Bug 52264 - gstrtspsrc - multicast missing udp buffer-size setting - no way to set udp duffer-size
Summary: gstrtspsrc - multicast missing udp buffer-size setting - no way to set udp du...
Alias: None
Product: GStreamer SDK
Classification: Unclassified
Component: Windows SDK Distribution (show other bugs)
Version: 2012.5
Hardware: x86 (IA32) Windows (All)
: medium critical
Assignee: bugs
QA Contact:
Depends on:
Reported: 2012-07-19 11:50 UTC by aha.unsworth
Modified: 2013-05-08 19:06 UTC (History)
0 users

See Also:
i915 platform:
i915 features:


Description aha.unsworth 2012-07-19 11:50:14 UTC
For receiving video data via RTSP when the video is sent via multicast there is no way to specify the udpsrc buffer-size.

Look at function gst_rtspsrc_stream_configure_mcast in file gstrtspsrc.c, there is a missing call to set udp buffer-size.

It should have the below code:
   if (src->udp_buffer_size != 0)
      g_object_set (G_OBJECT (stream->udpsrc[0]), "buffer-size",
          src->udp_buffer_size, NULL);

This is a problem as you do not get a change to set the udpsrc buffer-size, why? Because gstrtspsrc tries connecting with other options first, i.e. udp unicast, when it gets round to multicast it has already created the udpsrc, then just deletes it and creates a new one for multicast, but does not set the udpsrc buffer-size, and as it has already created the udpsrc and signalled the creation it appears you do not get a signal for udpsrc removed and re-created, so for multicast the udpsrc buffer-size is 0 (zero).

Why is this an issue?

On windows the native network buffer is not large and with video i-frames being huge the buffer is to small and you get i-frame corruption, it looks terrible, and there is no (easy) way to set the udpsrc buffer-size.

A lot of video sources are multicast so this is a bit of an issue, but at least the fix is simple (provided above).


Aha Unsworth
Comment 1 Sebastian Dröge (slomo) 2013-02-19 12:55:41 UTC
Thanks, could you provide a patch for this problem?
Comment 2 Thiago Santos 2013-05-08 19:06:33 UTC
Pushed your fix. Should be available in the next release.

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