Video synchronization

[enricom]

Thank you very much four your replies. Unfortunately this problem seems to be
quite complicated...my final solution is to double check the video position
controlling buffer timestamps (through an identity element just before the
video player) and also querying the video player with GST_FORMAT_DEFAULT. 
The problem is that the first method tells me which buffer is arriving but
not when it is going to be played (even if we can suppose that the identity
is passing it immediately to the player) whereas the second one in some
cases returns a frame number not correspondent to the one returned by the
identity element. For instance sometimes the video player tells me that it
is playing frame number 650 whereas the handoff signal says that the last
received buffer corresponds to frame number 630...and by analizing the
synchronization I found that it's the video player that is wrong...
Anyway thank you for your support!

Enrico



On 15 May 2012 12:07, Angel Martin <amartin@> wrote:
> Hi,
>
> Are you looking for something like this?
> http://gstreamer.freedesktop.org/data/doc/gstreamer/head/manual/html/chapter-queryevents.html
>
> Best,
>
> Angel
>

Also worth reading:
http://cgit.freedesktop.org/gstreamer/gstreamer/tree/docs/design/part-synchronisation.txt

Luis

> 2012/5/14 enricom <enri_marne87@>
>>
>> Hello, I would like to know if there's a way to extract the buffer
>> timestamp
>> of the video stream that a video player is playing at a certain moment.
>> So
>> far I've been using the timestamps extracted by an identity element
>> placed
>> just before the video player but the handoff signals are not generated
>> synchronously, so between 2 buffers of length = 0.04 s there's a system
>> time
>> delta extracted at the handoff signal generation slightly different than
>> 0.04 s...for this reason I suppose that either the video player receives
>> these buffers asynchronously, so it has a buffer itself and synchronizes
>> with the general clock, or the identity signal is emitted asynchronously
>> (or
>> maybe both)...
>> For audio/video synchronization purposes I need to know something like:
>> in
>> a
>> certain precise instant the video player is displaying a frame with
>> timestamp=x..is it possible?
>> Thank you very much.
>>
>> Enrico
>>
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