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
struct	_NvOSD_FrameRectParams
struct	_NvOSD_FrameLineParams

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 struct _NvOSD_FrameTextParams	NvOSD_FrameTextParams
typedef struct _NvOSD_FrameRectParams	NvOSD_FrameRectParams
typedef struct _NvOSD_FrameLineParams	NvOSD_FrameLineParams

Functions
void *	nvll_osd_create_context (void)
	Creates an NvOSD context. More...
void	nvll_osd_destroy_context (void *nvosd_ctx)
	Destroys an NvOSD context. More...
void	nvll_osd_set_clock_params (void *nvosd_ctx, NvOSD_TextParams *clk_params)
	Sets clock parameters for the given context. More...
int	nvll_osd_put_text (void *nvosd_ctx, NvOSD_FrameTextParams *frame_text_params)
	Overlays clock and given text at given location on a buffer. More...
int	nvll_osd_draw_rectangles (void *nvosd_ctx, NvOSD_FrameRectParams *frame_rect_params)
	Overlays boxes at given location on a buffer. More...
int	nvll_osd_draw_lines (void *nvosd_ctx, NvOSD_FrameLineParams *frame_line_params)
	Overlays lines on the buffer. More...
void *	nvll_osd_set_params (void *nvosd_ctx, int width, int height)
	Sets the resolution of the frames on which the NvOSDContext will operate. 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_FrameLineParams NvOSD_FrameLineParams

typedef struct _NvOSD_FrameRectParams NvOSD_FrameRectParams

typedef struct _NvOSD_FrameTextParams NvOSD_FrameTextParams

Function Documentation

void* nvll_osd_create_context

(

void

)

Creates an NvOSD context.

Returns

A pointer to NvOSD context, NULL in case of failure.

void nvll_osd_destroy_context

(

void *

nvosd_ctx

)

Destroys an NvOSD context.

Parameters

[in]

nvosd_ctx

A pointer to NvOSD context.

int nvll_osd_draw_lines	(	void *	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 pointer to NvOSD context.
[in]	frame_line_params	A pointer to the FrameLineParams struct containing line information to be overlayed.

Returns

0 for success, -1 for failure.

int nvll_osd_draw_rectangles	(	void *	nvosd_ctx,
		NvOSD_FrameRectParams *	frame_rect_params
	)

Overlays boxes at given location on a buffer.

Boxes can be configured with: a. Only border To draw boxes with only border, you 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 pointer to 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_put_text	(	void *	nvosd_ctx,
		NvOSD_FrameTextParams *	frame_text_params
	)

Overlays clock and given text at given location on a buffer.

To overlay the clock, you must set clock params using nvll_osd_set_clock_params(). Additionally, you must ensure that the length of text_params_list is at least num_strings.

Note

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

Parameters

[in]	nvosd_ctx	A pointer to NvOSD context.
[in]	frame_text_params	A pointer to the FrameTextParams struct containing rectangles information to be overlayed

Returns

0 for success, -1 for failure.

void nvll_osd_set_clock_params	(	void *	nvosd_ctx,
		NvOSD_TextParams *	clk_params
	)

Sets clock parameters for the 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 pointer to NvOSD context.
[in]	clk_params	A pointer to NvOSD_TextParams structure for the clock to be overlayed; NULL to disable the clock.

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

Sets the resolution of the frames on which the NvOSDContext will operate.

Parameters

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

Returns

0 for success, -1 for failure.