Dear Bin Lui,
The webcams that i use are OEM modules with chipsets: AU3820 and AVEO A318S. They are capable of 640x480 capture with 30fps with UVC support.
My output gives the following result:
root@am335x-evm::~# ./yavta --capture=10 -f YUYV -t 1/30 /dev/video0
Device /dev/video0 opened.
Device `USB Video Device' on `usb-musb-hdrc.1.auto-1' is a video capture device.
Video format set: YUYV (56595559) 640x480 (stride 1280) buffer size 614400
Video format: YUYV (56595559) 640x480 (stride 1280) buffer size 614400
Current frame rate: 1/30
Setting frame rate to: 1/30
Frame rate set: 1/30
8 buffers requested.
length: 614400 offset: 0
Buffer 0 mapped at address 0xb6d43000.
length: 614400 offset: 614400
Buffer 1 mapped at address 0xb6cad000.
length: 614400 offset: 1228800
Buffer 2 mapped at address 0xb6c17000.
length: 614400 offset: 1843200
Buffer 3 mapped at address 0xb6b81000.
length: 614400 offset: 2457600
Buffer 4 mapped at address 0xb6aeb000.
length: 614400 offset: 3072000
Buffer 5 mapped at address 0xb6a55000.
length: 614400 offset: 3686400
Buffer 6 mapped at address 0xb69bf000.
length: 614400 offset: 4300800
Buffer 7 mapped at address 0xb6929000.
Warning: bytes used 82976 != image size 614400
0 (0) [-] 4087 82976 bytes 79946.397622 79946.399844 0.001 fps
Warning: bytes used 116464 != image size 614400
1 (1) [-] 9181 116464 bytes 80964.945771 80964.949518 0.001 fps
Warning: bytes used 90104 != image size 614400
2 (2) [-] 12445 90104 bytes 81617.523119 81617.525384 0.002 fps
When i add the 'modprobe uvcvideo quirks=0x80 nodrop=1 timeout=5000' i get parts of the image, but corrupted (white dot at the end of the buffer). This .NET app is just a test application to show the picture on my screen. It works fine with 320x240).
Might is be that the URB data is corrupted somehow, or that the packet length is reported incorrectly?
512 bytes / 1024 bytes isochronous packets(
I'll try to obtain an Logitech Quickcam Pro C9000, to see if i can get similar results
Kind regards,
Mathijs