Red Hat Bugzilla – Bug 112773
'Fuzzy'' sound issue with via82xx / alc650 under Fedora Core 1 - both with Standard and ALSA drivers
Last modified: 2007-11-30 17:10:34 EST
Description of problem: User experiences 'fuzzy' sound particularly low base and high trebble using either the standard drivers as well as the alsa drivers. Version-Release number of selected component (if applicable): Linux localhost.localdomain 2.4.22-1.2135.nptl #1 Mon Dec 15 16:05:26 EST 2003 i686 athlon i386 GNU/Linux Motherboard - Asus A7V8X Problem is not exhibited under MS Windows XP How reproducible: Simply play any sound file both at the command line as well as in a X windows desktop such as GNOME or KDE. Steps to Reproduce: 1. Install sound card (during normal install process or alternatively install using alsa sound drivers) 2. Play any sound (wav, etc) with xmms or any other sound player 3. Actual results: Expected results: Additional info: Bug exhibited with all fedora kernels - 2115, 2229, 2235.... Outputs from various commands: [root@localhost ademalet]# /sbin/lsmod Module Size Used by Not tainted snd-pcm-oss 43908 0 (autoclean) snd-mixer-oss 15408 1 (autoclean) [snd-pcm-oss] snd-via82xx 16960 4 (autoclean) snd-ac97-codec 57676 0 (autoclean) [snd-via82xx] snd-pcm 84612 1 (autoclean) [snd-pcm-oss snd-via82xx] snd-timer 19172 0 (autoclean) [snd-pcm] gameport 3380 0 (autoclean) [snd-via82xx] snd-page-alloc 9396 0 (autoclean) [snd-via82xx snd-pcm] snd-mpu401-uart 5072 0 (autoclean) [snd-via82xx] snd-rawmidi 18048 0 (autoclean) [snd-mpu401-uart] snd-seq-device 5976 0 (autoclean) [snd-rawmidi] snd 45732 2 (autoclean) [snd-pcm-oss snd-mixer-oss snd-via82xx snd-ac97-codec snd-pcm snd-timer snd-mpu401-uart snd-rawmidi snd-seq-device] soundcore 6500 4 (autoclean) [snd] parport_pc 18468 1 (autoclean) lp 8356 0 (autoclean) parport 36800 1 (autoclean) [parport_pc lp] autofs 12052 0 (autoclean) (unused) b44 16680 1 ipt_REJECT 4216 1 (autoclean) ipt_state 1080 1 (autoclean) ip_conntrack 27752 1 (autoclean) [ipt_state] iptable_filter 2444 1 (autoclean) ip_tables 14560 3 [ipt_REJECT ipt_state iptable_filter] floppy 56348 0 (autoclean) sg 34796 0 (autoclean) sr_mod 17016 0 (autoclean) ide-scsi 11856 0 scsi_mod 109384 2 [sg sr_mod ide-scsi] ide-cd 34176 0 cdrom 33984 0 [sr_mod ide-cd] ohci1394 28520 0 (unused) ieee1394 203940 0 [ohci1394] nls_iso8859-1 3548 1 (autoclean) ntfs 58336 1 (autoclean) keybdev 2624 0 (unused) hid 23652 0 (unused) ehci-hcd 19784 0 (unused) usb-uhci 25740 0 (unused) usbcore 77984 1 [hid ehci-hcd usb-uhci] mousedev 5204 1 (autoclean) input 5824 0 (autoclean) [keybdev hid mousedev] radeon 118212 12 agpgart 55108 3 ext3 70532 2 jbd 50796 2 [ext3] -------------- root@localhost ademalet]# /sbin/lspci 00:00.0 Host bridge: VIA Technologies, Inc. VT8377 [KT400 AGP] Host Bridge 00:01.0 PCI bridge: VIA Technologies, Inc. VT8235 PCI Bridge 00:07.0 FireWire (IEEE 1394): VIA Technologies, Inc. IEEE 1394 Host Controller (rev 80) 00:08.0 RAID bus controller: Promise Technology, Inc. PDC20376 (rev 02) 00:09.0 Ethernet controller: Broadcom Corporation BCM4401 100Base-T (rev 01) 00:10.0 USB Controller: VIA Technologies, Inc. USB (rev 80) 00:10.1 USB Controller: VIA Technologies, Inc. USB (rev 80) 00:10.2 USB Controller: VIA Technologies, Inc. USB (rev 80) 00:10.3 USB Controller: VIA Technologies, Inc. USB 2.0 (rev 82) 00:11.0 ISA bridge: VIA Technologies, Inc. VT8235 ISA Bridge 00:11.1 IDE interface: VIA Technologies, Inc. VT82C586A/B/VT82C686/A/B/VT8233/A/C/VT8235 PIPC Bus Master IDE (rev 06) 00:11.5 Multimedia audio controller: VIA Technologies, Inc. VT8233/A/8235 AC97 Audio Controller (rev 50) 01:00.0 VGA compatible controller: ATI Technologies Inc Radeon R100 QD [Radeon 7200] -----------------------------
I suppose this is the same probelm that I encountered (however, the description fuzzy is a bit fuzzy). Does the problem go away when resampling the example to 48khz? To test this do the following: 1) Grab a cd (preferrably a soft one) and rip a track with 'cdparanoia -X TRACKNUM' 2) play the resulting wav file with 'play cdda.wav' and verify that the audio problem exist 3) use the following command line to resample the track to 48khz: sox cdda.wav -r 48000 cdda48.wav polyphase 4) now play the resulting wav file with 'play cdda48.wav' and here if the problem is gone My guess is that the hardware only supports 48khz, but the drivers emulates support for 44.1khz (cd rate). Some drivers does this better (xp, oss) than others (alsa) at the moment. I'll try to investigate this further myself, but "fixes from above" would be appreciated. ps. my hardware as reported by lspci: VIA Technologies, Inc. VT8233/A/8235/8237 AC97 Audio Controller (rev 50)
Firstly I think that the sound artefact is better described as 'sizzling sound' when playing 44.1khz audio. After some poking around in the ALSA jungle I found that the DXS autodetection doesn't work properly (It is my understanding that DXS is the ability to mix different sounds in hardware instead of just doing software mixing) DXS behaviour in alsa is controlled by the dxs_support parameter that can be sent to the snd_via82xx module when loaded. If I set dxs_support to 0 or 1 I get broken 44.1khz audio, however if I set the parameter parameter to 2, 3 or 4 the problem is gone. One thing that made this a lot more difficult to debug is the fact that /etc/modprobe.conf contains the following line: install snd-via82xx /sbin/modprobe --ignore-install snd-via82xx && /usr/sbin/alsactl restore >/dev/null 2>&1 || : A line that effectively and silently 'eats' all parameters sent to the snd-via82xx module as additional modprobe arguments. Could this be fixed in some better way? According to http://alsa.opensrc.org/index.php?page=via8233 the autodetection that is supposed to happen by default is done by a list of known good hardware i in the kernel, a list that apparently needs to be updated. I'll notify upstream about this for my particular hardware (An ASUS A7V8X motherboard with integrated VIA 8235 sound.) Others might want to do the same for their hardware if they also have this problem problem. In the meantime I can work around the problem by adding the line 'options snd-via82xx dxs_support=4' to my /etc/modprobe.conf
According to https://bugtrack.alsa-project.org/alsa-bug/bug_view_page.php?bug_id=0000284 this issue is supposedly fixed upstream in alsa now for my particular hardware.
Same problem, Fedora Core 2, latest errara kernel. FC2's stock kernel worked fine.
Thanks for the bug report. However, Red Hat no longer maintains this version of the product. Please upgrade to the latest version and open a new bug if the problem persists. The Fedora Legacy project (http://fedoralegacy.org/) maintains some older releases, and if you believe this bug is interesting to them, please report the problem in the bug tracker at: http://bugzilla.fedora.us/