how to set property for Appsrc?

[Soho Soho123]

Hi All,

Can someone  give me example about how to set latency for appsrc?
I can find the API about latency setting,
but I do not know how to use that:
which value is suitable for a rtp receiver?
Since  I implement a rtp socket to receive rtp packet, it can receive
rtp packet, when I call gst_app_src_push_buffer to input payload to
appsrc element. It seems does not workable, the audio data can not
hear from alsa device.
I would like to modify the property of Appsrc,
like set latency, is-live,
which value is suitable for a rtp receiver when I call API
gst_app_src_set_latency?
And How to set property "is-live"?

Thanks!
Best Regards,
Soho