anyone who can explain more on the difference between segment.abs_rate and segment.abs_applied_rate

[bcxa sz]

And I also found the explanation from gst_event_new_new_segment_full():
=====================================================
* The @applied_rate value provides information about any rate adjustment that
* has already been made to the timestamps and content on the buffers of the
 * stream. (@rate * @applied_rate) should always equal the rate that has been
 * requested for playback. For example, if an element has an input segment
 * with intended playback @rate of 2.0 and applied_rate of 1.0, it can adjust
 * incoming timestamps and buffer content by half and output a newsegment event
 * with @rate of 1.0 and @applied_rate of 2.0
---------------------------------------------------------------------------------------------

Can someone explain how and why the rate and applied_rate is changed
in above use case?

On Wed, Oct 19, 2011 at 10:14 AM, bcxa sz <bcxa.sz at gmail.com> wrote:
> Hi Developers,
>
> I am reading the design document on the sync and notice formulas to
> calculate the running time and the stream time:
>
> B.running_time = (B.time_stamp - NS.start) / NS.abs_rate + NS.accum
>
> stream_time =  (B.time_stamp - NS.start) / NS.abs_applied_rate + NS.accum
>
> Anyone can explain to me why the running_time use abs_rate but
> stream_time use abs_applied_rate?
>