Benny,
We have noticed a huge difference in voice quality (almost factor of 10
for jitter) between using portaudio and win32 direct sound implementation in
pjmedia. Using port audio implementation gives us choppy sound. I ran the
sndtest.exe with both implementations and the results are as below. No
significant difference is observed for portaudio after turning the
PJMEDIA_PREFER_DIRECT_SOUND flag also.
Is there a way to tune the portaudio implementation so that we can have
better voice quality ? I understand that the dsound.c backend is unstable so
we would ideally want to stay away from using the win32 direct sound
implementation
-------------------------PortAudio
implementation-----------------------------------
11:45:37.994 os_core_win32. pjlib 0.7.0-trunk for win32 initialized
11:45:38.073 pasound.c PA message: Pa_GetDeviceInfo: Num input
channels re
ported as 65535! Changed to 2.
11:45:38.073 pasound.c PA message: Pa_GetDeviceInfo: Num output
channels r
eported as 65535! Changed to 2.
11:45:38.229 pasound.c PortAudio sound library initialized, status=0
11:45:38.229 pasound.c PortAudio host api count=3
11:45:38.229 pasound.c Sound device count=8
11:45:38.229 pjlib WinNT IOCP I/O Queue created (008F62F4)
11:45:38.229 sndtest.c Found 8 devices:
11:45:38.244 sndtest.c 0: Microsoft Sound Mapper - Input (capture=2,
play
back=0)
11:45:38.244 sndtest.c 1: SoundMAX HD Audio (capture=2, playback=0)
11:45:38.244 sndtest.c 2: Microsoft Sound Mapper - Output (capture=0,
pla
yback=2)
11:45:38.244 sndtest.c 3: SoundMAX HD Audio (capture=0, playback=2)
11:45:38.244 sndtest.c 4: Primary Sound Capture Driver (capture=2,
playba
ck=0)
11:45:38.244 sndtest.c 5: SoundMAX HD Audio (capture=2, playback=0)
11:45:38.244 sndtest.c 6: Primary Sound Driver (capture=0,
playback=2)
11:45:38.244 sndtest.c 7: SoundMAX HD Audio (capture=0, playback=2)
11:45:38.401 sndtest.c Testing playback device Primary Sound Driver
11:45:38.401 sndtest.c Testing capture device Primary Sound Capture
Driver
11:45:38.604 sndtest.c Please wait while test is in progress (~11
secs)..
11:45:49.651 sndtest.c Dumping results:
11:45:49.666 sndtest.c Parameters: clock rate=8000Hz, 80
samples/frame
11:45:49.666 sndtest.c Playback stream report:
11:45:49.666 sndtest.c Duration: 9s.990
11:45:49.666 sndtest.c Frame interval: min=0.003ms, max=37.503ms
11:45:49.666 sndtest.c Jitter: min=9.982ms, avg=23.711ms, max=
37.498ms
11:45:49.666 sndtest.c Capture stream report:
11:45:49.666 sndtest.c Duration: 9s.990
11:45:49.666 sndtest.c Frame interval: min=0.003ms, max=36.672ms
11:45:49.666 sndtest.c Jitter: min=9.970ms, avg=23.711ms, max=
36.667ms
11:45:49.666 sndtest.c Checking for clock drifts:
11:45:49.666 sndtest.c No clock drifts is detected
11:45:49.666 sndtest.c Test completed with some warnings
-------------------------PortAudio
implementation-----------------------------------
-----------------------------Win32 Direct
Sound---------------------------------------
11:51:54.401 os_core_win32. pjlib 0.7.0-trunk for win32 initialized
11:51:54.619 dsound.c DirectSound initialized, found 3 devices:
11:51:54.619 dsound.c dev_id 0: Primary Sound Capture Driver (in=2,
out
=2)
11:51:54.619 dsound.c dev_id 1: SoundMAX HD Audio (in=0, out=2)
11:51:54.619 dsound.c dev_id 2: SoundMAX HD Audio (in=2, out=0)
11:51:54.619 pjlib WinNT IOCP I/O Queue created (00975EBC)
11:51:54.619 sndtest.c Found 3 devices:
11:51:54.619 sndtest.c 0: Primary Sound Capture Driver (capture=2,
playba
ck=2)
11:51:54.619 sndtest.c 1: SoundMAX HD Audio (capture=0, playback=2)
11:51:54.619 sndtest.c 2: SoundMAX HD Audio (capture=2, playback=0)
11:51:55.057 sndtest.c Please wait while test is in progress (~11
secs)..
11:52:06.166 sndtest.c Dumping results:
11:52:06.166 sndtest.c Parameters: clock rate=8000Hz, 80
samples/frame
11:52:06.166 sndtest.c Playback stream report:
11:52:06.166 sndtest.c Duration: 10s.000
11:52:06.166 sndtest.c Frame interval: min=0.008ms, max=19.914ms
11:52:06.166 sndtest.c Jitter: min=0.963ms, avg=3.453ms, max=
19.880ms
11:52:06.166 sndtest.c Capture stream report:
11:52:06.166 sndtest.c Duration: 10s.000
11:52:06.166 sndtest.c Frame interval: min=0.026ms, max=19.179ms
11:52:06.166 sndtest.c Jitter: min=0.516ms, avg=2.362ms, max=
19.129ms
11:52:06.166 sndtest.c Checking for clock drifts:
11:52:06.182 sndtest.c No clock drifts is detected
11:52:06.182 sndtest.c Test completed with some warnings
-----------------------------Win32 Direct
Sound---------------------------------------
Regards,
-Amit
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