I am trying to set up the ability to record line-in, but have been unable to make it work and would appreciate advice. (I have looked at quite a few web pages of various kinds of help for ALSA, but all of them seem to be rather vague on the details of recording.)
The hardware is very simple: ---- n7dr@shack:~$ cat /proc/asound/cards 0 [IXP ]: ATIIXP - ATI IXP ATI IXP rev 2 with ALC658D at 0xfe02a000, irq 17 n7dr@shack:~$ ---- The card has a mic input, a line input, and a speaker output. If I simply run aplay with a WAV file, I hear the contents of the file. For example: ---- n7dr@shack:~$ aplay -D hw:0,0 c*.wav ---- causes the named file to play. So *playing* seems to be fine. However, I have been unable to find any way to record the line input. Everything I have tried has resulted in silence in the output file. For example: ---- n7dr@shack:~$ arecord -D hw:0,0 -fdat foo.wav ---- produces the file foo.wav, with silence. amixer says: ---- n7dr@shack:~$ amixer Simple mixer control 'Master',0 Capabilities: pvolume pswitch pswitch-joined Playback channels: Front Left - Front Right Limits: Playback 0 - 65536 Mono: Front Left: Playback 55141 [84%] [on] Front Right: Playback 55141 [84%] [on] Simple mixer control 'Capture',0 Capabilities: cvolume cswitch cswitch-joined Capture channels: Front Left - Front Right Limits: Capture 0 - 65536 Front Left: Capture 53640 [82%] [off] Front Right: Capture 53640 [82%] [off] n7dr@shack:~$ ---- which seems to be OK, insofar as I understand it, except that there is no indication of whether the capture device is line-in or the mic line. I haven't been able to find anything that explicitly tells me how to set the capture device to be the line in. alsamixer looks like this when viewing the Capture item: ───────────────────── AlsaMixer v1.0.28 ─────────────────────┐ │ Card: PulseAudio F1: Help │ │ Chip: PulseAudio F2: System information │ │ View: Capture F6: Select sound card │ │ Item: Capture Esc: Exit │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ ┌──┐ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │▒▒│ │ │ │▒▒│ │ │ │▒▒│ │ │ │▒▒│ │ │ │▒▒│ │ │ │▒▒│ │ │ │▒▒│ │ │ │▒▒│ │ │ │▒▒│ │ │ │▒▒│ │ │ │▒▒│ │ │ │▒▒│ │ │ │▒▒│ │ │ │▒▒│ │ │ │▒▒│ │ │ │▒▒│ │ │ │▒▒│ │ │ │▒▒│ │ │ │▒▒│ │ │ │▒▒│ │ │ L└──┘R │ │ CAPTURE │ │ 82<>82 │ │ <Capture > │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ └─────────────────────────────────────────────────────────────┘ I've also tried plugging the incoming audio into the mic socket (in case that's what's being captured), and that just records silence as well. So I suppose that my questions are: 1. How do I tell alsa that I want to capture from line-in? 2. How do I actually record the audio that I'm sending on the line-in line? If more information is needed before these questions can be answered, please let me know and I'll provide it. Doc Evans -- Web: http://www.sff.net/people/N7DR
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