[mythtv] [mythtv-commits] Ticket #2127: Optimize Timeval Offset Calculation in VideoSync::OffsetTimeval()

[Martin Ebourne]

On Sun, 06 Aug 2006 13:01:44 -0700, Jim Westfall wrote:

> MythTV <mythtv at cvs.mythtv.org> wrote [08.06.06]:
>> #2127: Optimize Timeval Offset Calculation in VideoSync::OffsetTimeval()
>> --------------------------------+-------------------------------------------
>>  Reporter:  russell at digium.com  |       Owner:  ijr
>>      Type:  patch               |      Status:  new
>>  Priority:  minor               |   Milestone:     
>> Component:  mythtv              |     Version:     
>>  Severity:  medium              |  
>> --------------------------------+-------------------------------------------
>>  The attached patch provides a more efficient method for applying the
>>  microsecond offset to the supplied timeval structure.  In passing, I went
>>  ahead and documented the function using doxygen style
>>  comments.[[BR]][[BR]]IRC: russellb
> 
> You benchmarked your optimized code as being faster? seems like it would 
> be slower.

Slower? Just plain wrong!

What about when usec overflows to sec?

I dare say that the current method is very inefficient if offset is many
seconds and could be improved, but improved in a correct fashion
hopefully. If offset is nearly always less than a few seconds (which it
quite possibly is) then the current method looks likely to be efficient
already.

Cheers,

Martin.