Discussion:
[linux-uvc-devel] internal to external conversion : limited resolution
Yann Cantin
2014-11-26 22:09:47 UTC
Permalink
Hi,

I have a salvaged Acer laptop Crytaleye webcam (chicony cnf7017_a6) hooked to a usb cable.

All went ok, except that the maximum resolution is 640x480, not the 1280x1024 expected (1.3Mpixels) .

Is it possible that the conversion (internal to external thru usb cable) limit the board capability ?


Dmesg :
[51967.176051] usb 5-6: new high-speed USB device number 4 using ehci-pci
[51967.327762] usb 5-6: New USB device found, idVendor=04f2, idProduct=b044
[51967.327769] usb 5-6: New USB device strings: Mfr=2, Product=1, SerialNumber=3
[51967.327772] usb 5-6: Product: CNF7017
[51967.327775] usb 5-6: Manufacturer: Chicony Electronics Co., Ltd.
[51967.327777] usb 5-6: SerialNumber: SN0001
[51967.439577] media: Linux media interface: v0.10
[51967.481893] Linux video capture interface: v2.00
[51967.534397] uvcvideo: Found UVC 1.00 device CNF7017 (04f2:b044)
[51967.590793] input: CNF7017 as /devices/pci0000:00/0000:00:10.4/usb5/5-6/5-6:1.0/input/input15
[51967.591639] usbcore: registered new interface driver uvcvideo
[51967.591643] USB Video Class driver (1.1.1)

lsusb :
Bus 005 Device 004: ID 04f2:b044 Chicony Electronics Co., Ltd Acer CrystalEye Webcam
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 239 Miscellaneous Device
bDeviceSubClass 2 ?
bDeviceProtocol 1 Interface Association
bMaxPacketSize0 64
idVendor 0x04f2 Chicony Electronics Co., Ltd
idProduct 0xb044 Acer CrystalEye Webcam
bcdDevice 11.12
iManufacturer 2
iProduct 1
iSerial 3
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 524
bNumInterfaces 2
bConfigurationValue 1
iConfiguration 0
bmAttributes 0x80
(Bus Powered)
MaxPower 500mA
Interface Association:
bLength 8
bDescriptorType 11
bFirstInterface 0
bInterfaceCount 2
bFunctionClass 14 Video
bFunctionSubClass 3 Video Interface Collection
bFunctionProtocol 0
iFunction 5
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 14 Video
bInterfaceSubClass 1 Video Control
bInterfaceProtocol 0
iInterface 5
VideoControl Interface Descriptor:
bLength 13
bDescriptorType 36
bDescriptorSubtype 1 (HEADER)
bcdUVC 1.00
wTotalLength 104
dwClockFrequency 15.000000MHz
bInCollection 1
baInterfaceNr( 0) 1
VideoControl Interface Descriptor:
bLength 9
bDescriptorType 36
bDescriptorSubtype 3 (OUTPUT_TERMINAL)
bTerminalID 2
wTerminalType 0x0101 USB Streaming
bAssocTerminal 0
bSourceID 5
iTerminal 0
VideoControl Interface Descriptor:
bLength 26
bDescriptorType 36
bDescriptorSubtype 6 (EXTENSION_UNIT)
bUnitID 4
guidExtensionCode {7033f028-1163-2e4a-ba2c-6890eb334016}
bNumControl 8
bNrPins 1
baSourceID( 0) 3
bControlSize 1
bmControls( 0) 0x0f
iExtension 0
VideoControl Interface Descriptor:
bLength 26
bDescriptorType 36
bDescriptorSubtype 6 (EXTENSION_UNIT)
bUnitID 5
guidExtensionCode {3fae1228-d7bc-114e-a357-6f1edef7d61d}
bNumControl 8
bNrPins 1
baSourceID( 0) 4
bControlSize 1
bmControls( 0) 0xff
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 0x00000000
VideoControl Interface Descriptor:
bLength 12
bDescriptorType 36
bDescriptorSubtype 5 (PROCESSING_UNIT)
Warning: Descriptor too short
bUnitID 3
bSourceID 1
wMaxMultiplier 0
bControlSize 3
bmControls 0x000025bf
Brightness
Contrast
Hue
Saturation
Sharpness
Gamma
White Balance Component
Backlight Compensation
Power Line Frequency
White Balance Component, Auto
iProcessing 0
bmVideoStandards 0x21
None
PAL - 525/60
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 14
bDescriptorType 36
bDescriptorSubtype 1 (INPUT_HEADER)
bNumFormats 1
wTotalLength 277
bEndPointAddress 129
bmInfo 0
bTerminalLink 2
bStillCaptureMethod 0
bTriggerSupport 1
bTriggerUsage 1
bControlSize 1
bmaControls( 0) 27
VideoStreaming Interface Descriptor:
bLength 27
bDescriptorType 36
bDescriptorSubtype 4 (FORMAT_UNCOMPRESSED)
bFormatIndex 1
bNumFrameDescriptors 5
guidFormat {59555932-0000-1000-8000-00aa00389b71}
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 46
bDescriptorType 36
bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
bFrameIndex 1
bmCapabilities 0x00
Still image unsupported
wWidth 640
wHeight 480
dwMinBitRate 3072000
dwMaxBitRate 18432000
dwMaxVideoFrameBufferSize 614400
dwDefaultFrameInterval 333333
bFrameIntervalType 5
dwFrameInterval( 0) 333333
dwFrameInterval( 1) 500000
dwFrameInterval( 2) 666666
dwFrameInterval( 3) 1000000
dwFrameInterval( 4) 2000000
VideoStreaming Interface Descriptor:
bLength 46
bDescriptorType 36
bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
bFrameIndex 2
bmCapabilities 0x00
Still image unsupported
wWidth 352
wHeight 288
dwMinBitRate 1013760
dwMaxBitRate 6082560
dwMaxVideoFrameBufferSize 202752
dwDefaultFrameInterval 333333
bFrameIntervalType 5
dwFrameInterval( 0) 333333
dwFrameInterval( 1) 500000
dwFrameInterval( 2) 666666
dwFrameInterval( 3) 1000000
dwFrameInterval( 4) 2000000
VideoStreaming Interface Descriptor:
bLength 46
bDescriptorType 36
bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
bFrameIndex 3
bmCapabilities 0x00
Still image unsupported
wWidth 320
wHeight 240
dwMinBitRate 768000
dwMaxBitRate 4608000
dwMaxVideoFrameBufferSize 153600
dwDefaultFrameInterval 333333
bFrameIntervalType 5
dwFrameInterval( 0) 333333
dwFrameInterval( 1) 500000
dwFrameInterval( 2) 666666
dwFrameInterval( 3) 1000000
dwFrameInterval( 4) 2000000
VideoStreaming Interface Descriptor:
bLength 46
bDescriptorType 36
bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
bFrameIndex 4
bmCapabilities 0x00
Still image unsupported
wWidth 176
wHeight 144
dwMinBitRate 253440
dwMaxBitRate 1520640
dwMaxVideoFrameBufferSize 50688
dwDefaultFrameInterval 333333
bFrameIntervalType 5
dwFrameInterval( 0) 333333
dwFrameInterval( 1) 500000
dwFrameInterval( 2) 666666
dwFrameInterval( 3) 1000000
dwFrameInterval( 4) 2000000
VideoStreaming Interface Descriptor:
bLength 46
bDescriptorType 36
bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
bFrameIndex 5
bmCapabilities 0x00
Still image unsupported
wWidth 160
wHeight 120
dwMinBitRate 192000
dwMaxBitRate 1152000
dwMaxVideoFrameBufferSize 38400
dwDefaultFrameInterval 333333
bFrameIntervalType 5
dwFrameInterval( 0) 333333
dwFrameInterval( 1) 500000
dwFrameInterval( 2) 666666
dwFrameInterval( 3) 1000000
dwFrameInterval( 4) 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 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
--
Yann Cantin
A4FEB47F
--
Oleksij Rempel
2014-11-27 06:07:39 UTC
Permalink
Post by Yann Cantin
Hi,
I have a salvaged Acer laptop Crytaleye webcam (chicony cnf7017_a6) hooked to a usb cable.
All went ok, except that the maximum resolution is 640x480, not the 1280x1024 expected (1.3Mpixels) .
Is it possible that the conversion (internal to external thru usb cable) limit the board capability ?
Highest resolution provided by usb descriptor of this webcam is 640x480.
Post by Yann Cantin
wWidth 640
wHeight 480
[51967.176051] usb 5-6: new high-speed USB device number 4 using ehci-pci
[51967.327762] usb 5-6: New USB device found, idVendor=04f2, idProduct=b044
[51967.327769] usb 5-6: New USB device strings: Mfr=2, Product=1, SerialNumber=3
[51967.327772] usb 5-6: Product: CNF7017
[51967.327775] usb 5-6: Manufacturer: Chicony Electronics Co., Ltd.
[51967.327777] usb 5-6: SerialNumber: SN0001
[51967.439577] media: Linux media interface: v0.10
[51967.481893] Linux video capture interface: v2.00
[51967.534397] uvcvideo: Found UVC 1.00 device CNF7017 (04f2:b044)
[51967.590793] input: CNF7017 as /devices/pci0000:00/0000:00:10.4/usb5/5-6/5-6:1.0/input/input15
[51967.591639] usbcore: registered new interface driver uvcvideo
[51967.591643] USB Video Class driver (1.1.1)
Bus 005 Device 004: ID 04f2:b044 Chicony Electronics Co., Ltd Acer CrystalEye Webcam
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 239 Miscellaneous Device
bDeviceSubClass 2 ?
bDeviceProtocol 1 Interface Association
bMaxPacketSize0 64
idVendor 0x04f2 Chicony Electronics Co., Ltd
idProduct 0xb044 Acer CrystalEye Webcam
bcdDevice 11.12
iManufacturer 2
iProduct 1
iSerial 3
bNumConfigurations 1
bLength 9
bDescriptorType 2
wTotalLength 524
bNumInterfaces 2
bConfigurationValue 1
iConfiguration 0
bmAttributes 0x80
(Bus Powered)
MaxPower 500mA
bLength 8
bDescriptorType 11
bFirstInterface 0
bInterfaceCount 2
bFunctionClass 14 Video
bFunctionSubClass 3 Video Interface Collection
bFunctionProtocol 0
iFunction 5
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 14 Video
bInterfaceSubClass 1 Video Control
bInterfaceProtocol 0
iInterface 5
bLength 13
bDescriptorType 36
bDescriptorSubtype 1 (HEADER)
bcdUVC 1.00
wTotalLength 104
dwClockFrequency 15.000000MHz
bInCollection 1
baInterfaceNr( 0) 1
bLength 9
bDescriptorType 36
bDescriptorSubtype 3 (OUTPUT_TERMINAL)
bTerminalID 2
wTerminalType 0x0101 USB Streaming
bAssocTerminal 0
bSourceID 5
iTerminal 0
bLength 26
bDescriptorType 36
bDescriptorSubtype 6 (EXTENSION_UNIT)
bUnitID 4
guidExtensionCode {7033f028-1163-2e4a-ba2c-6890eb334016}
bNumControl 8
bNrPins 1
baSourceID( 0) 3
bControlSize 1
bmControls( 0) 0x0f
iExtension 0
bLength 26
bDescriptorType 36
bDescriptorSubtype 6 (EXTENSION_UNIT)
bUnitID 5
guidExtensionCode {3fae1228-d7bc-114e-a357-6f1edef7d61d}
bNumControl 8
bNrPins 1
baSourceID( 0) 4
bControlSize 1
bmControls( 0) 0xff
iExtension 0
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 0x00000000
bLength 12
bDescriptorType 36
bDescriptorSubtype 5 (PROCESSING_UNIT)
Warning: Descriptor too short
bUnitID 3
bSourceID 1
wMaxMultiplier 0
bControlSize 3
bmControls 0x000025bf
Brightness
Contrast
Hue
Saturation
Sharpness
Gamma
White Balance Component
Backlight Compensation
Power Line Frequency
White Balance Component, Auto
iProcessing 0
bmVideoStandards 0x21
None
PAL - 525/60
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
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 0
bNumEndpoints 0
bInterfaceClass 14 Video
bInterfaceSubClass 2 Video Streaming
bInterfaceProtocol 0
iInterface 0
bLength 14
bDescriptorType 36
bDescriptorSubtype 1 (INPUT_HEADER)
bNumFormats 1
wTotalLength 277
bEndPointAddress 129
bmInfo 0
bTerminalLink 2
bStillCaptureMethod 0
bTriggerSupport 1
bTriggerUsage 1
bControlSize 1
bmaControls( 0) 27
bLength 27
bDescriptorType 36
bDescriptorSubtype 4 (FORMAT_UNCOMPRESSED)
bFormatIndex 1
bNumFrameDescriptors 5
guidFormat {59555932-0000-1000-8000-00aa00389b71}
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
bLength 46
bDescriptorType 36
bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
bFrameIndex 1
bmCapabilities 0x00
Still image unsupported
wWidth 640
wHeight 480
dwMinBitRate 3072000
dwMaxBitRate 18432000
dwMaxVideoFrameBufferSize 614400
dwDefaultFrameInterval 333333
bFrameIntervalType 5
dwFrameInterval( 0) 333333
dwFrameInterval( 1) 500000
dwFrameInterval( 2) 666666
dwFrameInterval( 3) 1000000
dwFrameInterval( 4) 2000000
bLength 46
bDescriptorType 36
bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
bFrameIndex 2
bmCapabilities 0x00
Still image unsupported
wWidth 352
wHeight 288
dwMinBitRate 1013760
dwMaxBitRate 6082560
dwMaxVideoFrameBufferSize 202752
dwDefaultFrameInterval 333333
bFrameIntervalType 5
dwFrameInterval( 0) 333333
dwFrameInterval( 1) 500000
dwFrameInterval( 2) 666666
dwFrameInterval( 3) 1000000
dwFrameInterval( 4) 2000000
bLength 46
bDescriptorType 36
bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
bFrameIndex 3
bmCapabilities 0x00
Still image unsupported
wWidth 320
wHeight 240
dwMinBitRate 768000
dwMaxBitRate 4608000
dwMaxVideoFrameBufferSize 153600
dwDefaultFrameInterval 333333
bFrameIntervalType 5
dwFrameInterval( 0) 333333
dwFrameInterval( 1) 500000
dwFrameInterval( 2) 666666
dwFrameInterval( 3) 1000000
dwFrameInterval( 4) 2000000
bLength 46
bDescriptorType 36
bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
bFrameIndex 4
bmCapabilities 0x00
Still image unsupported
wWidth 176
wHeight 144
dwMinBitRate 253440
dwMaxBitRate 1520640
dwMaxVideoFrameBufferSize 50688
dwDefaultFrameInterval 333333
bFrameIntervalType 5
dwFrameInterval( 0) 333333
dwFrameInterval( 1) 500000
dwFrameInterval( 2) 666666
dwFrameInterval( 3) 1000000
dwFrameInterval( 4) 2000000
bLength 46
bDescriptorType 36
bDescriptorSubtype 5 (FRAME_UNCOMPRESSED)
bFrameIndex 5
bmCapabilities 0x00
Still image unsupported
wWidth 160
wHeight 120
dwMinBitRate 192000
dwMaxBitRate 1152000
dwMaxVideoFrameBufferSize 38400
dwDefaultFrameInterval 333333
bFrameIntervalType 5
dwFrameInterval( 0) 333333
dwFrameInterval( 1) 500000
dwFrameInterval( 2) 666666
dwFrameInterval( 3) 1000000
dwFrameInterval( 4) 2000000
bLength 6
bDescriptorType 36
bDescriptorSubtype 13 (COLORFORMAT)
bColorPrimaries 1 (BT.709,sRGB)
bTransferCharacteristics 1 (BT.709)
bMatrixCoefficients 4 (SMPTE 170M (BT.601))
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 1
bNumEndpoints 1
bInterfaceClass 14 Video
bInterfaceSubClass 2 Video Streaming
bInterfaceProtocol 0
iInterface 0
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
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 2
bNumEndpoints 1
bInterfaceClass 14 Video
bInterfaceSubClass 2 Video Streaming
bInterfaceProtocol 0
iInterface 0
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
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 3
bNumEndpoints 1
bInterfaceClass 14 Video
bInterfaceSubClass 2 Video Streaming
bInterfaceProtocol 0
iInterface 0
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
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 4
bNumEndpoints 1
bInterfaceClass 14 Video
bInterfaceSubClass 2 Video Streaming
bInterfaceProtocol 0
iInterface 0
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
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 5
bNumEndpoints 1
bInterfaceClass 14 Video
bInterfaceSubClass 2 Video Streaming
bInterfaceProtocol 0
iInterface 0
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
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 6
bNumEndpoints 1
bInterfaceClass 14 Video
bInterfaceSubClass 2 Video Streaming
bInterfaceProtocol 0
iInterface 0
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
--
Regards,
Oleksij
Yann Cantin
2014-11-27 07:49:11 UTC
Permalink
Hi,
Post by Oleksij Rempel
Post by Yann Cantin
I have a salvaged Acer laptop Crytaleye webcam (chicony cnf7017_a6) hooked to a usb cable.
All went ok, except that the maximum resolution is 640x480, not the 1280x1024 expected (1.3Mpixels) .
Is it possible that the conversion (internal to external thru usb cable) limit the board capability ?
Highest resolution provided by usb descriptor of this webcam is 640x480.
Post by Yann Cantin
wWidth 640
wHeight 480
Yes, i've seen them, that's the problem...

So, either this webcam is carrying a limited sensor and upscale is done in software (ACER ASPIRE 5738G was
advertized as 1.3Mpixels webcam), or there is a off-the-road way to pull true 1280x1024 stream.

Any ideas where and how to start looking ?
--
Yann Cantin
A4FEB47F
--
Oleksij Rempel
2014-11-27 08:18:13 UTC
Permalink
Post by Yann Cantin
Hi,
Post by Oleksij Rempel
Post by Yann Cantin
I have a salvaged Acer laptop Crytaleye webcam (chicony cnf7017_a6) hooked to a usb cable.
All went ok, except that the maximum resolution is 640x480, not the 1280x1024 expected (1.3Mpixels) .
Is it possible that the conversion (internal to external thru usb cable) limit the board capability ?
Highest resolution provided by usb descriptor of this webcam is 640x480.
Post by Yann Cantin
wWidth 640
wHeight 480
Yes, i've seen them, that's the problem...
So, either this webcam is carrying a limited sensor and upscale is done in software (ACER ASPIRE 5738G was
advertized as 1.3Mpixels webcam), or there is a off-the-road way to pull true 1280x1024 stream.
Any ideas where and how to start looking ?
use wireshark to monitor usb traffic. Note that webcam should be
attached after monitoring was started, only in this case wireshark will
be able to decode UVC stream.
--
Regards,
Oleksij
Loading...