Thanks, Jon. Let me see ‘aplay -l’, it produces a list of devices, such as
card 1: tegrasndt186ref [tegra-snd-t186ref-mobile-rt565x], device 0: ADMAIF1 CIF ADMAIF1-0
Subdevice #0: subdevice #0
card 1: tegrasndt186ref [tegra-snd-t186ref-mobile-rt565x], device 1: ADMAIF2 CIF ADMAIF2-1
Subdevice #0: subdevice #0
. . .
From your description, seems that I’m allowed to mux the DMIC to any audio DMA interfaces as long as they were not taken. By the way, is DMIC3 the set of digital MICs assign to the pins on the camera extension board? (just wonder if the number ‘3’ for DMIC3 means anything special).
It’d be great if you can help further. My volume problem is still there.
Let me be a little bit more specific,
What’s my DMIC hardware:
Two Knowles DMICs with L/R tied up and down, share the CLK and DATA pins connecting to camera connector AO_DMIC_IN_CLK and AO_DMIC_in_DAT (71 and 73) respectively.
What have been working:
(1) With the help of your ‘amixer’ command, I’m able to insert the audio to gst and generate ‘mpg’ video+audio using terminal command such as
gst-launch-1.0 nvcamerasrc sensor-id=0 ! ‘video/x-raw(memory:NVMM), width=2592, height=1944, framerate=15/1, format=I420’ ! nvvidconv flip-method=0 ! ‘video/x-raw, width=960, height=672, framerate=15/1, format=I420’ ! omxh264enc ! mpegtsmux name=mux alsasrc ‘device=hw:tegrasndt186ref,1’ ! audioresample ! audio/x-raw,rate=48000,channels=2 ! queue ! voaacenc bitrate=32000 ! queue ! mux. mux. ! filesink location=1cam_mix_audio.mpg sync=true async=false qos=true
(2) Tapping the left/right DMIC device on left or right while recording would produce the clear indication to distinguish the two audio channels.
(3) No obvious delay was observed between video and audio. That’s really good, since A/V sync was a major potential concern.
(4) Able to increase the level of output volume (default was at 50%) in “all settings, sound, output”
What’re the goal trying to achieve:
(1) Seek a better way to control the gain and volume for audio, either command line, python code, or others.
What’re the problems:
(1) The sound output volume is decent but not enough when the setting in system, sound, output is max out. Still searching solutions in how to further increase the volume (or DMIC gain) and how to use software to adjust the settings.
(2) The command ‘amixer -c tegrasndt186ref sset “DMIC3 Boost Gain” 25600’ would boost the gain and significantly increased audio record volume. But the also causes the stereo sound automatically converted to mono. Is there a command to boost the gain for stereo DMICs?
(3) “cset” the master volume control (MVC) with the commands as show in post#2 would instead fail the audio. No sound was produced by the commands. What’s the proper way to set the MVC?