[FFmpeg-devel] [PATCH] Use monotonic clock for measuringreltime.

Don Moir donmoir at comcast.net
Wed Apr 2 20:06:31 CEST 2014

>>>>Because only the local time changes, not the system time.
>> >Windows (though I think only old versions) demonstrate that you can have
>> >both the same, but it also demonstrates that it is a stupid idea that
>> >doesn't work properly even after adding hacks on top of hacks to make it
>> >somewhat work.
>> Not to big a deal because it is somewhat rare, but the time can fluctuate
>> like I said on windows at least with the use of GetSystemTimeAsFileTime
>> which is what av_gettime maps to under windows. Don't know for linux.

>You are aware that this part was about summer time changes?
>GetSystemTimeAsFileTime specifically is _not_ affected by that.

Any time the clock changes, GetSystemTimeAsFileTime is effected I think. I know it does when user sets the time or it's done 
automated. The way your suppose to deal with that is pole for message indication of it but thats silly.

>> The resolution of GetSystemTimeAsFileTime is 15ms and work arounds are not that elegant.

>As far as I can find out that is only true on XP and similarly old
>systems (though maybe not, because if it was there would be no reason
>for GetSystemTimePreciseAsFileTime, the documentation of both is quite

GetSystemTimeAsFileTime is same res above XP and if you want better res you need to use GetSystemTimePreciseAsFileTime for Windows 8 

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