windows time accuracy issue if based on CPU clock
See [4515]
However if the CPU clock IS reliable as Frequency, then VLC still falls back to a more sucky system. We need another fallback method, because it is causing problems on some systems. fenrir suggests: "you can try using timeBeginPeriod and timeGetTime (and timeEndPeriod, timeGetDevCaps)".
Reported by Gammaburst on a:
I'm running Win2k SP3, Tyan S2460 motherboard with dual 1.4 GHz Athlons. Plain GeForce 6800 graphics card with two 1600x1200 LCD screens, one rotated 90 degrees. Hercules Fortissimo II sound card.
Also a lot of info on this gamedev.net page below. (pulled from google cache, since it's for registered users only)
They use this check, perhaps something similar is useful for us?:
/ PIT and PMT are safe.
if(qpc_freq == 1193182 || qpc_freq == 3579545)
safe = true;
// make sure QPC doesn't use the TSC
// (if it were safe, we would have chosen it above)
else
{
// can't decide yet - assume unsafe
if(cpu_freq == 0.0)
safe = false;
else
{
// compare QPC freq to CPU clock freq - can't rule out HPET,
// because its frequency isn't known (it's at least 10 MHz).
double freq_dist = fabs(cpu_freq / qpc_freq - 1.0);
safe = freq_dist > 0.05;
// safe if freqs not within 5% (i.e. it doesn't use TSC)
}
}