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| R2012a Documentation → Embedded Coder | |
Learn more about Embedded Coder |
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| Contents | Index |
Embedded Coder/ Embedded Targets/ Processors/ Texas Instruments C6000/ DM642 EVM
Adding this block to your model lets you define the format of raw video captured by the video port on the DM642 EVM. The block outputs video as a stream of image frames built from the defined input.
You can select the video port the block reads from, set the size of the input data in bits per pixel, and define the frame sizes in pixels and lines.
When your process captures standard video input, like NTSC format video, another block for the DM642 EVM may be appropriate — the DM642 EVM Video ADC block.
By default, the block settings define NTSC format input video to capture — 640 pixels wide by 480 lines tall using 8 bits per pixel.
The block does not check your inputs to determine whether they form valid frames. You must be sure the values you assign work for you application.
The block does not support video capture from port 2 on the EVM.
Blanking intervals, both horizontal and vertical, represent the time needed for the scan to return to the starting point of the next line (the horizontal blanking period) or field or frame (the vertical blanking period).
This block allocates video capture buffers on the system heap, using a TI driver that allocates three frame buffers on the heap for continuous video capture. To use the block you must create a heap in external memory on the target with the label EXTERNALHEAP. If you do not create the heap, either using the default values in the DM642 Target Preferences block or setting your own values. Embedded Coder software returns an error.
Use Create heap and Heap size and set the heap size in the DM642EVM Target Preferences block to configure the heap. Select Define label and name the heap EXTERNALHEAP in Heap label.
The default settings for the Target Preferences create a heap with sufficient memory to handle the worst case memory allocation needs automatically. If you configure the heap without sufficient memory, you get a run-time error because the system cannot initialize the video driver.
Select the video port to be the source of the raw video data stream. Either 0 or 1 appear on the list and 0 is the default port.
Select the number of bits used to represent a pixel in the input video stream. List entries tell you the input pixel representation and the data type of the output pixels for each input size. You cannot enter values here. Select from the list.
Configure the width of each video frame in pixels. Enter the pixel count as an integer greater than zero.
Configure the height of a single frame of video in lines. Enter the number of lines as an integer greater than zero. Combined with the Number of bits per pixel, this specifies the video frame format.
Specify the rate at which picture elements (pixels) arrive at the block input. Usually you enter this in Hz using scientific notation as shown by the default value. You can enter the value in decimal notation as well.
The blanking signal that occurs at the end of each video scanning line. Enter the value as an integer number of pixels. One video line comprises the number of pixels in the line plus the horizontal blanking pixels.
The blanking signal that occurs at the end of each video field or frame. Enter this value as an integer number of lines (pixels). One frame includes the number of lines in the height of the frame plus the additional blanking lines.
With this option you tell the encoder whether to output video in row major or column major order. Most video capture and display systems use row major ordering. MATLAB and Simulink software use column major order. As a result, some Simulink blocks and MATLAB operations may not produce the output you expect unless you change the ordering for video from the default row major setting to column major.
Selects whether the block inherits the sample time from the model base rate or Simulink base rate as determined in the Solver options in Configuration Parameters. Selecting Inherit sample time directs the block to use the specified rate in model configuration. Entering -1 configures the block to accept the sample rate from the upstream HWI, Task, or Triggered Task blocks.
DM642 EVM Video ADC, DM642 EVM Video DAC
Learn more about Simulink through this collection of videos, articles, technical literature and the Getting Started with Simulink Guide.
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