aoss and teamspeak

aoss and teamspeak

[Tomas Carnecky]

I think I've foud the problem: snd_pcm_start() is never called !

Look at the output:

$ ALSA_OSS_DEBUG=1 LD_PRELOAD=./libaoss.so.0.0.0 TeamSpeak
ERROR: ld.so: object './libaoss.so.0.0.0' from LD_PRELOAD cannot be 
preloaded: ignored.
Opened PCM dsp0 for stream 0 (result = -2)
Opened PCM default for stream 0 (result = 0)
Opened PCM default for stream 1 (result = 0)
open("/dev/dsp", 2, 0) -> 18
ioctl(18, SNDCTL_DSP_RESET)
ioctl(18, SNDCTL_DSP_SETDUPLEX)
ioctl(18, SNDCTL_DSP_GETCAPS, 0x59202168) -> [13056]
ioctl(18, SNDCTL_DSP_SETFRAGMENT, 0x5920216c[3000c])
ioctl(18, SNDCTL_DSP_SETFMT, 0x59202168[16]) -> [16]
ioctl(18, SNDCTL_DSP_CHANNELS, 0x59202178[1]) -> [1]
ioctl(18, SNDCTL_DSP_SPEED, 0x5920216c[22050]) -> [22050]
ioctl(18, SNDCTL_DSP_GETBLKSIZE, 0x592022cc) -> [4096]
read(18, 0x83d1140, 4096) -> 4096
write(18, 0x83a3a70, 4096) -> 4096
read(18, 0x83d1140, 4096) -> 4096
write(18, 0x83a3a70, 4096) -> 4096
read(18, 0x83d1140, 4096) -> 4096
write(18, 0x83a3a70, 4096) -> 4096
read(18, 0x83d1140, 4096) -> 4096
write(18, 0x83a3a70, 4096) -> 4096
read(18, 0x83d1140, 4096) -> 4096

[and those read/write continue forever]

if you look at alsa-oss/alsa/pcm.c, you'll see that snd_pcm_start() is 
only called from the ioctl() handler, and only on SNDCTL_DSP_SETTRIGGER 
which never occurs in the teamspeak trace. Because TS2 works with native 
OSS, I assume that the alsa-oss emulator is buggy. I've added 
snd_pcm_start() to the read/write functions and everything works.

a little step-by-step guide:

first I had to remove (comment out) the "period_size" option from the 
capture device, it was set to 1024 and it caused 
snd_pcm_hw_params_set_periods_max() to fail, here is the output of a 
failed session, along with a few debug information:

ioctl(18, SNDCTL_DSP_SETFRAGMENT, 0x590e916c[3000c])
periods_min: 3, periods_max: 3, dsp->maxfrags: 3 <== capture device
periods_min: 15, periods_max: 15, dsp->maxfrags: 3 <== playback device 
that fails
dsp ioctl error = -22

then I had to adjust the SNDCTL_DSP_GETBLKSIZE return value, the normal 
value computed by the aoss library would be:
ioctl(18, SNDCTL_DSP_GETBLKSIZE, 0x592022cc) -> [8192]
but that caused memory corruption in TeamSpeak, any value below (4092, 
2048, 1024) work fine. Symptoms:

read(18, 0x83d9088, 8192) -> 8192
Runtime error 231 at 0806A7E9
Runtime error 231 at 0806A7E9
munmap((nil), 61439)
TeamSpeak.bin: pcm.c:1451: lib_oss_pcm_munmap: Assertion 
`str->mmap_buffer' failed.
Aborted

or

read(18, 0x83c8770, 8192) -> 8192
Runtime error 231 at 0806A7E9
X Error: BadWindow (invalid Window parameter) 3
   Major opcode:  4
X Error: BadValue (integer parameter out of range for operation) 2
   Major opcode:  56
X Error: BadRequest (invalid request code or no such operation) 1
   Major opcode:  249
X Error: BadWindow (invalid Window parameter) 3
   Major opcode:  12
X Error: BadLength (poly request too large or internal Xlib length error) 16
   Major opcode:  2
TeamSpeak.bin: Fatal IO error: client killed

or

read(18, 0x83d91d8, 8192) -> 8192
Runtime error 231 at 0806A7E9
Exception EAccessViolation in module TeamSpeak.bin at 0806A7E9.
Access violation at address 0805C238, accessing address FFFFFFFC.
munmap((nil), 61439)
TeamSpeak.bin: pcm.c:1451: lib_oss_pcm_munmap: Assertion 
`str->mmap_buffer' failed.
Aborted

system: Gentoo Linux 2.6.14.2 #8 SMP PREEMPT Sat Dec 3 23:51:59 GMT 2005 
x86_64 AMD Athlon(tm) 64 X2 Dual Core Processor 4400+ AuthenticAMD GNU/Linux

tom



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