VideoStreamOverlay Class
VideoStreamOverlay Class
Description
VideoStreamOverlay also known as On-Screen Display (OSD) that allows contents such as texts and shapes to be displayed on video streams. VideoStreamOverlay class is used to draw on video streams.
Syntax
Class VideoStreamOverlay
Members
| Public Constructors | |
| VideoStreamOverlay::VideoStreamOverlay | Constructs a VideoStreamOverlay object. |
| Public Methods | |
| VideoStreamOverlay::configVideo | Configure input video stream parameters. |
| VideoStreamOverlay::configTextSize | Configure text width and height shown on OSD. |
| VideoStreamOverlay::createBitmap | Create bitmap on video streams. |
| VideoStreamOverlay::begin | Enable OSD and start drawing on top of video streams. |
| VideoStreamOverlay::end | Stop OSD drawing on all video streams. |
| VideoStreamOverlay::endChannel | Stop OSD drawing on specified video stream. |
| VideoStreamOverlay::getTextHeight | Get current configuration of OSD text height. |
| VideoStreamOverlay::getTextWidth | Get current configuration of OSD text width. |
| VideoStreamOverlay::color | Convert ARGB color values into a format compatible for OSD use. |
| VideoStreamOverlay::drawLine | Draw a line in OSD frame buffer. |
| VideoStreamOverlay::drawPoint | Draw a point in OSD frame buffer. |
| VideoStreamOverlay::drawRect | Draw a rectangle on OSD frame buffer. |
| VideoStreamOverlay::drawText | Draw text on OSD frame buffer. |
| VideoStreamOverlay::update | Update OSD and display drawings on video streams. |
VideoStreamOverlay::configVideo
Description
Configure input video stream parameters.
Syntax
void configVideo(int ch, VideoSetting& config);
Parameters
ch: Channel to configure (Valid value: 0,1,2).
config: VideoSetting object.
Returns
NA
Example Code
LoopPostProcessing
(https://github.com/ambiot/ambpro2_arduino/blob/dev/Arduino_package/hardware/libraries/Multimedia/examples/MotionDetection/LoopPostProcessing/LoopPostProcessing.ino)
Notes and Warnings
Note that OSD only supports channel 0, 1 and 2. “VideoStreamOverlay.h” must be included to use the class function.
VideoStreamOverlay::configTextSize
Description
Configure text width and height shown on OSD.
Syntax
void configTextSize(int ch, int text_width, int text_height);
Parameters
ch: Channel to configure (Valid value: 0,1,2)
text_width: Text width in pixels. Default text width is 16.
text_height: Text height in pixels. Default height width is 32.
Returns
NA
Example Code
NA
Notes and Warnings
“VideoStreamOverlay.h” must be included to use the class function. Text size should be configured before OSD is started using begin().
VideoStreamOverlay::createBitmap
Description
Create bitmap on video streams.
Syntax
void createBitmap (int ch, int idx = 0);
Parameters
ch: Channel to configure (Valid value: 0,1,2)
idx: Layer index of OSD. The default value is 0. (Valid value: 0 to 5)
Returns
NA
Example Code
LoopPostProcessing
(https://github.com/ambiot/ambpro2_arduino/blob/dev/Arduino_package/hardware/libraries/Multimedia/examples/MotionDetection/LoopPostProcessing/LoopPostProcessing.ino)
Notes and Warnings
“VideoStreamOverlay.h” must be included to use the class function.
VideoStreamOverlay::begin
Description
Enable OSD and start drawing on top of video streams.
Syntax
void begin(void);
Parameters
NA
Returns
NA
Example Code
LoopPostProcessing
(https://github.com/ambiot/ambpro2_arduino/blob/dev/Arduino_package/hardware/libraries/Multimedia/examples/MotionDetection/LoopPostProcessing/LoopPostProcessing.ino)
Notes and Warnings
“VideoStreamOverlay.h” must be included to use the class function.
VideoStreamOverlay::end
Description
Stop OSD drawing on all video streams.
Syntax
void end(void);
Parameters
c: single data byte to write
str: pointer to char array containing data to write, expressed as a null terminated string
buf: pointer to array containing data to write
size: number of bytes to write
Returns
NA
Example Code
NA
Notes and Warnings
“VideoStreamOverlay.h” must be included to use the class function.
VideoStreamOverlay::endChannel
Description
Stop OSD drawing on specified video stream.
Syntax
void endChannel(int ch);
Parameters
ch: Channel to stop. (Valid value: 0,1,2).
Returns
NA
Example Code
NA
Notes and Warnings
“VideoStreamOverlay.h” must be included to use the class function.
VideoStreamOverlay::getTextHeight
Description
Get current configuration of OSD text height.
Syntax
int getTextHeight(int ch);
Parameters
ch: Channel to get the OSD text’s height. (Valid value: 0,1,2).
Returns
This function returns the OSD text’s height on selected channel.
Example Code
RTSPFaceDetection
(https://github.com/ambiot/ambpro2_arduino/blob/dev/Arduino_package/hardware/libraries/NeuralNetwork/examples/RTSPFaceDetection/RTSPFaceDetection.ino)
Notes and Warnings
“VideoStreamOverlay.h” must be included to use the class function.
VideoStreamOverlay::getTextWidth
Description
Get current configuration of OSD text width.
Syntax
int getTextWidth(int ch);
Parameters
ch: Channel to get the OSD text’s width. (Valid value: 0,1,2).
Returns
This function returns the OSD text’s width on selected channel.
Example Code
NA
Notes and Warnings
“VideoStreamOverlay.h” must be included to use the class function.
VideoStreamOverlay::color
Description
Convert ARGB color values into a format compatible for OSD use.
Syntax
uint32_t color(uint8_t red, uint8_t green, uint8_t blue, uint8_t alpha = 0xff);
Parameters
red: Intensity level of red color expressed as an 8-bit unsigned integer from 0 to 255.
green: Intensity level of green color expressed as an 8-bit unsigned integer from 0 to 255.
blue: Intensity level of blue color expressed as an 8-bit unsigned integer from 0 to 255.
alpha: Transparency of color expressed as an 8-bit unsigned integer from 0 to 255. Default value of 255. This value is optional.
Returns
This function returns the ARGB value in a format compatible for OSD use.
Example Code
NA
Notes and Warnings
“VideoStreamOverlay.h” must be included to use the class function.
VideoStreamOverlay::drawLine
Description
Draw a line in OSD frame buffer.
Syntax
void drawLine(int ch, int xmin, int ymin, int xmax, int ymax, int line_width, uint32_t color, int idx = 0);
Parameters
ch: Channel to draw on. (Valid value: 0,1,2)
xmin: x coordinate of the top left corner.
ymin: y coordinate of the top left corner.
xmax: x coordinate of the bottom right corner.
ymax: y coordinate of bottom right corner.
line_width: Width of a line.
color: Color of the line.
idx: Layer index of OSD. The default value is 0. (Valid value: 0 to 5)
Returns
NA
Example Code
NA
Notes and Warnings
VideoStreamOverlay::update() needs to be called for drawings to be shown on the video streams. “VideoStreamOverlay.h” must be included to use the class function.
VideoStreamOverlay::drawPoint
Description
Draw a point in OSD frame buffer.
Syntax
void VideoStreamOverlay::drawPoint(int ch, int xmin, int ymin, int point_width, uint32_t color, int idx = 0);
Parameters
ch: Channel to draw on. (Valid value: 0,1,2).
xmin: x coordinate of the point.
ymin: y coordinate of the point.
point_width: size of the point.
color: Color of the point.
idx: Layer index of OSD. The default value is 0. (Valid value: 0 to 5)
Returns
NA
Example Code
RTSPFaceDetection
(https://github.com/ambiot/ambpro2_arduino/blob/dev/Arduino_package/hardware/libraries/NeuralNetwork/examples/RTSPFaceDetection/RTSPFaceDetection.ino)
Notes and Warnings
VideoStreamOverlay::update() needs to be called for drawings to be shown on the video streams. “VideoStreamOverlay.h” must be included to use the class function.
VideoStreamOverlay::drawRect
Description
Draw a rectangle on OSD frame buffer.
Syntax
void drawRect(int ch, int xmin, int ymin, int xmax, int ymax, int line_width, uint32_t color, int idx = 0);
Parameters
ch: Channel to draw rectangle on.(Valid value: 0,1,2)
xmin: x coordinate of the top left corner.
ymin: y coordinate of the top left corner.
xmax: x coordinate of the bottom right corner.
ymax: y coordinate of bottom right corner.
line_width: Width of a rectangle’s border.
color: Color of the rectangle.
idx: Layer index of OSD. The default value is 0. (Valid value: 0 to 5)
Returns
NA
Example Code
Example: LoopPostProcessing
(https://github.com/ambiot/ambpro2_arduino/blob/dev/Arduino_package/hardware/libraries/Multimedia/examples/MotionDetection/LoopPostProcessing/LoopPostProcessing.ino)
Notes and Warnings
VideoStreamOverlay::update() needs to be called for drawings to be shown on the video streams. “VideoStreamOverlay.h” must be included to use the class function.
VideoStreamOverlay::drawText
Description
Draw text on OSD frame buffer.
Syntax
void drawText(int ch, int xmin, int ymin, const char *text_string, uint32_t color, int idx = 0);
Parameters
ch: Channel to draw text on. (Valid value: 0,1,2)
xmin: x coordinate of top left corner of text box.
ymin: y coordinate of top left corner of text box.
text_string: pointer to a character array containing the text to be displayed.
color: Color of the text.
idx: Layer index of OSD. The default value is 0. (Valid value: 0 to 5)
Returns
NA
Example Code
Example: LoopPostProcessing
(https://github.com/ambiot/ambpro2_arduino/blob/dev/Arduino_package/hardware/libraries/Multimedia/examples/MotionDetection/LoopPostProcessing/LoopPostProcessing.ino)
Notes and Warnings
VideoStreamOverlay::update() needs to be called for drawings to be shown on the video streams. “VideoStreamOverlay.h” must be included to use the class function.
VideoStreamOverlay::update
Description
Update OSD and display drawings on video streams.
Syntax
void update(int ch, int idx = 0);
Parameters
ch: Channel to display drawings. (Valid value: 0,1,2)
idx: Layer index of OSD. The default value is 0. (Valid value: 0 to 5)
Returns
NA
Example Code
Example: LoopPostProcessing
(https://github.com/ambiot/ambpro2_arduino/blob/dev/Arduino_package/hardware/libraries/Multimedia/examples/MotionDetection/LoopPostProcessing/LoopPostProcessing.ino)
Notes and Warnings
“VideoStreamOverlay.h” must be included to use the class function.
