Hi Fabio, We probably have a solution for you. So your sound devices already provide encoded (PCMA) frames, this is actually similar to how APS-Direct work! Basically APS-Direct is a feature (by means of config tweaks) to utilize APS sound device in Nokia handsets, which already provides encoded G.729/iLBC/AMR/G.711 codecs. Please see http://trac.pjsip.org/repos/wiki/Nokia_APS_VAS_Direct for more info, and get back here if there's anything unclear. As a bit of hint, pjsua should work more or less as usual when APS-Direct is enabled, though obviously we will loose the conferencing feature. Though the drawback of using APS-Direct approach is you won't be able to use many (if not most) PJMEDIA features, since PJMEDIA mostly works on PCM frames. But this may be your objective in the first place, as you wanted as less processing as possible. So depending on how you code your application (especially the part to handle multiple sound devices), there may be some design changes required. cheers Benny On Sat, May 23, 2009 at 4:17 PM, Fabio Cherchi <fabio.cherchi at yahoo.it>wrote: > Hi Benny and all, > > I'm developing an application running on uclinux-nios2 (85MHz) which simply > starts and stops multiple RTP streams from 16 different custom audio devices > (not defined as sounds ports) which provide PCMA already coded samples. > > In my first approach I used the conf bridge to connect each stream to a > custom pjmedia_port, but after the 5th-6th connection the cpu performance > becomes poor and the timing gap between each put_frame (same for get_frame) > becomes larger than 20ms (my frame length). > > I'm doing some check where I can improve the performance (I've already > applied Benny's suggestions about that on: > http://trac.pjsip.org/repos/wiki/FAQ#Performance). > First of all, I've already coded pcma samples, but the conf bridge works > only with L16 samples, so I need to do a double conversion before the > streaming. > Second, the CPU usage shows very high values when I'm adding a new call to > the conf bridge. > > I'm evaluating a different approach based on creating a different master > port for each call to directly connect the custom ports to the streams and > also I would like to use the pcma passthrough codec. > Do you think this would help to improve performances? > Is it possible that multiple master ports could have some timing conflicts > if running in the same application? > > Any suggestion will be very appreciated. > > Thanks, > Fabio > > _______________________________________________ > Visit our blog: http://blog.pjsip.org > > pjsip mailing list > pjsip at lists.pjsip.org > http://lists.pjsip.org/mailman/listinfo/pjsip_lists.pjsip.org > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.pjsip.org/pipermail/pjsip_lists.pjsip.org/attachments/20090523/087d83e7/attachment.html>
