Several bug reports suggest that the forcibly resetting IEC958 status bits is required for AD codecs to get the SPDIF output working properly after changing streams.
Original fix credit to Javeed Shaikh. BugLink: https://bugs.launchpad.net/ubuntu/+source/alsa- driver/+bug/359361 -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to alsa-driver in Ubuntu. https://bugs.launchpad.net/bugs/359361 Title: ALSA SPDIF Digital output clipping / crackling during playback Status in “alsa-driver” package in Ubuntu: Confirmed Bug description: When playing sound in Jaunty out of my HDA Intel SPDIF out, loud sounds clip. This is audible because from the strong distortion it produces, which I have seen some people characterize as "crackling". For example, if I go to system->preferences->sound and play the test sound, the sinusoid is audibly clipping. I have all of my sliders in alsamixer zeroed except for master (@100) and IEC958 (@100). Note that if I turn down the volume of the master and/or the IEC958, the clipping is still present---I've gone as low as -21dB (64/100) on both sliders simultaneously, and the clipping is still there. I looked around for solutions, this sounds similar to my problem: https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/285866 However, as I noted, I've tried reducing my levels, and my PCM mixer level is all the way at 0 (-58.50 dB) anyway. Not to mention that these are digital outputs, so having them at the 0dB gain position (100% for the master and IEC958 sliders) should be fine... Yes I am certain it's not my speakers clipping. Oddly enough, at one point I was able to get it not to clip in the gnome sound settings control by going through some sequence of trying different backends (various options for ALSA, for OSS, etc.). I have not been able to reliably reproduce the non-clipping, but I will keep trying. For some reason, I hear the clipping when I listen to music using gnome-listen, but not when using Amarok using Xine as the backend. Please help me stop the clipping. ProblemType: Bug Architecture: amd64 ArecordDevices: **** List of CAPTURE Hardware Devices **** card 0: Intel [HDA Intel], device 0: AD198x Analog [AD198x Analog] Subdevices: 2/2 Subdevice #0: subdevice #0 Subdevice #1: subdevice #1 AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/dsp', '/dev/snd/controlC0', '/dev/snd/pcmC0D0c', '/dev/snd/pcmC0D0p', '/dev/snd/pcmC0D1p', '/dev/snd/seq', '/dev/snd/timer', '/dev/sequencer2', '/dev/sequencer'] failed with exit code 1: Card0.Amixer.info: Card hw:0 'Intel'/'HDA Intel at 0xfe020000 irq 17' Mixer name : 'Analog Devices AD1984' Components : 'HDA:11d41984,17aa20d7,00100400' Controls : 30 Simple ctrls : 19 DistroRelease: Ubuntu 9.04 Package: alsa-base 1.0.18.dfsg-1ubuntu8 PackageArchitecture: all ProcEnviron: LANG=en_US.UTF-8 SHELL=/bin/bash SourcePackage: alsa-driver Uname: Linux 2.6.28-11-generic x86_64 --- AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.21. Architecture: amd64 ArecordDevices: **** List of CAPTURE Hardware Devices **** card 0: Intel [HDA Intel], device 0: AD198x Analog [AD198x Analog] Subdevices: 2/2 Subdevice #0: subdevice #0 Subdevice #1: subdevice #1 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: edlarson 1435 F.... pulseaudio Card0.Amixer.info: Card hw:0 'Intel'/'HDA Intel at 0xfe020000 irq 17' Mixer name : 'Analog Devices AD1984' Components : 'HDA:11d41984,17aa20d7,00100400' Controls : 29 Simple ctrls : 18 Card29.Amixer.info: Card hw:29 'ThinkPadEC'/'ThinkPad Console Audio Control at EC reg 0x30, fw 7KHT24WW-1.08' Mixer name : 'ThinkPad EC 7KHT24WW-1.08' Components : '' Controls : 1 Simple ctrls : 1 Card29.Amixer.values: Simple mixer control 'Console',0 Capabilities: pswitch pswitch-joined penum Playback channels: Mono Mono: Playback [on] DistroRelease: Ubuntu 10.04 InstallationMedia: Ubuntu 10.04 "Lucid Lynx" - Beta amd64 (20100318) Package: alsa-driver (not installed) ProcEnviron: LANG=en_US.utf8 SHELL=/bin/bash ProcVersionSignature: Ubuntu 2.6.32-21.32-generic 2.6.32.11+drm33.2 Tags: lucid Uname: Linux 2.6.32-21-generic x86_64 UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare dmi.bios.date: 11/14/2008 dmi.bios.vendor: LENOVO dmi.bios.version: 7LETC5WW (2.25 ) dmi.board.name: 7732CTO dmi.board.vendor: LENOVO dmi.board.version: Not Available dmi.chassis.asset.tag: No Asset Information dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: Not Available dmi.modalias: dmi:bvnLENOVO:bvr7LETC5WW(2.25):bd11/14/2008:svnLENOVO:pn7732CTO:pvrThinkPadR61:rvnLENOVO:rn7732CTO:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable: dmi.product.name: 7732CTO dmi.product.version: ThinkPad R61 dmi.sys.vendor: LENOVO To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/359361/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
