Difference between revisions of "Sound"
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Manipulating these are done with the ''audioctl'' and ''mixerctl'' commands. At kernel configuration time the dmesg may look like this with the auich(4) card. | Manipulating these are done with the ''audioctl'' and ''mixerctl'' commands. At kernel configuration time the dmesg may look like this with the auich(4) card. | ||
| − | auich0 at pci0 dev 6 function 0 "NVIDIA nForce3 250 AC97" rev 0xa1: irq 11, nForce3 AC97 | + | auich0 at pci0 dev 6 function 0 "NVIDIA nForce3 250 AC97" rev |
| − | audio0 at auich0 | + | 0xa1: irq 11, nForce3 AC97 |
| − | auich0: measured ac97 link rate at 47995 Hz, will use 48000 Hz | + | audio0 at auich0 |
| + | auich0: measured ac97 link rate at 47995 Hz, will use 48000 Hz | ||
Playing mp3's can be done with mpg123 or mplayer, with mplayer I usually use the -srate 48000 option to resample the rate to the hardfixed 48000 Hz of this particular card. | Playing mp3's can be done with mpg123 or mplayer, with mplayer I usually use the -srate 48000 option to resample the rate to the hardfixed 48000 Hz of this particular card. | ||
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Recording is done the following way: | Recording is done the following way: | ||
| − | (audioctl record.encoding=slinear_le record.channels=2 record.precision=16 ; \ | + | (audioctl record.encoding=slinear_le record.channels=2 \ |
| − | cat /dev/sound ) > blah.raw | + | record.precision=16 ; \ |
| + | cat /dev/sound ) > blah.raw | ||
This writes a raw file of PCM data but without the headers, I found that sox can attach a header, like so: | This writes a raw file of PCM data but without the headers, I found that sox can attach a header, like so: | ||
| − | sox -r 48000 -w -s -c 2 blah.raw blah.wav | + | sox -r 48000 -w -s -c 2 blah.raw blah.wav |
Revision as of 01:57, 23 October 2006
Sound on UNIX has improved tremendously over the last ten years. Especially for Free UNIXes.
In OpenBSD the interface to the sound card are /dev/sound, /dev/audio, /dev/audioctl, /dev/mixer.
Manipulating these are done with the audioctl and mixerctl commands. At kernel configuration time the dmesg may look like this with the auich(4) card.
auich0 at pci0 dev 6 function 0 "NVIDIA nForce3 250 AC97" rev 0xa1: irq 11, nForce3 AC97 audio0 at auich0 auich0: measured ac97 link rate at 47995 Hz, will use 48000 Hz
Playing mp3's can be done with mpg123 or mplayer, with mplayer I usually use the -srate 48000 option to resample the rate to the hardfixed 48000 Hz of this particular card.
Recording is done the following way:
(audioctl record.encoding=slinear_le record.channels=2 \ record.precision=16 ; \ cat /dev/sound ) > blah.raw
This writes a raw file of PCM data but without the headers, I found that sox can attach a header, like so:
sox -r 48000 -w -s -c 2 blah.raw blah.wav
