Hi Karsten, As Keith already said, we were able to get sipXtapi working on ARM926EJ-S @ 100MHz (or 133MHz, do not recall exactly, but << 200MHz!) with G.711 in three-way conference mode with some CPU power still available. We also were able to get 1-to-1 call with Speex NB 8kbps *almost* working on that CPU freq, only a few MIPS missing for it to work perfectly.
First thing you need to do is to enable Topology graph instead of old PhoneMediaInterface by defining following preprocessor defines: ENABLE_TOPOLOGY_FLOWGRAPH_INTERFACE_FACTORY DISABLE_DEFAULT_PHONE_MEDIA_INTERFACE_FACTORY Among other things this will enable use of our new audio I/O interface. OSS version of this interface should work fairly well in embedded environment. Though, as Keith said, we still had to write our own audio I/O kernel driver and sipX interface driver to get stable audio quality. Biggest problem with ALSA drivers (and, so, OSS drivers as well, because we used oss emulation) on our dev.board was that they were not able to wake up thread, waiting for audio I/O operation completition on time, delaying it by various amounts of time. We're synchronizing our audio processing to this I/O completion events, so this is very improtant to get them working and waking up our processing thread ASAP after I/O operation is done. I guess this is your most issue wich you should solve. Other our issue, which is probably not that important for you, was general mutex performance on ARM. We need to replace mutex operations in some essential places to lock-free operations to speed-up our code and meet real-time requirement. Though, you have 4x CPU power, so this might not be that big issue for you. I plan to commit my lock-free work to svn someday, but I'm not sure they're ready for wide usage nowdays. But, if you want to give them a try, I'll post them here. -- Regards, Alexander Chemeris. SIPez LLC. SIP VoIP, IM and Presence Consulting http://www.SIPez.com tel: +1 (617) 273-4000 _______________________________________________ sipxtapi-dev mailing list [email protected] List Archive: http://list.sipfoundry.org/archive/sipxtapi-dev/
