RE: How to change USB Audio class in ncs

Baldur — Thu, 21 Apr 2022 21:53:24 GMT

Hi all

I had the same problem (for many days), wanted 44.1kHz sampling rate in stead of the default 48kHz. With the hint from Andrej102 I changed the content of the usb_audio_internal.h file as follows:

// fs = 48kHz version

#define INIT_AS_FORMAT_I(ch_cnt, res) \

{ \

.bLength = sizeof(struct format_type_i_descriptor), \

.bDescriptorType = USB_DESC_CS_INTERFACE, \

.bDescriptorSubtype = USB_AUDIO_FORMAT_TYPE, \

.bFormatType = 0x01, \

.bNrChannels = MAX(1, ch_cnt), \

.bSubframeSize = res/8, \

.bBitResolution = res, \

.bSamFreqType = 1, \

.tSamFreq = {0x80, 0xBB, 0x00}, \

}

// fs= 44100Hz version

#define INIT_AS_FORMAT_I(ch_cnt, res) \

{ \

.bLength = sizeof(struct format_type_i_descriptor), \

.bDescriptorType = USB_DESC_CS_INTERFACE, \

.bDescriptorSubtype = USB_AUDIO_FORMAT_TYPE, \

.bFormatType = 0x01, \

.bNrChannels = MAX(1, ch_cnt), \

.bSubframeSize = res/8, \

.bBitResolution = res, \

.bSamFreqType = 1, \

.tSamFreq = {0x44, 0xAC, 0x00}, \

}

And it worked. Remember, in Windows, to delete the audio drivers under Audio inputs and outputs AND Sound, video and game controllers in Device manager between changes to make them take effect.

Baldur

RE: How to change USB Audio class in ncs

longrain — Wed, 11 Aug 2021 02:16:25 GMT

Hi,

Take a look at this file:

zephyr\subsys\usb\class\audio\usb_audio_internal.h

RE: How to change USB Audio class in ncs

Andrej102 — Wed, 21 Jul 2021 13:59:17 GMT

I have the same problem. Please tell me in which file and what changes you have made.

RE: How to change USB Audio class in ncs

longrain — Thu, 01 Jul 2021 09:48:11 GMT

I have solved this。

I haveto modify the header file , and can not configure these in prj.conf .