000000 / frequency.QuadPart;
> +
> +# else
> +
> struct timeval tv;
> gettimeofday(&tv,NULL);
> return (int64_t)tv.tv_sec * 1000000 + tv.tv_usec;
> +
> +# endif
> }
DON'T USE THIS if you do not actually understand how to get this
working relibaly. A good reasoning is provided here:
http://www.virtualdub.org/blog/pivot/entry.php?id=106
Also there was some technical note from MS about this issues,
but I do not recall url for it. I saw QueryPerformanceCounter()
badness myself on my Core2 Duo - it provided totally different
values being called on different cores.
--
Regards,
Alexander Chemeris.
SIPez LLC.
SIP VoIP, IM and Presence Consulting
http://www.SIPez.com
tel: +1 (617) 273-4000
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