Re: [Alsa-user] PCM plugin last
Robert Bielik wrote: >> It might be possible to run dmix on a virtual loopback sound card and route >> that one to the LADSPA plugin > > Can this loopback routing be done entirely within a .asoundrc configuration? No; some program must be running to record from the loopback card and play to the actual device. Regards, Clemens ___ Alsa-user mailing list Alsa-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/alsa-user
Re: [Alsa-user] PCM plugin last
Hi Clemens, > The dmix plugin plays shared-memory tricks with the ring buffer and therefore > requires to run on top of a hw device. > It might be possible to run dmix on a virtual loopback sound card and route > that one to the LADSPA plugin, but I guess using PulseAudio would be a better > idea. Interesting though. Can this loopback routing be done entirely within a .asoundrc configuration? Regards, /Robert The information in this email (including any attachments) may contain confidential and/or proprietary material. Any review, retransmission or use of this information by persons or entities other than the intended, authorized recipient is prohibited. If you received this email in error, please notify the sender and delete the material. For information regarding how Dirac handles personal data, please visit https://www.dirac.com/privacy-policy. ___ Alsa-user mailing list Alsa-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/alsa-user
Re: [Alsa-user] PCM plugin last
On Wed, 27 May 2020, Clemens Ladisch via Alsa-user wrote: > Robert Bielik wrote: > > I’d like to know if there is any way to get the following sound chain > > through ALSA: > > > > Mediaplayer -> dmix -> LADSPA -> plughw:0,0 > > The dmix plugin plays shared-memory tricks with the ring buffer and therefore > requires to run on top of a hw device. > > It might be possible to run dmix on a virtual loopback sound card and route > that one to the LADSPA plugin, but I guess using PulseAudio would be a better > idea. It's possible, and I don't see anything wrong with the idea except at the moment it seems to be frightfully buggy. Here's a snipped of .asoundrc that creates a "local" audio bus which is combined with: $ modprobe snd-aloop $ echo "0,0,0" > /proc/asound/Loopback/timer_source # your soundcard $ alsaloop -C local -P plug:master $ aplay -D plug:local music.wav You'll need to define your "master" device with the LADSPA plugin. The problems I am having are the "alsaloop" program terminates unexpectedly, gets in 100% CPU spin and won't exit, or some lock is taken in the kernel that hangs X11 and prevents process termination (kernel 5.6.14) I couldn't make head nor tail of alsaloop flow, so I wrote my own code to copy audio from one device to another which so far seems much more reliable for my case. # # The bus for local audio so it can be routed to other applications # # Pin the sample rate and format so that the Loopback device isn't # affected by whichever side is first to open and with which parameters. # pcm.local { type asym # # Mix incoming audio from multiple sources # playback.pcm { type dmix ipc_key 3187 slave { rate 48000 channels 2 format S16_LE buffer_size 4096 period_size 256 pcm { type hw card "Loopback" device 0 subdevice 3 } } } # # Make it accessable to anyone who wants it # capture.pcm { type dsnoop ipc_key 23811 slave { rate 48000 channels 2 format S16_LE buffer_size 4096 period_size 256 pcm { type hw card "Loopback" device 1 subdevice 3 } } } } pcm.master { type ladspa; ... # your chosen configuration here } -- Mark___ Alsa-user mailing list Alsa-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/alsa-user
Re: [Alsa-user] PCM plugin last
Robert Bielik wrote: > I’d like to know if there is any way to get the following sound chain through > ALSA: > > Mediaplayer -> dmix -> LADSPA -> plughw:0,0 The dmix plugin plays shared-memory tricks with the ring buffer and therefore requires to run on top of a hw device. It might be possible to run dmix on a virtual loopback sound card and route that one to the LADSPA plugin, but I guess using PulseAudio would be a better idea. Regards, Clemens ___ Alsa-user mailing list Alsa-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/alsa-user
[Alsa-user] PCM plugin last
I’d like to know if there is any way to get the following sound chain through ALSA: Mediaplayer -> dmix -> LADSPA -> plughw:0,0 For my application it is crucial that the LADSPA plugin be applied AFTER dmix. Regards /Robert The information in this email (including any attachments) may contain confidential and/or proprietary material. Any review, retransmission or use of this information by persons or entities other than the intended, authorized recipient is prohibited. If you received this email in error, please notify the sender and delete the material. For information regarding how Dirac handles personal data, please visit https://www.dirac.com/privacy-policy. ___ Alsa-user mailing list Alsa-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/alsa-user