November 2010 - h323plus - lists.packetizer.com

crash when SessionID=0
by Marek Domaracky 13 Jun '11

13 Jun '11

Hi, I'm working on H.239 implementation and find out that devices might ask SessionID=0 for a new video channel. In particular I did a test with Mirial. I was checking the thread http://lists.packetizer.com/pipermail/h323plus/2009-December/001269.html and it's mentioned that the SessionID=0 is invalid. I know it's not following the standard as for RTPSession the range is from 1..255, but for compatibility, don't you think we should allow it? I did a test call from Mirial to Tandberg and Tandberg didn't have a problem with it. The lines involved are rtp.cxx from PAssert(id > 0 && id < 256, PInvalidParameter); to PAssert(id >= 0 && id < 256, PInvalidParameter); and h323.cxx // We must have a valid sessionID if (sessionID < 1 || sessionID > 255) to if (sessionID < 0 || sessionID > 255) Thanks, Marek

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Re: [h323plus] enabling DirectShow video input
by Alessandro Angeli 05 Dec '10

05 Dec '10

From: "Alessandro Angeli" <packetizer.com(a)riseoftheants.com> Date: Tuesday 02 November 2010 18:26 > It seems to (almost) work now. Both endpoints see the webcams and both > load the Vic H.261 plugin (but not the ffmpeg H.263 one). However, the > server side (-n -l) only receives the video while the client side (-n > <host>) neither sends not receives. Audio and text are fine. I figured it out. The value of CLSID_SampleGrabber in vidinput_directx2.cxx is wrong (copied&pasted from CLSID_NullRenderer): Data1 should be 0xC1F400A0 and not 0xC1F400A4. -- Alessandro

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Bandwidth Control during conference
by kc ooi 26 Nov '10

26 Nov '10

Dear all h323plus member, Is there any function that allow for bandwidth changing during conference undergoing? For example, if I initial a conference with bandwidth 768kbits, I want to limit my bandwidth to 512kbits during conference. How I can do this? Thanks.

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Transfer call
by Igor Pavlov 14 Nov '10

14 Nov '10

Hi, I am using H323Connection::TransferCall() and capture network packets with Wireshark, so when transfering the call in wireshark I see Malformed Packet ( CS : empty [Malformed Packet] ) The problem in these strings (in h450pdu.cxx in function H450ServiceAPDU::BuildCallTransferInitiate()) invoke.IncludeOptionalField(X880_Invoke::e_argument); invoke.m_argument.EncodeSubType(argument); If I comment these strings then I see just CS : Empty. And of course have no transfer of call. I have some questions : 1. Who is wrong ? h323plus or Wireshark 2. How do deternine if remote h323 client support transfering call ? Because I have Tandberg T-1000 wich is not reacting on my transfer call response, maybe because of malformed packet or because it does not support it at all Thank you, Igor Pavlov.

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Re: [h323plus] enabling DirectShow video input
by Alessandro Angeli 02 Nov '10

02 Nov '10

From: "Robert Jongbloed" <robert.jongbloed(a)bigpond.com> Date: Tuesday 02 November 2010 19:17 >> The "Linker/General/Output File" of "SVN Get Revision" is now set to >> >> $(SolutionDir)/svn_getrev.exe >> >> which creates a invalid path: the / should be removed or at least >> replaced with a \. > > While I find it strange that this has worked for me for I do not know > how long, I never had this problem before either, but it makes sense: $(SolutionDir) ends in \ and that path would use a \/ sequence. The filesystem (at least on Win7/x64) is able to cope with /, \\ or // beside the correct \, but not (understandably) \/ or /\. -- Alessandro

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enabling DirectShow video input
by Alessandro Angeli 02 Nov '10

02 Nov '10

I successfully built the debug configurations of ptlib 2.4.5 (static), h323plus 1.21.0 and simpleplus 1.21.0 in VS2008SP1 + WinSDK 7.1 on Win7/x64. Audio and text work fine. However, video does not work: "No Video Grabber available Disabling Video Support!". DirectShow support in vidinput_directx.cxx is compiled successfully and the DirectShow branches in simpleplus/main.cxx are active, since P_DIRECTSHOW is #define'd as 1 in ptbuildopts.h. I tried #define'ing P_DSHOW to 1 as well in simpleplus, without any difference. As far as I can tell, the problem is that the DirectShow service is never registered on startup. I expanded the PCREATE_VIDINPUT_PLUGIN(DirectShow) macro in vidinput_directx.cxx to put a breakpoint in PPlugin_PVideoInputDevice_DirectShow_Registration::<ctor>() and that code is compiled but never executed. Actually, it appears to never be mapped into memory at all, which should imply that the linker is removing it from the final EXE, but adding /OPT:NOREF in the build config of simpleplus does not make a difference. However FakeVideo is registered and it also uses the PCREATE_VIDINPUT_PLUGIN() macro, and I can not spot any difference between the way FakeVideo and DirectShow are compiled and linked. The only reference to a similar issue I could find is from over one year ago: http://lists.packetizer.com/pipermail/h323plus/2009-August/001165.html But the current code already uses PCREATE_VIDINPUT_PLUGIN() and, as I said, FakeVideo uses the same macro but is correctly registered. -- Alessandro

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