Subject: sdr and vic problems

From: Work Work Work <[email-masked]>
Date: Thu, 15 Aug 1996 18:59:02 +0800 (SGT)

Hello,

I have 2 SUN Ultra SPARC1 with creator graphics engine (24-bit) running
mbone applications over an ATM network.  Below are some of my queries:

1.	I wanted to increase the maximum bandwidth of vic to about 8 Mbps.
	I can do it for point to point connection using the -B parameter
	of vic, but how do I do it from sdr?

2.	According to the man page of vic, it says that "vic will take
	advantage of certain hardware compression and decompression
	units, if present".  How do I know whether vic is using hardware
	decompression instead of software decompression.  There is an
	option on the vic panel that says to use h/w decompression, but
	I see no difference in performance even if I did not select the
	option.  So, is it because my workstation does not have the
	h/w decompression?  If so, what kind of h/w decompression is 
	available for vic to use on a Sun wks?

3.	For point to point transmission, the framerate of the source can be
	up to 25 fps.  However, on the receiver workstation, the framerate
	is about 18-20 fps.  There are also packets loss.  How can I tell
	what is causing the packet loss, ie is it due to the ATM network, or
	because the receiver wks cannot decompress the video stream fast 
	enough?

4.	When I tried to send using large image size using jpeg format, I
	have the error "RTVC_CMS_SEND_MESSAGE:Not enough space".  I am
	using the SunVideo card for encoding and compressing the video 
	stream.  The source of the video stream is a video player.  What
	is causing the problem?

Thanks in advance.

Regards,

Tung Kwong Yeong
Computer Centre
National University of Singapore
email: [email-masked]

---

From: Petri Helenius <[email-masked]>
Date: Thu, 15 Aug 1996 14:13:14 +0300 (EET DST)

> 	stream.  The source of the video stream is a video player.  What
This is the fault of the way VIC accesses the sunvideo driver. The
sunvideo card only supports compressed capture using medium resolution
and the large resolution must be used only as 'raw capture' and I
guess that VIC is trying to do a compressed capture which fails by the
specification of the driver. I've mailed this information to the vic
support address and have received no feedback so far.

Pete

---

From: Mark Handley <[email-masked]>
Date: Thu, 15 Aug 96 12:27:24 +0100

>	of vic, but how do I do it from sdr?

You would have to write a modified sdr plugin.  Unfortunately sdr
doesn't (right now) allow plugins to request non-predefined values via
the GUI.  Also, the SDP "b=" field is not properly supported , so
right now a modified plugin wouldn't help you much.

If you just want to fix the max point on the slider for your own
usage, but not actually specify anything in the session description,
the following plugin would suffice (but is dangerous because it
overrides the built-in safety features in vic that prevent people
blowing away the net, so you'll have to be *really* careful when using
vic in normal mbone sessions):

media:video
proto:rtp
tool:vic
create:no
fmt:h261
{
  flags:-f h261
}
fmt:nv
{
  flags:-f nv -Anv
}
fmt:jpeg
{
  flags:-f jpeg
}
fmt:celb
{
  flags:-f celb
}
fmt:vic
{
  flags:-f h261
}
fmt:ivs
{
  flags:-f h261 -Aivs
}
flags:-t $(TTL)
flags:-B 8192
flags:-I $(CHAN)
flags:-C $(SESSNAME)
flags:$(ADDRESS)/$(PORT)

See the built-in help for what to do with this plugin.

Mark