How to query the GstSegment "rate"?

[Andy Robinson]

On 25/04/16 07:21, Sebastian Dröge wrote:
> On Sa, 2016-04-23 at 14:55 +0100, Andy Robinson wrote:
>> I imagine there must be some way of querying the
>> pipeline for the rate once it is in paused state, but how?
>
> You could try the SEGMENT query, if something in your pipeline is
> answering it then it will contain the rate.
>
> But the bigger question is why you need to query the rate and don't
> know it already. In the end it was your code that was setting that
> exact rate via a seek :)
>
>
> Also what's the bigger picture here? Why do you want to convert from
> stream time to the scaled stream time by rate (which is not exactly the
> running time in general, but maybe you actually want the running
> time?)?
>

Even if I don't do any seek, a Segment event goes down the pipeline and 
it has a rate of 0.5 - I know this from putting diagnostics in the pipeline.

The file is here if you are interested:
http://www.seventhstring.com/other2/JAttendraiShort50.mov
It plays ok in Parole Media Player on Linux, or QuickTime on Mac. It's 
60 secs long and was produced, using QuickTime, by slowing down a 30 sec 
clip to half speed.

When I play it in my app, I find that when I want to seek using 
gst_element_seek_simple within this video I must use the pre-slowdown 
times, e.g. if I want to seek to the 40th second of the 60 second video, 
I must actually seek to a time of 20 secs, and also must make a similar 
adjustment to the values returned by gst_element_query_position.

It seems to me that I need to get that 0.5 rate number and use it as a 
multiplier when I call gst_element_seek_simple but if there is a better 
way, please advise me.

Of course, maybe the file is simply erroneous, illegal, though it does 
play ok in some (not all) players.

Regards,
Andy Robinson, Seventh String Software, www.seventhstring.com