xiaocq2001
commented
1 year ago To use UVC on device side, following things need to be done:
- Prepare descriptors (passed to stack as "framework"), .e.g., a simulated video camera:
/* Define device payloadwork. */
#define W(d) UX_DW0(d), UX_DW1(d)
#define DW(d) UX_DW0(d), UX_DW1(d), UX_DW2(d), UX_DW3(d)
#define GUID_YUY2 0x59,0x55,0x59,0x32, 0x00,0x00, 0x10,0x00, 0x80,0x00, 0x00,0xAA,0x00,0x38,0x9B,0x71 /* 32595559-0000-0010-8000-00AA00389B71 */
#define _DEVICE_DESCRIPTOR() \
/* --------------------------------------- Device Descriptor */ \
/* 0 bLength, bDescriptorType */ 18, 0x01, \
/* 2 bcdUSB */ W(0x200), \
/* 4 bDeviceClass, bDeviceSubClass, bDeviceProtocol */ 0xEF, 0x02, 0x01, \
/* 7 bMaxPacketSize0 */ 64, \
/* 8 idVendor, idProduct */ 0x84, 0x84, 0x01, 0x00, \
/* 12 bcdDevice */ UX_DW0(0x100),UX_DW1(0x100), \
/* 14 iManufacturer, iProduct, iSerialNumber */ 0, 0, 0, \
/* 17 bNumConfigurations */ 1,
#define _DEVICE_QUALIFIER_DESCRIPTOR() \
/* ----------------------------- Device Qualifier Descriptor */ \
/* 0 bLength, bDescriptorType */ 10, 0x06, \
/* 2 bcdUSB */ W(0x200), \
/* 4 bDeviceClass, bDeviceSubClass, bDeviceProtocol */ 0xEF, 0x02, 0x01, \
/* 7 bMaxPacketSize0 */ 8, \
/* 8 bNumConfigurations */ 1, \
/* 9 bReserved */ 0,
#define _CONFIGURE_DESCRIPTOR(total_len,n_ifc,cfg_v) \
/* -------------------------------- Configuration Descriptor */ \
/* 0 bLength, bDescriptorType */ 9, 0x02, \
/* 2 wTotalLength */ W(total_len), \
/* 4 bNumInterfaces, bConfigurationValue */ (n_ifc), (cfg_v), \
/* 6 iConfiguration */ 0, \
/* 7 bmAttributes, bMaxPower */ 0x80, 50,
#define _IAD_DESCRIPTOR(ifc_0,ifc_cnt,cls,sub,protocol) \
/* ------------------------ Interface Association Descriptor */ \
/* 0 bLength, bDescriptorType */ 8, 0x0B, \
/* 2 bFirstInterface, bInterfaceCount */ (ifc_0), (ifc_cnt), \
/* 4 bFunctionClass, bFunctionSubClass, bFunctionProtocol */ (cls), (sub), (protocol), \
/* 7 iFunction */ 0,
#define _INTERFACE_DESCRIPTOR(ifc,alt,n_ep,cls,sub,protocol) \
/* ------------------------------------ Interface Descriptor */ \
/* 0 bLength, bDescriptorType */ 9, 0x04, \
/* 2 bInterfaceNumber, bAlternateSetting */ (ifc), (alt), \
/* 4 bNumEndpoints */ (n_ep), \
/* 5 bInterfaceClass, bInterfaceSubClass, bInterfaceProtocol */ (cls), (sub), (protocol), \
/* 8 iInterface */ 0,
#define _ENDPOINT_DESCRIPTOR(addr,attr,pkt_siz,interval) \
/* ------------------------------------- Endpoint Descriptor */ \
/* 0 bLength, bDescriptorType */ 7, 0x05, \
/* 2 bEndpointAddress, bmAttributes */ (addr), (attr), \
/* 4 wMaxPacketSize, bInterval */ W(pkt_siz), (interval),
#define _VC_DESCRIPTORS_LEN (13+17+9+13)
#define _VC_DESCRIPTORS() \
/*--------------------------- Class VC Interface Descriptor (VC_HEADER). */ \
13, 0x24, 0x01, W(0x110), \
W(_VC_DESCRIPTORS_LEN), /* wTotalLength. */ \
DW(UX_DEMO_CLOCK_FREQUENCY), /* dwClockFrequency. */ \
1, /* bInCollection. */ \
1, /* BaInterfaceNr(1). */ \
/*--------------------------- Input Terminal (VC_INPUT_TERMINAL, Camera) */ \
17, 0x24, 0x02, \
0x01, /* bTerminalID, ITT_CAMERA */ \
W(0x201), /* wTerminalType */ \
0x00, 0x00, W(0), W(0), W(0), \
0x02, W(0), /* bControlSize, bmControls */ \
/*---------------------------- Output Terminal (VC_OUTPUT_TERMINAL, USB) */ \
9, 0x24, 0x03, \
0x02, /* bTerminalID */ \
W(0x0101), /* wTerminalType, TT_STREAMING */ \
0x00, 0x05/* bSourceID */, 0x00, \
/*--------------------------------- Processing Unit (VC_PROCESSING_UNIT) */ \
13, 0x24, 0x05, \
0x05, /* bUnitID */ \
0x01, /* bSourceID */ \
W(0), /* wMaxMultiplier */ \
3, 0x00, 0x00, 0x00, /* bControlSize, bmControls */ \
0, /* iProcessing */ \
0x00, /* bmVideoStandards */ \
#define _VS_FORMAT_DESCRIPTORS_UNCOMPRESSED_LEN (27+30)
#define _VS_FORMAT_DESCRIPTORS_UNCOMPRESSED() \
/*------------------------------- VS Format Descriptor (VS_FORMAT_UNCOMPRESSED) */ \
27, 0x24, 0x04, \
0x01, /* bFormatIndex */ \
0x01, /* bNumFrameDescriptors */ \
GUID_YUY2, /* YUY2 : YUV 4:2:2 */ \
16, /* bBitsPerPixel */ \
0x01, /* bDefaultFrameIndex */ \
0x00, 0x00, \
0x00, /* bmInterlaceFlags */ \
0x00, /* bCopyProtect */ \
/*--------------------------------- VS Frame Descriptor (VS_FRAME_UNCOMPRESSED) */ \
30, 0x24, 0x05, \
0x01, /* bFrameIndex */ \
0x00, /* bmCapabilities */ \
W(176), W(144), /* wWidth, wHeight */ \
DW(912384), DW(912384), /* dwMinBitRate, dwMaxBitRate */ \
DW(UX_DEMO_FRAME_DATA_SIZE), /* dwMaxVideoFrameBufSize */ \
DW(UX_DEMO_FRAME_INTERVAL), /* dwDefaultFrameInterval */ \
0x01, /* bFrameIntervalType */ \
DW(UX_DEMO_FRAME_INTERVAL), /* dwMinFrameInterval(1) */
#define _VS_IN_DESCRIPTORS_LEN (14+_VS_FORMAT_DESCRIPTORS_UNCOMPRESSED_LEN)
#define _VS_IN_DESCRIPTORS() \
/*------------------------- Class VS Header Descriptor (VS_INPUT_HEADER) */ \
14, 0x24, 0x01, \
0X01, /* bNumFormats */ \
W(_VS_IN_DESCRIPTORS_LEN), /* wTotalLength */ \
0x81, /* bEndpointAddress */ \
0x00, \
0x02, /* bTerminalLink */ \
0x00, /* bStillCaptureMethod */ \
0x00, 0x00, /* bTriggerSupport, bTriggerUsage */ \
0x01, 0x00, /* bControlSize, bmaControls */ \
_VS_FORMAT_DESCRIPTORS_UNCOMPRESSED()
#define _VS_OUT_DESCRIPTORS_LEN (11+_VS_FORMAT_DESCRIPTORS_UNCOMPRESSED_LEN)
#define _VS_OUT_DESCRIPTORS() \
/*------------------------- Class VS Header Descriptor (VS_OUTPUT_HEADER) */ \
11, 0x24, 0x02, \
0x01, /* bNumFormats */ \
W(_VS_OUT_DESCRIPTORS_LEN), /* wTotalLength */ \
0x02, /* bEndpointAddress */ \
0x00, \
0x03, /* bTerminalLink */ \
0x01, 0x00, /* bControlSize, bmaControls */ \
_VS_FORMAT_DESCRIPTORS_UNCOMPRESSED()
#define _CONFIGURE_DESCRIPTORS_LEN (9+ 8+ 9+_VC_DESCRIPTORS_LEN+ 9+_VS_IN_DESCRIPTORS_LEN+9+7)
#if UX_SLAVE_REQUEST_CONTROL_MAX_LENGTH < _CONFIGURE_DESCRIPTORS_LEN
#error Please increase control request buffer size
#endif
#if UX_SLAVE_REQUEST_DATA_MAX_LENGTH < UX_DEMO_MAX_PAYLOAD_SIZE
#error Please increase endpoint data buffer size
#endif
unsigned char device_payloadwork_full_speed[] = {
_DEVICE_DESCRIPTOR()
_CONFIGURE_DESCRIPTOR(_CONFIGURE_DESCRIPTORS_LEN,2,1)
_IAD_DESCRIPTOR(0,2,0x0E,0x03,0x00)
_INTERFACE_DESCRIPTOR(0,0,0,0x0E,0x01,0x00)
_VC_DESCRIPTORS()
_INTERFACE_DESCRIPTOR(1,0,0,0x0E,0x02,0x00)
_VS_IN_DESCRIPTORS()
_INTERFACE_DESCRIPTOR(1,1,1,0x0E,0x02,0x00)
_ENDPOINT_DESCRIPTOR(0x81,0x05,UX_DEMO_ENDPOINT_SIZE,UX_DEMO_ENDPOINT_INTERVAL_FS)
};
#define DEVICE_FRAMEWORK_LENGTH_FULL_SPEED sizeof(device_payloadwork_full_speed)
unsigned char device_payloadwork_high_speed[] = {
_DEVICE_DESCRIPTOR()
_DEVICE_QUALIFIER_DESCRIPTOR()
_CONFIGURE_DESCRIPTOR(_CONFIGURE_DESCRIPTORS_LEN,2,1)
_IAD_DESCRIPTOR(0,2,0x0E,0x03,0x00)
_INTERFACE_DESCRIPTOR(0,0,0,0x0E,0x01,0x00)
_VC_DESCRIPTORS()
_INTERFACE_DESCRIPTOR(1,0,0,0x0E,0x02,0x00)
_VS_IN_DESCRIPTORS()
_INTERFACE_DESCRIPTOR(1,1,1,0x0E,0x02,0x00)
_ENDPOINT_DESCRIPTOR(0x81,0x05,UX_DEMO_ENDPOINT_SIZE,UX_DEMO_ENDPOINT_INTERVAL_HS)
};
#define DEVICE_FRAMEWORK_LENGTH_HIGH_SPEED sizeof(device_payloadwork_high_speed)
- Setup video stream and video, e.g., for upper simulated camera:
/* Set the parameters for Video streams. */
video_stream_parameter[0].ux_device_class_video_stream_parameter_callbacks.ux_device_class_video_stream_change = demo_video_write_change;
video_stream_parameter[0].ux_device_class_video_stream_parameter_callbacks.ux_device_class_video_stream_payload_done = demo_video_write_done;
video_stream_parameter[0].ux_device_class_video_stream_parameter_max_payload_buffer_nb = UX_DEMO_PAYLOAD_BUFFER_NB;
video_stream_parameter[0].ux_device_class_video_stream_parameter_max_payload_buffer_size = UX_DEMO_MAX_PAYLOAD_SIZE;
video_stream_parameter[0].ux_device_class_video_stream_parameter_thread_entry = ux_device_class_video_write_thread_entry;
/* Set the parameters for Video device. */
video_parameter.ux_device_class_video_parameter_streams_nb = 1;
video_parameter.ux_device_class_video_parameter_streams = video_stream_parameter;
video_parameter.ux_device_class_video_parameter_callbacks.ux_slave_class_video_instance_activate = demo_video_instance_activate;
video_parameter.ux_device_class_video_parameter_callbacks.ux_slave_class_video_instance_deactivate = demo_video_instance_deactivate;
video_parameter.ux_device_class_video_parameter_callbacks.ux_device_class_video_request = demo_video_vc_request_process;
video_stream_parameter[0].ux_device_class_video_stream_parameter_callbacks.ux_device_class_video_stream_request = demo_video_vs_request_process;
/* Initialize the device Video class. This class owns interfaces starting with 0. */
status = ux_device_stack_class_register(_ux_system_device_class_video_name, ux_device_class_video_entry,
1, 0, &video_parameter);callback.ux_device_class_video_stream_change: callback invoked if host select interface alternate setting (0 to close video stream, other value to open video stream in specific data rate)
callbacks.ux_device_class_video_stream_payload_done: callback invoked when a video frame is sent to host (example here is video camera)
_max_payload_buffer_nb and _max_payload_buffer_size: passed to stack to create a ring buffer to caching payloads, the size is usually the max possible isochronous endpoint size.
_thread_entry: ux_device_class_video_write_thread_entry for camera (device sending data to host).
At least stream request should be assigned, since application should handle some request (following the request is simply accepted, but in real application video parameters should be applied and returned in specific format):
UINT demo_video_vs_request_process(UX_DEVICE_CLASS_VIDEO_STREAM *stream, UX_SLAVE_TRANSFER *transfer)
{
UINT status = UX_ERROR;
UCHAR bRequest;
USHORT wValue_CS; /* In high byte. */
USHORT wLength;
UCHAR *data;
/* Decode setup packet. */
bRequest = transfer -> ux_slave_transfer_request_setup[UX_SETUP_REQUEST];
wValue_CS = transfer -> ux_slave_transfer_request_setup[UX_SETUP_VALUE + 1];
wLength = ux_utility_short_get(transfer -> ux_slave_transfer_request_setup + UX_SETUP_LENGTH);
data = transfer -> ux_slave_transfer_request_data_pointer;
/* Check CS. */
switch(wValue_CS)
{
case UX_DEVICE_CLASS_VIDEO_VS_PROBE_CONTROL:
switch(bRequest)
{
case UX_DEVICE_CLASS_VIDEO_SET_CUR:
/* Simply accept without change setting. */
status = UX_SUCCESS;
break;
case UX_DEVICE_CLASS_VIDEO_GET_CUR:
case UX_DEVICE_CLASS_VIDEO_GET_MIN:
case UX_DEVICE_CLASS_VIDEO_GET_MAX:
/* Simply send our data back (first 26 bytes). */
/* Check request length. */
if (wLength < 26)
break;
/* Copy data for transfer. */
ux_utility_memory_copy(data, video_probe_commit_buffer, 26);
/* Transfer request. */
status = ux_device_stack_transfer_request(transfer, 26, wLength);
break;
default:
break;
}
break;
case UX_DEVICE_CLASS_VIDEO_VS_COMMIT_CONTROL:
/* Simply accept request. */
status = UX_SUCCESS;
break;
/* CS not supported now. */
default:
break;
}
return(status);
}- After host activate the stream (change callback with none-zero alternate setting), in application payload buffer can be filled to streaming data,
ux_device_class_video_write_payload_getis used to get data buffer to fill things andux_device_class_video_write_payload_commitis used to commit the filled buffer. Background transfer is started onceux_device_class_video_transmission_startis called. Once a payload is sent there is a callback to let application to fill more buffer .
static VOID demo_video_write_a_payload(UX_DEVICE_CLASS_VIDEO_STREAM *stream)
{
UCHAR *buffer;
ULONG buffer_length, length;
UX_DEVICE_CLASS_VIDEO_PAYLOAD_HEADER *header;
UCHAR *data;
UCHAR *frame_data;
/* If disabled, no write. */
if (video_payload_data_length == 0)
return;
/* Get payload buffer. */
ux_device_class_video_write_payload_get(stream, &buffer, &buffer_length);
header = (UX_DEVICE_CLASS_VIDEO_PAYLOAD_HEADER *)buffer;
data = buffer + UX_DEMO_PAYLOAD_HEADER_SIZE;
/* Get frame data buffer. */
frame_data = video_frame_buffer + video_frame_write_pos;
/* Calculate data length. */
length = video_frame_buffer_size - video_frame_write_pos;
if (length > video_payload_data_length)
length = video_payload_data_length;
/* Fill data. */
ux_utility_memory_copy(data, frame_data, length);
/* Fill payload header (no PTS nor SCR, total 10 bytes). */
header -> bHeaderLength = UX_DEMO_PAYLOAD_HEADER_SIZE;
header -> bmHeaderInfo.value = video_frame_count & 0x1; /* FID @ B0 */
header -> bmHeaderInfo.bm.bEOH = 1;
/* Move write pos. */
video_frame_write_pos += length;
if (video_frame_write_pos >= video_frame_buffer_size)
{
/* EOF. */
header -> bmHeaderInfo.bm.bEOF = 1;
video_frame_write_pos = 0;
/* A frame sent. */
video_frame_count ++;
}
/* Commit payload buffer. */
ux_device_class_video_write_payload_commit(stream, length + UX_DEMO_PAYLOAD_HEADER_SIZE);
}VOID demo_video_write_change(UX_DEVICE_CLASS_VIDEO_STREAM *stream, ULONG alternate_setting)
{
INT i;
/* Stop video payload loop back if stream closed. */
if (alternate_setting == 0)
{
video_payload_data_length = 0;
return;
}
/* Payload data length: exclude header. */
video_payload_data_length = ux_device_class_video_max_payload_length(stream);
video_payload_data_length -= UX_DEMO_PAYLOAD_HEADER_SIZE;
/* Frame not started. */
video_frame_write_pos = 0;
/* Write buffers until achieve threadshold. */
for (i = 0; i < UX_DEMO_TRANSMIT_START_THRESHOLD; i ++)
demo_video_write_a_payload(stream);
ux_device_class_video_transmission_start(stream);
}VOID demo_video_write_done(UX_DEVICE_CLASS_VIDEO_STREAM *stream, ULONG length)
{
/* Invoked when a payload sent to host, currently no use for loop back. */
(void)stream;
(void)length;
if (length)
{
/* A payload sent. */
video_payload_count ++;
/* Prepare next payload. */
demo_video_write_a_payload(stream);
}
}
MaheshAvula-Alifsemi
.
Describe the bug Actually I am trying to give uvc device class support, I am looking for any sample application or any document to understand the flow of UVC.
Can anyone help on this.
Please also mention any information which could help others to understand the problem you're facing: