Audio Class 2: descriptor for feedback endpoint?

[kf6gpe]

I'm currently trying to implement isochronous feedback on a USB audio endpoint. I'm getting close, I think, although the target isn't working with Windows yet (I can get things to work with my former endpoint, and I see bytes going through the wire via tinyusb's debug hooks, so I'm above the level of hardware.

I think I've just got issues with the descriptors.

Here's my descriptors definition --- it's for two-channel bidirectional audio at 4800 and 44100, largely lifted from the tinyusb audio examples (thanks!)

// Unit numbers are arbitrary selected
#define UAC2_ENTITY_CLOCK                   0x04
#define UAC2_ENTITY_INPUT_TERMINAL          0x01
#define UAC2_ENTITY_OUTPUT_TERMINAL         0x03
#define UAC2_ENTITY_FEATURE_UNIT            0x02



// From the headset example

// Speaker path
#define UAC2_ENTITY_SPK_INPUT_TERMINAL  0x01
#define UAC2_ENTITY_SPK_FEATURE_UNIT    0x02
#define UAC2_ENTITY_SPK_OUTPUT_TERMINAL 0x03
// Microphone path
#define UAC2_ENTITY_MIC_INPUT_TERMINAL  0x11
#define UAC2_ENTITY_MIC_OUTPUT_TERMINAL 0x13

enum
{
  ITF_NUM_AUDIO_CONTROL = 0,
  ITF_NUM_AUDIO_STREAMING_SPK,
  ITF_NUM_AUDIO_STREAMING_MIC,
  ITF_NUM_TOTAL
};

#define TUD_AUDIO_HEADSET_STEREO_FEEDBACK_DESC_LEN (TUD_AUDIO_DESC_IAD_LEN\
    + TUD_AUDIO_DESC_STD_AC_LEN\
    + TUD_AUDIO_DESC_CS_AC_LEN\
    + TUD_AUDIO_DESC_CLK_SRC_LEN\
    + TUD_AUDIO_DESC_INPUT_TERM_LEN\
    + TUD_AUDIO_DESC_FEATURE_UNIT_TWO_CHANNEL_LEN\
    + TUD_AUDIO_DESC_OUTPUT_TERM_LEN\
    + TUD_AUDIO_DESC_INPUT_TERM_LEN\
    + TUD_AUDIO_DESC_OUTPUT_TERM_LEN\
    /* Interface 1, Alternate 0 */\
    + TUD_AUDIO_DESC_STD_AS_INT_LEN\
    /* Interface 1, Alternate 0 */\
    + TUD_AUDIO_DESC_STD_AS_INT_LEN\
    + TUD_AUDIO_DESC_CS_AS_INT_LEN\
    + TUD_AUDIO_DESC_TYPE_I_FORMAT_LEN\
    + TUD_AUDIO_DESC_STD_AS_ISO_EP_LEN\
    + TUD_AUDIO_DESC_CS_AS_ISO_EP_LEN\
\
    /* Interface 2, Alternate 0 */\
    + TUD_AUDIO_DESC_STD_AS_INT_LEN\
    /* Interface 2, Alternate 1 */\
    + TUD_AUDIO_DESC_STD_AS_INT_LEN\
    + TUD_AUDIO_DESC_CS_AS_INT_LEN\
    + TUD_AUDIO_DESC_TYPE_I_FORMAT_LEN\
    + TUD_AUDIO_DESC_STD_AS_ISO_EP_LEN\
    + TUD_AUDIO_DESC_CS_AS_ISO_EP_LEN\
\
    /* Isochronous feedback endpoints */\
    + TUD_AUDIO_DESC_STD_AS_ISO_FB_EP_LEN\
)

#define TUD_AUDIO_HEADSET_STEREO_FEEDBACK_DESCRIPTOR(_stridx, _epout, _epin, _epfb) \
    /* Standard Interface Association Descriptor (IAD) */\
    TUD_AUDIO_DESC_IAD(/*_firstitfs*/ ITF_NUM_AUDIO_CONTROL, /*_nitfs*/ 3, /*_stridx*/ 0x00),\
    /* Standard AC Interface Descriptor(4.7.1) */\
    TUD_AUDIO_DESC_STD_AC(/*_itfnum*/ ITF_NUM_AUDIO_CONTROL, /*_nEPs*/ 0x00, /*_stridx*/ _stridx),\
    /* Class-Specific AC Interface Header Descriptor(4.7.2) */\
    TUD_AUDIO_DESC_CS_AC(/*_bcdADC*/ 0x0200, /*_category*/ AUDIO_FUNC_HEADSET, /*_totallen*/ TUD_AUDIO_DESC_CLK_SRC_LEN+TUD_AUDIO_DESC_FEATURE_UNIT_TWO_CHANNEL_LEN+TUD_AUDIO_DESC_INPUT_TERM_LEN+TUD_AUDIO_DESC_OUTPUT_TERM_LEN+TUD_AUDIO_DESC_INPUT_TERM_LEN+TUD_AUDIO_DESC_OUTPUT_TERM_LEN, /*_ctrl*/ AUDIO_CS_AS_INTERFACE_CTRL_LATENCY_POS),\
    /* Clock Source Descriptor(4.7.2.1) */\
    TUD_AUDIO_DESC_CLK_SRC(/*_clkid*/ UAC2_ENTITY_CLOCK, AUDIO_CLOCK_SOURCE_ATT_INT_FIX_CLK, /*_ctrl*/ (AUDIO_CTRL_R << AUDIO_CLOCK_SOURCE_CTRL_CLK_FRQ_POS), /*_assocTerm*/ UAC2_ENTITY_SPK_INPUT_TERMINAL,  /*_stridx*/ 0x00),    \
    /* Input Terminal Descriptor(4.7.2.4) */\
    TUD_AUDIO_DESC_INPUT_TERM(/*_termid*/ UAC2_ENTITY_SPK_INPUT_TERMINAL, /*_termtype*/ AUDIO_TERM_TYPE_USB_STREAMING, /*_assocTerm*/ 0x00, /*_clkid*/ UAC2_ENTITY_CLOCK, /*_nchannelslogical*/ 0x02, /*_channelcfg*/ AUDIO_CHANNEL_CONFIG_NON_PREDEFINED, /*_idxchannelnames*/ 0x00, /*_ctrl*/ 0 * (AUDIO_CTRL_R << AUDIO_IN_TERM_CTRL_CONNECTOR_POS), /*_stridx*/ 0x00),\
    /* Feature Unit Descriptor(4.7.2.8) */\
    TUD_AUDIO_DESC_FEATURE_UNIT_TWO_CHANNEL(/*_unitid*/ UAC2_ENTITY_SPK_FEATURE_UNIT, /*_srcid*/ UAC2_ENTITY_SPK_INPUT_TERMINAL, /*_ctrlch0master*/ (AUDIO_CTRL_RW << AUDIO_FEATURE_UNIT_CTRL_MUTE_POS | AUDIO_CTRL_RW << AUDIO_FEATURE_UNIT_CTRL_VOLUME_POS), /*_ctrlch1*/ (AUDIO_CTRL_RW << AUDIO_FEATURE_UNIT_CTRL_MUTE_POS | AUDIO_CTRL_RW << AUDIO_FEATURE_UNIT_CTRL_VOLUME_POS), /*_ctrlch2*/ (AUDIO_CTRL_RW << AUDIO_FEATURE_UNIT_CTRL_MUTE_POS | AUDIO_CTRL_RW << AUDIO_FEATURE_UNIT_CTRL_VOLUME_POS), /*_stridx*/ 0x00),\
    /* Output Terminal Descriptor(4.7.2.5) */\
    TUD_AUDIO_DESC_OUTPUT_TERM(/*_termid*/ UAC2_ENTITY_SPK_OUTPUT_TERMINAL, /*_termtype*/ AUDIO_TERM_TYPE_OUT_HEADPHONES, /*_assocTerm*/ UAC2_ENTITY_SPK_INPUT_TERMINAL, /*_srcid*/ UAC2_ENTITY_SPK_FEATURE_UNIT, /*_clkid*/ UAC2_ENTITY_CLOCK, /*_ctrl*/ 0x0000, /*_stridx*/ 0x00),\
    /* Input Terminal Descriptor(4.7.2.4) */\
    TUD_AUDIO_DESC_INPUT_TERM(/*_termid*/ UAC2_ENTITY_MIC_INPUT_TERMINAL, /*_termtype*/ AUDIO_TERM_TYPE_IN_GENERIC_MIC, /*_assocTerm*/ 0x00, /*_clkid*/ UAC2_ENTITY_CLOCK, /*_nchannelslogical*/ 0x01, /*_channelcfg*/ AUDIO_CHANNEL_CONFIG_NON_PREDEFINED, /*_idxchannelnames*/ 0x00, /*_ctrl*/ 0 * (AUDIO_CTRL_R << AUDIO_IN_TERM_CTRL_CONNECTOR_POS), /*_stridx*/ 0x00),\
    /* Output Terminal Descriptor(4.7.2.5) */\
    TUD_AUDIO_DESC_OUTPUT_TERM(/*_termid*/ UAC2_ENTITY_MIC_OUTPUT_TERMINAL, /*_termtype*/ AUDIO_TERM_TYPE_USB_STREAMING, /*_assocTerm*/ 0x00, /*_srcid*/ UAC2_ENTITY_MIC_INPUT_TERMINAL, /*_clkid*/ UAC2_ENTITY_CLOCK, /*_ctrl*/ 0x0000, /*_stridx*/ 0x00),\
\
    /* Standard AS Interface Descriptor(4.9.1) */\
    /* Interface 1, Alternate 0 - default alternate setting with 0 bandwidth */\
    TUD_AUDIO_DESC_STD_AS_INT(/*_itfnum*/ (uint8_t)(ITF_NUM_AUDIO_STREAMING_SPK), /*_altset*/ 0x00, /*_nEPs*/ 0x00, /*_stridx*/ 0x05),\
    /* Standard AS Interface Descriptor(4.9.1) */\
    /* Interface 1, Alternate 1 - alternate interface for data streaming */\
    TUD_AUDIO_DESC_STD_AS_INT(/*_itfnum*/ (uint8_t)(ITF_NUM_AUDIO_STREAMING_SPK), /*_altset*/ 0x01, /*_nEPs*/ 0x02, /*_stridx*/ 0x05),\
    /* Class-Specific AS Interface Descriptor(4.9.2) */\
    TUD_AUDIO_DESC_CS_AS_INT(/*_termid*/ UAC2_ENTITY_SPK_INPUT_TERMINAL, /*_ctrl*/ AUDIO_CTRL_NONE, /*_formattype*/ AUDIO_FORMAT_TYPE_I, /*_formats*/ AUDIO_DATA_FORMAT_TYPE_I_PCM, /*_nchannelsphysical*/ CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_RX, /*_channelcfg*/ AUDIO_CHANNEL_CONFIG_NON_PREDEFINED, /*_stridx*/ 0x00),\
    /* Type I Format Type Descriptor(2.3.1.6 - Audio Formats) */\
    TUD_AUDIO_DESC_TYPE_I_FORMAT(CFG_TUD_AUDIO_FUNC_1_FORMAT_1_N_BYTES_PER_SAMPLE_RX, CFG_TUD_AUDIO_FUNC_1_FORMAT_1_RESOLUTION_RX),\
    /* Standard AS Isochronous Audio Data Endpoint Descriptor(4.10.1.1) */\
    TUD_AUDIO_DESC_STD_AS_ISO_EP(/*_ep*/ _epout, /*_attr*/ (uint8_t) (TUSB_XFER_ISOCHRONOUS | TUSB_ISO_EP_ATT_ASYNCHRONOUS | TUSB_ISO_EP_ATT_DATA), /*_maxEPsize*/ TUD_AUDIO_EP_SIZE(CFG_TUD_AUDIO_FUNC_1_MAX_SAMPLE_RATE, CFG_TUD_AUDIO_FUNC_1_FORMAT_1_N_BYTES_PER_SAMPLE_RX, CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_RX), /*_interval*/ 0x01),\
    /* Class-Specific AS Isochronous Audio Data Endpoint Descriptor(4.10.1.2) */\
    TUD_AUDIO_DESC_CS_AS_ISO_EP(/*_attr*/ AUDIO_CS_AS_ISO_DATA_EP_ATT_NON_MAX_PACKETS_OK, /*_ctrl*/ AUDIO_CTRL_NONE, /*_lockdelayunit*/ AUDIO_CS_AS_ISO_DATA_EP_LOCK_DELAY_UNIT_UNDEFINED, /*_lockdelay*/ 0x0000),\
    \
    /* Standard AS Interface Descriptor(4.9.1) */\
    /* Interface 2, Alternate 0 - default alternate setting with 0 bandwidth */\
    TUD_AUDIO_DESC_STD_AS_INT(/*_itfnum*/ (uint8_t)(ITF_NUM_AUDIO_STREAMING_MIC), /*_altset*/ 0x00, /*_nEPs*/ 0x00, /*_stridx*/ 0x04),\
    /* Standard AS Interface Descriptor(4.9.1) */\
    /* Interface 2, Alternate 1 - alternate interface for data streaming */\
    TUD_AUDIO_DESC_STD_AS_INT(/*_itfnum*/ (uint8_t)(ITF_NUM_AUDIO_STREAMING_MIC), /*_altset*/ 0x01, /*_nEPs*/ 0x01, /*_stridx*/ 0x04),\
    /* Class-Specific AS Interface Descriptor(4.9.2) */\
    TUD_AUDIO_DESC_CS_AS_INT(/*_termid*/ UAC2_ENTITY_MIC_OUTPUT_TERMINAL, /*_ctrl*/ AUDIO_CTRL_NONE, /*_formattype*/ AUDIO_FORMAT_TYPE_I, /*_formats*/ AUDIO_DATA_FORMAT_TYPE_I_PCM, /*_nchannelsphysical*/ CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX, /*_channelcfg*/ AUDIO_CHANNEL_CONFIG_NON_PREDEFINED, /*_stridx*/ 0x00),\
    /* Type I Format Type Descriptor(2.3.1.6 - Audio Formats) */\
    TUD_AUDIO_DESC_TYPE_I_FORMAT(CFG_TUD_AUDIO_FUNC_1_FORMAT_1_N_BYTES_PER_SAMPLE_TX, CFG_TUD_AUDIO_FUNC_1_FORMAT_1_RESOLUTION_TX),\
    /* Standard AS Isochronous Audio Data Endpoint Descriptor(4.10.1.1) */\
    TUD_AUDIO_DESC_STD_AS_ISO_EP(/*_ep*/ _epin, /*_attr*/ (uint8_t) (TUSB_XFER_ISOCHRONOUS | TUSB_ISO_EP_ATT_ASYNCHRONOUS | TUSB_ISO_EP_ATT_DATA), /*_maxEPsize*/ TUD_AUDIO_EP_SIZE(CFG_TUD_AUDIO_FUNC_1_MAX_SAMPLE_RATE, CFG_TUD_AUDIO_FUNC_1_FORMAT_1_N_BYTES_PER_SAMPLE_TX, CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX), /*_interval*/ 0x01),\
    /* Class-Specific AS Isochronous Audio Data Endpoint Descriptor(4.10.1.2) */\
    TUD_AUDIO_DESC_CS_AS_ISO_EP(/*_attr*/ AUDIO_CS_AS_ISO_DATA_EP_ATT_NON_MAX_PACKETS_OK, /*_ctrl*/ AUDIO_CTRL_NONE, /*_lockdelayunit*/ AUDIO_CS_AS_ISO_DATA_EP_LOCK_DELAY_UNIT_UNDEFINED, /*_lockdelay*/ 0x0000),\
	\
    /* 4.10.2.1 Standard AS Isochronous Feedback Endpoint Descriptor */\
    TUD_AUDIO_DESC_STD_AS_ISO_FB_EP(/*_ep*/ _epfb, /*_interval*/ 1)\

Has anyone else gotten this working? Care to share your descriptor, or eyeball mine and let me know if you see something I may be missing?

Thanks loads. Once again, kudos to folks who have contributed to tinyusb. We've gotten quite far with it already.

[HiFiPhile]

What kind of problem you met ?

In my project I separated input & output to 2 UAC instances so it's easier to deal with, as I've independent clock source.

Here is my desc:

// Unit numbers are arbitrary selected
// Output path
#define UAC2_ENTITY_USB2IIS_CLOCK           0x04
#define UAC2_ENTITY_USB2IIS_INPUT_TERMINAL  0x01
#define UAC2_ENTITY_USB2IIS_FEATURE_UNIT    0x02
#define UAC2_ENTITY_USB2IIS_OUTPUT_TERMINAL 0x03
// Input path
#define UAC2_ENTITY_MIC_CLOCK               0x05
#define UAC2_ENTITY_MIC_INPUT_TERMINAL      0x01
#define UAC2_ENTITY_MIC_FEATURE_UNIT        0x06
#define UAC2_ENTITY_MIC_OUTPUT_TERMINAL     0x03

#define TUD_AUDIO_USB2IIS_DESC_LEN (TUD_AUDIO_DESC_IAD_LEN\
    + TUD_AUDIO_DESC_STD_AC_LEN\
    + TUD_AUDIO_DESC_CS_AC_LEN\
    + TUD_AUDIO_DESC_CLK_SRC_LEN\
    + TUD_AUDIO_DESC_INPUT_TERM_LEN\
    + TUD_AUDIO_DESC_FEATURE_UNIT_TWO_CHANNEL_LEN\
    + TUD_AUDIO_DESC_OUTPUT_TERM_LEN\
    /* Interface 1, Alternate 0 */\
    + TUD_AUDIO_DESC_STD_AS_INT_LEN\
    /* Interface 1, Alternate 1 */\
    + TUD_AUDIO_DESC_STD_AS_INT_LEN\
    + TUD_AUDIO_DESC_CS_AS_INT_LEN\
    + TUD_AUDIO_DESC_TYPE_I_FORMAT_LEN\
    + TUD_AUDIO_DESC_STD_AS_ISO_EP_LEN\
    + TUD_AUDIO_DESC_CS_AS_ISO_EP_LEN\
    + TUD_AUDIO_DESC_STD_AS_ISO_FB_EP_LEN\
    /* Interface 1, Alternate 2 */\
    + TUD_AUDIO_DESC_STD_AS_INT_LEN\
    + TUD_AUDIO_DESC_CS_AS_INT_LEN\
    + TUD_AUDIO_DESC_TYPE_I_FORMAT_LEN\
    + TUD_AUDIO_DESC_STD_AS_ISO_EP_LEN\
    + TUD_AUDIO_DESC_CS_AS_ISO_EP_LEN\
    + TUD_AUDIO_DESC_STD_AS_ISO_FB_EP_LEN\
    /* Interface 1, Alternate 3 */\
    + TUD_AUDIO_DESC_STD_AS_INT_LEN\
    + TUD_AUDIO_DESC_CS_AS_INT_LEN\
    + TUD_AUDIO_DESC_TYPE_I_FORMAT_LEN\
    + TUD_AUDIO_DESC_STD_AS_ISO_EP_LEN\
    + TUD_AUDIO_DESC_CS_AS_ISO_EP_LEN\
    + TUD_AUDIO_DESC_STD_AS_ISO_FB_EP_LEN)

#define TUD_AUDIO_USB2IIS_DESCRIPTOR(_stridx, _epout, _epfb) \
    /* Standard Interface Association Descriptor (IAD) */\
    TUD_AUDIO_DESC_IAD(/*_firstitfs*/ ITF_NUM_AUDIO_CONTROL_IIS, /*_nitfs*/ 2, /*_stridx*/ 0x00),\
    /* Standard AC Interface Descriptor(4.7.1) */\
    TUD_AUDIO_DESC_STD_AC(/*_itfnum*/ ITF_NUM_AUDIO_CONTROL_IIS, /*_nEPs*/ 0x00, /*_stridx*/ _stridx),\
    /* Class-Specific AC Interface Header Descriptor(4.7.2) */\
    TUD_AUDIO_DESC_CS_AC(/*_bcdADC*/ 0x0200, /*_category*/ AUDIO_FUNC_CONVERTER, /*_totallen*/ TUD_AUDIO_DESC_CLK_SRC_LEN+TUD_AUDIO_DESC_FEATURE_UNIT_TWO_CHANNEL_LEN+TUD_AUDIO_DESC_INPUT_TERM_LEN+TUD_AUDIO_DESC_OUTPUT_TERM_LEN, /*_ctrl*/ AUDIO_CS_AS_INTERFACE_CTRL_LATENCY_POS),\
    /* Clock Source Descriptor(4.7.2.1) */\
    TUD_AUDIO_DESC_CLK_SRC(/*_clkid*/ UAC2_ENTITY_USB2IIS_CLOCK, /*_attr*/ 3, /*_ctrl*/ 7, /*_assocTerm*/ 0x00,  /*_stridx*/ 0x00),    \
    /* Input Terminal Descriptor(4.7.2.4) */\
    TUD_AUDIO_DESC_INPUT_TERM(/*_termid*/ UAC2_ENTITY_USB2IIS_INPUT_TERMINAL, /*_termtype*/ AUDIO_TERM_TYPE_USB_STREAMING, /*_assocTerm*/ 0x00, /*_clkid*/ UAC2_ENTITY_USB2IIS_CLOCK, /*_nchannelslogical*/ 0x02, /*_channelcfg*/ AUDIO_CHANNEL_CONFIG_NON_PREDEFINED, /*_idxchannelnames*/ 0x00, /*_ctrl*/ 0 * (AUDIO_CTRL_R << AUDIO_IN_TERM_CTRL_CONNECTOR_POS), /*_stridx*/ 0x00),\
    /* Feature Unit Descriptor(4.7.2.8) */\
    TUD_AUDIO_DESC_FEATURE_UNIT_TWO_CHANNEL(/*_unitid*/ UAC2_ENTITY_USB2IIS_FEATURE_UNIT, /*_srcid*/ UAC2_ENTITY_USB2IIS_INPUT_TERMINAL, /*_ctrlch0master*/ (AUDIO_CTRL_RW << AUDIO_FEATURE_UNIT_CTRL_MUTE_POS | AUDIO_CTRL_RW << AUDIO_FEATURE_UNIT_CTRL_VOLUME_POS), /*_ctrlch1*/ (AUDIO_CTRL_RW << AUDIO_FEATURE_UNIT_CTRL_MUTE_POS | AUDIO_CTRL_RW << AUDIO_FEATURE_UNIT_CTRL_VOLUME_POS), /*_ctrlch2*/ (AUDIO_CTRL_RW << AUDIO_FEATURE_UNIT_CTRL_MUTE_POS | AUDIO_CTRL_RW << AUDIO_FEATURE_UNIT_CTRL_VOLUME_POS), /*_stridx*/ 0x00),\
    /* Output Terminal Descriptor(4.7.2.5) */\
    TUD_AUDIO_DESC_OUTPUT_TERM(/*_termid*/ UAC2_ENTITY_USB2IIS_OUTPUT_TERMINAL, /*_termtype*/ AUDIO_TERM_TYPE_OUT_HEADPHONES, /*_assocTerm*/ 0x00, /*_srcid*/ UAC2_ENTITY_USB2IIS_FEATURE_UNIT, /*_clkid*/ UAC2_ENTITY_USB2IIS_CLOCK, /*_ctrl*/ 0x0000, /*_stridx*/ _stridx),\
    /* Standard AS Interface Descriptor(4.9.1) */\
    /* Interface 1, Alternate 0 - default alternate setting with 0 bandwidth */\
    TUD_AUDIO_DESC_STD_AS_INT(/*_itfnum*/ (uint8_t)(ITF_NUM_AUDIO_STREAMING_IIS), /*_altset*/ 0x00, /*_nEPs*/ 0x00, /*_stridx*/ 0),\
    /* Standard AS Interface Descriptor(4.9.1) */\
    /* Interface 1, Alternate 1 - alternate interface for data streaming */\
    TUD_AUDIO_DESC_STD_AS_INT(/*_itfnum*/ (uint8_t)(ITF_NUM_AUDIO_STREAMING_IIS), /*_altset*/ 0x01, /*_nEPs*/ 0x02, /*_stridx*/ 0),\
    /* Class-Specific AS Interface Descriptor(4.9.2) */\
    TUD_AUDIO_DESC_CS_AS_INT(/*_termid*/ UAC2_ENTITY_USB2IIS_INPUT_TERMINAL, /*_ctrl*/ AUDIO_CTRL_NONE, /*_formattype*/ AUDIO_FORMAT_TYPE_I, /*_formats*/ AUDIO_DATA_FORMAT_TYPE_I_PCM, /*_nchannelsphysical*/ CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_RX, /*_channelcfg*/ AUDIO_CHANNEL_CONFIG_NON_PREDEFINED, /*_stridx*/ 0x00),\
    /* Type I Format Type Descriptor(2.3.1.6 - Audio Formats) */\
    TUD_AUDIO_DESC_TYPE_I_FORMAT(CFG_TUD_AUDIO_FUNC_1_FORMAT_1_N_BYTES_PER_SAMPLE_RX, CFG_TUD_AUDIO_FUNC_1_FORMAT_1_RESOLUTION_RX),\
    /* Standard AS Isochronous Audio Data Endpoint Descriptor(4.10.1.1) */\
    TUD_AUDIO_DESC_STD_AS_ISO_EP(/*_ep*/ _epout, /*_attr*/ (uint8_t)((uint8_t)TUSB_XFER_ISOCHRONOUS | (uint8_t)TUSB_ISO_EP_ATT_ASYNCHRONOUS | (uint8_t)TUSB_ISO_EP_ATT_DATA), /*_maxEPsize*/ TUD_AUDIO_EP_SIZE(CFG_TUD_AUDIO_FUNC_1_MAX_SAMPLE_RATE, CFG_TUD_AUDIO_FUNC_1_FORMAT_1_N_BYTES_PER_SAMPLE_RX, CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_RX), /*_interval*/ 0x01),\
    /* Class-Specific AS Isochronous Audio Data Endpoint Descriptor(4.10.1.2) */\
    TUD_AUDIO_DESC_CS_AS_ISO_EP(/*_attr*/ AUDIO_CS_AS_ISO_DATA_EP_ATT_NON_MAX_PACKETS_OK, /*_ctrl*/ AUDIO_CTRL_NONE, /*_lockdelayunit*/ AUDIO_CS_AS_ISO_DATA_EP_LOCK_DELAY_UNIT_MILLISEC, /*_lockdelay*/ 0x0001),\
    /* Standard AS Isochronous Feedback Endpoint Descriptor(4.10.2.1) */\
    TUD_AUDIO_DESC_STD_AS_ISO_FB_EP(/*_ep*/ _epfb, /*_interval*/ 4),\
    /* Interface 1, Alternate 2 - alternate interface for data streaming */\
    TUD_AUDIO_DESC_STD_AS_INT(/*_itfnum*/ (uint8_t)(ITF_NUM_AUDIO_STREAMING_IIS), /*_altset*/ 0x02, /*_nEPs*/ 0x02, /*_stridx*/ 0),\
    /* Class-Specific AS Interface Descriptor(4.9.2) */\
    TUD_AUDIO_DESC_CS_AS_INT(/*_termid*/ UAC2_ENTITY_USB2IIS_INPUT_TERMINAL, /*_ctrl*/ AUDIO_CTRL_NONE, /*_formattype*/ AUDIO_FORMAT_TYPE_I, /*_formats*/ AUDIO_DATA_FORMAT_TYPE_I_PCM, /*_nchannelsphysical*/ CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_RX, /*_channelcfg*/ AUDIO_CHANNEL_CONFIG_NON_PREDEFINED, /*_stridx*/ 0x00),\
    /* Type I Format Type Descriptor(2.3.1.6 - Audio Formats) */\
    TUD_AUDIO_DESC_TYPE_I_FORMAT(CFG_TUD_AUDIO_FUNC_1_FORMAT_2_N_BYTES_PER_SAMPLE_RX, CFG_TUD_AUDIO_FUNC_1_FORMAT_2_RESOLUTION_RX),\
    /* Standard AS Isochronous Audio Data Endpoint Descriptor(4.10.1.1) */\
    TUD_AUDIO_DESC_STD_AS_ISO_EP(/*_ep*/ _epout, /*_attr*/ ((uint8_t)TUSB_XFER_ISOCHRONOUS | (uint8_t)TUSB_ISO_EP_ATT_ASYNCHRONOUS | (uint8_t)TUSB_ISO_EP_ATT_DATA), /*_maxEPsize*/ TUD_AUDIO_EP_SIZE(CFG_TUD_AUDIO_FUNC_1_MAX_SAMPLE_RATE, CFG_TUD_AUDIO_FUNC_1_FORMAT_2_N_BYTES_PER_SAMPLE_RX, CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_RX), /*_interval*/ 0x01),\
    /* Class-Specific AS Isochronous Audio Data Endpoint Descriptor(4.10.1.2) */\
    TUD_AUDIO_DESC_CS_AS_ISO_EP(/*_attr*/ AUDIO_CS_AS_ISO_DATA_EP_ATT_NON_MAX_PACKETS_OK, /*_ctrl*/ AUDIO_CTRL_NONE, /*_lockdelayunit*/ AUDIO_CS_AS_ISO_DATA_EP_LOCK_DELAY_UNIT_MILLISEC, /*_lockdelay*/ 0x0001),\
    /* Standard AS Isochronous Feedback Endpoint Descriptor(4.10.2.1) */\
    TUD_AUDIO_DESC_STD_AS_ISO_FB_EP(/*_ep*/ _epfb, /*_interval*/ 4),\
    /* Interface 1, Alternate 3 - alternate interface for data streaming */\
    TUD_AUDIO_DESC_STD_AS_INT(/*_itfnum*/ (uint8_t)(ITF_NUM_AUDIO_STREAMING_IIS), /*_altset*/ 0x03, /*_nEPs*/ 0x02, /*_stridx*/ _stridx),\
    /* Class-Specific AS Interface Descriptor(4.9.2) */\
    TUD_AUDIO_DESC_CS_AS_INT(/*_termid*/ UAC2_ENTITY_USB2IIS_INPUT_TERMINAL, /*_ctrl*/ AUDIO_CTRL_NONE, /*_formattype*/ AUDIO_FORMAT_TYPE_I, /*_formats*/ AUDIO_DATA_FORMAT_TYPE_I_PCM, /*_nchannelsphysical*/ CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_RX, /*_channelcfg*/ AUDIO_CHANNEL_CONFIG_NON_PREDEFINED, /*_stridx*/ 0x00),\
    /* Type I Format Type Descriptor(2.3.1.6 - Audio Formats) */\
    TUD_AUDIO_DESC_TYPE_I_FORMAT(CFG_TUD_AUDIO_FUNC_1_FORMAT_3_N_BYTES_PER_SAMPLE_RX, CFG_TUD_AUDIO_FUNC_1_FORMAT_3_RESOLUTION_RX),\
    /* Standard AS Isochronous Audio Data Endpoint Descriptor(4.10.1.1) */\
    TUD_AUDIO_DESC_STD_AS_ISO_EP(/*_ep*/ _epout, /*_attr*/ ((uint8_t)TUSB_XFER_ISOCHRONOUS | (uint8_t)TUSB_ISO_EP_ATT_ASYNCHRONOUS | (uint8_t)TUSB_ISO_EP_ATT_DATA), /*_maxEPsize*/ TUD_AUDIO_EP_SIZE(CFG_TUD_AUDIO_FUNC_1_MAX_SAMPLE_RATE, CFG_TUD_AUDIO_FUNC_1_FORMAT_3_N_BYTES_PER_SAMPLE_RX, CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_RX), /*_interval*/ 0x01),\
    /* Class-Specific AS Isochronous Audio Data Endpoint Descriptor(4.10.1.2) */\
    TUD_AUDIO_DESC_CS_AS_ISO_EP(/*_attr*/ AUDIO_CS_AS_ISO_DATA_EP_ATT_NON_MAX_PACKETS_OK, /*_ctrl*/ AUDIO_CTRL_NONE, /*_lockdelayunit*/ AUDIO_CS_AS_ISO_DATA_EP_LOCK_DELAY_UNIT_MILLISEC, /*_lockdelay*/ 0x0001),\
    /* Standard AS Isochronous Feedback Endpoint Descriptor(4.10.2.1) */\
    TUD_AUDIO_DESC_STD_AS_ISO_FB_EP(/*_ep*/ _epfb, /*_interval*/ 4)


#define TUD_AUDIO_MIC_DESC_LEN (TUD_AUDIO_DESC_IAD_LEN\
  + TUD_AUDIO_DESC_STD_AC_LEN\
  + TUD_AUDIO_DESC_CS_AC_LEN\
  + TUD_AUDIO_DESC_CLK_SRC_LEN\
  + TUD_AUDIO_DESC_INPUT_TERM_LEN\
  + TUD_AUDIO_DESC_OUTPUT_TERM_LEN\
  + TUD_AUDIO_DESC_FEATURE_UNIT_ONE_CHANNEL_LEN\
  + TUD_AUDIO_DESC_STD_AS_INT_LEN\
  + TUD_AUDIO_DESC_STD_AS_INT_LEN\
  + TUD_AUDIO_DESC_CS_AS_INT_LEN\
  + TUD_AUDIO_DESC_TYPE_I_FORMAT_LEN\
  + TUD_AUDIO_DESC_STD_AS_ISO_EP_LEN\
  + TUD_AUDIO_DESC_CS_AS_ISO_EP_LEN)

#define TUD_AUDIO_MIC_DESCRIPTOR(_itfnum, _stridx, _nBytesPerSample, _nBitsUsedPerSample, _epin, _epsize) \
  /* Standard Interface Association Descriptor (IAD) */\
  TUD_AUDIO_DESC_IAD(/*_firstitfs*/ _itfnum, /*_nitfs*/ 0x02, /*_stridx*/ 0x00),\
  /* Standard AC Interface Descriptor(4.7.1) */\
  TUD_AUDIO_DESC_STD_AC(/*_itfnum*/ _itfnum, /*_nEPs*/ 0x00, /*_stridx*/ _stridx),\
  /* Class-Specific AC Interface Header Descriptor(4.7.2) */\
  TUD_AUDIO_DESC_CS_AC(/*_bcdADC*/ 0x0200, /*_category*/ AUDIO_FUNC_MICROPHONE, /*_totallen*/ TUD_AUDIO_DESC_CLK_SRC_LEN+TUD_AUDIO_DESC_INPUT_TERM_LEN+TUD_AUDIO_DESC_OUTPUT_TERM_LEN+TUD_AUDIO_DESC_FEATURE_UNIT_ONE_CHANNEL_LEN, /*_ctrl*/ AUDIO_CS_AS_INTERFACE_CTRL_LATENCY_POS),\
  /* Clock Source Descriptor(4.7.2.1) */\
  TUD_AUDIO_DESC_CLK_SRC(/*_clkid*/ UAC2_ENTITY_MIC_CLOCK, /*_attr*/ AUDIO_CLOCK_SOURCE_ATT_INT_FIX_CLK, /*_ctrl*/ (AUDIO_CTRL_R << AUDIO_CLOCK_SOURCE_CTRL_CLK_FRQ_POS), /*_assocTerm*/ UAC2_ENTITY_MIC_INPUT_TERMINAL,  /*_stridx*/ 0x00),\
  /* Input Terminal Descriptor(4.7.2.4) */\
  TUD_AUDIO_DESC_INPUT_TERM(/*_termid*/ UAC2_ENTITY_MIC_INPUT_TERMINAL, /*_termtype*/ AUDIO_TERM_TYPE_IN_GENERIC_MIC, /*_assocTerm*/ 0x00, /*_clkid*/ UAC2_ENTITY_MIC_CLOCK, /*_nchannelslogical*/ 0x01, /*_channelcfg*/ AUDIO_CHANNEL_CONFIG_NON_PREDEFINED, /*_idxchannelnames*/ 0x00, /*_ctrl*/ AUDIO_CTRL_R << AUDIO_IN_TERM_CTRL_CONNECTOR_POS, /*_stridx*/ 0x00),\
  /* Output Terminal Descriptor(4.7.2.5) */\
  TUD_AUDIO_DESC_OUTPUT_TERM(/*_termid*/ UAC2_ENTITY_MIC_OUTPUT_TERMINAL, /*_termtype*/ AUDIO_TERM_TYPE_USB_STREAMING, /*_assocTerm*/ 0x00, /*_srcid*/ UAC2_ENTITY_MIC_FEATURE_UNIT, /*_clkid*/ UAC2_ENTITY_MIC_CLOCK, /*_ctrl*/ 0x0000, /*_stridx*/ 0x00),\
  /* Feature Unit Descriptor(4.7.2.8) */\
  TUD_AUDIO_DESC_FEATURE_UNIT_ONE_CHANNEL(/*_unitid*/ UAC2_ENTITY_MIC_FEATURE_UNIT, /*_srcid*/ UAC2_ENTITY_MIC_INPUT_TERMINAL, /*_ctrlch0master*/ AUDIO_CTRL_RW << AUDIO_FEATURE_UNIT_CTRL_MUTE_POS | AUDIO_CTRL_RW << AUDIO_FEATURE_UNIT_CTRL_VOLUME_POS, /*_ctrlch1*/ AUDIO_CTRL_RW << AUDIO_FEATURE_UNIT_CTRL_MUTE_POS | AUDIO_CTRL_RW << AUDIO_FEATURE_UNIT_CTRL_VOLUME_POS, /*_stridx*/ 0x00),\
  /* Standard AS Interface Descriptor(4.9.1) */\
  /* Interface 1, Alternate 0 - default alternate setting with 0 bandwidth */\
  TUD_AUDIO_DESC_STD_AS_INT(/*_itfnum*/ (uint8_t)((_itfnum)+1), /*_altset*/ 0x00, /*_nEPs*/ 0x00, /*_stridx*/ 0x00),\
  /* Standard AS Interface Descriptor(4.9.1) */\
  /* Interface 1, Alternate 1 - alternate interface for data streaming */\
  TUD_AUDIO_DESC_STD_AS_INT(/*_itfnum*/ (uint8_t)((_itfnum)+1), /*_altset*/ 0x01, /*_nEPs*/ 0x01, /*_stridx*/ 0x00),\
  /* Class-Specific AS Interface Descriptor(4.9.2) */\
  TUD_AUDIO_DESC_CS_AS_INT(/*_termid*/ UAC2_ENTITY_MIC_OUTPUT_TERMINAL, /*_ctrl*/ AUDIO_CTRL_NONE, /*_formattype*/ AUDIO_FORMAT_TYPE_I, /*_formats*/ AUDIO_DATA_FORMAT_TYPE_I_PCM, /*_nchannelsphysical*/ 0x01, /*_channelcfg*/ AUDIO_CHANNEL_CONFIG_NON_PREDEFINED, /*_stridx*/ 0x00),\
  /* Type I Format Type Descriptor(2.3.1.6 - Audio Formats) */\
  TUD_AUDIO_DESC_TYPE_I_FORMAT(_nBytesPerSample, _nBitsUsedPerSample),\
  /* Standard AS Isochronous Audio Data Endpoint Descriptor(4.10.1.1) */\
  TUD_AUDIO_DESC_STD_AS_ISO_EP(/*_ep*/ _epin, /*_attr*/ (uint8_t) (TUSB_XFER_ISOCHRONOUS | TUSB_ISO_EP_ATT_ASYNCHRONOUS | TUSB_ISO_EP_ATT_DATA), /*_maxEPsize*/ _epsize, /*_interval*/ 0x01),\
  /* Class-Specific AS Isochronous Audio Data Endpoint Descriptor(4.10.1.2) */\
  TUD_AUDIO_DESC_CS_AS_ISO_EP(/*_attr*/ AUDIO_CS_AS_ISO_DATA_EP_ATT_NON_MAX_PACKETS_OK, /*_ctrl*/ AUDIO_CTRL_NONE, /*_lockdelayunit*/ AUDIO_CS_AS_ISO_DATA_EP_LOCK_DELAY_UNIT_UNDEFINED, /*_lockdelay*/ 0x0000)

[kf6gpe]

Thanks so much. That really helped.

For others and future me looking at my code above, the critical thing I was doing wrong was the arguments that I passed to TUD_AUDIO_DESC_CS_AS_ISO_EP --- the lockdelay unit and the lock delay.

If you're ever in the Bay Area of California, look me up. I'll buy you a coffee or beer.

[HiFiPhile]

Thanks, never went to the US before :)
A new PR #2282 is up for some IN transfer improvements, for your it's case useful as you use 44.1k & 48k multi-rate, you can test it out.

[kf6gpe]

Excellent, thank you!! I'll have a look. Ray Rischpater, KF6GPE | kf6gpe.org | @kf6gpe <http://www.twitter.com/kf6gpe>

…

On Tue, Oct 17, 2023 at 12:19 PM HiFiPhile ***@***.***> wrote: Thanks, never went to the US before :) A new PR #2282 <#2282> is up for some IN transfer improvements, for your it's case useful as you use 44.1k & 48k multi-rate, you can test it out. — Reply to this email directly, view it on GitHub <#2281 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAK6QRABT36OBIIAFHXR6J3X73K53AVCNFSM6AAAAAA6C5KEKCVHI2DSMVQWIX3LMV43SRDJONRXK43TNFXW4Q3PNVWWK3TUHM3TGMBXGU3TG> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[Lurcy38]

hello guys,
I read this thread concerning the feedback UAC. it seams I work on the same topic.
in my FW, I have experimented some cracks while recording a long sequence. When I send a perfect wave. On Audacity, I can see some a flat zones of 1ms randomly. Probably due to an host starvation or overrun.
My understanding is that I need to manage the clock divergence using the feedback EP.
But I didn’t see any example implementing this feature completly .
Did you start your implementation from scratch or from an existing sample?
If yes, could you please share where did you found it ..
Many thanks
lurcy

[kf6gpe]

That does sound like buffer overrun/underrun. IIRC, thttps://github.com//pull/1235 has some sample code you can start with. You'll either need to signal the feedback EP --- no more than a buffer's worth at a time due to a Windows limitation --- or you can use the incoming byte stream against what you're expecting to do slight sample rate conversion on the fly.