get noise with vmix

[s_m_l_x]

my os is ubuntu 10.04 amd64, soundcard is cmi8738. i get a problem, if i enable the vmix then i will get noise. so i try to change the vmix use fixedfloat but i also get noise, then i see some case with memlimit, my pc have 8GB RAM, so i try to modify the memlimit from (memlimit < 0x00000000ffffffffLL) to (memlimit <= 0x00000000ffffffffLL) and it without effect, please help me .

[igorzwx]

my os is ubuntu 10.04 amd64, soundcard is cmi8738. i get a problem, if i enable the vmix then i will get noise. so i try to change the vmix use fixedfloat but i also get noise, then i see some case with memlimit, my pc have 8GB RAM, so i try to modify the memlimit from (memlimit < 0x00000000ffffffffLL) to (memlimit <= 0x00000000ffffffffLL) and it without effect, please help me .

It may depend on Ubuntu 10.04.
The first problem is, of course, PulseAudio.
If PulseAudio is removed, you may still have other problems. Many Russian users reported strange problems with Ubuntu 10.04 and OSS4. Microphone may not work anymore, or they should reboot the system to get rid of noise or distortions, and so on.

It may also depend on the resampler you use.

You may try OSS4 with Arch LiveCD (pae kernel, up to 8GB RAM).
viewtopic.php?f=3&t=3933
If there will be the same problems, then your OSS4 driver is buggy (or it is a kernel problem).

"Diagnosis also is used in many other trades and professions to determine the causes of symptoms, mitigations for problems, or solutions to issues."
http://en.wikipedia.org/wiki/Diagnosis

[s_m_l_x]

thank you igorzwx , i think this problem was from vmix, the card low driver is ok , when i disable the vmix, only one app to use oss, then there is work fine, if i attach a device (and use -M), I will get the noise.

[igorzwx]

thank you igorzwx , i think this problem was from vmix, the card low driver is ok , when i disable the vmix, only one app to use oss, then there is work fine, if i attach a device (and use -M), I will get the noise.

It may also depend on the sample rate
http://wiki.archlinux.org/index.php/OSS ... ample_Rate
and the resampling algorithm
viewtopic.php?f=3&t=3543

I makes sense to test with Arch LiveCD, I presume.

Troubleshooting
http://wiki.archlinux.org/index.php/OSS#Troubleshooting

[s_m_l_x]

just now i have change the samplerate to 44.1khz, and change the algorithm from low to Production and off, and try to change the dma buffer size from 32 to 128, it always get noise, i think algorithm has been ok, only mixer has some problem. it very strange, on my notebook (acer 2GB RAM, same ubuntu 10.04 amd64), vmix work fine, but my cpu is different, my pc is intel q8200 (4core), notebook is amd tk-55 (2core), and i try compile source use ./configure --portable-build , it without effect also......

[igorzwx]

but my cpu is different, my pc is intel q8200 (4core), notebook is amd tk-55 (2core), and i try compile source use ./configure --portable-build , it without effect also......

In this case, I would try Arch LiveCD with pae kernel (or else).
You see, if there is the same problem with Arch, you may search Arch Wiki and Arch forum (or ask there).
If you have a solution for Arch, you may try something similar for Ubuntu.
This approach proved to be very helpful for many Russian users.

[cesium]

[Edit: I see you've already tried this. nvm. Try this: Add "vmix_no_autoattach=1" line to /usr/lib/oss/conf/osscore.conf, restart OSS with "sudo soundoff" and "sudo soundon", and then attach vmix manually, like this: "sudo vmixctl attach -M /dev/dsp /dev/dsp_in" (You may need to use slightly different /dev params). Then test again.] Can you paste output of 'ossinfo -v3' and of 'lspci -vnn' for the card? How did you test for noise? Try testing using "osstest -V"...

[s_m_l_x]

just now i have change alsa to test , if i use vmix ,play any sound (wav,mp3,...) all have noise, it's my lspci -vnn :



00:00.0 Host bridge [0600]: Intel Corporation 4 Series Chipset DRAM Controller [8086:2e20] (rev 03)
Subsystem: Micro-Star International Co., Ltd. Device [1462:7514]
Flags: bus master, fast devsel, latency 0
Capabilities: <access denied>
Kernel modules: intel-agp

00:01.0 PCI bridge [0604]: Intel Corporation 4 Series Chipset PCI Express Root Port [8086:2e21] (rev 03)
Flags: bus master, fast devsel, latency 0
Bus: primary=00, secondary=01, subordinate=01, sec-latency=0
I/O behind bridge: 0000b000-0000bfff
Memory behind bridge: fa000000-fe9fffff
Prefetchable memory behind bridge: 00000000d0000000-00000000dfffffff
Capabilities: <access denied>
Kernel driver in use: pcieport
Kernel modules: shpchp

00:1a.0 USB Controller [0c03]: Intel Corporation 82801JI (ICH10 Family) USB UHCI Controller #4 [8086:3a37]
Subsystem: Micro-Star International Co., Ltd. Device [1462:7514]
Flags: bus master, medium devsel, latency 0, IRQ 16
I/O ports at ac00 [size=32]
Capabilities: <access denied>
Kernel driver in use: uhci_hcd

00:1a.1 USB Controller [0c03]: Intel Corporation 82801JI (ICH10 Family) USB UHCI Controller #5 [8086:3a38]
Subsystem: Micro-Star International Co., Ltd. Device [1462:7514]
Flags: bus master, medium devsel, latency 0, IRQ 21
I/O ports at a880 [size=32]
Capabilities: <access denied>
Kernel driver in use: uhci_hcd

00:1a.2 USB Controller [0c03]: Intel Corporation 82801JI (ICH10 Family) USB UHCI Controller #6 [8086:3a39]
Subsystem: Micro-Star International Co., Ltd. Device [1462:7514]
Flags: bus master, medium devsel, latency 0, IRQ 19
I/O ports at a800 [size=32]
Capabilities: <access denied>
Kernel driver in use: uhci_hcd

00:1a.7 USB Controller [0c03]: Intel Corporation 82801JI (ICH10 Family) USB2 EHCI Controller #2 [8086:3a3c] (prog-if 20)
Subsystem: Micro-Star International Co., Ltd. Device [1462:7514]
Flags: bus master, medium devsel, latency 0, IRQ 18
Memory at f9fffc00 (32-bit, non-prefetchable) [size=1K]
Capabilities: <access denied>
Kernel driver in use: ehci_hcd

00:1c.0 PCI bridge [0604]: Intel Corporation 82801JI (ICH10 Family) PCI Express Root Port 1 [8086:3a40]
Flags: bus master, fast devsel, latency 0
Bus: primary=00, secondary=02, subordinate=02, sec-latency=0
I/O behind bridge: 0000c000-0000cfff
Memory behind bridge: fea00000-feafffff
Prefetchable memory behind bridge: 00000000f0000000-00000000f01fffff
Capabilities: <access denied>
Kernel driver in use: pcieport
Kernel modules: shpchp

00:1c.1 PCI bridge [0604]: Intel Corporation 82801JI (ICH10 Family) PCI Express Port 2 [8086:3a42]
Flags: bus master, fast devsel, latency 0
Bus: primary=00, secondary=03, subordinate=03, sec-latency=0
I/O behind bridge: 00001000-00001fff
Memory behind bridge: f0200000-f03fffff
Prefetchable memory behind bridge: 00000000f0400000-00000000f05fffff
Capabilities: <access denied>
Kernel driver in use: pcieport
Kernel modules: shpchp

00:1c.5 PCI bridge [0604]: Intel Corporation 82801JI (ICH10 Family) PCI Express Root Port 6 [8086:3a4a]
Flags: bus master, fast devsel, latency 0
Bus: primary=00, secondary=04, subordinate=04, sec-latency=0
I/O behind bridge: 0000d000-0000dfff
Memory behind bridge: feb00000-febfffff
Prefetchable memory behind bridge: 00000000f8f00000-00000000f8ffffff
Capabilities: <access denied>
Kernel driver in use: pcieport
Kernel modules: shpchp

00:1d.0 USB Controller [0c03]: Intel Corporation 82801JI (ICH10 Family) USB UHCI Controller #1 [8086:3a34]
Subsystem: Micro-Star International Co., Ltd. Device [1462:7514]
Flags: bus master, medium devsel, latency 0, IRQ 23
I/O ports at a480 [size=32]
Capabilities: <access denied>
Kernel driver in use: uhci_hcd

00:1d.1 USB Controller [0c03]: Intel Corporation 82801JI (ICH10 Family) USB UHCI Controller #2 [8086:3a35]
Subsystem: Micro-Star International Co., Ltd. Device [1462:7514]
Flags: bus master, medium devsel, latency 0, IRQ 19
I/O ports at a400 [size=32]
Capabilities: <access denied>
Kernel driver in use: uhci_hcd

00:1d.2 USB Controller [0c03]: Intel Corporation 82801JI (ICH10 Family) USB UHCI Controller #3 [8086:3a36]
Subsystem: Micro-Star International Co., Ltd. Device [1462:7514]
Flags: bus master, medium devsel, latency 0, IRQ 18
I/O ports at a080 [size=32]
Capabilities: <access denied>
Kernel driver in use: uhci_hcd

00:1d.7 USB Controller [0c03]: Intel Corporation 82801JI (ICH10 Family) USB2 EHCI Controller #1 [8086:3a3a] (prog-if 20)
Subsystem: Micro-Star International Co., Ltd. Device [1462:7514]
Flags: bus master, medium devsel, latency 0, IRQ 23
Memory at f9fff800 (32-bit, non-prefetchable) [size=1K]
Capabilities: <access denied>
Kernel driver in use: ehci_hcd

00:1e.0 PCI bridge [0604]: Intel Corporation 82801 PCI Bridge [8086:244e] (rev 90) (prog-if 01)
Flags: bus master, fast devsel, latency 0
Bus: primary=00, secondary=05, subordinate=05, sec-latency=32
I/O behind bridge: 0000e000-0000efff
Capabilities: <access denied>

00:1f.0 ISA bridge [0601]: Intel Corporation 82801JIB (ICH10) LPC Interface Controller [8086:3a18]
Subsystem: Micro-Star International Co., Ltd. Device [1462:7514]
Flags: bus master, medium devsel, latency 0
Capabilities: <access denied>
Kernel modules: iTCO_wdt

00:1f.2 IDE interface [0101]: Intel Corporation 82801JI (ICH10 Family) 4 port SATA IDE Controller #1 [8086:3a20] (prog-if 8f [Master SecP SecO PriP PriO])
Subsystem: Micro-Star International Co., Ltd. Device [1462:7514]
Flags: bus master, 66MHz, medium devsel, latency 0, IRQ 19
I/O ports at a000 [size=8]
I/O ports at 9c00 [size=4]
I/O ports at 9880 [size=8]
I/O ports at 9800 [size=4]
I/O ports at 9480 [size=16]
I/O ports at 9400 [size=16]
Capabilities: <access denied>
Kernel driver in use: ata_piix

00:1f.3 SMBus [0c05]: Intel Corporation 82801JI (ICH10 Family) SMBus Controller [8086:3a30]
Subsystem: Micro-Star International Co., Ltd. Device [1462:7514]
Flags: medium devsel, IRQ 14
Memory at f9fff400 (64-bit, non-prefetchable) [size=256]
I/O ports at 0400 [size=32]
Kernel modules: i2c-i801

00:1f.5 IDE interface [0101]: Intel Corporation 82801JI (ICH10 Family) 2 port SATA IDE Controller #2 [8086:3a26] (prog-if 85 [Master SecO PriO])
Subsystem: Micro-Star International Co., Ltd. Device [1462:7514]
Flags: bus master, 66MHz, medium devsel, latency 0, IRQ 19
I/O ports at 9000 [size=8]
I/O ports at 8c00 [size=4]
I/O ports at 8880 [size=8]
I/O ports at 8800 [size=4]
I/O ports at 8480 [size=16]
I/O ports at 8400 [size=16]
Capabilities: <access denied>
Kernel driver in use: ata_piix

01:00.0 VGA compatible controller [0300]: nVidia Corporation G94 [GeForce 9600 GT] [10de:0622] (rev a1)
Subsystem: nVidia Corporation Device [10de:058f]
Flags: bus master, fast devsel, latency 0, IRQ 16
Memory at fd000000 (32-bit, non-prefetchable) [size=16M]
Memory at d0000000 (64-bit, prefetchable) [size=256M]
Memory at fa000000 (64-bit, non-prefetchable) [size=32M]
I/O ports at bc00 [size=128]
[virtual] Expansion ROM at fc000000 [disabled] [size=512K]
Capabilities: <access denied>
Kernel driver in use: nvidia
Kernel modules: nvidia, nvidiafb, nouveau

02:00.0 SATA controller [0106]: JMicron Technology Corp. JMB362/JMB363 Serial ATA Controller [197b:2363] (rev 03) (prog-if 01)
Subsystem: Micro-Star International Co., Ltd. Device [1462:7514]
Flags: bus master, fast devsel, latency 0, IRQ 16
Memory at feafe000 (32-bit, non-prefetchable) [size=8K]
Capabilities: <access denied>
Kernel driver in use: ahci
Kernel modules: ahci

02:00.1 IDE interface [0101]: JMicron Technology Corp. JMB362/JMB363 Serial ATA Controller [197b:2363] (rev 03) (prog-if 85 [Master SecO PriO])
Subsystem: Micro-Star International Co., Ltd. Device [1462:7514]
Flags: bus master, fast devsel, latency 0, IRQ 17
I/O ports at cc00 [size=8]
I/O ports at c880 [size=4]
I/O ports at c800 [size=8]
I/O ports at c480 [size=4]
I/O ports at c400 [size=16]
Capabilities: <access denied>
Kernel driver in use: pata_jmicron
Kernel modules: pata_jmicron

04:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller [10ec:8168] (rev 02)
Subsystem: Micro-Star International Co., Ltd. Device [1462:514c]
Flags: bus master, fast devsel, latency 0, IRQ 28
I/O ports at d800 [size=256]
Memory at f8fff000 (64-bit, prefetchable) [size=4K]
Memory at f8fe0000 (64-bit, prefetchable) [size=64K]
Expansion ROM at febf0000 [disabled] [size=64K]
Capabilities: <access denied>
Kernel driver in use: r8169
Kernel modules: r8168

05:03.0 Multimedia audio controller [0401]: C-Media Electronics Inc CM8738 [13f6:0111] (rev 10)
Subsystem: C-Media Electronics Inc CM8738 [13f6:0111]
Flags: bus master, medium devsel, latency 64, IRQ 22
I/O ports at e800 [size=256]
Capabilities: <access denied>
Kernel driver in use: C-Media PCI
Kernel modules: snd-cmipci

[cesium]

Please paste output of 'ossinfo -v3' too. I wonder which 8738 revision this is... Also, you didn't mention which program you used for testing. Please test using OSS's supplied program - 'osstest -V', 'ossplay', etc.

[s_m_l_x]

ossinfo -v3 :


Version info: OSS 4.2 (b 2003/201007241610) (0x00040100) GPL
Platform: Linux/x86_64 2.6.32-23-generic #37-Ubuntu SMP Fri Jun 11 08:03:28 UTC 2010 (smlx-desktop)

Number of audio devices: 2
Number of audio engines: 6
Number of MIDI devices: 0
Number of mixer devices: 1


Device objects
0: osscore0 OSS core services
1: oss_cmpci0 CMedia CM8738
2: oss_usb0 USB audio core services

MIDI devices (/dev/midi*)

Mixer devices
0: CMedia CMPCI (Mixer 0 of device object 1)
Device file /dev/oss/oss_cmpci0/mix0, Legacy device /dev/mixer0
Priority: 1
Caps:
Device handle: PCI011113f6-0000:05:03.0-mx01
Device priority: 1


Audio devices
CMedia CM8738 (rev 37) /dev/oss/oss_cmpci0/pcm0 (device index 0)
Legacy device /dev/dsp0
Caps: DUPLEX TRIGGER MMAP
Modes: IN/OUT
Engine 1: 0/CMedia CM8738 (rev 37)
Available for use
Engine 2: 1/CMedia CM8738 (rev 37) (vmix)
Available for use
Engine 3: 2/CMedia CM8738 (rev 37) (vmix)
Available for use
Engine 4: 3/CMedia CM8738 (rev 37) (vmix)
Available for use
Engine 5: 4/CMedia CM8738 (rev 37) (vmix)
Available for use
Input formats (0x00000418):
AFMT_U8 - 8 bit unsigned
AFMT_S16_LE - 16 bit signed little endian
AFMT_AC3 - AC3 (Dolby Digital) encoded audio
Output formats (0x00000418):
AFMT_U8 - 8 bit unsigned
AFMT_S16_LE - 16 bit signed little endian
AFMT_AC3 - AC3 (Dolby Digital) encoded audio
Device handle: PCI011113f6-0000:05:03.0-au01
Related mixer dev: 0
Sample rate source: 0
Preferred channel configuration: Not indicated
Supported number of channels (min - max): 2 - 6
Native sample rates (min - max): 5000 - 48000
HW Type: ANALOG_OUT ANALOG_IN DIGITAL_OUT DIGITAL_IN Minimum latency: Not indicated

CMedia CM8738 (playback only) /dev/oss/oss_cmpci0/pcm1 (device index 1)
Legacy device /dev/dsp1
Caps: TRIGGER MMAP
Modes: OUTPUT
Out engine 1: 5/CMedia CM8738 (playback only)
Available for use
Input formats (0x00000418):
AFMT_U8 - 8 bit unsigned
AFMT_S16_LE - 16 bit signed little endian
AFMT_AC3 - AC3 (Dolby Digital) encoded audio
Output formats (0x00000418):
AFMT_U8 - 8 bit unsigned
AFMT_S16_LE - 16 bit signed little endian
AFMT_AC3 - AC3 (Dolby Digital) encoded audio
Device handle: PCI011113f6-0000:05:03.0-au02
Related mixer dev: 0
Sample rate source: 0
Preferred channel configuration: Not indicated
Supported number of channels (min - max): 2 - 6
Native sample rates (min - max): 5000 - 48000
HW Type: ANALOG_OUT ANALOG_IN DIGITAL_OUT DIGITAL_IN Minimum latency: Not indicated


Nodes
/dev/dsp -> /dev/oss/oss_cmpci0/pcm0
/dev/dsp_in -> /dev/oss/oss_cmpci0/pcm0
/dev/dsp_out -> /dev/oss/oss_cmpci0/pcm0
/dev/dsp_ac3 -> /dev/oss/oss_cmpci0/pcm0
/dev/dsp_mmap -> /dev/oss/oss_cmpci0/pcm0
/dev/dsp_multich -> /dev/oss/oss_cmpci0/pcm0
/dev/dsp_spdifout -> /dev/oss/oss_cmpci0/pcm0
/dev/dsp_spdifin -> /dev/oss/oss_cmpci0/pcm0


use audacious, mplayer, ossplay, test in osstest -V :
Platform: Linux/x86_64 2.6.32-23-generic #37-Ubuntu SMP Fri Jun 11 08:03:28 UTC 2010

*** Scanning sound adapter #-1 ***
/dev/oss/oss_cmpci0/pcm0 (audio engine 0): CMedia CM8738 (rev 37)
- Performing audio playback test...
<left> OK <right> OK <stereo> OK <measured srate 47825.00 Hz (-0.36%)>
/dev/oss/oss_cmpci0/pcm1 (audio engine 5): CMedia CM8738 (playback only)
- Performing audio playback test...
<left> OK <right> OK <stereo> OK <measured srate 48004.00 Hz (0.01%)>

*** All tests completed OK ***

[cesium]

Ideas:
A) Is sound on pcm1 fine?
B) If vmix0-channels is set at Multich, set it back to Stereo and test again.
C) Test a low vmix rate (e.g. 22050).
D) See PM for a diff to test...

[igorzwx]

just now i have change alsa to test , if i use vmix ,play any sound (wav,mp3,...) all have noise, it's my lspci -vnn :
05:03.0 Multimedia audio controller [0401]: C-Media Electronics Inc CM8738 [13f6:0111] (rev 10)

Very strange... On 25 Июня 2010, a Russian Ubuntu 10.04 user with a similar soundcard (Звуковая карта c-media 8738) reported very strange things.
He installed OSS4, ran osstest, sound quality was excellent.
Then he tried to reboot Ubuntu, and the result was a failure. He tried everything one could imagine, but it did not help.

The reason why he tried OSS4 was that he had strong sound distortions with ALSA. The removal of PulseAudio did not help.

An idea:
1. You may try ESound instead of vmix

something like this:

sudo apt-get install -y esound esound-clients esound-common libesd0

--------------------------------------------------------------------------------------
EDIT:
Now, I am testing ESound with Ubuntu 9.04 and OSS4 - it works!

I have not yet managed to play music in different players simultaneously, but I do not need to reload OSS4 (or reboot the system) to free the audio device. It might be a practical solution, if you do not need anything special.

$ ossmix vmix0-enable OFF
Value of mixer control vmix0-enable set to OFF
$ ossmix | grep vmix0-enable
vmix0-enable ON|OFF (currently OFF)

1. Install ESound
2. Install "gnome-sound-properties"
3. run "gnome-sound-properties" and change playback to Autodetect/ESound

If you really want to have vmix (with simultaneous playback), you may better try to patch the kernel.

----------------------------------------------------------------------------------------
EDIT:
It is also possible to play sound simultaneously with ESound and OSS4 (with vmix disabled!)
You need things like these:

Esound audio output plugin for VLC

sudo apt-get install vlc-plugin-esd

Adobe Flash Player platform support library for Esound and OSS

sudo apt-get install flashplugin-nonfree-extrasound

Change audio playback in VLC to "EsounD audio output" (and save).

gnome-sound-properties -> Autotect/ESound

and disable vmix

ossmix vmix0-enable OFF

Now, you can start several VLC players simultaneously, and also play video in Youtube (with Chrome or Firefox or else).

It works. I tried it on an old compulter (of 2003). The CPU load (caused by ESound) was insignificant. Sound quality was normal.

ESound is really a good thing, much better than PulseAudio or DMix (I mean the quality of audio output with DMix, and its CPU load with resampler).

Of course, you should not expect too much of ESound, but it is really a good practical solution for very old computers and netbooks (if you have ALSA installed).

Also see how to allow multiple programs to play sound at once
http://wiki.archlinux.org/index.php/All ... nd_at_once

-------------------------------------------------------------------
EDIT: vmix is a kind of rootkit (or trojan, if you like) installed into the Linux kernel. It is a cool thing indeed.
It should be in the kernel, otherwise, it makes a little sense.
Since it is in the kernel, it might be reasonable to try to patch the kernel to fix the problem (just an assumption, of course).

[s_m_l_x]

Ideas:
A) Is sound on pcm1 fine?
B) If vmix0-channels is set at Multich, set it back to Stereo and test again.
C) Test a low vmix rate (e.g. 22050).
D) See PM for a diff to test...

use the patch looks like ok , i need long time to test, thanks cesium, igorzwx.

[igorzwx]

use the patch looks like ok , i need long time to test, thanks cesium, igorzwx.

You may find something here:
http://www.google.com/search?q=arch%20l ... 8&oe=UTF-8

and in Arch Wiki:

Kernel Customization with kernel26 Package
http://wiki.archlinux.org/index.php/Ker ... 26_Package

Custom Kernel Compilation with ABS
http://wiki.archlinux.org/index.php/Cus ... n_with_ABS

Kernel Patches and Patchsets
http://wiki.archlinux.org/index.php/Ker ... _Patchsets