Class VideoStreamOverlay

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::drawPlus	Draw “+” on OSD frame buffer.
VideoStreamOverlay::update	Update OSD and display drawings on video streams.
VideoStreamOverlay::initOSDBitmapPos	Set image position on video stream.
VideoStreamOverlay::initOSDBitmapBlk	Set block index of image on video stream.
VideoStreamOverlay::initOSDBitmapBuf	Set buffer containing image data and its length
VideoStreamOverlay::resizeWidth	Get resized width of image for overlaying on a video stream.
VideoStreamOverlay::resizeHeight	Get resized height of image for overlaying on a video stream.
VideoStreamOverlay::heapsizeCal	Get heapsize for an image overlay given its resized dimensions and color format.
VideoStreamOverlay::drawImage	Draw image on OSD frame buffer.
VideoStreamOverlay::displayImage	Update OSD and display images on video streams.

VideoStreamOverlay::configVideo

Description

Configure input video stream parameters.

Syntax

void configVideo(int ch, VideoSetting& config);

Parameters

ch: Channel to configure.

0
1
2

config: VideoSetting object.

Returns

NA

Example Code

Example: MotionDetection/LoopPostProcessing

Note

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.

0
1
2

text_width: Text width in pixels. (Default value is 16)

text_height: Text height in pixels (Default value is 32)

Returns

NA

Example Code

NA

Note

“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.

0
1
2

idx: Layer index of OSD.

0 to 5 (Default value is 0)

Returns

NA

Example Code

Example: MotionDetection/LoopPostProcessing

Note

“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);
void begin(VideoSetting &config, int ch, int idx = 0);

Parameters

ch: Channel to enable OSD.

0
1
2

config: VideoSetting object.

idx: Layer index of OSD.

Returns

NA

Example Code

Example: MotionDetection/LoopPostProcessing

Note

“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

NA

Returns

NA

Example Code

NA

Note

“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.

0
1
2

Returns

NA

Example Code

NA

Note

“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.

0
1
2

Returns

This function returns the OSD text’s height on selected channel.

Example Code

Example: RTSPFaceDetection

Note

“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.

0
1
2

Returns

This function returns the OSD text’s width on the selected channel.

Example Code

NA

Note

“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.

0 to 255

green: Intensity level of green color expressed as an 8-bit unsigned integer. - 0 to 255

blue: Intensity level of blue color expressed as an 8-bit unsigned integer. - 0 to 255

alpha: Transparency of color expressed as an 8-bit unsigned integer. - 0 to 255 (Default value is 255. This value is optional)

Returns 

This function returns the ARGB value in a format compatible for OSD use.

Example Code

NA

Note

“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.

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.

0 to 5 (Default value is 0)

Returns

NA

Example Code

NA

Note

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.

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.

0 to 5 (Default value is 0)

Returns

NA

Example Code

Example: RTSPFaceDetection

Note

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.

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.

0 to 5 (Default value is 0)

Returns

NA

Example Code

Example: MotionDetection/LoopPostProcessing

Note

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.

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.

0 to 5 (Default value is 0)

Returns

NA

Example Code

Example: MotionDetection/LoopPostProcessing

Note

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::drawPlus

Description

Draw “+” on OSD frame buffer.

Syntax

void drawPlus(int ch, int x_center, int y_center, int L, int line_width, uint32_t color, int idx = 0);

Parameters

ch: Channel to draw text on.

0
1
2

xmin: x coordinate of the center of the plus symbol.

ymin: y coordinate of the center of the plus symbol.

L: Length of each arm of the plus symbol.

line width: Thickness of the lines of the plus symbol.

color: Color of the text.

idx: Layer index of OSD.

0 to 5 (Default value is 0)

Returns

NA

Example Code

Example: MotionDetection/LoopPostProcessing

Note

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.

0
1
2

idx: Layer index of OSD.

0 to 5 (Default value is 0)

Returns

NA

Example Code

Example: MotionDetection/LoopPostProcessing

Note

“VideoStreamOverlay.h” must be included to use the class function.

VideoStreamOverlay::initOSDBitmapPos

Description

Set image position on video stream.

Syntax

void initOSDBitmapPos(osd_pict_st *bmp_info, int chn_id, uint32_t start_x, uint32_t start_y, uint32_t width, uint32_t height);

Parameters

bmp_info: Pointer to osd_pict_st structure which contains information about an OSD image.

chn_id: Channel used.

start_x: x-coordinate for the starting position of the image on the video stream.

start_y: y-coordinate for the starting position of the bitmap on the video stream.

width: Width of the image

height: Height of the image

Returns

NA

Example Code

NA

Note

“VideoStreamOverlay.h” must be included to use the class function.

VideoStreamOverlay::initOSDBitmapBlk

Description

Set block index of image on video stream.

Syntax

void initOSDBitmapBlk(osd_pict_st *bmp_info, int blk_idx, enum rts_osd2_blk_fmt blk_fmt, uint32_t clr_1bpp);

Parameters

bmp_info: Pointer to osd_pict_st structure which contains information about an OSD image.

blk_idx: Block index for each image (Valid value 0-23).

blk_fmt: Specifies the format of the block.

clr_1bpp: Set the RGB color when format is RTS_OSD2_BLK_FMT_1BP.

Returns

NA

Example Code

NA

Note

“VideoStreamOverlay.h” must be included to use the class function. Each image requires setting a new block index.

void initOSDBitmapBuf(osd_pict_st *bmp_info, uint8_t *buf, uint32_t buf_len);

Parameters

bmp_info: Pointer to osd_pict_st structure which contains information about an OSD image.

buf: pointer to a buffer containing the raw image data

buf_len: The length of buffer, specifying the size of the data buffer in bytes.

Returns

NA

Example Code

NA

Note

“VideoStreamOverlay.h” must be included to use the class function.

int resizeWidth(int pict_width, int pict_scaling_up_factor, int pict_scaling_down_factor);

Parameters

pict_width: The original width of the image.

pict_scaling_up_factor: The factor by which to scale up the width.

pict_scaling_down_factor: The factor by which to scale down the width.

Returns

This function returns the calculated resized width.

Example Code

Example: VideoOSDImage

Note

“VideoStreamOverlay.h” must be included to use the class function.

int resizeHeight(int pict_height, int pict_scaling_up_factor, int pict_scaling_down_factor);

Parameters

pict_height: The original height of the image.

pict_scaling_up_factor: The factor by which to scale up the height.

pict_scaling_down_factor: The factor by which to scale down the height.

Returns

This function returns the calculated resized height.

Example Code

Example: VideoOSDImage

Note

“VideoStreamOverlay.h” must be included to use the class function.

unsigned int heapsizeCal(int resize_width, int resize_height, rts_osd2_blk_fmt image_format);

Parameters

resize_width: The resized width of an image.

resize_height: The height width of an image.

image_format: The color format of an image.

Returns

This function returns the calculated heapsize as an unsigned int.

Example Code

Example: VideoOSDImage

Note

“VideoStreamOverlay.h” must be included to use the class function.

void drawImage(int ch, unsigned char *osd_array[], osd_pict_st pict_osd_buffer, unsigned int heapsize, void *pict_name, int pict_width, int pict_height, rts_osd2_blk_fmt pict_format, int resize_width, int resize_height, int start_x, int start_y, int pict_blk_idx)

Parameters

ch: Channel used to draw image on.

osd_array: A pointer array that use to hold overlay data for the image that will be drawn.

pict_osd_buffer: A structure contains metadata associated with the image.

heapsize: Calculated heap size necessary to store the image data.

pict_name: A pointer that reference a name or identifier for the image.

pict_width: Original width of image.

pict_height: Original height of image.

pict_format: Color format of image.

resize_width: Resized width of image.

resize_height: Resized height of image.

start_x: starting x coordinate on the video stream where the image should be displayed.

start_y: starting y coordinate on the video stream where the image should be displayed.

pict_blk_idx: Block index for the image. (Valid value: 0-23)

Returns

NA

Example Code

Example: VideoOSDImage

Note

“VideoStreamOverlay.h” must be included to use the class function.

void displayImage(int ch)

“VideoStreamOverlay.h” must be included to use the class function. Each image requires setting a new block index.