Re: [RFC] Video events, version 2.2

[Sakari Ailus <sakari.ailus@maxwell.research.nokia.com>]

Ivan T. Ivanov wrote:
> Hi Sakari, 

Hi,

> On Fri, 2009-10-23 at 13:18 +0300, Sakari Ailus wrote:
[clip]
>> struct v4l2_event {
>> 	__u32		count;
>> 	__u32		type;
>> 	__u32		sequence;
>> 	struct timeval	timestamp;
> 
> Can we use 'struct timespec' here. This will force actual 
> implementation to use high-resolution source if possible, 
> and remove hundreds gettimeofday() in user space, which 
> should be used for event synchronization, with more 
> power friendly clock_getres(CLOCK_MONOTONIC).

Good point. I originally picked timeval since it was used in 
v4l2_buffer. The spec tells to use gettimeofday() for system time but 
clock skewing is causes problems in video encoding. 
clock_getres(CLOCK_MONOTONIC) is free of clock skewing and thus should 
be more suitable for this kind of use.

I also propose to use timespec instead of timeval.

-- 
Sakari Ailus
sakari.ailus@maxwell.research.nokia.com