Difference between revisions of "2253"

Revision as of 11:27, 15 October 2015

Cross-compiling Linux driver for ARM

From sdk_2253_x.y.z_linux/driver:

 PATH=<path-to-cross-compiler/bin>:$PATH \
 make -C <path-to-target-kernel-directory> SUBDIRS=`pwd` \
 CROSS_COMPILE=arm-none-linux-gnueabi- ARCH=arm modules

Copy the s2253.ko file to the target's /lib/modules/`uname -r`/extra directory, and run "depmod -a".

For the demo application, modify the Makefile path to the cross compiler, then do "make demo_arm".

Connecting to USB 3.0 ports on Linux

When connecting the board to a port on a USB 3.0 (SuperSpeed) hub, if the device does not work, check the dmesg log for these messages:

 [  378.352045] usb 9-1: new high-speed USB device number 19 using xhci_hcd
 [  378.369004] usb 9-1: device descriptor read/8, error -75
 [  378.488958] usb 9-1: device descriptor read/8, error -75

Reconnect the device to a USB 2.0 port, or contact support@sensoray.com for RMA. Boards manufactured after April 2013 have corrected this issue. (Windows is not affected.)

Overlay Specifications

One line of text for each video stream (A, B, Output) up to 160 characters, and may include newline (^n) or date (^d) or time (^t) codes inserted.

For styled text, there are 16 overlay regions for Stream A and B, and 255 regions for Output Stream. Bitmaps or PNG images can only be used on the Output Stream. The overlay resolution is not directly limited, but the decoding of the PNG image takes time, and transferring large BMP images over USB and then decoding takes time. For the Output Stream, the overlay image is applied to a masking buffer once and the output video is rendered in hardware. For the Encoded Streams, the overlay image must be rendered in software for every frame, and too many or too large overlays can cause video frames to be dropped.