On-Screen Display API¶

group ee_nvosd_api_group

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

Defines

NVOSD_PRINT_E(f_, ...)¶

MAX_IN_BUF¶

MAX_BORDER_WIDTH¶

Typedefs

typedef void *NvOSDCtxHandle¶

typedef struct _NvOSD_FrameTextParams NvOSD_FrameTextParams¶: Holds information about the text in a frame.

typedef struct _NvOSD_FrameRectParams NvOSD_FrameRectParams¶: Holds information about the rectangles in a frame.

typedef struct _NvOSD_FrameSegmentMaskParams NvOSD_FrameSegmentMaskParams¶: Holds information about the rectangles in a frame.

typedef struct _NvOSD_FrameLineParams NvOSD_FrameLineParams¶: Holds information about the lines in a frame.

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.

Functions

NvOSDCtxHandle nvll_osd_create_context(void)¶

Creates an NvOSD context.

Return: 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.

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.

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.

Return

0 for success, or -1 for failure.

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.

int nvll_osd_draw_segment_masks(NvOSDCtxHandle nvosd_ctx, NvOSD_FrameSegmentMaskParams *frame_mask_params)¶

Overlays segment masks at a given location in a buffer.

You must ensure that the length of mask_params_list is at least num_segments.

Return

0 for success, -1 for failure.

Parameters

[in] nvosd_ctx: A handle for an NvOSD context.
[in] frame_mask_params: A pointer to the FrameSegmentMaskParams struct containing mask information to be overlayed.

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.

Return

0 for success, -1 for failure.

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.

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.

Return

0 if successful, or -1 otherwise.

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.

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.

Return

0 if successful, or -1 otherwise.

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.

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.

Return

0 if successful, or -1 otherwise.

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.

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.

Return

0 if successful, or -1 otherwise.

Parameters

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

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.

Return

A pointer to the internally allocated Host Memory.

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.

struct _NvOSD_FrameTextParams: #include <nvll_osd_api.h>
Holds information about the text in a frame.

struct _NvOSD_FrameRectParams: #include <nvll_osd_api.h>
Holds information about the rectangles in a frame.

struct _NvOSD_FrameSegmentMaskParams: #include <nvll_osd_api.h>
Holds information about the rectangles in a frame.

struct _NvOSD_FrameLineParams: #include <nvll_osd_api.h>
Holds information about the lines in a frame.

struct _NvOSD_FrameArrowParams: #include <nvll_osd_api.h>
Holds information about the arrows in a frame.

struct _NvOSD_FrameCircleParams: #include <nvll_osd_api.h>
Holds information about the circles in a frame.

Data Structures