这段时间一直在做USB声卡调试，之前做了x86上的调试，这次分享在英伟达Jetson nano平台上接USB声卡。 nano上运行Ubuntu 18.04的系统。当然USB声卡调试也是跟x86大致相同。下面我们就来分享下调试过程：
- 检查是否有USB声卡设备：
在终端中输入命令：lsusb
$ lsusb
Bus 002 Device 002: ID 0bda:0411 Realtek Semiconductor Corp.
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 032: ID 0d8c:0012 C-Media Electronics, Inc.
Bus 001 Device 031: ID 05e3:0608 Genesys Logic, Inc. Hub
Bus 001 Device 002: ID 0bda:5411 Realtek Semiconductor Corp.
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
其中 Bus 001 Device 032: ID 0d8c:0012 C-Media Electronics, Inc. 就是USB声卡。
- 查看声卡设备信息 ：
在终端中输入命令：aplay -l
$ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: tegrahda [tegra-hda], device 3: HDMI 0 [HDMI 0]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: tegrasndt210ref [tegra-snd-t210ref-mobile-rt565x], device 0: ADMAIF1 CIF ADMAIF1-0 []
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: tegrasndt210ref [tegra-snd-t210ref-mobile-rt565x], device 1: ADMAIF2 CIF ADMAIF2-1 []
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: tegrasndt210ref [tegra-snd-t210ref-mobile-rt565x], device 2: ADMAIF3 CIF ADMAIF3-2 []
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: tegrasndt210ref [tegra-snd-t210ref-mobile-rt565x], device 3: ADMAIF4 CIF ADMAIF4-3 []
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: tegrasndt210ref [tegra-snd-t210ref-mobile-rt565x], device 4: ADMAIF5 CIF ADMAIF5-4 []
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: tegrasndt210ref [tegra-snd-t210ref-mobile-rt565x], device 5: ADMAIF6 CIF ADMAIF6-5 []
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: tegrasndt210ref [tegra-snd-t210ref-mobile-rt565x], device 6: ADMAIF7 CIF ADMAIF7-6 []
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: tegrasndt210ref [tegra-snd-t210ref-mobile-rt565x], device 7: ADMAIF8 CIF ADMAIF8-7 []
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: tegrasndt210ref [tegra-snd-t210ref-mobile-rt565x], device 8: ADMAIF9 CIF ADMAIF9-8 []
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: tegrasndt210ref [tegra-snd-t210ref-mobile-rt565x], device 9: ADMAIF10 CIF ADMAIF10-9 []
Subdevices: 1/1
Subdevice #0: subdevice #0
card 2: Device [USB Audio Device], device 0: USB Audio [USB Audio]
Subdevices: 1/1
Subdevice #0: subdevice #0
其中 card 2: Device [USB Audio Device], device 0: USB Audio [USB Audio] 为usb声卡设备信息。
- 查看usb声卡控制参数
在终端中输入amixer -c 2
$ amixer -c 2
Simple mixer control 'Speaker',0
Capabilities: pvolume pswitch pswitch-joined
Playback channels: Front Left - Front Right
Limits: Playback 0 - 37
Mono:
Front Left: Playback 4 [11%] [-33.00dB] [on]
Front Right: Playback 4 [11%] [-33.00dB] [on]
Simple mixer control 'Mic',0
Capabilities: pvolume pvolume-joined cvolume cvolume-joined pswitch pswitch-joined cswitch cswitch-joined
Playback channels: Mono
Capture channels: Mono
Limits: Playback 0 - 31 Capture 0 - 35
Mono: Playback 16 [52%] [-7.00dB] [off] Capture 20 [57%] [8.00dB] [on]
Simple mixer control 'Auto Gain Control',0
Capabilities: pswitch pswitch-joined
Playback channels: Mono
Mono: Playback [on]
命令中 2 就是指 card 2 即USB声卡设备。
可以看出声音控制就是 Speaker
- 调节声音大小
amixer -c 2 set Speaker 50%
$ amixer -c 2 set Speaker 50%
Simple mixer control 'Speaker',0
Capabilities: pvolume pswitch pswitch-joined
Playback channels: Front Left - Front Right
Limits: Playback 0 - 37
Mono:
Front Left: Playback 19 [51%] [-18.00dB] [on]
Front Right: Playback 19 [51%] [-18.00dB] [on]
- 播放音频文件
aplay xxx.wav
在终端中播放音频 :
$ aplay /home/nano/audio/leisheng.wav
Playing WAVE '/home/nano/audio/leisheng.wav' : Unsigned 8 bit, Rate 11025 Hz, Mono
最后也通过 'pactl' 命令来获取USB声卡的信息
$ pactl list sinks
Sink #1
State: SUSPENDED
Name: alsa_output.platform-sound.analog-stereo
Description: Built-in Audio Analog Stereo
Driver: module-alsa-card.c
Sample Specification: s16le 2ch 44100Hz
Channel Map: front-left,front-right
Owner Module: 9
Mute: no
Volume: front-left: 65536 / 100% / 0.00 dB, front-right: 65536 / 100% / 0.00 dB
balance 0.00
Base Volume: 65536 / 100% / 0.00 dB
Monitor Source: alsa_output.platform-sound.analog-stereo.monitor
Latency: 0 usec, configured 0 usec
Flags: HARDWARE DECIBEL_VOLUME LATENCY
Properties:
alsa.resolution_bits = "16"
device.api = "alsa"
device.class = "sound"
alsa.class = "generic"
alsa.subclass = "generic-mix"
alsa.name = ""
alsa.id = "ADMAIF1 CIF ADMAIF1-0"
alsa.subdevice = "0"
alsa.subdevice_name = "subdevice #0"
alsa.device = "0"
alsa.card = "1"
alsa.card_name = "tegra-snd-t210ref-mobile-rt565x"
alsa.long_card_name = "tegra-snd-t210ref-mobile-rt565x"
device.bus_path = "platform-sound"
sysfs.path = "/devices/sound/sound/card1"
device.form_factor = "internal"
device.string = "front:1"
device.buffering.buffer_size = "32768"
device.buffering.fragment_size = "16384"
device.access_mode = "mmap+timer"
device.profile.name = "analog-stereo"
device.profile.description = "Analog Stereo"
device.description = "Built-in Audio Analog Stereo"
module-udev-detect.discovered = "1"
device.icon_name = "audio-card"
Ports:
analog-output: Analog Output (priority: 9900)
Active Port: analog-output
Formats:
pcm
Sink #2
State: SUSPENDED
Name: alsa_output.usb-C-Media_Electronics_Inc._USB_Audio_Device-00.analog-stereo
Description: USB Audio Device Analog Stereo
Driver: module-alsa-card.c
Sample Specification: s16le 2ch 44100Hz
Channel Map: front-left,front-right
Owner Module: 25
Mute: no
Volume: front-left: 18471 / 28% / -33.00 dB, front-right: 18471 / 28% / -33.00 dB
balance 0.00
Base Volume: 65536 / 100% / 0.00 dB
Monitor Source: alsa_output.usb-C-Media_Electronics_Inc._USB_Audio_Device-00.analog-stereo.monitor
Latency: 0 usec, configured 0 usec
Flags: HARDWARE HW_MUTE_CTRL HW_VOLUME_CTRL DECIBEL_VOLUME LATENCY
Properties:
alsa.resolution_bits = "16"
device.api = "alsa"
device.class = "sound"
alsa.class = "generic"
alsa.subclass = "generic-mix"
alsa.name = "USB Audio"
alsa.id = "USB Audio"
alsa.subdevice = "0"
alsa.subdevice_name = "subdevice #0"
alsa.device = "0"
alsa.card = "2"
alsa.card_name = "USB Audio Device"
alsa.long_card_name = "C-Media Electronics Inc. USB Audio Device at usb-70090000.xusb-2.3.1, full spee"
alsa.driver_name = "snd_usb_audio"
device.bus_path = "platform-70090000.xusb-usb-0:2.3.1:1.0"
sysfs.path = "/devices/70090000.xusb/usb1/1-2/1-2.3/1-2.3.1/1-2.3.1:1.0/sound/card2"
udev.id = "usb-C-Media_Electronics_Inc._USB_Audio_Device-00"
device.bus = "usb"
device.vendor.id = "0d8c"
device.vendor.name = "C-Media Electronics, Inc."
device.product.id = "0012"
device.product.name = "USB Audio Device"
device.serial = "C-Media_Electronics_Inc._USB_Audio_Device"
device.string = "front:2"
device.buffering.buffer_size = "352800"
device.buffering.fragment_size = "176400"
device.access_mode = "mmap+timer"
device.profile.name = "analog-stereo"
device.profile.description = "Analog Stereo"
device.description = "USB Audio Device Analog Stereo"
alsa.mixer_name = "USB Mixer"
alsa.components = "USB0d8c:0012"
module-udev-detect.discovered = "1"
device.icon_name = "audio-card-usb"
Ports:
analog-output-speaker: Speakers (priority: 10000)
Active Port: analog-output-speaker
Formats:
pcm
可以看到alsa_output.usb-C-Media_Electronics_Inc._USB_Audio_Device-00.analog-stereo详细的信息。