[gst-devel] window too big with resolution greater than 352 × 288

[Francesco Argese]

> Probably the higher resolution means your encoded frames are larger,
> perhaps exceeding the MTU on the network, or just being dropped since
> you're using UDP.

Yes, probably this is the problem. I can confirm it because now I have
tried with a version of gstreamer including debug (the same posted in
this mailing and compiled with OABuild) and the application give me
the following error:

ERROR: from element /GstPipeline:pipeline0/GstUDPSrc:udpsrc0: Could
not read from resource.
Additional debug info:
..\..\gst\udp\gstudpsrc.c(563): gst_udpsrc_create ():
/GstPipeline:pipeline0/GstUDPSrc:udpsrc0:
receive error -1 (WSA error: 10040)

Capturing udp packets toward the network analyzer Wireshark, I have
understand that the packet exceeding a size near to 1500 are discarded
by Windows (then return that error reported on this site
(http://www.ultrabac.com/kb/ubq000192.htm) as message too long).  With
low resolution the packet are always under this limit so it works
well.

The error WSA error: 10040 is the following: A message sent on a
datagram socket was larger than the
internal message buffer or some other network limit, or the
buffer used to receive a datagram into was smaller than
the datagram itself.

> Use a TCP transport, or a network protocol designed to handle lossy transports.

I haven't tcp plugins in my gstreamer distribution on windows (i have
checked it with a gst-inspect-0.10 | grep tcp). I have tried to use a
different payloader also with codec h263 or mpeg4 but i have the
following error at the receiver (it seems that the udpsrc problem is
resolved in this manner):

$ gst-launch-0.10 -v udpsrc port=5000 ! application/x-rtp,media=video,payload=9
6,encoding-name=MP4V-ES ! rtpmp4vdepay ! video/mpeg,mpegversion=4,systemstream=
false ! ffdec_mpeg4 ! ffmpegcolorspace ! directdrawsink
New clock: GstSystemClock
Setting pipeline to PAUSED ...
Pipeline is live and does not need PREROLL ...
Setting pipeline to PLAYING ...
**
** ERROR:(..\..\libs\gst\base\gstbasetransform.c:1141):gst_base_transform_prepare_output_buffer:
assertion failed: (*out_buf != NULL)
This application has requested the Runtime to terminate it in an unusual way.
Please contact the application's support team for more information.

The pipeline to send this flow is the following:

gst-launch-0.10 videotestsrc ! video/x-raw-rgb,width=640,height=480 ! ffmpegc
olorspace ! video/x-raw-yuv ! ffenc_mpeg4 ! video/mpeg,width=640,height=480,mpe
gversion=4,systemstream=false ! rtpmp4vpay ! application/x-rtp,media=video,payl
oad=96,encoding-name=MP4V-ES ! udpsink host=10.10.0.1 port=5000
New clock: GstSystemClock

It seems that the buffer is not initialized. What could be the
problem? Probably the rtp payloader? I have tried also with other
encoders (h263, h263p) and their relative payloaders and depayloaders
with the same result. These does not work also with lower resolution
(the problem is different).

Another question: is there a manner to specify the size of the sending
udp packet? It probably could resolve my problems with gdppay that
work well with small resolution (on Linux also with greater
resolution).

Thanks
Francesco