{"type":"doc","content":[{"type":"paragraph","content":[{"text":"This article demonstrates how to create a virtual UVC device to stream video as webcam on SP7350 platforms.","type":"text"}]},{"type":"paragraph"},{"type":"paragraph","content":[{"text":"Table of Contents","type":"text","marks":[{"type":"strong"}]}]},{"type":"extension","attrs":{"layout":"default","extensionType":"com.atlassian.confluence.macro.core","extensionKey":"toc","parameters":{"macroParams":{"minLevel":{"value":"1"},"maxLevel":{"value":"6"},"outline":{"value":"false"},"style":{"value":"default"},"type":{"value":"list"},"printable":{"value":"true"}},"macroMetadata":{"macroId":{"value":"ee349505-475c-4573-97e9-0eb68c980ed1"},"schemaVersion":{"value":"1"},"title":"Table of Contents"}},"localId":"835f5d82-f41f-4a60-9497-f61dcc8af139"}},{"type":"heading","attrs":{"level":1},"content":[{"text":"Kernel Setup","type":"text"}]},{"type":"paragraph","content":[{"text":"Enter the kernel configuration by running the following command in the top directory of project.","type":"text"}]},{"type":"codeBlock","content":[{"text":"# make kconfig","type":"text"}]},{"type":"paragraph"},{"type":"orderedList","attrs":{"order":1},"content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"If USB 2.0 device controller is selected for the uvc gadget, select submenus for USB 2.0 controller : Device Drivers > USB support > USB Gadget Support > USB Peripheral Controller. Select <*> for ","type":"text"},{"text":"“Sunplus USB 2.0 Device Controller“","type":"text","marks":[{"type":"strong"}]},{"text":".","type":"text"}]}]}]},{"type":"mediaSingle","attrs":{"layout":"center","width":572,"widthType":"pixel"},"content":[{"type":"media","attrs":{"width":572,"alt":"image-20240628-071046.png","id":"6d21e2b6-ec03-4fde-8465-b96b67dfad01","collection":"contentId-2011791410","type":"file","height":437}}]},{"type":"paragraph"},{"type":"orderedList","attrs":{"order":2},"content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"If USB 3.0 device controller is selected for the uvc gadget, select submenus for USB 3.0 controller : Device Drivers > USB support. Select <*> for ","type":"text"},{"text":"“DesignWare USB3 DRD Core Support“","type":"text","marks":[{"type":"strong"}]},{"text":" and select ","type":"text"},{"text":"“Dual Role mode“","type":"text","marks":[{"type":"strong"}]},{"text":" for “DWC3 Mode Selection“.","type":"text"}]}]}]},{"type":"mediaSingle","attrs":{"layout":"center","width":572,"widthType":"pixel"},"content":[{"type":"media","attrs":{"width":572,"alt":"image-20240628-071240.png","id":"a67ad7ad-ea07-4253-bd2f-46863492121a","collection":"contentId-2011791410","type":"file","height":436}}]},{"type":"paragraph"},{"type":"orderedList","attrs":{"order":3},"content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Select submenus for USB Gadget configfs : Device Drivers > USB support > USB Gadget Support. Select for ","type":"text"},{"text":"“USB Gadget functions configurable through configfs“","type":"text","marks":[{"type":"strong"}]},{"text":". Select [*] for ","type":"text"},{"text":"“USB Webcam function“","type":"text","marks":[{"type":"strong"}]},{"text":".","type":"text"}]}]}]},{"type":"mediaSingle","attrs":{"layout":"center","width":571,"widthType":"pixel"},"content":[{"type":"media","attrs":{"width":571,"alt":"image-20240619-073724.png","id":"3c092e2e-777c-490b-9d14-a4215f758037","collection":"contentId-2011791410","type":"file","height":627}}]},{"type":"paragraph"},{"type":"orderedList","attrs":{"order":4},"content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Execute the ","type":"text"},{"text":"make","type":"text","marks":[{"type":"strong"},{"type":"em"}]},{"text":" command to build the Linux image.","type":"text"}]}]}]},{"type":"heading","attrs":{"level":1},"content":[{"text":"ConfigFS","type":"text"}]},{"type":"paragraph","content":[{"text":"Configure uvc gadget through configfs saved as a file named setup_uvc shown below. ","type":"text"}]},{"type":"paragraph","content":[{"text":"For USB 2.0 uvc gadget, ","type":"text"},{"text":"UDC_NAME=”f8102800.usb”","type":"text","marks":[{"type":"strong"}]},{"text":".","type":"text"}]},{"type":"paragraph","content":[{"text":"For USB 3.0 uvc gadget, ","type":"text"},{"text":"UDC_NAME=”f80a1000.dwc3”","type":"text","marks":[{"type":"strong"}]},{"text":".","type":"text"}]},{"type":"codeBlock","content":[{"text":"#!/bin/sh\n\nCONFIGFS_HOME=/sys/kernel/config\nVID=0xabcd\nPID=0x1234\nserial_number=\"myserial\"\nmanufacturer=\"mymfg\"\nproduct=\"myproduct\"\nname=\"c\"\nnumber=\"1\"\nconfiguration=\"\"\nmaxpower=\"120\"\n\n### UVC gadget function\nCONFIG=\"configs/$name.$number\"\n\n# FUNCTION=\".\"\n# where corresponds to one of allowed function names and instance name is an arbitrary string allowed in a filesystem\nFUNCTION=\"uvc.0\"\nSTREAM_MAXPACKET=\"2048\"\n\n# where is one of those found in /sys/class/udc/*\nUDC_NAME=\"f8102800.usb\"\n# UDC_NAME=\"f80a1000.dwc3\"\n\n# load libcomposite module\nmodprobe libcomposite\n\n# disable debug message\necho 0 > /sys/module/sunplus_udc/parameters/dmsg\n\n### 1. Create a gadget ###\nif ! mountpoint -q $CONFIGFS_HOME\nthen\n mount -t configfs none $CONFIGFS_HOME\nfi\n\nmkdir -p $CONFIGFS_HOME/usb_gadget/g1\n\n# cd to its configfs node\ncd $CONFIGFS_HOME/usb_gadget/g1\n\n# Each gadget needs to have its vendor id and product id specified:\n# configure it (vid/pid can be anything if USB Class is used for driver compat)\necho $VID > idVendor\necho $PID > idProduct\n\n# A gadget also needs its serial number, manufacturer and product strings\n# In order to have a place to store them, a strings subdirectory must be createdfor each language\n# Create English string\nmkdir -p strings/0x409\n\n# Then the strings can be specified(configure its serial/mfg/product):\necho $serial_number > strings/0x409/serialnumber\necho $manufacturer > strings/0x409/manufacturer\necho $product > strings/0x409/product\n\n### 2. Creating the configurations ###\n# Each gadget will consist of a number of configurations, their corresponding directories must be created:\n# where can be any string which is legal in a filesystem and the is the configuration's number\nmkdir -p configs/$name.$number\n\n# Each configuration also needs its strings, so a subdirectory must be created for each language.\nmkdir -p configs/$name.$number/strings/0x409\n\n# Then the configuration string can be specified:\n# echo $configuration > configs/c.1/strings/0x409/configuration\n# Some attributes can also be set for a configuration, e.g.:\n# echo $maxpower > configs/$name.$number/MaxPower\n\n### 3. Creating the functions ###\n# The gadget will provide some functions, for each function its corresponding directory must be created:\n# Create UVC gadget function\nmkdir -p functions/$FUNCTION\n\n# Each function provides its specific set of attributes, with either read-only or read-write access.\n# Where applicable they need to be written to as appropriate.\n\ncreate_function() {\n # Example usage:\n # create_function \n\n WIDTH=$1\n HEIGHT=$2\n FORMAT=$3\n NAME=$4\n\n wdir=functions/$FUNCTION/streaming/$FORMAT/$NAME/${HEIGHT}p\n mkdir -p $wdir\n\n echo $WIDTH > $wdir/wWidth\n echo $HEIGHT > $wdir/wHeight\n\n echo 29491200 > $wdir/dwMinBitRate\n echo 29491200 > $wdir/dwMaxBitRate\n\n echo $(( $WIDTH * $HEIGHT * 2 )) > $wdir/dwMaxVideoFrameBufferSize\n\n # dwFrameInterfal is in 100-ns units (fps = 1/(dwFrameInterval * 10000000))\n # 333333 -> 30 fps\n # 666666 -> 15 fps\n # 5000000 -> 2 fps\n cat < $wdir/dwFrameInterval\n333333\n666666\n5000000\nEOF\n}\n\n# YUY2 resolution\ncreate_function 640 360 uncompressed u\ncreate_function 640 480 uncompressed u\ncreate_function 1280 720 uncompressed u\n\n# MJPEG resolution\ncreate_function 640 360 mjpeg m\ncreate_function 640 480 mjpeg m\ncreate_function 1280 720 mjpeg m\n\n# Create header\nmkdir -p functions/$FUNCTION/streaming/header/h\ncd functions/$FUNCTION/streaming/header/h\nln -s ../../uncompressed/u\nln -s ../../mjpeg/m\ncd ../../class/fs\nln -s ../../header/h\ncd ../../class/hs\nln -s ../../header/h\ncd ../../class/ss\nln -s ../../header/h\ncd ../../../control\nmkdir -p header/h\nln -s header/h class/fs\nln -s header/h class/ss\ncd ../../../\n\n# Configure max packet size\necho $STREAM_MAXPACKET > functions/$FUNCTION/streaming_maxpacket\n\n### 4. Associating the functions with theireirthe functions with theirheir eir configurations\n# At this moment a number of gadgets is created, each of which has a number of\n# configurations specified and a number of functions available. What remains\n# is specifying which function is available in which configuration (the same\n# function can be used in multiple configurations). This is achieved with\n# creating symbolic links:\n# Assign configuration to function\nln -s functions/$FUNCTION configs/$name.$number\n\n### 5. Enabling the gadget\n# In order to enable the gadget it must be bound to a UDC (USB Device Controller).\n# Bind USB Device Controller (UDC)\necho $UDC_NAME > UDC","type":"text"}]},{"type":"paragraph"},{"type":"heading","attrs":{"level":1},"content":[{"text":"Userspace Application","type":"text"}]},{"type":"paragraph","content":[{"text":"The UVC gadget userspace enhancement sample application (uvc-gadget) is adapted for UVC gadget test and it is available on the website ","type":"text"},{"text":"https://github.com/wlhe/uvc-gadget","type":"text","marks":[{"type":"link","attrs":{"href":"https://github.com/wlhe/uvc-gadget"}}]},{"text":".","type":"text"}]},{"type":"paragraph","content":[{"text":" ","type":"text"}]},{"type":"heading","attrs":{"level":1},"content":[{"text":"UVC Gadget Test","type":"text"}]},{"type":"paragraph","content":[{"text":"When USB 2.0 device controller is configured as the uvc gadget, an USB webcam will be connected to the USB 3.0 port for the test. ","type":"text"}]},{"type":"mediaSingle","attrs":{"layout":"center","width":575,"widthType":"pixel"},"content":[{"type":"media","attrs":{"width":575,"alt":"image-20240702-031833.png","id":"f194748c-8036-4242-a9a1-57061ade54f3","collection":"contentId-2011791410","type":"file","height":178}},{"type":"caption","content":[{"text":"USB 2.0 uvc gadget test topology","type":"text"}]}]},{"type":"paragraph"},{"type":"paragraph","content":[{"text":"When USB 3.0 device controller is configured as the uvc gadget, an USB webcam will be connected to the USB 2.0 port for the test.","type":"text"}]},{"type":"mediaSingle","attrs":{"layout":"center","width":575,"widthType":"pixel"},"content":[{"type":"media","attrs":{"width":575,"alt":"image-20240702-031736.png","id":"a458d168-d910-496f-9f7a-a645b9e94fe4","collection":"contentId-2011791410","type":"file","height":179}},{"type":"caption","content":[{"text":"USB 3.0 uvc gadget test topology","type":"text"}]}]},{"type":"paragraph"},{"type":"paragraph","content":[{"text":"After updating the image to the platform and booting the system, use ","type":"text"},{"text":"sh setup_uvc","type":"text","marks":[{"type":"strong"},{"type":"em"}]},{"text":" command to configure USB 2.0 or USB 3.0 device controllers as uvc gadgets. ","type":"text"}]},{"type":"mediaSingle","attrs":{"layout":"center","width":524,"widthType":"pixel"},"content":[{"type":"media","attrs":{"width":524,"alt":"image-20240702-024146.png","id":"272b5942-e46d-4c09-b12f-c1e6965b41b2","collection":"contentId-2011791410","type":"file","height":50}}]},{"type":"paragraph"},{"type":"paragraph","content":[{"text":"/dev/video0 is the device file representing the uvc gadget. After connecting an USB webcam to the USB 2.0 / USB 3.0 port, /dev/video1 is the device file representing it.","type":"text"}]},{"type":"mediaSingle","attrs":{"layout":"center","width":525,"widthType":"pixel"},"content":[{"type":"media","attrs":{"width":525,"alt":"image-20240702-052542.png","id":"14a7c43a-f8a1-48f7-9d4c-373194f7c4f3","collection":"contentId-2011791410","type":"file","height":660}}]},{"type":"paragraph"},{"type":"paragraph","content":[{"text":"After connecting the SP7350 board to a Windows PC through an USB cable, use the following command to be ready to capture videos from the USB webcam with the format of 640x360 YUY2.","type":"text"}]},{"type":"codeBlock","content":[{"text":"./uvc-gadget -u /dev/video0 -v /dev/video1 -f0 -o1 -r0","type":"text"}]},{"type":"mediaSingle","attrs":{"layout":"center","width":628,"widthType":"pixel"},"content":[{"type":"media","attrs":{"width":628,"alt":"image-20240702-054029.png","id":"72ed3eb5-bb43-4a3a-a331-21651c75e22d","collection":"contentId-2011791410","type":"file","height":499}}]},{"type":"paragraph"},{"type":"paragraph","content":[{"text":"In Device Manager of the Windows PC, ","type":"text"},{"text":"UVC Camera","type":"text","marks":[{"type":"strong"}]},{"text":" will show up in Cameras.","type":"text"}]},{"type":"mediaSingle","attrs":{"layout":"center","width":614,"widthType":"pixel"},"content":[{"type":"media","attrs":{"width":614,"alt":"image-20240801-042036.png","id":"7d16729b-f0cd-41c9-ac2f-53d22c4892f7","collection":"contentId-2011791410","type":"file","height":508}}]},{"type":"paragraph"},{"type":"paragraph","content":[{"text":"In Windows PC, a multimedia player PotPlayer is used to play the videos from the uvc gadget.","type":"text"}]},{"type":"mediaSingle","attrs":{"layout":"center","width":645,"widthType":"pixel"},"content":[{"type":"media","attrs":{"width":645,"alt":"image-20240801-051053.png","id":"592eb7ed-d118-4775-bfdf-7344411a3a51","collection":"contentId-2011791410","type":"file","height":457}}]},{"type":"paragraph"},{"type":"paragraph","content":[{"text":"Use the following command to be ready to capture videos from the USB webcam with the format of 640x360 MJPEG.","type":"text"}]},{"type":"codeBlock","content":[{"text":"./uvc-gadget -u /dev/video0 -v /dev/video1 -f1 -o1 -r0","type":"text"}]},{"type":"mediaSingle","attrs":{"layout":"center","width":629,"widthType":"pixel"},"content":[{"type":"media","attrs":{"width":629,"alt":"image-20240702-060734.png","id":"6e37860d-6fe1-4ef7-938a-c84e9d406f93","collection":"contentId-2011791410","type":"file","height":481}}]},{"type":"paragraph"},{"type":"paragraph","content":[{"text":"In Windows PC, a multimedia player PotPlayer is used to play the videos from the uvc gadget.","type":"text"}]},{"type":"mediaSingle","attrs":{"layout":"center","width":645,"widthType":"pixel"},"content":[{"type":"media","attrs":{"width":645,"alt":"image-20240801-051224.png","id":"f2559bd8-3484-493a-9f03-9ed3f6016132","collection":"contentId-2011791410","type":"file","height":459}}]},{"type":"paragraph"},{"type":"heading","attrs":{"level":1},"content":[{"text":"Clear ConfigFS Configuration","type":"text"}]},{"type":"paragraph","content":[{"text":"The following script can be used to clear configfs configuration of the gadget.","type":"text"}]},{"type":"codeBlock","content":[{"text":"#!/bin/bash\n\nname=\"c\"\nnumber=\"1\"\nFUNCTION=\"uvc.0\"\nCONFIG=\"configs/$name.$number\"\n\nCONFIGFS_HOME=/sys/kernel/config\n\nif [ -d $CONFIGFS_HOME/usb_gadget/g1 ]\nthen\n if [ -d $CONFIGFS_HOME/usb_gadget/g1/functions/$FUNCTION ]\n then\n r1=\"360\"\n r2=\"480\"\n r3=\"720\"\n resolution=(\"r1\" \"r2\" \"r3\")\n\n wdir=functions/$FUNCTION/streaming/header/h\n if [ -d $CONFIGFS_HOME/usb_gadget/g1/$wdir ]\n then\n for i in \"${resolution[@]}\"; do\n rmdir $CONFIGFS_HOME/usb_gadget/g1/$wdir/m/${!i}p\n rmdir $CONFIGFS_HOME/usb_gadget/g1/$wdir/u/${!i}p\n done\n\n rm $CONFIGFS_HOME/usb_gadget/g1/$wdir/m\n rm $CONFIGFS_HOME/usb_gadget/g1/$wdir/u\n fi\n\n t1=\"mjpeg/m\"\n t2=\"uncompressed/u\"\n type=(\"t1\" \"t2\")\n\n wdir=functions/$FUNCTION/streaming\n for i in \"${type[@]}\"; do\n if [ -d $CONFIGFS_HOME/usb_gadget/g1/$wdir/${!i} ]\n then\n rmdir $CONFIGFS_HOME/usb_gadget/g1/$wdir/${!i}\n fi\n done\n\n s1=\"fs\"\n s2=\"hs\"\n s3=\"ss\"\n speed=(\"s1\" \"s2\" \"s3\")\n\n wdir=functions/$FUNCTION/streaming/class\n for i in \"${speed[@]}\"; do\n if [ -d $CONFIGFS_HOME/usb_gadget/g1/$wdir/${!i}/h ]\n then\n rm $CONFIGFS_HOME/usb_gadget/g1/$wdir/${!i}/h\n fi\n done\n\n if [ -d /sys/kernel/config/usb_gadget/g1/functions/uvc.0/streaming/header/h ]\n then\n rmdir /sys/kernel/config/usb_gadget/g1/functions/uvc.0/streaming/header/h\n fi\n\n wdir=functions/$FUNCTION/control/class\n for i in \"${speed[@]}\"; do\n if [ -d $CONFIGFS_HOME/usb_gadget/g1/$wdir/${!i}/h ]\n then\n rm $CONFIGFS_HOME/usb_gadget/g1/$wdir/${!i}/h\n fi\n done\n\n if [ -d /sys/kernel/config/usb_gadget/g1/functions/uvc.0/control/header/h ]\n then\n rmdir /sys/kernel/config/usb_gadget/g1/functions/uvc.0/control/header/h\n fi\n fi\n\n wdir=$CONFIG\n if [ -d $CONFIGFS_HOME/usb_gadget/g1/$wdir ]\n then\n if [ -d $CONFIGFS_HOME/usb_gadget/g1/$wdir/uvc.0 ]\n then\n rm $CONFIGFS_HOME/usb_gadget/g1/$wdir/uvc.0\n fi\n\n if [ -d $CONFIGFS_HOME/usb_gadget/g1/$wdir/strings/0x409 ]\n then\n rmdir $CONFIGFS_HOME/usb_gadget/g1/$wdir/strings/0x409\n fi\n\n rmdir $CONFIGFS_HOME/usb_gadget/g1/$wdir\n fi\n\n if [ -d $CONFIGFS_HOME/usb_gadget/g1/strings/0x409 ]\n then\n rmdir $CONFIGFS_HOME/usb_gadget/g1/strings/0x409\n fi\n\n if [ -d $CONFIGFS_HOME/usb_gadget/g1/functions/$FUNCTION ]\n then\n rmdir $CONFIGFS_HOME/usb_gadget/g1/functions/$FUNCTION\n fi\n\n rmdir $CONFIGFS_HOME/usb_gadget/g1\nfi\n\nif grep -q \"^\"usb_f_uvc\"\" /proc/modules\nthen\n rmmod usb_f_uvc\nfi\n\nif grep -q \"^\"libcomposite\"\" /proc/modules\nthen\n rmmod libcomposite\nfi","type":"text"}]}],"version":1}

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