vcap

Video device capture for V4L2 on Petalinux

Build Instructions

Build a Native Executable

# make native

The resulting binary will be written to ./build/native/vcap.

Build a Cross-compiled Executable

Specify the cross-compiler toolchain prefix and the path of required libraries such as V4L2 (following example using prefix of libs bundled with xsdk from installed zc702 base TRD)

# VENDOR_ROOT_PATH=~/Documents/xsdk \
    CROSS_TOOLCHAIN_PREFIX=/opt/Xilinx/SDK/2015.4/gnu/arm/lin \
    make cross

The resulting binary will be written to ./build/cross/vcap.

Identifying Video Device and Configuration

List the available video devices

# v4l2-ctl --list-devices

Choose the flags for vcap from the set of supported options for your device (following examples using /dev/video7)

# v4l2-ctl -d /dev/video7 --list-formats-ex

Dump Video to File

Invoke vcap using the options that you have chosen for your device, dumping the yuyv422 video to file

# ./vcap -d /dev/video7 -c 120 -r 640x480 -f 30 -o > out.yuv

Read the output of ./vcap -h for more information on the options.

The shell script playback.sh may be used to play the resulting video using ffplay

# ./playback.sh out.yuv 30 640x480

Output to HDMI on zc702 board

Copy the cross-compiled binary to the bin directory of the SD card image containing the TRD. Then, eject the SD card from the development machine and use it to boot the zc702 board.

Open a serial terminal to the board and login (serial port may vary)

screen /dev/ttyUSB0 115200

Run vcap with arguments to continuously write to HDMI.

# /media/card/bin/vcap -d /dev/video7 -c 0 -r 640x480 -f 30 -v