On-Screen Display API

Detailed Description

Defines the NvOSD library to be used to draw rectangles and text over the frame.

Data Structures
struct	_NvOSD_FrameTextParams
	Holds information about the text in a frame. More...
struct	_NvOSD_FrameRectParams
	Holds information about the rectangles in a frame. More...
struct	_NvOSD_FrameLineParams
	Holds information about the lines in a frame. More...
struct	_NvOSD_FrameArrowParams
	Holds information about the arrows in a frame. More...
struct	_NvOSD_FrameCircleParams
	Holds information about the circles in a frame. More...

Macros
#define	NVOSD_PRINT_E(f_,...)   printf("libnvosd (%d):(ERROR) : " f_, __LINE__, ##__VA_ARGS__)
#define	MAX_IN_BUF   16
#define	MAX_BORDER_WIDTH   32

Typedefs
typedef void *	NvOSDCtxHandle
typedef struct _NvOSD_FrameTextParams	NvOSD_FrameTextParams
	Holds information about the text in a frame. More...
typedef struct _NvOSD_FrameRectParams	NvOSD_FrameRectParams
	Holds information about the rectangles in a frame. More...
typedef struct _NvOSD_FrameLineParams	NvOSD_FrameLineParams
	Holds information about the lines in a frame. More...
typedef struct _NvOSD_FrameArrowParams	NvOSD_FrameArrowParams
	Holds information about the arrows in a frame. More...
typedef struct _NvOSD_FrameCircleParams	NvOSD_FrameCircleParams
	Holds information about the circles in a frame. More...

Functions
NvOSDCtxHandle	nvll_osd_create_context (void)
	Creates an NvOSD context. More...
void	nvll_osd_destroy_context (NvOSDCtxHandle nvosd_ctx)
	Destroys an NvOSD context. More...
void	nvll_osd_set_clock_params (NvOSDCtxHandle nvosd_ctx, NvOSD_TextParams *clk_params)
	Sets clock parameters for a given context. More...
int	nvll_osd_put_text (NvOSDCtxHandle nvosd_ctx, NvOSD_FrameTextParams *frame_text_params)
	/brief Overlays clock and given text at a given location in a buffer. More...
int	nvll_osd_draw_rectangles (NvOSDCtxHandle nvosd_ctx, NvOSD_FrameRectParams *frame_rect_params)
	Overlays boxes at a given location in a buffer. More...
int	nvll_osd_draw_lines (NvOSDCtxHandle nvosd_ctx, NvOSD_FrameLineParams *frame_line_params)
	Overlays lines on the buffer. More...
int	nvll_osd_draw_arrows (NvOSDCtxHandle nvosd_ctx, NvOSD_FrameArrowParams *frame_arrow_params)
	Overlays arrows on the buffer. More...
int	nvll_osd_draw_circles (NvOSDCtxHandle nvosd_ctx, NvOSD_FrameCircleParams *frame_circle_params)
	Overlays circles on the buffer. More...
void *	nvll_osd_set_params (NvOSDCtxHandle nvosd_ctx, int width, int height)
	Sets the resolution of the frames on which the NvOSDContext is to operate. More...
int	nvll_osd_init_colors_for_hw_blend (void *nvosd_ctx, NvOSD_Color_info *color_info, int num_classes)
	Initializes colors for HW based blending. More...

Macro Definition Documentation

#define MAX_BORDER_WIDTH   32

Definition at line 56 of file nvll_osd_api.h.

#define MAX_IN_BUF   16

Definition at line 55 of file nvll_osd_api.h.

#define NVOSD_PRINT_E	(		f_,
			...
	)		printf("libnvosd (%d):(ERROR) : " f_, __LINE__, ##__VA_ARGS__)

Definition at line 52 of file nvll_osd_api.h.

Typedef Documentation

typedef struct _NvOSD_FrameArrowParams NvOSD_FrameArrowParams

Holds information about the arrows in a frame.

typedef struct _NvOSD_FrameCircleParams NvOSD_FrameCircleParams

Holds information about the circles in a frame.

typedef struct _NvOSD_FrameLineParams NvOSD_FrameLineParams

Holds information about the lines in a frame.

typedef struct _NvOSD_FrameRectParams NvOSD_FrameRectParams

Holds information about the rectangles in a frame.

typedef struct _NvOSD_FrameTextParams NvOSD_FrameTextParams

Holds information about the text in a frame.

typedef void* NvOSDCtxHandle

Definition at line 63 of file nvll_osd_api.h.

Function Documentation

NvOSDCtxHandle nvll_osd_create_context

(

void

)

Creates an NvOSD context.

Returns

A handle for an NvOSD context if successful, or NULL otherwise.

void nvll_osd_destroy_context

(

NvOSDCtxHandle

nvosd_ctx

)

Destroys an NvOSD context.

Parameters

[in]

nvosd_ctx

A handle for the NvOSD context to be destroyed.

int nvll_osd_draw_arrows	(	NvOSDCtxHandle	nvosd_ctx,
		NvOSD_FrameArrowParams *	frame_arrow_params
	)

Overlays arrows on the buffer.

The length of arrow_params_list must equal num_arrows. The client is responsible for allocating this array.

Note

Currently only MODE_CPU is supported. Specifying other modes has no effect.

Parameters

[in]	nvosd_ctx	A handle for an NvOSD context.
[in]	frame_arrow_params	A pointer to the FrameArrowParams struct containing arrow information to be overlayed.

Returns

0 if successful, or -1 otherwise.

int nvll_osd_draw_circles	(	NvOSDCtxHandle	nvosd_ctx,
		NvOSD_FrameCircleParams *	frame_circle_params
	)

Overlays circles on the buffer.

You must ensure that the length of circle_params_list equals num_circles.

Note

Currently only MODE_CPU is supported. Specifying other modes has no effect.

Parameters

[in]	nvosd_ctx	A handle for an NvOSD context.
[in]	frame_circle_params	A pointer to the FrameCircleParams struct containing circle information to be overlayed.

Returns

0 if successful, or -1 otherwise.

int nvll_osd_draw_lines	(	NvOSDCtxHandle	nvosd_ctx,
		NvOSD_FrameLineParams *	frame_line_params
	)

Overlays lines on the buffer.

The length of line_params_list must be equal to num_lines. The client is responsible for allocating this array.

Note

Currently only MODE_CPU is supported. Specifying other modes will have no effect.

Parameters

[in]	nvosd_ctx	A handle for an NvOSD context.
[in]	frame_line_params	A pointer to the FrameLineParams struct containing line information to be overlayed.

Returns

0 if successful, or -1 otherwise.

int nvll_osd_draw_rectangles	(	NvOSDCtxHandle	nvosd_ctx,
		NvOSD_FrameRectParams *	frame_rect_params
	)

Overlays boxes at a given location in a buffer.

Boxes can be configured with: a. Border only: Uou must set border_width and set has_bg_color to 0 for the given box. b. Border and background color To draw boxes with border and background color, you must set border_width and set has_bg_color to 1, and specify background color parameters for the given box. c. Solid fill acting as mask region To draw boxes with solid fill acting as mask region, you must set border_width to 0 and has_bg_color to 1 for the given box.

You must ensure that the length of rect_params_list is at least num_rects.

Parameters

[in]	nvosd_ctx	A handle for an NvOSD context.
[in]	frame_rect_params	A pointer to the FrameRectParams struct containing rectangles information to be overlayed.

Returns

0 for success, -1 for failure.

int nvll_osd_init_colors_for_hw_blend	(	void *	nvosd_ctx,
		NvOSD_Color_info *	color_info,
		int	num_classes
	)

Initializes colors for HW based blending.

Applicable ONLY for Jetson.

Parameters

[in]	nvosd_ctx	A pointer to NvOSD context.
[in]	color_info	A pointer to the Color_info struct containing color information.
[in]	num_classes	Number of classes.

Returns

A pointer to the internally allocated Host Memory.

int nvll_osd_put_text	(	NvOSDCtxHandle	nvosd_ctx,
		NvOSD_FrameTextParams *	frame_text_params
	)

/brief Overlays clock and given text at a given location in a buffer.

To overlay the clock, you must call nvll_osd_set_clock_params(). You must also ensure that the length of text_params_list is at least NvOSD_FrameTextParams::num_strings.

Note

Currently only the NvOSD_Mode value MODE_CPU is supported. Specifying other modes has no effect.

Parameters

[in]	nvosd_ctx	A handle for an NvOSD context.
[in]	frame_text_params	A pointer to a structure containing information about rectangles to be overlayed.

Returns

0 for success, or -1 for failure.

void nvll_osd_set_clock_params	(	NvOSDCtxHandle	nvosd_ctx,
		NvOSD_TextParams *	clk_params
	)

Sets clock parameters for a given context.

The clock is overlayed when nvll_osd_put_text() is called. If no other text is to be overlayed, nvll_osd_put_text() must be called with num_strings as 0 and text_params_list as NULL.

Parameters

[in]	nvosd_ctx	A handle for an NvOSD context.
[in]	clk_params	A pointer to a structure for the clock to be overlayed; NULL to disable the clock.

void* nvll_osd_set_params	(	NvOSDCtxHandle	nvosd_ctx,
		int	width,
		int	height
	)

Sets the resolution of the frames on which the NvOSDContext is to operate.

Parameters

[in]	nvosd_ctx	A handle for the NvOSD context.
[in]	width	Width of the input frames.
[in]	height	Height of the input frames.

Returns

0 if successful, or -1 otherwise.