Difference between revisions of "Sound"
From Linuxintro
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| + | Linux sound is one big mess. We have ALSA, OSS, PulseAudio, gstreamer, arts, phonon as subsystems. This article explains the concepts and helps people fixing their sound problems. | ||
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| + | The "normal" Linux sound system is [http://en.wikipedia.org/wiki/Advanced_Linux_Sound_Architecture ALSA]. It emulates the older [http://en.wikipedia.org/wiki/Open_Sound_System OSS]. ALSA allows several applications to play sound at the same time, OSS does not. This is because OSS provides a single sound device file, /dev/dsp that applications lock when outputting to it. To raise confusion, ALSA emulates OSS by also providing /dev/dsp. | ||
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Try this: | Try this: | ||
dd if=/dev/dsp of=audio.raw | dd if=/dev/dsp of=audio.raw | ||
Revision as of 16:01, 11 August 2009
Linux sound is one big mess. We have ALSA, OSS, PulseAudio, gstreamer, arts, phonon as subsystems. This article explains the concepts and helps people fixing their sound problems.
The "normal" Linux sound system is ALSA. It emulates the older OSS. ALSA allows several applications to play sound at the same time, OSS does not. This is because OSS provides a single sound device file, /dev/dsp that applications lock when outputting to it. To raise confusion, ALSA emulates OSS by also providing /dev/dsp.
Try this:
dd if=/dev/dsp of=audio.raw dd if=audio.raw of=/dev/dsp
See
http://www.linuxjournal.com/article/6735
Soundcard Intel 82801G on Ubuntu 8.10: recording problems
- recording via external microphone very quiet
- recording via internal microphone cannot be heard
alsamixer -c 0
tstaerk@dell-desktop:~/alsa$ modprobe -l | grep snd-hda /lib/modules/2.6.27-14-generic/kernel/sound/pci/hda/snd-hda-intel.ko tstaerk@dell-desktop:~/alsa$ md5sum /lib/modules/2.6.27-14-generic/kernel/sound/pci/hda/snd-hda-intel.ko bec085930fe6b6e7c448c5ba7d3e50fa /lib/modules/2.6.27-14-generic/kernel/sound/pci/hda/snd-hda-intel.ko tstaerk@dell-desktop:~/alsa$ ll /lib/modules/2.6.27-14-generic/kernel/sound/pci/hda/snd-hda-intel.ko bash: ll: command not found tstaerk@dell-desktop:~/alsa$ ls -l /lib/modules/2.6.27-14-generic/kernel/sound/pci/hda/snd-hda-intel.ko -rw-r--r-- 1 root root 511592 2009-07-25 01:48 /lib/modules/2.6.27-14-generic/kernel/sound/pci/hda/snd-hda-intel.ko modinfo snd-hda-intel filename: /lib/modules/2.6.27-14-generic/kernel/sound/pci/hda/snd-hda-intel.ko description: Intel HDA driver license: GPL srcversion: C4633ED01D74A5D02607392 alias: pci:v00006549d00001200sv*sd*bc*sc*i* alias: pci:v000010DEd00000BD7sv*sd*bc*sc*i* alias: pci:v000010DEd00000BD6sv*sd*bc*sc*i* alias: pci:v000010DEd00000BD5sv*sd*bc*sc*i* alias: pci:v000010DEd00000BD4sv*sd*bc*sc*i* alias: pci:v000010DEd00000AC3sv*sd*bc*sc*i* alias: pci:v000010DEd00000AC2sv*sd*bc*sc*i* alias: pci:v000010DEd00000AC1sv*sd*bc*sc*i* alias: pci:v000010DEd00000AC0sv*sd*bc*sc*i* alias: pci:v000010DEd000007FDsv*sd*bc*sc*i* alias: pci:v000010DEd000007FCsv*sd*bc*sc*i* alias: pci:v000010DEd00000777sv*sd*bc*sc*i* alias: pci:v000010DEd00000776sv*sd*bc*sc*i* alias: pci:v000010DEd00000775sv*sd*bc*sc*i* alias: pci:v000010DEd00000774sv*sd*bc*sc*i* alias: pci:v000010DEd0000055Dsv*sd*bc*sc*i* alias: pci:v000010DEd0000055Csv*sd*bc*sc*i* alias: pci:v000010DEd0000044Bsv*sd*bc*sc*i* alias: pci:v000010DEd0000044Asv*sd*bc*sc*i* alias: pci:v000010DEd000003F0sv*sd*bc*sc*i* alias: pci:v000010DEd000003E4sv*sd*bc*sc*i* alias: pci:v000010DEd00000371sv*sd*bc*sc*i* alias: pci:v000010DEd0000026Csv*sd*bc*sc*i* alias: pci:v000010B9d00005461sv*sd*bc*sc*i* alias: pci:v00001039d00007502sv*sd*bc*sc*i* alias: pci:v00001106d00003288sv*sd*bc*sc*i* alias: pci:v00001002d0000AA48sv*sd*bc*sc*i* alias: pci:v00001002d0000AA40sv*sd*bc*sc*i* alias: pci:v00001002d0000AA38sv*sd*bc*sc*i* alias: pci:v00001002d0000AA30sv*sd*bc*sc*i* alias: pci:v00001002d0000AA28sv*sd*bc*sc*i* alias: pci:v00001002d0000AA20sv*sd*bc*sc*i* alias: pci:v00001002d0000AA18sv*sd*bc*sc*i* alias: pci:v00001002d0000AA10sv*sd*bc*sc*i* alias: pci:v00001002d0000AA08sv*sd*bc*sc*i* alias: pci:v00001002d0000AA00sv*sd*bc*sc*i* alias: pci:v00001002d0000970Fsv*sd*bc*sc*i* alias: pci:v00001002d0000960Fsv*sd*bc*sc*i* alias: pci:v00001002d00007919sv*sd*bc*sc*i* alias: pci:v00001002d0000793Bsv*sd*bc*sc*i* alias: pci:v00001002d00004383sv*sd*bc*sc*i* alias: pci:v00001002d0000437Bsv*sd*bc*sc*i* alias: pci:v00008086d0000811Bsv*sd*bc*sc*i* alias: pci:v00008086d00003B56sv*sd*bc*sc*i* alias: pci:v00008086d00003A6Esv*sd*bc*sc*i* alias: pci:v00008086d00003A3Esv*sd*bc*sc*i* alias: pci:v00008086d0000293Fsv*sd*bc*sc*i* alias: pci:v00008086d0000293Esv*sd*bc*sc*i* alias: pci:v00008086d00002911sv*sd*bc*sc*i* alias: pci:v00008086d0000284Bsv*sd*bc*sc*i* alias: pci:v00008086d0000269Asv*sd*bc*sc*i* alias: pci:v00008086d000027D8sv*sd*bc*sc*i* alias: pci:v00008086d00002668sv*sd*bc*sc*i* depends: snd-pcm,snd-page-alloc,snd vermagic: 2.6.27-14-generic SMP mod_unload modversions 586 parm: power_save:Automatic power-saving timeout (in second, 0 = disable). (int) parm: index:Index value for Intel HD audio interface. (array of int) parm: id:ID string for Intel HD audio interface. (array of charp) parm: enable:Enable Intel HD audio interface. (array of bool) parm: model:Use the given board model. (array of charp) parm: position_fix:Fix DMA pointer (0 = auto, 1 = none, 2 = POSBUF). (array of int) parm: bdl_pos_adj:BDL position adjustment offset. (array of int) parm: probe_mask:Bitmask to probe codecs (default = -1). (array of int) parm: single_cmd:Use single command to communicate with codecs (for debugging only). (bool) parm: enable_msi:Enable Message Signaled Interrupt (MSI) (int) parm: power_save_controller:Reset controller in power save mode. (bool)
