diff options
Diffstat (limited to 'src/class/audio/audio_device.h')
| -rw-r--r-- | src/class/audio/audio_device.h | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/src/class/audio/audio_device.h b/src/class/audio/audio_device.h index 731fd6c01..f406cf281 100644 --- a/src/class/audio/audio_device.h +++ b/src/class/audio/audio_device.h @@ -186,9 +186,9 @@ #define CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP 0 // Feedback - 0 or 1 #endif -// Disable/enable conversion from 16.16 to 10.14 format on high-speed devices. See tud_audio_n_fb_set(). -#ifndef CFG_TUD_AUDIO_DISABLE_FEEDBACK_FORMAT_CORRECTION -#define CFG_TUD_AUDIO_DISABLE_FEEDBACK_FORMAT_CORRECTION 0 // 0 or 1 +// Enable/disable conversion from 16.16 to 10.14 format on full-speed devices. See tud_audio_n_fb_set(). +#ifndef CFG_TUD_AUDIO_ENABLE_FEEDBACK_FORMAT_CORRECTION +#define CFG_TUD_AUDIO_ENABLE_FEEDBACK_FORMAT_CORRECTION 0 // 0 or 1 #endif // Audio interrupt control EP size - disabled if 0 @@ -459,15 +459,15 @@ TU_ATTR_WEAK bool tud_audio_rx_done_post_read_cb(uint8_t rhport, uint16_t n_byte #if CFG_TUD_AUDIO_ENABLE_EP_OUT && CFG_TUD_AUDIO_ENABLE_FEEDBACK_EP TU_ATTR_WEAK bool tud_audio_fb_done_cb(uint8_t rhport); -// User code should call this function with feedback value in 16.16 format for FS and HS. -// Value will be corrected for FS to 10.14 format automatically. -// (see Universal Serial Bus Specification Revision 2.0 5.12.4.2). -// Feedback value will be sent at FB endpoint interval till it's changed. + +// This function is used to provide data rate feedback from an asynchronous sink. Feedback value will be sent at FB endpoint interval till it's changed. +// +// The feedback format is specified to be 16.16 for HS and 10.14 for FS devices (see Universal Serial Bus Specification Revision 2.0 5.12.4.2). By default, +// the choice of format is left to the caller and feedback argument is sent as-is. If CFG_TUD_AUDIO_ENABLE_FEEDBACK_FORMAT_CORRECTION is set, then tinyusb +// expects 16.16 format and handles the conversion to 10.14 on FS. // -// Note that the USB Audio 2.0 driver on Windows 10 is not following the spec and expects 16.16 -// format for FS. You can define CFG_TUD_AUDIO_DISABLE_FEEDBACK_FORMAT_CORRECTION=1 as a workaround -// to transmit the feedback value unchanged. Be aware that this might break feedback on other hosts, -// though at least on Linux the ALSA driver will happily accept either format. +// Note that due to a bug in its USB Audio 2.0 driver, Windows currently requires 16.16 format for _all_ USB 2.0 devices. On Linux and macOS it seems the +// driver can work with either format. So a good compromise is to keep format correction disabled and stick to 16.16 format. bool tud_audio_n_fb_set(uint8_t func_id, uint32_t feedback); static inline bool tud_audio_fb_set(uint32_t feedback); #endif |