I have a simple application that receives RTP streams and plays them to a
custom headset. The headset has up to 8 USB audio endpoints (configurable on
the headset). I want to send up to 8 RTP streams to 8 different audio
endpoints within the headset (the headset allows me to select which stream is
being heard with an HID device or by serial API).
‘aplay -L’ shows up as:
sysdefault:CARD=HS1
HS1, USB Audio
Default Audio Device
front:CARD=HS1,DEV=0
HS1, USB Audio
Front speakers
surround21:CARD=HS1,DEV=0
HS1, USB Audio
2.1 Surround output to Front and Subwoofer speakers
surround40:CARD=HS1,DEV=0
HS1, USB Audio
4.0 Surround output to Front and Rear speakers
surround41:CARD=HS1,DEV=0
HS1, USB Audio
4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=HS1,DEV=0
HS1, USB Audio
5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=HS1,DEV=0
HS1, USB Audio
5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=HS1,DEV=0
HS1, USB Audio
7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
iec958:CARD=HS1,DEV=0
HS1, USB Audio
IEC958 (S/PDIF) Digital Audio Output
I have a .asoundrc that looks like so:
pcm.hs1_0 {
type hw
card 1
}
ctl.hs1_0 {
type hw
card 1
}
pcm.Digital1 {
type route
slave.pcm hs1_0
ttable.0.0 1
}
pcm.Digital2 {
type route
slave.pcm hs1_0
ttable.1.1 1
}
pcm.Digital3 {
type route
slave.pcm hs1_0
ttable.2.2 1
}
pcm.Digital4 {
type route
slave.pcm hs1_0
ttable.3.3 1
}
pcm.Digital5 {
type route
slave.pcm hs1_0
ttable.4.4 1
}
pcm.Digital6 {
type route
slave.pcm hs1_0
ttable.5.5 1
}
pcm.Digital7 {
type route
slave.pcm hs1_0
ttable.6.6 1
}
pcm.Digital8 {
type route
slave.pcm hs1_0
ttable.7.7 1
}
I can successfully ‘snd_pcm_open(&handle1, “Digital1”, SND_PCM_STREAM_PLAYBACK,
0)’ but (as I guess is obvious), I can’t ‘snd_pcm_open(&handle2, “Digital2”,
SND_PCM_STREAM_PLAYBACK, 0)’, I get EBUSY.
Clearly my approach is wrong and I don’t understand the right way to do what I
want. It appears as though it works to some extent. If I
snd_pcm_open(….”Digital2”,….) or snd_pcm_open(….,”Digital1”,…) then I do get
audio in the expected places. I just can’t seem to do it simultaneously.
What’s the correct way to write PCM to specific USB endpoints simultaneously?
_______________________________________________
Alsa-user mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/alsa-user
