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UAC recording and playback*

1. Linux environment*

1.1 Linux system*

Use aplay | arecord on the command line

view device

arecord -l

root@ubuntu:/disk3# arecord -l
List of CAPTURE Hardware Devices **
card 0: AudioPCI [Ensoniq AudioPCI], device 0: ES1371/1 [ES1371 DAC2/ADC]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: Dongle [NationalChip UAC Dongle], device 0: USB Audio [USB Audio]
Subdevices: 0/1
Subdevice #0: subdevice #0

  • It can be seen that 8008 is recognized as a usb sound card, "NationalChip UAC Dongle"

  • Recording: According to the above information, it is found that 8008 is card 1, device 0. Therefore, the pcm method of recording mono, 16K, 16bit is

    arecord -r 16000 -c 1 -f S16_LE -D hw:1,0 > 1.wav

  • Play 48K 16bit pcm audio:

    aplay -r 48000 -c 2 -f S16_LE -D hw:1,0 1.wav

1.2 android system*

  • View the current sound card

    rk3288:/ # cat /proc/asound/cards
0 [rkhdmianalogsnd]: rk-hdmi-analog- - rk-hmi-analog-snd          
rk-hdmi-analog-snd 1 [Dongle ]: USB-Audio - NationalChip UAC Dongle (8008c sound card device, the device name is configured in the code)        
NationalChip NationalChip UAC Dongle at usbff540000.usb-1.2, high speed

  • View pcm device list

    rk3288:/ # cat /proc/asound/pcm
00-00: HDMI-ANALOG multicodec-0 : : playback 1 : capture 1
01-00: USB Audio : USB Audio : playback 1 : capture 1

  • Check which processes currently occupy the pcm device node

    lsof | grep pcm

  • Check which audio device nodes are available

    rk3288:/ # ls /dev/snd/
controlC0 controlC1 pcmC0D0c pcmC0D0p pcmC1D0c pcmC1D0p timer

  • From the above information, we can see that our current device is card1device0 on Android

Use tinyalsa to operate the sound card

  • The corresponding tools are as follows. These applications follow the alsa driver rules, and the recording needs to be connected with the underlying hardware.

  • tinymix: view configuration mixer

  • tinypcminfo: View pcm channel related information

    rk3288:/ # tinypcminfo -D 1 -d 0
Info for card 1, device 0:
PCM out:
Access: 0x000009
Format[0]: 0x000004
Format[1]: 00000000
Format Name: S16_LE
Subformat: 0x000001  
Rate: min=48000Hz max=48000Hz
Channels: min=2 max=2
Sample bits: min=16 max=16
Period size: min=48 max=131072
Period count: min=2 max=1024

PCM in:
Access: 0x000009
Format[0]: 0x000004
Format[1]: 00000000
Format Name: S16_LE
Subformat: 0x000001  
Rate: min=16000Hz max=16000Hz
Channels: min=4 max=4
Sample bits: min=16 max=16
Period size: min=16 max=65536
Period count: min=2 max=1024

  • tinycap: recording

    tinycap data/cap.wav -D 1 -d 0 -c 4 -r 16000 -b 16
-D sound card selection
-c channel 4 means 4 channels
-r sampling rate
-b number of bits to sample

  • tinyplay: play audio

    tinyplay data/cap.wav -D 1 -d

1.3 ubuntu interface tools*

  • Install audacity recording software

    sudo apt-get install audacity

  • Make sure the usb sound card device is recognized correctly

  • Open the audicity software and set it up

    • Device selection Nationalchip UAC Dongle

    • Sampling rate 16000

    • The number of channels is UAC firmware burned according to actual needs

  • Save the audio, if necessary, you can save the audio in wav format, select custom mixing in the edit-preferences, so that the original audio data of 4 channels can be saved

Attention

Do not verify the above operations on the linxu virtual machine, as recording exceptions may occur.

2. Windows environment*

GX8008 only supports UAC2.0

GX8008C supports UAC1.0 and UAC2.0

The UAC protocol supported by the relevant firmware can be clearly communicated with FAE

For systems before win10, drive-free support UAC1.0. Win10 relatively new system supports UAC1.0 and UAC2.0

  • Win10 version that supports UAC2.0

    Starting with Windows 10, release 1703, a USB Audio 2.0 driver is shipped with Windows. It is designed to support the USB Audio 2.0 device class. The driver is a WaveRT audio port class miniport. For more information about the USB Audio 2.0 device class,

  • Directly use audacity to record, also use audacity to record, the method is the same as under linux, but there are two problems below

    • When recording more than two channels of data, it may be necessary to switch the recording frame of audacity
    • When modifying the recording configuration, there will be a problem that the new configuration cannot be recorded

  • When the above problems occur, follow the steps below:

    • You can see that the current sound card cannot detect the volume level of the microphone (the sound card device is: Source/Sink)

    • Uninstall the device from device manager

    • Confirm uninstallation

    • uninstalled successfully

    • Re-scan the hardware, it will re-scan to our UAC sound card

    • It can be seen that the sound card can detect the volume output

    • Finally, when using audacity to record 4-channel data (the number of channels that can be recorded is related to the final firmware, the 4-channel provided in this article is just an example), the recording framework can only choose WASAPI, and this framework can only see 4 channels