GStreamer AAC audio stream delay in iOS

[Tim Müller]

On Thu, 2015-10-01 at 23:20 -0700, Bilal wrote:

Hi,

> I'm beginner on GStreamer. Playing aac audio stream RTSP on my iOS
> device
> using GStreamer SDK, its working fine, but delay is above 2.0
> seconds. Its
> just audio stream not video.
> 
> Can I make this delay lower then 2.0 seconds? Bec when I play same
> stream on
> VLC delay is lower then 1 second. I'm following "GStreamer tutorial
> 5" for
> iOS.
> 
> There may be some buffering issue.
> 
> This is how I'm creating the pipeline
> 
> pipeline = gst_parse_launch("playbin2", &error);

It looks like you're using the old and unmaintained 0.10 GStreamer SDK
from gstreamer.com.

Use the 1.6.x binaries from here instead:
http://gstreamer.freedesktop.org/data/pkg/

and port your code over to GStreamer 1.x. You will have to use
"playbin" instead of "playbin2" in 1.6.

Ported versions of the tutorials are here:
http://cgit.freedesktop.org/~slomo/gst-sdk-tutorials/tree/gst-sdk/tutor
ials

Having said that, the reason for this delay is that the default value
for the rtspsrc "latency" property is 2000ms = 2 seconds. You can set
this much lower of course.

You would typically connect to playbin's "source-setup" signal and in
the callback do e.g.

  g_object_set (source, "latency", 250, NULL);

If you don't have a "source-setup" signal in 0.10 yet, use the
"notify::source" signal and do g_object_get (playbin, "source",
&source, NULL); to retrieve the source element. But best to just
upgrade to 1.6, since we no longer support 0.10.

Cheers
 -Tim

-- 
Tim Müller, Centricular Ltd - http://www.centricular.com

Join us at the GStreamer Conference: 8-9 October 2015 in Dublin, Ireland