Description
Hi. Im using (and loving) ThreadX and USBX Host stack to interface with an UVC.
I started with this issue and managed to get MJPEG working flawlessly - the stack is very accessible and the example in the above link was quite self-explanatory.
The next step in my application is implementing H264 capture. I have an UVC - descriptor below - that has two streaming interfaces:
- UNCOMPRESSED + MJPEG
- FRAME BASED (H264)
UVC Descriptor
Bus 001 Device 030: ID 32e4:9331 HD USB Camera HD USB Camera
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 239 Miscellaneous Device
bDeviceSubClass 2
bDeviceProtocol 1 Interface Association
bMaxPacketSize0 64
idVendor 0x32e4
idProduct 0x9331
bcdDevice 1.00
iManufacturer 2 HD USB Camera
iProduct 1 HD USB Camera
iSerial 3 2020070302
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 0x05eb
bNumInterfaces 5
bConfigurationValue 1
iConfiguration 0
bmAttributes 0x80
(Bus Powered)
MaxPower 500mA
Interface Association:
bLength 8
bDescriptorType 11
bFirstInterface 0
bInterfaceCount 3
bFunctionClass 14 Video
bFunctionSubClass 3 Video Interface Collection
bFunctionProtocol 0
iFunction 5 HD USB Camera
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 14 Video
bInterfaceSubClass 1 Video Control
bInterfaceProtocol 0
iInterface 5 HD USB Camera
VideoControl Interface Descriptor:
bLength 14
bDescriptorType 36
bDescriptorSubtype 1 (HEADER)
bcdUVC 1.00
wTotalLength 0x0072
dwClockFrequency 15.000000MHz
bInCollection 2
baInterfaceNr( 0) 1
baInterfaceNr( 1) 2
VideoControl Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 3 (OUTPUT_TERMINAL)
bTerminalID 5
wTerminalType 0x0101 USB Streaming
bAssocTerminal 0
bSourceID 4
iTerminal 0
VideoControl Interface Descriptor:
bLength 26
bDescriptorType 36
bDescriptorSubtype 6 (EXTENSION_UNIT)
bUnitID 3
guidExtensionCode {28f03370-6311-4a2e-ba2c-6890eb334016}
bNumControls 8
bNrInPins 1
baSourceID( 0) 2
bControlSize 1
bmControls( 0) 0x1f
iExtension 0
VideoControl Interface Descriptor:
bLength 27
bDescriptorType 36
bDescriptorSubtype 6 (EXTENSION_UNIT)
bUnitID 4
guidExtensionCode {dddf7394-973e-4727-bed9-04ed6426dc67}
bNumControls 16
bNrInPins 1
baSourceID( 0) 3
bControlSize 2
bmControls( 0) 0xff
bmControls( 1) 0x01
iExtension 0
VideoControl Interface Descriptor:
bLength 18
bDescriptorType 36
bDescriptorSubtype 2 (INPUT_TERMINAL)
bTerminalID 1
wTerminalType 0x0201 Camera Sensor
bAssocTerminal 0
iTerminal 0
wObjectiveFocalLengthMin 0
wObjectiveFocalLengthMax 0
wOcularFocalLength 0
bControlSize 3
bmControls 0x0000000e
Auto-Exposure Mode
Auto-Exposure Priority
Exposure Time (Absolute)
VideoControl Interface Descriptor:
bLength 11
bDescriptorType 36
bDescriptorSubtype 5 (PROCESSING_UNIT)
Warning: Descriptor too short
bUnitID 2
bSourceID 1
wMaxMultiplier 0
bControlSize 2
bmControls 0x0000177f
Brightness
Contrast
Hue
Saturation
Sharpness
Gamma
White Balance Temperature
Backlight Compensation
Gain
Power Line Frequency
White Balance Temperature, Auto
iProcessing 0
bmVideoStandards 0x09
None
SECAM - 625/50
VideoControl Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 3 (OUTPUT_TERMINAL)
bTerminalID 6
wTerminalType 0x0101 USB Streaming
bAssocTerminal 0
bSourceID 4
iTerminal 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x83 EP 3 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0010 1x 16 bytes
bInterval 6
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 0
bNumEndpoints 0
bInterfaceClass 14 Video
bInterfaceSubClass 2 Video Streaming
bInterfaceProtocol 0
iInterface 0
VideoStreaming Interface Descriptor:
bLength 15
bDescriptorType 36
bDescriptorSubtype 1 (INPUT_HEADER)
bNumFormats 2
wTotalLength 0x0307
bEndpointAddress 0x81 EP 1 IN
bmInfo 0
bTerminalLink 5
bStillCaptureMethod 2
bTriggerSupport 1
bTriggerUsage 1
bControlSize 1
bmaControls( 0) 0
bmaControls( 1) 0
VideoStreaming Interface Descriptor:
bLength 11
bDescriptorType 36
bDescriptorSubtype 6 (FORMAT_MJPEG)
bFormatIndex 1
bNumFrameDescriptors 8
bFlags 0
Fixed-size samples: No
bDefaultFrameIndex 1
bAspectRatioX 0
bAspectRatioY 0
bmInterlaceFlags 0x00
Interlaced stream or variable: No
Fields per frame: 1 fields
Field 1 first: No
Field pattern: Field 1 only
bCopyProtect 0
VideoStreaming Interface Descriptor:
bLength 50
bDescriptorType 36
bDescriptorSubtype 7 (FRAME_MJPEG)
bFrameIndex 1
bmCapabilities 0x00
Still image unsupported
wWidth 1920
wHeight 1080
dwMinBitRate 165888000
dwMaxBitRate 995328000
dwMaxVideoFrameBufferSize 4147789
dwDefaultFrameInterval 333333
bFrameIntervalType 6
dwFrameInterval( 0) 333333
dwFrameInterval( 1) 400000
dwFrameInterval( 2) 500000
dwFrameInterval( 3) 666666
dwFrameInterval( 4) 1000000
dwFrameInterval( 5) 2000000
VideoStreaming Interface Descriptor:
bLength 38
bDescriptorType 36
bDescriptorSubtype 7 (FRAME_MJPEG)
bFrameIndex 2
bmCapabilities 0x00
Still image unsupported
wWidth 2048
wHeight 1536
dwMinBitRate 251658240
dwMaxBitRate 754974720
dwMaxVideoFrameBufferSize 6292045
dwDefaultFrameInterval 666666
bFrameIntervalType 3
dwFrameInterval( 0) 666666
dwFrameInterval( 1) 1000000
dwFrameInterval( 2) 2000000
VideoStreaming Interface Descriptor:
bLength 38
bDescriptorType 36
bDescriptorSubtype 7 (FRAME_MJPEG)
bFrameIndex 3
bmCapabilities 0x00
Still image unsupported
wWidth 1600
wHeight 1200
dwMinBitRate 153600000
dwMaxBitRate 460800000
dwMaxVideoFrameBufferSize 3840589
dwDefaultFrameInterval 666666
bFrameIntervalType 3
dwFrameInterval( 0) 666666
dwFrameInterval( 1) 1000000
dwFrameInterval( 2) 2000000
VideoStreaming Interface Descriptor:
bLength 50
bDescriptorType 36
bDescriptorSubtype 7 (FRAME_MJPEG)
bFrameIndex 4
bmCapabilities 0x00
Still image unsupported
wWidth 1280
wHeight 1024
dwMinBitRate 104857600
dwMaxBitRate 629145600
dwMaxVideoFrameBufferSize 2622029
dwDefaultFrameInterval 333333
bFrameIntervalType 6
dwFrameInterval( 0) 333333
dwFrameInterval( 1) 400000
dwFrameInterval( 2) 500000
dwFrameInterval( 3) 666666
dwFrameInterval( 4) 1000000
dwFrameInterval( 5) 2000000
VideoStreaming Interface Descriptor:
bLength 50
bDescriptorType 36
bDescriptorSubtype 7 (FRAME_MJPEG)
bFrameIndex 5
bmCapabilities 0x00
Still image unsupported
wWidth 1280
wHeight 720
dwMinBitRate 73728000
dwMaxBitRate 442368000
dwMaxVideoFrameBufferSize 1843789
dwDefaultFrameInterval 333333
bFrameIntervalType 6
dwFrameInterval( 0) 333333
dwFrameInterval( 1) 400000
dwFrameInterval( 2) 500000
dwFrameInterval( 3) 666666
dwFrameInterval( 4) 1000000
dwFrameInterval( 5) 2000000
VideoStreaming Interface Descriptor:
bLength 46
bDescriptorType 36
bDescriptorSubtype 7 (FRAME_MJPEG)
bFrameIndex 6
bmCapabilities 0x00
Still image unsupported
wWidth 800
wHeight 600
dwMinBitRate 38400000
dwMaxBitRate 230400000
dwMaxVideoFrameBufferSize 960589
dwDefaultFrameInterval 333333
bFrameIntervalType 5
dwFrameInterval( 0) 333333
dwFrameInterval( 1) 500000
dwFrameInterval( 2) 666666
dwFrameInterval( 3) 1000000
dwFrameInterval( 4) 2000000
VideoStreaming Interface Descriptor:
bLength 50
bDescriptorType 36
bDescriptorSubtype 7 (FRAME_MJPEG)
bFrameIndex 7
bmCapabilities 0x00
Still image unsupported
wWidth 640
wHeight 480
dwMinBitRate 24576000
dwMaxBitRate 147456000
dwMaxVideoFrameBufferSize 614989
dwDefaultFrameInterval 333333
bFrameIntervalType 6
dwFrameInterval( 0) 333333
dwFrameInterval( 1) 400000
dwFrameInterval( 2) 500000
dwFrameInterval( 3) 666666
dwFrameInterval( 4) 1000000
dwFrameInterval( 5) 2000000
VideoStreaming Interface Descriptor:
bLength 50
bDescriptorType 36
bDescriptorSubtype 7 (FRAME_MJPEG)
bFrameIndex 8
bmCapabilities 0x00
Still image unsupported
wWidth 1920
wHeight 1080
dwMinBitRate 165888000
dwMaxBitRate 995328000
dwMaxVideoFrameBufferSize 4147789
dwDefaultFrameInterval 333333
bFrameIntervalType 6
dwFrameInterval( 0) 333333
dwFrameInterval( 1) 400000
dwFrameInterval( 2) 500000
dwFrameInterval( 3) 666666
dwFrameInterval( 4) 1000000
dwFrameInterval( 5) 2000000
VideoStreaming Interface Descriptor:
bLength 34
bDescriptorType 36
bDescriptorSubtype 3 (STILL_IMAGE_FRAME)
bEndpointAddress 0x00 EP 0 OUT
bNumImageSizePatterns 7
wWidth( 0) 1920
wHeight( 0) 1080
wWidth( 1) 2048
wHeight( 1) 1536
wWidth( 2) 1600
wHeight( 2) 1200
wWidth( 3) 1280
wHeight( 3) 1024
wWidth( 4) 1280
wHeight( 4) 720
wWidth( 5) 800
wHeight( 5) 600
wWidth( 6) 640
wHeight( 6) 480
bNumCompressionPatterns 0
VideoStreaming Interface Descriptor:
bLength 27
bDescriptorType 36
bDescriptorSubtype 4 (FORMAT_UNCOMPRESSED)
bFormatIndex 2
bNumFrameDescriptors 8
guidFormat {32595559-0000-0010-8000-00aa00389b71}
bBitsPerPixel 16
bDefaultFrameIndex 1
bAspectRatioX 0
bAspectRatioY 0
bmInterlaceFlags 0x00
Interlaced stream or variable: No
Fields per frame: 2 fields
Field 1 first: No
Field pattern: Field 1 only
bCopyProtect 0
VideoStreaming Interface Descriptor:
bLength 30
bDescriptorType 36
bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
bFrameIndex 1
bmCapabilities 0x00
Still image unsupported
wWidth 1920
wHeight 1080
dwMinBitRate 165888000
dwMaxBitRate 165888000
dwMaxVideoFrameBufferSize 4147200
dwDefaultFrameInterval 2000000
bFrameIntervalType 1
dwFrameInterval( 0) 2000000
VideoStreaming Interface Descriptor:
bLength 30
bDescriptorType 36
bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
bFrameIndex 2
bmCapabilities 0x00
Still image unsupported
wWidth 2048
wHeight 1536
dwMinBitRate 150994944
dwMaxBitRate 150994944
dwMaxVideoFrameBufferSize 6291456
dwDefaultFrameInterval 3333333
bFrameIntervalType 1
dwFrameInterval( 0) 3333333
VideoStreaming Interface Descriptor:
bLength 30
bDescriptorType 36
bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
bFrameIndex 3
bmCapabilities 0x00
Still image unsupported
wWidth 1600
wHeight 1200
dwMinBitRate 153600000
dwMaxBitRate 153600000
dwMaxVideoFrameBufferSize 3840000
dwDefaultFrameInterval 2000000
bFrameIntervalType 1
dwFrameInterval( 0) 2000000
VideoStreaming Interface Descriptor:
bLength 30
bDescriptorType 36
bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
bFrameIndex 4
bmCapabilities 0x00
Still image unsupported
wWidth 1280
wHeight 1024
dwMinBitRate 104857600
dwMaxBitRate 104857600
dwMaxVideoFrameBufferSize 2621440
dwDefaultFrameInterval 2000000
bFrameIntervalType 1
dwFrameInterval( 0) 2000000
VideoStreaming Interface Descriptor:
bLength 34
bDescriptorType 36
bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
bFrameIndex 5
bmCapabilities 0x00
Still image unsupported
wWidth 1280
wHeight 720
dwMinBitRate 73728000
dwMaxBitRate 147456000
dwMaxVideoFrameBufferSize 1843200
dwDefaultFrameInterval 1000000
bFrameIntervalType 2
dwFrameInterval( 0) 1000000
dwFrameInterval( 1) 2000000
VideoStreaming Interface Descriptor:
bLength 42
bDescriptorType 36
bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
bFrameIndex 6
bmCapabilities 0x00
Still image unsupported
wWidth 800
wHeight 600
dwMinBitRate 38400000
dwMaxBitRate 153600000
dwMaxVideoFrameBufferSize 960000
dwDefaultFrameInterval 500000
bFrameIntervalType 4
dwFrameInterval( 0) 500000
dwFrameInterval( 1) 666666
dwFrameInterval( 2) 1000000
dwFrameInterval( 3) 2000000
VideoStreaming Interface Descriptor:
bLength 50
bDescriptorType 36
bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
bFrameIndex 7
bmCapabilities 0x00
Still image unsupported
wWidth 640
wHeight 480
dwMinBitRate 24576000
dwMaxBitRate 147456000
dwMaxVideoFrameBufferSize 614400
dwDefaultFrameInterval 333333
bFrameIntervalType 6
dwFrameInterval( 0) 333333
dwFrameInterval( 1) 400000
dwFrameInterval( 2) 500000
dwFrameInterval( 3) 666666
dwFrameInterval( 4) 1000000
dwFrameInterval( 5) 2000000
VideoStreaming Interface Descriptor:
bLength 30
bDescriptorType 36
bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
bFrameIndex 8
bmCapabilities 0x00
Still image unsupported
wWidth 1920
wHeight 1080
dwMinBitRate 165888000
dwMaxBitRate 165888000
dwMaxVideoFrameBufferSize 4147200
dwDefaultFrameInterval 2000000
bFrameIntervalType 1
dwFrameInterval( 0) 2000000
VideoStreaming Interface Descriptor:
bLength 34
bDescriptorType 36
bDescriptorSubtype 3 (STILL_IMAGE_FRAME)
bEndpointAddress 0x00 EP 0 OUT
bNumImageSizePatterns 7
wWidth( 0) 1920
wHeight( 0) 1080
wWidth( 1) 2048
wHeight( 1) 1536
wWidth( 2) 1600
wHeight( 2) 1200
wWidth( 3) 1280
wHeight( 3) 1024
wWidth( 4) 1280
wHeight( 4) 720
wWidth( 5) 800
wHeight( 5) 600
wWidth( 6) 640
wHeight( 6) 480
bNumCompressionPatterns 0
VideoStreaming Interface Descriptor:
bLength 6
bDescriptorType 36
bDescriptorSubtype 13 (COLORFORMAT)
bColorPrimaries 1 (BT.709,sRGB)
bTransferCharacteristics 1 (BT.709)
bMatrixCoefficients 4 (SMPTE 170M (BT.601))
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 1
bNumEndpoints 1
bInterfaceClass 14 Video
bInterfaceSubClass 2 Video Streaming
bInterfaceProtocol 0
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 5
Transfer Type Isochronous
Synch Type Asynchronous
Usage Type Data
wMaxPacketSize 0x0080 1x 128 bytes
bInterval 1
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 2
bNumEndpoints 1
bInterfaceClass 14 Video
bInterfaceSubClass 2 Video Streaming
bInterfaceProtocol 0
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 5
Transfer Type Isochronous
Synch Type Asynchronous
Usage Type Data
wMaxPacketSize 0x0100 1x 256 bytes
bInterval 1
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 3
bNumEndpoints 1
bInterfaceClass 14 Video
bInterfaceSubClass 2 Video Streaming
bInterfaceProtocol 0
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 5
Transfer Type Isochronous
Synch Type Asynchronous
Usage Type Data
wMaxPacketSize 0x0320 1x 800 bytes
bInterval 1
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 4
bNumEndpoints 1
bInterfaceClass 14 Video
bInterfaceSubClass 2 Video Streaming
bInterfaceProtocol 0
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 5
Transfer Type Isochronous
Synch Type Asynchronous
Usage Type Data
wMaxPacketSize 0x0b20 2x 800 bytes
bInterval 1
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 5
bNumEndpoints 1
bInterfaceClass 14 Video
bInterfaceSubClass 2 Video Streaming
bInterfaceProtocol 0
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 5
Transfer Type Isochronous
Synch Type Asynchronous
Usage Type Data
wMaxPacketSize 0x1320 3x 800 bytes
bInterval 1
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 6
bNumEndpoints 1
bInterfaceClass 14 Video
bInterfaceSubClass 2 Video Streaming
bInterfaceProtocol 0
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 5
Transfer Type Isochronous
Synch Type Asynchronous
Usage Type Data
wMaxPacketSize 0x1400 3x 1024 bytes
bInterval 1
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 2
bAlternateSetting 0
bNumEndpoints 0
bInterfaceClass 14 Video
bInterfaceSubClass 2 Video Streaming
bInterfaceProtocol 0
iInterface 0
VideoStreaming Interface Descriptor:
bLength 14
bDescriptorType 36
bDescriptorSubtype 1 (INPUT_HEADER)
bNumFormats 1
wTotalLength 0x00f8
bEndpointAddress 0x82 EP 2 IN
bmInfo 0
bTerminalLink 6
bStillCaptureMethod 0
bTriggerSupport 0
bTriggerUsage 0
bControlSize 1
bmaControls( 0) 0
VideoStreaming Interface Descriptor:
bLength 28
bDescriptorType 36
bDescriptorSubtype 16 (FORMAT_FRAME_BASED)
bFormatIndex 1
bNumFrameDescriptors 4
guidFormat {34363248-0000-0010-8000-00aa00389b71}
bBitsPerPixel 16
bDefaultFrameIndex 1
bAspectRatioX 0
bAspectRatioY 0
bmInterlaceFlags 0x00
Interlaced stream or variable: No
Fields per frame: 2 fields
Field 1 first: No
Field pattern: Field 1 only
bCopyProtect 0
bVariableSize 1
VideoStreaming Interface Descriptor:
bLength 50
bDescriptorType 36
bDescriptorSubtype 17 (FRAME_FRAME_BASED)
bFrameIndex 1
bmCapabilities 0x00
Still image unsupported
wWidth 1920
wHeight 1080
dwMinBitRate 55296000
dwMaxBitRate 331776000
dwDefaultFrameInterval 333333
bFrameIntervalType 6
dwBytesPerLine 0
dwFrameInterval( 0) 333333
dwFrameInterval( 1) 400000
dwFrameInterval( 2) 500000
dwFrameInterval( 3) 666666
dwFrameInterval( 4) 1000000
dwFrameInterval( 5) 2000000
VideoStreaming Interface Descriptor:
bLength 50
bDescriptorType 36
bDescriptorSubtype 17 (FRAME_FRAME_BASED)
bFrameIndex 2
bmCapabilities 0x00
Still image unsupported
wWidth 1280
wHeight 720
dwMinBitRate 24576000
dwMaxBitRate 147456000
dwDefaultFrameInterval 333333
bFrameIntervalType 6
dwBytesPerLine 0
dwFrameInterval( 0) 333333
dwFrameInterval( 1) 400000
dwFrameInterval( 2) 500000
dwFrameInterval( 3) 666666
dwFrameInterval( 4) 1000000
dwFrameInterval( 5) 2000000
VideoStreaming Interface Descriptor:
bLength 50
bDescriptorType 36
bDescriptorSubtype 17 (FRAME_FRAME_BASED)
bFrameIndex 3
bmCapabilities 0x00
Still image unsupported
wWidth 640
wHeight 360
dwMinBitRate 6144000
dwMaxBitRate 36864000
dwDefaultFrameInterval 333333
bFrameIntervalType 6
dwBytesPerLine 0
dwFrameInterval( 0) 333333
dwFrameInterval( 1) 400000
dwFrameInterval( 2) 500000
dwFrameInterval( 3) 666666
dwFrameInterval( 4) 1000000
dwFrameInterval( 5) 2000000
VideoStreaming Interface Descriptor:
bLength 50
bDescriptorType 36
bDescriptorSubtype 17 (FRAME_FRAME_BASED)
bFrameIndex 4
bmCapabilities 0x00
Still image unsupported
wWidth 1920
wHeight 1080
dwMinBitRate 55296000
dwMaxBitRate 331776000
dwDefaultFrameInterval 333333
bFrameIntervalType 6
dwBytesPerLine 0
dwFrameInterval( 0) 333333
dwFrameInterval( 1) 400000
dwFrameInterval( 2) 500000
dwFrameInterval( 3) 666666
dwFrameInterval( 4) 1000000
dwFrameInterval( 5) 2000000
VideoStreaming Interface Descriptor:
bLength 6
bDescriptorType 36
bDescriptorSubtype 13 (COLORFORMAT)
bColorPrimaries 1 (BT.709,sRGB)
bTransferCharacteristics 1 (BT.709)
bMatrixCoefficients 4 (SMPTE 170M (BT.601))
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 2
bAlternateSetting 1
bNumEndpoints 1
bInterfaceClass 14 Video
bInterfaceSubClass 2 Video Streaming
bInterfaceProtocol 0
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x82 EP 2 IN
bmAttributes 5
Transfer Type Isochronous
Synch Type Asynchronous
Usage Type Data
wMaxPacketSize 0x0080 1x 128 bytes
bInterval 1
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 2
bAlternateSetting 2
bNumEndpoints 1
bInterfaceClass 14 Video
bInterfaceSubClass 2 Video Streaming
bInterfaceProtocol 0
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x82 EP 2 IN
bmAttributes 5
Transfer Type Isochronous
Synch Type Asynchronous
Usage Type Data
wMaxPacketSize 0x0100 1x 256 bytes
bInterval 1
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 2
bAlternateSetting 3
bNumEndpoints 1
bInterfaceClass 14 Video
bInterfaceSubClass 2 Video Streaming
bInterfaceProtocol 0
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x82 EP 2 IN
bmAttributes 5
Transfer Type Isochronous
Synch Type Asynchronous
Usage Type Data
wMaxPacketSize 0x0320 1x 800 bytes
bInterval 1
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 2
bAlternateSetting 4
bNumEndpoints 1
bInterfaceClass 14 Video
bInterfaceSubClass 2 Video Streaming
bInterfaceProtocol 0
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x82 EP 2 IN
bmAttributes 5
Transfer Type Isochronous
Synch Type Asynchronous
Usage Type Data
wMaxPacketSize 0x0b20 2x 800 bytes
bInterval 1
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 2
bAlternateSetting 5
bNumEndpoints 1
bInterfaceClass 14 Video
bInterfaceSubClass 2 Video Streaming
bInterfaceProtocol 0
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x82 EP 2 IN
bmAttributes 5
Transfer Type Isochronous
Synch Type Asynchronous
Usage Type Data
wMaxPacketSize 0x1320 3x 800 bytes
bInterval 1
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 2
bAlternateSetting 6
bNumEndpoints 1
bInterfaceClass 14 Video
bInterfaceSubClass 2 Video Streaming
bInterfaceProtocol 0
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x82 EP 2 IN
bmAttributes 5
Transfer Type Isochronous
Synch Type Asynchronous
Usage Type Data
wMaxPacketSize 0x1400 3x 1024 bytes
bInterval 1
Interface Association:
bLength 8
bDescriptorType 11
bFirstInterface 3
bInterfaceCount 2
bFunctionClass 1 Audio
bFunctionSubClass 0
bFunctionProtocol 0
iFunction 0
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 3
bAlternateSetting 0
bNumEndpoints 0
bInterfaceClass 1 Audio
bInterfaceSubClass 1 Control Device
bInterfaceProtocol 0
iInterface 0
AudioControl Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 1 (HEADER)
bcdADC 1.00
wTotalLength 0x002b
bInCollection 1
baInterfaceNr(0) 4
AudioControl Interface Descriptor:
bLength 12
bDescriptorType 36
bDescriptorSubtype 2 (INPUT_TERMINAL)
bTerminalID 1
wTerminalType 0x0201 Microphone
bAssocTerminal 0
bNrChannels 2
wChannelConfig 0x0000
iChannelNames 0
iTerminal 0
AudioControl Interface Descriptor:
bLength 13
bDescriptorType 36
bDescriptorSubtype 6 (FEATURE_UNIT)
bUnitID 2
bSourceID 1
bControlSize 2
bmaControls(0) 0x0001
Mute Control
bmaControls(1) 0x0002
Volume Control
bmaControls(2) 0x0002
Volume Control
iFeature 0
AudioControl Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 3 (OUTPUT_TERMINAL)
bTerminalID 3
wTerminalType 0x0101 USB Streaming
bAssocTerminal 0
bSourceID 2
iTerminal 0
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 4
bAlternateSetting 0
bNumEndpoints 0
bInterfaceClass 1 Audio
bInterfaceSubClass 2 Streaming
bInterfaceProtocol 0
iInterface 0
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 4
bAlternateSetting 1
bNumEndpoints 1
bInterfaceClass 1 Audio
bInterfaceSubClass 2 Streaming
bInterfaceProtocol 0
iInterface 0
AudioStreaming Interface Descriptor:
bLength 7
bDescriptorType 36
bDescriptorSubtype 1 (AS_GENERAL)
bTerminalLink 3
bDelay 1 frames
wFormatTag 0x0001 PCM
AudioStreaming Interface Descriptor:
bLength 29
bDescriptorType 36
bDescriptorSubtype 2 (FORMAT_TYPE)
bFormatType 1 (FORMAT_TYPE_I)
bNrChannels 2
bSubframeSize 2
bBitResolution 16
bSamFreqType 7 Discrete
tSamFreq[ 0] 8000
tSamFreq[ 1] 11025
tSamFreq[ 2] 16000
tSamFreq[ 3] 22050
tSamFreq[ 4] 24000
tSamFreq[ 5] 44100
tSamFreq[ 6] 48000
Endpoint Descriptor:
bLength 9
bDescriptorType 5
bEndpointAddress 0x84 EP 4 IN
bmAttributes 5
Transfer Type Isochronous
Synch Type Asynchronous
Usage Type Data
wMaxPacketSize 0x00c0 1x 192 bytes
bInterval 4
bRefresh 0
bSynchAddress 0
AudioStreaming Endpoint Descriptor:
bLength 7
bDescriptorType 37
bDescriptorSubtype 1 (EP_GENERAL)
bmAttributes 0x01
Sampling Frequency
bLockDelayUnits 0 Undefined
wLockDelay 0x0192
Device Qualifier (for other device speed):
bLength 10
bDescriptorType 6
bcdUSB 2.00
bDeviceClass 239 Miscellaneous Device
bDeviceSubClass 2
bDeviceProtocol 1 Interface Association
bMaxPacketSize0 64
bNumConfigurations 1
Device Status: 0x0002
(Bus Powered)
Remote Wakeup Enabled
I tried (and failed hilariously) to switch the current interface. Take, for example, the following function:
VOID uvc_parameter_list (UX_HOST_CLASS_VIDEO * video)
{
ULONG format_index;
UX_HOST_CLASS_VIDEO_PARAMETER_FORMAT_DATA format_parameter;
UINT status = UX_SUCCESS;
int i;
/* format types */
for (format_index = 1; format_index <= video->ux_host_class_video_number_formats; format_index++)
{
/* Get format data for current format index. */
format_parameter.ux_host_class_video_parameter_format_requested = format_index;
status = _ux_host_class_video_format_data_get(video, &format_parameter);
printi("FOUND FORMAT %lx", format_parameter.ux_host_class_video_parameter_format_subtype);
if (UX_SUCCESS == status)
{
/* Save number of frames in the video instance. */
video->ux_host_class_video_number_frames = format_parameter.ux_host_class_video_parameter_number_frame_descriptors;
uvc_parameter_frame_list(video);
}
}
}
This works great (for the default interface) - but I'd like to also parse the secondary interface (the H264 one) and switch to that interface when the user requests H264 video.
Right now I managed to get that working (to test the functionality), by setting the parameters for MJPEG and before starting acquisition, switching the interface number to the (known) H264 one. Which is ugly and naturally not production-worthy.
status = ux_host_class_video_frame_parameters_set(video, UX_HOST_CLASS_VIDEO_VS_FORMAT_MJPEG, 1920,1080,333333);
[...]
for (int j = 0; j < 128; ++j)
{
video->ux_host_class_video_streaming_interface = video->ux_host_class_video_streaming_interface->ux_interface_next_interface;
if(video->ux_host_class_video_streaming_interface->ux_interface_descriptor.bInterfaceNumber == 2)
{
break;
}
}
status = _ux_host_class_video_channel_start(video, &channel_parameter);
The parsing of the video packets is the exact same one would use to validate and reconstruct a JPEG, I'm using the same function and I'm getting valid AUs (multiple NALs for consecutive packets with the same FIDs).
I have a hunch that the stack is currently written to only support one interface (it makes sense, 90% of UVCs in the wild only have one), but I'm sure there's a way to select/ switch the interface numbers after the initial parsing and still be able to get info about the current interface, correctly request the stream format etc. I just couldn't find it.
I'd appreciate any kind of pointers regarding this issue.
Thank you kindly!