Hi, I didn't find something about latency in your test case. Which data said your calling latensy is high? regards, Gang 2009/3/21 Kimberly Gibbs <kimberly_gibbs at yahoo.com> > Greetings, > > I am seeking guidance to improve voice latency for an embedded VoIP > application using PJSIP 1.0.1. The target is an OMAP3530zoom. When > establishing a call between pjsua on a PC and a (slightly modified) > simple-pjsua on the target, there is high latency on the OMAP. Latency is > highest when all clock rates (conf bridge and sound device) are set to 8 Khz > (>2 seconds) and lowest when all clock rates are set to 44100 Hz (~500 > msec). This behavior is puzzling because I would expect less latency with a > lower clock rate. I have followed the suggestions in the FAQ regarding > latency and optimization. > > I have included the sndinfo and sndtest results below for 8Khz and 44100 > Hz. The attached document contains screen shots of the media stats dump and > codec list. > > Being new to VoIP development, I would greatly appreciate your insight and > any suggestions you might have for further tuning. > > Thanks in advance, > Kim > > Using PJSIP 1.0.1 > > target board: OMAP3530zoom > > *************************************************** > sndtest - --rate=8000 > (Frame interval max=256.012, max Jitter = 256) > *************************************************** > > 00:07:35.884 sndtest.c 0: /dev/dsp (capture=16, playback=16) > 00:07:35.884 sndtest.c default sampling rate: 44100 > 00:07:36.408 sndtest.c Testing playback device /dev/dsp > 00:07:36.408 sndtest.c Testing capture device /dev/dsp > 00:07:36.929 sndtest.c Please wait while test is in progress (~11 > secs).. > 00:07:52.541 sndtest.c Dumping results: > 00:07:52.541 sndtest.c Parameters: clock rate=8000Hz, 80 > samples/frame > 00:07:52.541 sndtest.c Playback stream report: > 00:07:52.541 sndtest.c Duration: 9s.990 > 00:07:52.541 sndtest.c Frame interval: min=0.000ms, max=256.042ms > 00:07:52.541 sndtest.c Jitter: min=9.756ms, avg=28.725ms, > max=256.042ms > 00:07:52.541 sndtest.c Capture stream report: > 00:07:52.542 sndtest.c Duration: 9s.980 > 00:07:52.542 sndtest.c Frame interval: min=0.000ms, max=256.012ms > 00:07:52.542 sndtest.c Jitter: min=9.756ms, avg=28.741ms, > max=256.012ms > 00:07:52.542 sndtest.c Checking for clock drifts: > 00:07:52.542 sndtest.c No clock drifts is detected > 00:07:52.542 sndtest.c Test completed with some warnings > 00:07:52.939 pasound.c PortAudio sound library shutting down.. > > *************************************************** > sndtest - --rate=44100 > (Frame interval max=46.783, max Jitter = 46.783) > *************************************************** > > 00:05:16.571 sndtest.c 0: /dev/dsp (capture=16, playback=16) > 00:05:16.571 sndtest.c default sampling rate: 44100 > 00:05:16.979 sndtest.c Testing playback device /dev/dsp > 00:05:16.979 sndtest.c Testing capture device /dev/dsp > 00:05:17.410 sndtest.c Please wait while test is in progress (~11 > secs).. > 00:05:29.424 sndtest.c Dumping results: > 00:05:29.424 sndtest.c Parameters: clock rate=44100Hz, 441 > samples/frame > 00:05:29.424 sndtest.c Playback stream report: > 00:05:29.424 sndtest.c Duration: 10s.030 > 00:05:29.424 sndtest.c Frame interval: min=0.000ms, max=46.783ms > 00:05:29.424 sndtest.c Jitter: min=9.756ms, avg=25.605ms, > max=46.753ms > 00:05:29.424 sndtest.c Capture stream report: > 00:05:29.424 sndtest.c Duration: 10s.030 > 00:05:29.424 sndtest.c Frame interval: min=0.000ms, max=46.783ms > 00:05:29.424 sndtest.c Jitter: min=9.756ms, avg=25.591ms, > max=46.783ms > 00:05:29.425 sndtest.c Checking for clock drifts: > 00:05:29.425 sndtest.c No clock drifts is detected > 00:05:29.425 sndtest.c Test completed with some warnings > 00:05:29.596 pasound.c PortAudio sound library shutting down.. > > *************************************************** > sndinfo output > *************************************************** > > 00:10:22.066 os_core_unix.c pjlib 1.0.1 for POSIX initialized > 00:10:23.787 pasound.c PortAudio sound library initialized, status=0 > 00:10:23.787 pasound.c PortAudio host api count=1 > 00:10:23.787 pasound.c Sound device count=1 > 00:10:23.788 pjlib select() I/O Queue created (0x48e04) > Device #00: > Name : /dev/dsp > # of input channels : 16 > # of output channels: 16 > Default clock rate : 44100 Hz > > > *************************************************** > config_site.h > *************************************************** > > > #define PJ_CONFIG_MAXIMUM_SPEED > #define PJMEDIA_SOUND_IMPLEMENTATION PJMEDIA_SOUND_PORTAUDIO_SOUND > #define PJMEDIA_PREFER_DIRECT_SOUND 0 > > #define PJMEDIA_SND_DEFAULT_REC_LATENCY 40 > #define PJMEDIA_SND_DEFAULT_PLAY_LATENCY 40 > > #define PJMEDIA_SOUND_USE_DELAYBUF 0 > #define PJMEDIA_SOUND_BUFFER_COUNT 6 > > // Per pjsip recommendations - CPU optimize > #if defined(PJ_CONFIG_MAXIMUM_SPEED) > > # define PJ_ENABLE_EXTRA_CHECK 0 > # undef PJ_OS_HAS_CHECK_STACK > # define PJ_OS_HAS_CHECK_STACK 0 > # define PJ_DEBUG 0 > # define PJSIP_SAFE_MODULE 0 > > # define PJSIP_UNESCAPE_IN_PLACE 1 > # define PJ_HASH_USE_OWN_TOLOWER 1 > #endif > > > Kimberly Gibbs > kimberly_gibbs at yahoo.com > LinkedIn: http://www.linkedin.com/in/kimberlygibbs > > > > _______________________________________________ > 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/20090322/f9741d5a/attachment-0001.html>
