问题
My latest microprocessor( Freescale iMX233 ) has 8 hardware overlay plus inbuilt YUV to RGB conversion functionality. They have exposed these functionality through v4l2 driver. v4l2 Documentation doesn't say it properly that how to use it. Is there any tutorial available or any reference code which I can use to learn v4l2 apis?
回答1:
The V4L2 API isn't the greatest API out there and it is not very easy to use it. There are however a few resources available.
The first one is the "official" V4L2 doc
The series of article written on lwn focus more on the driver side of V4L2, but still they are a very interesting reading if you want to understand how V4L2 works and to use it right.
Finally, this simple but quite complete video capture example is a good code basis for anyone wanting to use the V4L2 API. It shows the 3 ways (memory mapped buffers, read() calls and application allocated buffers) of acquiring data through a camera sensor.
来源：https://stackoverflow.com/questions/1738828/how-to-use-learn-video4linux2-on-screen-display-output-apis