Ubuntu

skype bad sound quality 7.04 feisty

Asked by bLaNG

skype is working fine for file transfer and chat, but i have trouble with voip via skype. the mic quality is horrible most of the time. while i hear my on voice via speak clearly, the opponent on the other side mainly gets scrambeld sound with bits and pieces of quite clear sound.

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Markus Thielmann (thielmann) said : 		#1

Thanks for your question. It's great you found your way from heise to Ubuntu Answers :-)

We need a few more information:

1) What Skype version do you run? You'll find that under "Help/Info" or "Hilfe/Info"
2) Please provide your Skype sound device preferences. You'll find that under "Aktionen/Optionen/Geräte". Most important: ALSA or OSS?
3) Please provide the content of "/etc/asound.conf" (if it exists) and "~/.asoundrc" (if it exists)
4) Please provide the output of the terminal command "cat /proc/asound/cards"
5) Please provide the output of the terminal command "lsmod | grep snd"

- I assume you had a working Skype on Windows without these problems, right?

Revision history for this message
bLaNG (guido-bertling) said : 		#2

ever greater you found me back here after recommending ;) thx

1) Skype Version 1.3.0.53_API

2) ALSA (for C-Media PCI CMI8738-MC8)

3) content of "~/.asoundrc"

# ALSA library configuration file

# Include settings that are under the control of asoundconf(1).
# (To disable these settings, comment out this line.)
</home/blang/.asoundrc.asoundconf>

asound.conf:

# ALSA library configuration file managed by asoundconf(1).
#
# MANUAL CHANGES TO THIS FILE WILL BE OVERWRITTEN!
#
# Manual changes to the ALSA library configuration should be implemented
# by editing the ~/.asoundrc file, not by editing this file.
!defaults.pcm.card CMI8738MC8
defaults.ctl.card CMI8738MC8
defaults.pcm.device 0
defaults.pcm.subdevice -1
defaults.pcm.nonblock 1
defaults.pcm.ipc_key 5678293
defaults.pcm.ipc_gid audio
defaults.pcm.ipc_perm 0660
defaults.pcm.dmix_max_periods 0
defaults.pcm.dmix_rate 48000
defaults.pcm.dmix_format S16
defaults.pcm.front.card defaults.pcm.card
defaults.pcm.front.device defaults.pcm.device
defaults.pcm.rear.card defaults.pcm.card
defaults.pcm.rear.device defaults.pcm.device
defaults.pcm.center_lfe.card defaults.pcm.card
defaults.pcm.center_lfe.device defaults.pcm.device
defaults.pcm.side.card defaults.pcm.card
defaults.pcm.side.device defaults.pcm.device
defaults.pcm.surround40.card defaults.pcm.card
defaults.pcm.surround40.device defaults.pcm.device
defaults.pcm.surround41.card defaults.pcm.card
defaults.pcm.surround41.device defaults.pcm.device
defaults.pcm.surround50.card defaults.pcm.card
defaults.pcm.surround50.device defaults.pcm.device
defaults.pcm.surround51.card defaults.pcm.card
defaults.pcm.surround51.device defaults.pcm.device
defaults.pcm.surround71.card defaults.pcm.card
defaults.pcm.surround71.device defaults.pcm.device
defaults.pcm.iec958.card defaults.pcm.card
defaults.pcm.iec958.device defaults.pcm.device
defaults.pcm.modem.card defaults.pcm.card
defaults.pcm.modem.device defaults.pcm.device
defaults.rawmidi.card 0
defaults.rawmidi.device 0
defaults.rawmidi.subdevice -1
defaults.hwdep.card 0
defaults.hwdep.device 0
defaults.timer.class 2
defaults.timer.sclass 0
defaults.timer.card 0
defaults.timer.device 0
defaults.timer.subdevice 0

4)

0 [CMI8738MC8 ]: CMI8738-MC8 - C-Media PCI CMI8738-MC8
                      C-Media PCI CMI8738-MC8 (model 68) at 0xb400, irq 19

5)

snd_cmipci 37024 8
gameport 16520 1 snd_cmipci
snd_pcm_oss 44544 0
snd_mixer_oss 17408 1 snd_pcm_oss
snd_pcm 79876 4 snd_cmipci,snd_pcm_oss
snd_page_alloc 10888 1 snd_pcm
snd_opl3_lib 11520 1 snd_cmipci
snd_hwdep 9988 1 snd_opl3_lib
snd_mpu401_uart 9472 1 snd_cmipci
snd_seq_dummy 4740 0
snd_seq_oss 32896 0
snd_seq_midi 9600 0
snd_rawmidi 25472 2 snd_mpu401_uart,snd_seq_midi
snd_seq_midi_event 8448 2 snd_seq_oss,snd_seq_midi
snd_seq 52592 6 snd_seq_dummy,snd_seq_oss,snd_seq_midi,snd_seq_midi_event
snd_timer 23684 5 snd_pcm,snd_opl3_lib,snd_seq
snd_seq_device 9100 6 snd_opl3_lib,snd_seq_dummy,snd_seq_oss,snd_seq_midi,snd_rawmidi,snd_seq
snd 54020 24 snd_cmipci,snd_pcm_oss,snd_mixer_oss,snd_pcm,snd_opl3_lib,snd_hwdep,snd_mpu401_uart,snd_seq_oss,snd_rawmidi,snd_seq,snd_timer,snd_seq_device
soundcore 8672 1 snd

yeah, skype was running fine under xp sp2. some additional info, i allready changed setting of the alsa mixer to enable mic and mic boost.

thx again for helping!

Revision history for this message
Markus Thielmann (thielmann) said : 		#3

O.k., now we need also:

1) /home/blang/.asoundrc.asoundconf
2) output of "amixer"

Revision history for this message
bLaNG (guido-bertling) said : 		#4

allright, here we go:

1)

# ALSA library configuration file managed by asoundconf(1).
#
# MANUAL CHANGES TO THIS FILE WILL BE OVERWRITTEN!
#
# Manual changes to the ALSA library configuration should be implemented
# by editing the ~/.asoundrc file, not by editing this file.
!defaults.pcm.card CMI8738MC8
defaults.ctl.card CMI8738MC8
defaults.pcm.device 0
defaults.pcm.subdevice -1
defaults.pcm.nonblock 1
defaults.pcm.ipc_key 5678293
defaults.pcm.ipc_gid audio
defaults.pcm.ipc_perm 0660
defaults.pcm.dmix_max_periods 0
defaults.pcm.dmix_rate 48000
defaults.pcm.dmix_format S16
defaults.pcm.front.card defaults.pcm.card
defaults.pcm.front.device defaults.pcm.device
defaults.pcm.rear.card defaults.pcm.card
defaults.pcm.rear.device defaults.pcm.device
defaults.pcm.center_lfe.card defaults.pcm.card
defaults.pcm.center_lfe.device defaults.pcm.device
defaults.pcm.side.card defaults.pcm.card
defaults.pcm.side.device defaults.pcm.device
defaults.pcm.surround40.card defaults.pcm.card
defaults.pcm.surround40.device defaults.pcm.device
defaults.pcm.surround41.card defaults.pcm.card
defaults.pcm.surround41.device defaults.pcm.device
defaults.pcm.surround50.card defaults.pcm.card
defaults.pcm.surround50.device defaults.pcm.device
defaults.pcm.surround51.card defaults.pcm.card
defaults.pcm.surround51.device defaults.pcm.device
defaults.pcm.surround71.card defaults.pcm.card
defaults.pcm.surround71.device defaults.pcm.device
defaults.pcm.iec958.card defaults.pcm.card
defaults.pcm.iec958.device defaults.pcm.device
defaults.pcm.modem.card defaults.pcm.card
defaults.pcm.modem.device defaults.pcm.device
defaults.rawmidi.card 0
defaults.rawmidi.device 0
defaults.rawmidi.subdevice -1
defaults.hwdep.card 0
defaults.hwdep.device 0
defaults.timer.class 2
defaults.timer.sclass 0
defaults.timer.card 0
defaults.timer.device 0
defaults.timer.subdevice 0

2)

Simple mixer control 'Master',0
  Capabilities: pvolume
  Playback channels: Front Left - Front Right
  Limits: Playback 0 - 31
  Mono:
  Front Left: Playback 23 [74%]
  Front Right: Playback 23 [74%]
Simple mixer control '3D Control - Switch',0
  Capabilities: pswitch pswitch-joined
  Playback channels: Mono
  Mono: Playback [off]
Simple mixer control 'PCM',0
  Capabilities: pvolume pswitch pswitch-joined cswitch
  Playback channels: Front Left - Front Right
  Capture channels: Front Left - Front Right
  Limits: Playback 0 - 255
  Front Left: Playback 255 [100%] [0.00dB] [on] Capture [off]
  Front Right: Playback 255 [100%] [0.00dB] [on] Capture [off]
Simple mixer control 'Synth',0
  Capabilities: pvolume pswitch pswitch-joined cswitch
  Playback channels: Front Left - Front Right
  Capture channels: Front Left - Front Right
  Limits: Playback 0 - 31
  Front Left: Playback 25 [81%] [on] Capture [off]
  Front Right: Playback 25 [81%] [on] Capture [off]
Simple mixer control 'Line',0
  Capabilities: pvolume pswitch cswitch
  Playback channels: Front Left - Front Right
  Capture channels: Front Left - Front Right
  Limits: Playback 0 - 31
  Front Left: Playback 28 [90%] [on] Capture [off]
  Front Right: Playback 28 [90%] [on] Capture [off]
Simple mixer control 'Line-In Mode',0
  Capabilities: enum
  Items: 'Line-In' 'Rear Output' 'Bass Output'
  Item0: 'Line-In'
Simple mixer control 'CD',0
  Capabilities: pvolume pswitch cswitch
  Playback channels: Front Left - Front Right
  Capture channels: Front Left - Front Right
  Limits: Playback 0 - 31
  Front Left: Playback 25 [81%] [on] Capture [off]
  Front Right: Playback 25 [81%] [on] Capture [off]
Simple mixer control 'Mic',0
  Capabilities: pvolume pvolume-joined cvolume pswitch pswitch-joined cswitch cswitch-joined
  Playback channels: Mono
  Capture channels: Mono
  Limits: Playback 0 - 31 Capture 0 - 7
  Mono: Playback 29 [94%] [off] Capture 7 [100%] [on]
Simple mixer control 'Mic Boost',0
  Capabilities: pswitch pswitch-joined cswitch cswitch-joined
  Playback channels: Mono
  Capture channels: Mono
  Mono: Playback [on] Capture [on]
Simple mixer control 'Mic-In Mode',0
  Capabilities: enum
  Items: 'Mic-In' 'Center/LFE Output'
  Item0: 'Mic-In'
Simple mixer control 'Phone',0
  Capabilities: pvolume pvolume-joined pswitch pswitch-joined
  Playback channels: Mono
  Limits: Playback 0 - 7
  Mono: Playback 7 [100%] [off]
Simple mixer control 'IEC958 5V',0
  Capabilities: pswitch pswitch-joined
  Playback channels: Mono
  Mono: Playback [on]
Simple mixer control 'IEC958 Copyright',0
  Capabilities: pswitch pswitch-joined
  Playback channels: Mono
  Mono: Playback [off]
Simple mixer control 'IEC958 In Monitor',0
  Capabilities: pswitch pswitch-joined
  Playback channels: Mono
  Mono: Playback [off]
Simple mixer control 'IEC958 In Phase Inverse',0
  Capabilities: pswitch pswitch-joined
  Playback channels: Mono
  Mono: Playback [off]
Simple mixer control 'IEC958 In Select',0
  Capabilities: pswitch pswitch-joined
  Playback channels: Mono
  Mono: Playback [off]
Simple mixer control 'IEC958 In Valid',0
  Capabilities: pswitch pswitch-joined
  Playback channels: Mono
  Mono: Playback [off]
Simple mixer control 'IEC958 Loop',0
  Capabilities: pswitch pswitch-joined
  Playback channels: Mono
  Mono: Playback [off]
Simple mixer control 'IEC958 Output',0
  Capabilities: pswitch pswitch-joined
  Playback channels: Mono
  Mono: Playback [off]
Simple mixer control 'PC Speaker',0
  Capabilities: pvolume pvolume-joined pswitch pswitch-joined
  Playback channels: Mono
  Limits: Playback 0 - 3
  Mono: Playback 3 [100%] [on]
Simple mixer control 'Aux',0
  Capabilities: pvolume pswitch cswitch
  Playback channels: Front Left - Front Right
  Capture channels: Front Left - Front Right
  Limits: Playback 0 - 15
  Front Left: Playback 2 [13%] [off] Capture [off]
  Front Right: Playback 2 [13%] [off] Capture [off]
Simple mixer control 'Four Channel Mode',0
  Capabilities: pswitch pswitch-joined
  Playback channels: Mono
  Mono: Playback [on]

Revision history for this message
Markus Thielmann (thielmann) said : 		#5

Allright, sorry for the delay, I just needed to collect a few ideas :-)

Please keep in mind, that -in most cases- you need to restart alsa with "sudo /etc/init.d/alsa-base restart".

1) Try using the microphone witch "microphone capture" off. It's a switch in Gnomes Alsamixer (in the "switches" tab). If you don't see it, just open Preferences and select the checkbox.

2) Try to use the following ~/.asoundrc. Please back up your old file. If it doesn't change anything to you, please use the original file:

>>> SNIP >>>
pcm.!dmix {

       type dmix

       ipc_key 5678293

       ipc_key_add_uid yes

       slave {

               pcm "hw:0,0"

               format S16_LE

               rate 44100

       }

}

pcm.!dsnoop {

       type dsnoop

       ipc_key 5778293

       ipc_key_add_uid yes

       slave {

               pcm "hw:0,0"

               format S16_LE

               rate 44100

       }

}
>>> SNIP >>>

3) Please check if you've got choppy sound also when recording your voice locally. Maybe the problem is related to skype, not to ubuntu.

4) Please give http://share.skype.com/sites/garage/2007/05/skype_for_linux_14_alpha_relea.html a try.

Can you help with this problem?

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