Best regards,

2012/4/30 Jan Willamowius <jan@willamowius.de>

Hi Diego,

a H.323-SIP gateway with video support sounds very promising.
Do you plan to release it OpenSource ? If you need someone to test it,
feel free to send it my way. ;-)

Cheers,
Jan

--
Jan Willamowius, Founder of the GNU Gatekeeper Project
EMail : jan@willamowius.de
Website: http://www.gnugk.org
Support: http://www.willamowius.com/gnugk-support.html

Diego Carvalho wrote:
> Hi Simon,
> I am very grateful for the version of the H264 plugin with the _SGINAL_ONLY
> option. After using it I finally could make video work on my application.
> Now I have 2 more challenges:
> 1 - Link the H264 and G722 plugins statically. How can I do this?
> 2 - I still have problems with capability negotiation. You said me to
> override H323Connection::OnSetLocalCapabilities to remove the codecs that
> SIP doesn't support. But this function is called in the very beginning of a
> call, when I don't have SIP info yet. So I answer the call with
> H323Connection::AnswerCallPending and then start the SIP call. So I will
> have the SIP info only before sending the Connect PDU (e.g before calling
> H323Connection::AnswerCallNow). Is there another way to modify the local
> capabilities with this constraint?
> I appreciate any help. Thanks in advance.
>
> 2012/4/10 Simon Horne <s.horne@packetizer.com>
>

> > Diego****
> >
> > ** **
> >
> > Today I checked into the CVS a compile directive _*SIGNAL*_ONLY which

> > will compile the plugin without dependencies on FFMPEG or X264. You only

> > need h264-x264.h/.cxx. You can use this in conjunction with _*STATIC*_LINK

> > to build a static library to statically link the codec into the h323plus

> > library.****
> >
> >
> > http://h323plus.cvs.sourceforge.net/viewvc/h323plus/h323plus/plugins/video/H.264/
> > ****

> >
> > You will need to configure the makefile.in with these switches (not done

> > yet)****
> >
> > ** **

> >
> > Also G.722 has serious interop issues. Mainly due to IMHO an error in the
> > RFC. Although the codec is a 16k codec the RTP timestamps are incremented
> > as 8k in the RFC. On the H.323 side they almost always use a 16k timestamp

> > while on the SIP side it’s mostly 8k. ****
> >
> > ** **
> >
> > Simon****
> >
> > ** **
> >
> > *From:* h323plus-bounces@lists.packetizer.com [mailto:
> > h323plus-bounces@lists.packetizer.com] *On Behalf Of *Diego Carvalho
> > *Sent:* 10 April 2012 04:41
> >
> > *To:* h323plus@lists.packetizer.com
> > *Subject:* Re: [h323plus] H323-SIP Gateway with H264 Support****
> >
> > ** **

> >
> > Hi Simon, thanks a lot for you help, but I will have to bother you again.
> > Now I could compile the H264 plugin after remove the code you told me but I
> > couldn't make my program load it. I tried 3 different things: first I put
> > the .so and the help in the same folder as my app, second I tried to
> > install the plugins in the default folder (/usr/local/lib/opal-1.24.0/) and
> > finally I tried to set PWLIBPLUGINDIR. None of these worked. I also tried
> > to load the G722 plugin and at least this one should work because I didn't
> > change it. Am I missing something?
> > I also tried to enable the stack's log. At first glance, it didn't show
> > anything about plugins. Then I used the following code, from Simple app:
> >
> > PDirectory DefaultDir = PProcess::Current().GetFile().GetDirectory();
> > PPluginManager & pluginMgr = PPluginManager::GetPluginManager();
> > pluginMgr.LoadPluginDirectory(DefaultDir);
> >
> > This makes the app loads the plugins from the current directory. After
> > this the log shows:
> >
> > 2012/04/09 11:08:17.701 4 pluginmgr.cxx(96) PLUGIN
> > Enumerating plugin directory /home/diego/H323Gateway/bin/Debug/
> > 2012/04/09 11:08:17.701 5 pluginmgr.cxx(106) PLUGIN
> > Checking /home/diego/H323Gateway/bin/Debug/g722_audio_pwplugin.so against
> > suffix _ptplugin
> > 2012/04/09 11:08:17.701 5 pluginmgr.cxx(106) PLUGIN
> > Checking /home/diego/H323Gateway/bin/Debug/g722_audio_pwplugin.so against
> > suffix _pwplugin
> > 2012/04/09 11:08:17.702 3 h323pluginmgr.cxx(2529) H323PLUGIN
> > Loading plugin codec g722_audio_pwplugin
> > 2012/04/09 11:08:17.702 5 pluginmgr.cxx(106) PLUGIN
> > Checking /home/diego/H323Gateway/bin/Debug/h264_video_pwplugin_helper
> > against suffix _ptplugin
> > 2012/04/09 11:08:17.702 5 pluginmgr.cxx(106) PLUGIN
> > Checking /home/diego/H323Gateway/bin/Debug/h264_video_pwplugin_helper
> > against suffix _pwplugin
> > 2012/04/09 11:08:17.702 5 pluginmgr.cxx(106) PLUGIN
> > Checking /home/diego/H323Gateway/bin/Debug/h264_video_pwplugin.so against
> > suffix _ptplugin
> > 2012/04/09 11:08:17.702 5 pluginmgr.cxx(106) PLUGIN
> > Checking /home/diego/H323Gateway/bin/Debug/h264_video_pwplugin.so against
> > suffix _pwplugin
> > 2012/04/09 11:08:18.053 3 h323pluginmgr.cxx(2525) H323PLUGIN
> > Plugin Codec DLL h264_video_pwplugin contains no codec definitions
> > 2012/04/09 11:08:18.058 5 pluginmgr.cxx(106) PLUGIN
> > Checking /home/diego/H323Gateway/bin/Debug/H323Gateway against suffix
> > _ptplugin
> > 2012/04/09 11:08:18.058 5 pluginmgr.cxx(106) PLUGIN
> > Checking /home/diego/H323Gateway/bin/Debug/H323Gateway against suffix
> > _pwplugin
> >
> > So it seems that it loaded G722 correctly and encontered an error while
> > loading H264. But when the app starts, there is no G722 on capabilities
> > table. I also tried to use the G722 plugin in the Simple app and got the
> > same result. The app shows this in its start up:
> >
> > Codecs (in preference order):
> > Table:
> > G.711-ALaw-64k <1>
> > G.711-uLaw-64k <2>
> > UserInput/hookflash <3>
> > UserInput/basicString <4>
> > UserInput/dtmf <5>
> > UserInput/RFC2833 <6>
> > UserInput/Navigation <7>
> > UserInput/Softkey <8>
> > UserInput/PointDevice <9>
> > UserInput/Modal <10>
> >
> > So, no G722.
> >
> > A last thing is how to link the plugins statically. You said something
> > about the CVS. Does it mean that the option to load the plugins statically
> > is not available in the current version (1.24.0)?

> > Thanks in advance.****
> >
> > 2012/4/3 Simon Horne <s.horne@packetizer.com>****
> >
> > Diego****
> >
> > ****
> >
> > There are 2 functions to load the plugin.****
> >
> > PLUGIN_CODEC_IMPLEMENT(H264) ****
> >
> > PLUGIN_CODEC_DLL_API struct PluginCodec_Definition *
> > PLUGIN_CODEC_GET_CODEC_FN(unsigned * count, unsigned version)****
> >
> > These are left as they are (including all the macro associated with them)*
> > ***
> >
> > ****

> >
> > All Encryption/Decryption is handled by the H264Encoder/H264Decoder
> > classes. Simple remove these classes and everything referenced by the

> > classes.****
> >
> > Where they are instanced.****

> >
> > static void * create_encoder(const struct PluginCodec_Definition *

> > /*codec*/)****

> >
> > static void * create_decoder(const struct PluginCodec_Definition *

> > /*codec*/)****
> >
> > return NULL.****
> >
> > ****
> >
> > That’s it. It should compile without needing FFMPEG or X264.****
> >
> > ****
> >
> > Simon****
> >
> > ****
> >
> > ****
> >
> > *From:* h323plus-bounces@lists.packetizer.com [mailto:
> > h323plus-bounces@lists.packetizer.com] *On Behalf Of *Diego Carvalho
> > *Sent:* 04 April 2012 03:57****
> >
> >
> > *To:* h323plus@lists.packetizer.com
> > *Subject:* Re: [h323plus] H323-SIP Gateway with H264 Support****
> >
> > ****

> >
> > Hi Simon.
> > Again, I would like to thank you because you helped me to solve two
> > problems: make SIP and H323 endpoints exchange media directly and set
> > capabilities by call basis. Actually, the code you showed me didn't work in
> > my tests (remove all capabilities and then add the ones I want) but I could
> > at least remove the capabilities I don't want. Anyway, now my last big
> > problem is the H264 support. I'm totally lost. You said: "Simply supply
> > the codec definitions and the codec will be available in h323plus. ". But
> > supply where? I don't know where to define the PluginCodec_Definition or
> > the other things you mentioned. Since I'm not an expert on H264 (I know
> > enough to make things work, lol) I would like to use what is already
> > done, I mean, is it possible to make some changes in the H264 plugin to
> > make it work only for signaling or I need to make something from the
> > scratch? Regardless the answer, give me some instructions, please. Thanks

> > in advance.****
> >
> > 2012/3/27 Simon Horne <s.horne@packetizer.com>****
> >
> > Diego****
> >
> > ****
> >
> > Sorry for delay in replying****
> >
> > With Reference to the document you linked to****
> >
> > The plugin codec exports 2 functions for capability registration****
> >
> > unsigned int PWLibPlugin_GetAPIVersion()****
> >
> > PluginCodec_Definition<http://www.voxgratia.org/docs/codec_plugins.html#PluginCodec_Definition>* OpalCodecPlugin_GetCodecs(unsigned * count, unsigned version)
> > ****
> >
> > ****

> >
> > The OpalCodecPlugin_GetCodecs function returns all the information you
> > need on the signaling side. Simply supply the codec definitions and the

> > codec will be available in h323plus. ****
> >
> > You DO NOT need to create the Codec Methods which link to FFMPEG/x264.****
> >
> > ****

> >
> > For only supplying the codecs you need rather than removing them for the
> > call. Clone the Capability List then remove all the orginal and add back

> > the ones you want.****
> >
> > In your derived ****
> >
> > void H323Connection::OnSetLocalCapabilities()****
> >
> > ****
> >
> > H323Capabilities * myCapabilities(localCapabilities);****
> >
> > localCapabilities.RemoveAll();****
> >
> > ****
> >
> > H323Capability * cap = myCapabilities.FindCapability(“H.264*”);****
> >
> > If (cap)****
> >
> > LocalCapabilities.Add(cap);****
> >
> > ****
> >
> > ****
> >
> > Simon****
> >
> > ****
> >
> > *From:* Diego Carvalho [mailto:diego.cdomingos2010@gmail.com]
> > *Sent:* 28 March 2012 06:37
> > *To:* Simon Horne****
> >
> >
> > *Subject:* [h323plus] H323-SIP Gateway with H264 Support****
> >
> > ****

> >
> > Hi Simon, thanks for answering again. Today I could establish SIP -> H323

> > audio calls. So now I only need to deal with the 2 points below.****

> >
> > I'm really interested in being able to add H.264 in the capability set
> > without having to link the library with FFMPEG/X264, but I couldn't
> > understand what you explained. I searched on the internet and found this:
> > http://www.voxgratia.org/docs/codec_plugins.html
> > that I believe is related to what you explained but even with this page I
> > couldn't realize what I have to do. Is it possible to configure the plugin
> > that comes with the source in this way? I mean, use the plugin in
> > h323plus/plugin/video/H.264 for only signaling, without have to link with
> > FFMPEG/X264.
> > Another question is again about the capabilities. You said that I can
> > remove the capabilities that aren't supported by the SIP endpoint. But this
> > way, I will have to add all possible capabilities to my gateway and them
> > remove the ones that SIP doesn't support. It would be much easier if my
> > gateway could start without any capabilities and then I add the ones that
> > SIP supports. Is that possible? If not, I will have to do what you
> > explained but when I will add all the capabilities again to be ready to
> > handle the next call?

> > Again, thanks for all the help. ****
> >
> > ****
> >
> > 2012/3/23 Simon Horne <s.horne@packetizer.com>****
> >
> > Diego****
> >
> > ****

> >
> > There is some issues with changes in FFMPEG v54 and a number of function
> > names changed and others were depreciated recommend v52. I am currently
> > working through issues with v54. Again X264 is a moving target but last I
> > looked it compiled on Linux. On Windows is a whole different story

> > unfortunately.****
> >
> > ****

> >
> > If you are only using the codec for signaling there should be no need to
> > link to either FFMPEG or X264 and you can gut the plugins and only define
> > the PluginCodec_Definitions, Plugin_Codec_Implementation() and
> > PLUGIN_CODEC_GET_CODEC_FN. These are the signaling parts of the codec. The
> > Encoder/Decoder contexts can be removed. There is some changes in the CVS
> > to also allow you to load these plugins statically see the

> > openh323buildopt.h.in.****
> >
> > ****

> >
> > To filter capabilities on a call by call basis you can do this by
> > overriding H323Capabilities::OnSetLocalCapabilities() and use the
> > localCapabilities.Remove() function to remove the capabilities not used on

> > the SIP side.****
> >
> > ****
> >
> > Simon****
> >
> > ****
> >
> > *From:* h323plus-bounces@lists.packetizer.com [mailto:
> > h323plus-bounces@lists.packetizer.com] *On Behalf Of *Diego Carvalho
> > *Sent:* 23 March 2012 22:44
> > *To:* h323plus@lists.packetizer.com****
> >
> >
> > *Subject:* Re: [h323plus] H323-SIP Gateway with H264 Support****
> >
> > ****

> >
> > Hi Simon and "chr_cb". First of all, thanks for your help. Today I was
> > able to establish an audio only call between H323 and SIP using the gateway
> > I'm developing. This is great but I still have some problems and I
> > appreciate any help on this:
> > 1) Like I said, it was an audio only call. I was able to compile the
> > plugins with the packages from Ubuntu repositories (libx264-dev,
> > libavcodec-dev and libavutil-dev) but my project also uses ffmpeg and x264
> > so I would like to compile with the latest source code from git we use. The
> > config.log shows some errors and on the internet I saw somebody saying that
> > only a specific version of ffmpeg allows the compilation. Is that true? If
> > so, what would be the version of ffmpeg and x264 I should use? Again, I
> > would like to reiterate that I only want to have H264 on my capabilities
> > list (I don't want to capture/render video). Do I indeed need the plugin?
> > Is there another way?
> > 2) If I set the gateway capabilities in the beginning it works but I want
> > so set them in a later time. Specifically, I receive the call and send an
> > invite on hold to SIP. Then it will answer with 200 OK with SDP. In this
> > moment, when I have the SIP SDP, I want to set the gateway capabilities
> > based on what the SIP side supports. How can I do this? If I try to add in
> > this moment it simply doesn't add them.

> > Thanks in advance.****
> >
> > 2012/3/13 Simon Horne <s.horne@packetizer.com>****

> >
> > Diego
> >
> > The plugins load default capability instances into the H323Endpoint.
> > When the H323Connection is created these capabilities are cloned
> > In H323Connection::OnSetLocalCapabilities()
> > Simply remove the unmatched capabilities
> > localCapabilities.Remove("H.264*");
> >
> > The H323_ExternalRTPChannel does not handle RTP but can be used to not use
> > the internal RTP system. You can have your own external RTP stack or not
> > have one at all.
> > You needed to read and populate H245_H2250LogicalChannelParameters in the
> > send and receive message of the class with those of the SIP Client.
> >
> > I do have serious doubts what you are planning will work not because it
> > can't technically work but because of the differences in H.323 and SIP with
> > Video. H.323 is very strict on rules while SIP is very loose on
> > interpretations.
> > Here are the problems
> > 1. RTP packetization H.323 says strictly single NAL SIP is undefined 2
> > options (Single NAL/Fragmented units) . You will get video on the H.323
> > side
> > just fine but your SIP side with some devices may not be able to decode.
> > 2. Payload Type for H.264 is specified as being flexible but a lot of SIP
> > implementations have them fixed (usually 96 or 97) so H.323 requests 103
> > SIP always ends 97 no video on the H.323 side. There is no way you can fix
> > this with signaling as SIP tells the other party what it is going to send
> > and H.323 tells the party what it wants to receive. You have to proxy the
> > media to fix the payload type number.
> >
> > Good luck.
> >
> > Simon
> >
> >
> > ============================================================================
> > =============================================
> >
> > From: Diego Carvalho [mailto:diego.cdomingos2010@gmail.com]
> > Sent: 14 March 2012 06:09
> > To: Simon Horne

> > Subject: Re: [h323plus] H323-SIP Gateway with H264 Support****

> >
> >
> > Hi Simon, thanks for answering but I still have some doubts:
> > You said that this plugin will add the capability automatically. Actually,
> > as I said, I'm building a H323-SIP gateway so, for instance, when the SIP
> > endpoint is making a call I want to add the H264 capability only if the SIP
> > endpoint offers it. Will I be able to add the capability manually? For
> > instance, using localCapabilities.Add(new H323_H264Capability()). To
> > sumarize, I want to be able to add (or remove if it was automatically added
> > and the current call does not offer it) manualy the H264 capability.
> > Also I don't know if the H323_ExternalRTPChannel applies to my situation.
> > It's used to pass the RTP to another device. I don't want to handle the RTP
> > at all (to be clear: I don't want RTP arriving on the gateway's network
> > card). I want to send to h323 the RTP address/port SIP offered and
> > vice-versa, so the RTP will flow directly between the endpoints. Any
> > thoughts? Thanks in advance.
> > 2012/3/13 Simon Horne <s.horne@packetizer.com>
> > Diego
> >
> > H.264 is a video plugin in the plugin/video directory. You will need X264
> > and FFMPEG. For Ubuntu they are libx264-dev libavcodec-dev and
> > libavutil-dev.
> >
> > You build the plugin .so and the helper (in the gpl subdirectory) and place
> > them both in the same directory as you app. The application will load them
> > at startup and automatically add the capability to the capabilityset etc
> >
> > If you don’t want to use the plugin for RTP then have a look at the
> > H323_ExternalRTPChannel. This will bypass the RTP handling in the codec to
> > whatever you want.
> > http://www.voxgratia.org/docs/external_rtp.html
> > (its from 2004 but still current)
> >
> > Simon
> >
> >
> > From: h323plus-bounces@lists.packetizer.com
> > [mailto:h323plus-bounces@lists.packetizer.com] On Behalf Of Diego Carvalho
> > Sent: 14 March 2012 03:05
> > To: h323plus@lists.packetizer.com
> > Subject: [h323plus] H323-SIP Gateway with H264 Support
> >
> > Hi all,
> > I'm working on a h323-sip gateway with video (H264) support and I'm facing
> > some problems. I'm new with H323plus and with h323 protocol itself (I'm
> > learning as I go) so excuse me if I say something stupid.
> > First of all, I believe that the stack can be used to build a gateway but
> > it
> > seems that it's more focused on terminals. Am I right? So is it possible or
> > not to build a gateway using it?
> > Second, there is no native support for H264. The documentation shows the
> > class hierarchy. For audio we have, for instance, H323Cabability ->
> > H323RealTimeCapability -> H323AudioCapability -> H323_G711Cabability but we
> > don't have H323Cabability -> H323RealTimeCapability -> H323VideoCapability
> > -> H323_H264Cabability. I tried to create this one, extending from
> > H323Cabability -> H323RealTimeCapability -> H323VideoCapability ->
> > H323GenericVideoCabability and then I discovered that I would need to
> > override a function called CreateCodec to return a codec that handles the
> > video. But I don't want to handle the RTP media. I just want to put H264 in
> > the terminal capability set and establish a connection in a way that the
> > H323 and SIP terminals can exchange the media directly. I've heard about a
> > H264 plugin but it seems that it is for handling the media, so I don't know
> > if it fits my purpose. How can I achieve this? Is there any plan to support
> > H264 natively on H323plus? Also I need to get the remote RTP port. The only
> > way I found to do this is trough H323Connection::OnStartLocicalChannel but
> > this is called after a channel to handle the data is created and again, I

> > don't want to handle the RTP data. I appreciate any help. Thanks.****
> >
> > ****
> >
> > ****
> >
> > ****
> >
> > ****
> >
> > ** **
> >