[x264-devel] VUI Header - timing info

[Sven Dueking]

Hi,

Can someone please explain the follwing calculation to me?

if( param->i_fps_num > 0 && param->i_fps_den > 0)
{
        sps->vui.b_timing_info_present = 1;
        sps->vui.i_num_units_in_tick = param->i_fps_den;
        sps->vui.i_time_scale = param->i_fps_num * 2;
        sps->vui.b_fixed_frame_rate = 1;
}

param->i_fps_num = (int)(fps * 1000 + .5); 
where fps is the frame rate and 
param->i_fps_den = 1000;

So, in case that the frame rate is equal to 30
sps->vui.i_time_scale is 60000

tc = sps->vui.i_num_units_in_tick / sps->vui.i_time_scale
(C2 in the standard).

tc is a clock tick an is the minimum interval of time can be
represented in the coded data. 
I am not sure, but I think is is the time interval between
two frames or in other words something like the display time offset.
Is this right ? I think in this case the calculation is not correct.
From my point of view sps->vui.i_time_scale must be equal to
param->i_fps_num.


Regards,
Sven






..............................................................................
Confidentiality Notice
The information contained in this Email, and any attachments, is intended for the named recipients only. It may contain confidential and/or legally privileged information. If you are not the intended recipient, you must not copy, store, distribute or take any action in reliance on it. Any views expressed do not necessarily reflect the views of the company.

If you receive this Email by mistake, please advise the sender by using the reply facility in your Email software and then delete it.
.............................................................................

-- 
This is the x264-devel mailing-list
To unsubscribe, go to: http://developers.videolan.org/lists.html