I have a few questions regarding Mixer, DSP and MIDI in XK-AUDIO-316-MC.
I have flashed it with the sw_usb_audio reference firmware. My configuration is:
INCLUDE_ONLY_IN_2AMi8o8mxxxxx_mix8 =
XCC_FLAGS_2AMi8o8mxxxxx_mix8 = $(BUILD_FLAGS) -DMAX_MIX_COUNT=8 \
-DSPDIF_TX=0 \
-DMIDI=1 \
-DLEVEL_METER_HOST=1 \
-DIN_VOLUME_IN_MIXER=1 \
-DIN_VOLUME_AFTER_MIX=0 \
-DOUT_VOLUME_IN_MIXER=1 \
-DOUT_VOLUME_AFTER_MIX=1
I have also built xmos_mixer from host_usb_mixer_control. I am on Mac. The amount of code is overwhelming and I seek guidance.1. There is only one volume control (like
./xmos_mixer --set-value 0 64 0), but from the code (and my configuration), there should be both input and output volume adjustments. How to adjust both input and output volumes with the xmos_mixer utility?
2.
./xmos_mixer --get-mixer-levels-outputdoesn't work. When I call it, the audio stops, the device becomes unresponsive (I need to unplug it from USB and plug it back again to bring it back to life). After a quick look, it seems that
datalength = usb_mixer_mem_get(dst, offset, levels);call in mixer_app.cpp hangs everything and never returns.
3. Could you guide me how to insert DSP (like FIR filters and effects you have in a separate sw_audio_effects repository) in between the audio input and the mixer. My desired pipeline for each channel is:
Direct Monitoring for minimal latency
___________________________________________________
/ \
Audio In -> DSP - USB Host Out ------> Audio Out
\
-- USB Host In
I currently seem to be able to have it (minus the DSP part) with something like:
./xmos_mixer --set-aud-channel-map 0 16 # Mix 1 out to audio channel 1 out ./xmos_mixer --set-aud-channel-map 1 17 # Mix 2 out to audio channel 2 out ... ./xmos_mixer --set-value 0 0 0 # DAW channel 1 to Mix 1 ./xmos_mixer --set-value 0 64 0 # Audio channel 1 to Mix 1 ./xmos_mixer --set-value 0 9 0 # DAW channel 2 to Mix 2 ./xmos_mixer --set-value 0 73 0 # Audio channel 2 to Mix 2 ...So, I get:
Audio Output Channel Map ------------------------ 0 (DEVICE OUT - Analogue 1) source is 16 (MIX - Mix 1) 1 (DEVICE OUT - Analogue 2) source is 17 (MIX - Mix 2) 2 (DEVICE OUT - Analogue 3) source is 18 (MIX - Mix 3) 3 (DEVICE OUT - Analogue 4) source is 19 (MIX - Mix 4) 4 (DEVICE OUT - Analogue 5) source is 20 (MIX - Mix 5) 5 (DEVICE OUT - Analogue 6) source is 21 (MIX - Mix 6) 6 (DEVICE OUT - Analogue 7) source is 22 (MIX - Mix 7) 7 (DEVICE OUT - Analogue 8) source is 23 (MIX - Mix 8)and:
Mixer Values (0)
----------------
Mixer Outputs
1 2 3 4 5 6 7 8
DAW - Analogue 1 0:[0000.000] 1:[ -inf ] 2:[ -inf ] 3:[ -inf ] 4:[ -inf ] 5:[ -inf ] 6:[ -inf ] 7:[ -inf ]
DAW - Analogue 2 8:[ -inf ] 9:[0000.000] 10:[ -inf ] 11:[ -inf ] 12:[ -inf ] 13:[ -inf ] 14:[ -inf ] 15:[ -inf ]
DAW - Analogue 3 16:[ -inf ] 17:[ -inf ] 18:[0000.000] 19:[ -inf ] 20:[ -inf ] 21:[ -inf ] 22:[ -inf ] 23:[ -inf ]
DAW - Analogue 4 24:[ -inf ] 25:[ -inf ] 26:[ -inf ] 27:[0000.000] 28:[ -inf ] 29:[ -inf ] 30:[ -inf ] 31:[ -inf ]
DAW - Analogue 5 32:[ -inf ] 33:[ -inf ] 34:[ -inf ] 35:[ -inf ] 36:[0000.000] 37:[ -inf ] 38:[ -inf ] 39:[ -inf ]
DAW - Analogue 6 40:[ -inf ] 41:[ -inf ] 42:[ -inf ] 43:[ -inf ] 44:[ -inf ] 45:[0000.000] 46:[ -inf ] 47:[ -inf ]
DAW - Analogue 7 48:[ -inf ] 49:[ -inf ] 50:[ -inf ] 51:[ -inf ] 52:[ -inf ] 53:[ -inf ] 54:[0000.000] 55:[ -inf ]
DAW - Analogue 8 56:[ -inf ] 57:[ -inf ] 58:[ -inf ] 59:[ -inf ] 60:[ -inf ] 61:[ -inf ] 62:[ -inf ] 63:[0000.000]
AUD - Analogue 1 64:[0000.000] 65:[ -inf ] 66:[ -inf ] 67:[ -inf ] 68:[ -inf ] 69:[ -inf ] 70:[ -inf ] 71:[ -inf ]
AUD - Analogue 2 72:[ -inf ] 73:[0000.000] 74:[ -inf ] 75:[ -inf ] 76:[ -inf ] 77:[ -inf ] 78:[ -inf ] 79:[ -inf ]
AUD - Analogue 3 80:[ -inf ] 81:[ -inf ] 82:[0000.000] 83:[ -inf ] 84:[ -inf ] 85:[ -inf ] 86:[ -inf ] 87:[ -inf ]
AUD - Analogue 4 88:[ -inf ] 89:[ -inf ] 90:[ -inf ] 91:[0000.000] 92:[ -inf ] 93:[ -inf ] 94:[ -inf ] 95:[ -inf ]
AUD - Analogue 5 96:[ -inf ] 97:[ -inf ] 98:[ -inf ] 99:[ -inf ] 100:[0000.000] 101:[ -inf ] 102:[ -inf ] 103:[ -inf ]
AUD - Analogue 6 104:[ -inf ] 105:[ -inf ] 106:[ -inf ] 107:[ -inf ] 108:[ -inf ] 109:[0000.000] 110:[ -inf ] 111:[ -inf ]
AUD - Analogue 7 112:[ -inf ] 113:[ -inf ] 114:[ -inf ] 115:[ -inf ] 116:[ -inf ] 117:[ -inf ] 118:[0000.000] 119:[ -inf ]
AUD - Analogue 8 120:[ -inf ] 121:[ -inf ] 122:[ -inf ] 123:[ -inf ] 124:[ -inf ] 125:[ -inf ] 126:[ -inf ] 127:[0000.000]
128:[ -inf ] 129:[ -inf ] 130:[ -inf ] 131:[ -inf ] 132:[ -inf ] 133:[ -inf ] 134:[ -inf ] 135:[ -inf ]
136:[ -inf ] 137:[ -inf ] 138:[ -inf ] 139:[ -inf ] 140:[ -inf ] 141:[ -inf ] 142:[ -inf ] 143:[ -inf ]
So, I seem to have the proper routing out of the box. And I want to extend the code to insert effects so that the DSP processed result goes to both direct monitoring and to the USB host. I see lib_dsp module in the repository, and I am seeking help about how to inject it properly. The effects for each input channel are supposed to be different, so that the DSP part should be channel-aware and should allow to chain more than one effect/filter.4. I want to be able to send MIDI messages to the USB host from the DSP part. Will that be possible and how to do that properly?
5. And I suppose it should be fairly simple to load data to DSP from the host via USB. Like I am able to control the mixer with the xmos_mixer tool, I would want to be able to enable/disable effects, load FIR coefficients and so on. Could you point me to some examples for that?
6. If I run my app_usb_aud_xk_316_mc.xe with xsim — is it possible to have some kind of virtual usb device so that it is possible to test things without the device?
