PAL Polycom VS SP128 Bug?

[cribbinsb]

I've been doing some interoperability testing with PAL endpoints and I believe I've found a rather nasty bug with the PAL polycom viewstation sp128. Any call between the SP128 and any non-polycom endpoint (e.g. a PAL Tandberg 1000) produces extremely jerky decoded video on the SP128. In contrast, calls to a PAL polycom FX are just fine. I've tried polycom tech support but they've not been very useful so far... I'll keep trying but in the meantime has anyone else seen this issue or similar? The SP128 has the latest software (Poly sp 7.5.2 Dec 2003).

[cribbinsb]

I should also say that I know this is definitely a decode bug on the sp128 as I have tools such that I can call the TB1000, PolyFX and PolySP128 and transmit them identical h.263 media and I verify that the PolyFX and TB1000 decode it perfectly smoothly whereas the SP128 is extremely jerky.

Also interesting is that the SP128 has the same jerky problem when calling NTSC polycoms (I've tried a VSX7000 and an NTSC FX). Again, same media sent to a Poly FX or a TB1000 is fine. It seems the only thing the SP128 can decode smoothly is video from another PAL polycom. This situation is so bad that I can't believe I'm the only person to have noticed it...!? ;)

[George]

Welcome to the forums cribbinsb,


Just playing devil's advocate here but could this not lend itself to a configuration issue on the SP128 as well? Or have you already dispelled that possibility?

[cribbinsb]

Hi George,
I've seen the problem on two PAL SP128s, one was at a customer site (not set up by us) and the other in our lab. Whilst this doesn't rule out a configuration issue it would seem to make it unlikely, unless they're both independently misconfigured? Also I can't think of why any configuration option would produce the effect we see. It's very strange, like a kind of periodic stuttering. It also seems to get worse over time as the call progresses.

However I do need to get this sorted out so if it did somehow turn out to be a config issue this would be a good solution. So if anyone has any ideas I'd certainly be pleased to hear them! Are there any polycom experts (or employees) out there who can help ??

[dfreeman]

Can you roll the software back to 7.2.4? I've seen more than just this interop issue with 7.5.x

[cribbinsb]

Thanks for the suggestion. I just tried 7.2.4 and it has the same problem :(

[Skylark]

Im very intersested in that what tool your useing to transmit the h.263 and how can I get my hands on that?

[cribbinsb]

OK. We eventually got polycom to look into this. Turns out that the issue is caused by a bug in the h.263 codec used in the SP. The result is that as I observed: the PAL SP can't smoothly decode video from anything except another PAL viewstation. They say they'll fix if for the next release of SP software.

Skylark, sorry for not getting back to you sooner. The tools I was using are all homegrown and not generally available. Sorry!