On Mon, 29 Aug 2016, Muammar El Khatib wrote:
>
> Would you mind testing if this procedure makes possible to record
> your audio using alsa?
Muammar,
Sorry for the delay. Did a quick test. Problem is I got (too) many
sound cards on this horse ;)
# cat /proc/asound/cards
0 [Live ]: EMU10K1 - SB Live! 5.1 [SB0060]
SB Live! 5.1 [SB0060] (rev.7, serial:0x80611102) at
0xd000, irq 17
1 [PCH ]: HDA-Intel - HDA Intel PCH
HDA Intel PCH at 0xf7230000 irq 29
2 [NVidia ]: HDA-Intel - HDA NVidia
HDA NVidia at 0xf7080000 irq 17
3 [Controller ]: USB-Audio - USB Audio Controller
USB Audio Controller at usb-0000:00:1d.0-1.5, full speed
4 [Loopback ]: Loopback - Loopback
Loopback 1
And asound.conf, ~/.asoundrc is still black magic for me, even after
so many years :(
Could you please heavily comment your proposed configuration so I can
locate and modify the relevant bits, before testing again?
> 1. Do
> modprobe snd-aloop
>
> 2. Add the following content to ~/.asoundrc
>
> pcm.!default {
> type asym
> playback.pcm "LoopAndReal"
> #capture.pcm "looprec"
> capture.pcm "hw:0,0"
> }
>
> pcm.looprec {
> type hw
> card "Loopback"
> device 1
> subdevice 0
> }
>
> pcm.LoopAndReal {
> type plug
> slave.pcm mdev
> route_policy "duplicate"
> }
>
> pcm.mdev {
> type multi
> slaves.a.pcm pcm.MixReale
> slaves.a.channels 2
> slaves.b.pcm pcm.MixLoopback
> slaves.b.channels 2
> bindings.0.slave a
> bindings.0.channel 0
> bindings.1.slave a
> bindings.1.channel 1
> bindings.2.slave b
> bindings.2.channel 0
> bindings.3.slave b
> bindings.3.channel 1
> }
>
> pcm.MixReale {
> type dmix
> ipc_key 1024
> slave {
> pcm "hw:0,0"
> rate 48000
> #rate 44100
> periods 128
> period_time 0
> period_size 1024 # must be power of 2
> buffer_size 8192
> }
> }
>
> pcm.MixLoopback {
> type dmix
> ipc_key 1025
> slave {
> pcm "hw:Loopback,0,0"
> rate 48000
> #rate 44100
> periods 128
> period_time 0
> period_size 1024 # must be power of 2
> buffer_size 8192
> }
> }
>
> 3. Install ffmpeg, and execute this command while playing anything in your
> computer:
>
> ffmpeg -f alsa -ac 2 -ar 44100 -i hw:0 -t 30 out.wav
>
> Does ffmpeg capture the audio in out.wav?.
It did capture a totally silent wav. And I guess main reason is
loopback device number.
Cheers,
--
Cristian
