Xilinx Zynq-7000 User Manual page 44

Similarly, there are three more cases (4, 5, and 6) where instead of an internally generated
pattern, external video is used. See
used instead of TPG for the video source. Cases 4, 5, and 6 are the same as cases 1, 2, and
3 with the only difference being the input source. In cases 1, 2, and 3, the input comes from
TPG, whereas in cases 4, 5, and 6, the input comes from external video.
User Space Device Control
In many cases it is not necessary to write a custom kernel driver simply to access some
memory-mapped registers in a custom IP core. The Userspace IO (UIO) framework permits
simple user space interrupt handling. Such IPs can be configured and controlled from the
user space by using UIO Framework drivers.The UIO framework was designed to allow a
light weight, low overhead access to hardware devices directly from user space.
These IPs are configured and controlled from the user space:
• TPG
• Video Timing Controller
• Croma Resampler
• YUV to RGB Converter
• AXI performance Monitor
The APIs to configure these IPs are explained in the sobel_lib (common library for sobel
QT and cmd application), which is part of the application source code provided with the
Base TRD.
Software Sobel Filter Processing
This section describes the implementation of the software Sobel filter algorithm for edge
detection. The algorithm runs in a separate thread and is turned On and Off by the
controlling block. The application is compiled with the highest compiler optimization level
(O3), so that the algorithm gives best performance. This algorithm takes the buffer address
of the original frame as input and writes the filter image on the buffer address provided as
output.
The following API is used for software Sobel filter processing:
void img_process(ZNQ_S32 *rgb_in_strm32, ZNQ_S32 *rgb_out_strm32, int height, int
width, int stride);
An object's edge detection filter algorithm for imaging/video looks for gradient magnitude
changes in the image background and processing is performed in both the horizontal and
vertical directions. The algorithm takes the RGB raw formatted image and detects the image
object's edges based on the pixel luminance values.
Input : ZNQ_S32 *rgb_data_in
Zynq-7000 AP SoC ZC702 Base TRD
UG925 (v6.0) February 21, 2014
Figure 2-8 and Figure 2-9
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Software Architecture
with external video (HDMI IN)
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