Rectangles
[Video]

Data Structures
struct	gavl_rectangle_i_t
struct	gavl_rectangle_f_t
Functions
GAVL_PUBLIC void	gavl_rectangle_i_crop_to_format (gavl_rectangle_i_t *r, const gavl_video_format_t *format)
	Crop an integer rectangle so it fits into the image size of a video format.
GAVL_PUBLIC void	gavl_rectangle_f_crop_to_format (gavl_rectangle_f_t *r, const gavl_video_format_t *format)
	Crop a floating point rectangle so it fits into the image size of a video format.
GAVL_PUBLIC void	gavl_rectangle_crop_to_format_noscale (gavl_rectangle_i_t *src_rect, gavl_rectangle_i_t *dst_rect, const gavl_video_format_t *src_format, const gavl_video_format_t *dst_format)
	Set 2 rectangles as source and destination when no scaling is available.
GAVL_PUBLIC void	gavl_rectangle_crop_to_format_scale (gavl_rectangle_f_t *src_rect, gavl_rectangle_i_t *dst_rect, const gavl_video_format_t *src_format, const gavl_video_format_t *dst_format)
	Crop 2 rectangles to their formats when scaling is available.
GAVL_PUBLIC void	gavl_rectangle_i_set_all (gavl_rectangle_i_t *r, const gavl_video_format_t *format)
	Let an integer rectangle span the whole image size of a video format.
GAVL_PUBLIC void	gavl_rectangle_f_set_all (gavl_rectangle_f_t *r, const gavl_video_format_t *format)
	Let a float rectangle span the whole image size of a video format.
GAVL_PUBLIC void	gavl_rectangle_i_crop_left (gavl_rectangle_i_t *r, int num_pixels)
	Crop an integer rectangle by some pixels from the left border.
GAVL_PUBLIC void	gavl_rectangle_i_crop_right (gavl_rectangle_i_t *r, int num_pixels)
	Crop an integer rectangle by some pixels from the right border.
GAVL_PUBLIC void	gavl_rectangle_i_crop_top (gavl_rectangle_i_t *r, int num_pixels)
	Crop an integer rectangle by some pixels from the top border.
GAVL_PUBLIC void	gavl_rectangle_i_crop_bottom (gavl_rectangle_i_t *r, int num_pixels)
	Crop an integer rectangle by some pixels from the bottom border.
GAVL_PUBLIC void	gavl_rectangle_f_crop_left (gavl_rectangle_f_t *r, double num_pixels)
	Crop a float rectangle by some pixels from the left border.
GAVL_PUBLIC void	gavl_rectangle_f_crop_right (gavl_rectangle_f_t *r, double num_pixels)
	Crop a float rectangle by some pixels from the right border.
GAVL_PUBLIC void	gavl_rectangle_f_crop_top (gavl_rectangle_f_t *r, double num_pixels)
	Crop a float rectangle by some pixels from the top border.
GAVL_PUBLIC void	gavl_rectangle_f_crop_bottom (gavl_rectangle_f_t *r, double num_pixels)
	Crop a float rectangle by some pixels from the bottom border.
GAVL_PUBLIC void	gavl_rectangle_i_align (gavl_rectangle_i_t *r, int h_align, int v_align)
	Align a rectangle.
GAVL_PUBLIC void	gavl_rectangle_i_align_to_format (gavl_rectangle_i_t *r, const gavl_video_format_t *format)
	Align a rectangle to a format.
GAVL_PUBLIC void	gavl_rectangle_i_copy (gavl_rectangle_i_t *dst, const gavl_rectangle_i_t *src)
	Copy an integer rectangle.
GAVL_PUBLIC void	gavl_rectangle_f_copy (gavl_rectangle_f_t *dst, const gavl_rectangle_f_t *src)
	Copy a float rectangle.
GAVL_PUBLIC void	gavl_rectangle_i_to_f (gavl_rectangle_f_t *dst, const gavl_rectangle_i_t *src)
	Convert an integer rectangle to a floating point rectangle.
GAVL_PUBLIC void	gavl_rectangle_f_to_i (gavl_rectangle_i_t *dst, const gavl_rectangle_f_t *src)
	Convert a floating point rectangle to an integer rectangle.
GAVL_PUBLIC int	gavl_rectangle_i_is_empty (const gavl_rectangle_i_t *r)
	Check if an integer rectangle is empty.
GAVL_PUBLIC int	gavl_rectangle_f_is_empty (const gavl_rectangle_f_t *r)
	Check if a float rectangle is empty.
GAVL_PUBLIC void	gavl_rectangle_fit_aspect (gavl_rectangle_i_t *dst_rect, const gavl_video_format_t *src_format, const gavl_rectangle_f_t *src_rect, const gavl_video_format_t *dst_format, float zoom, float squeeze)
	Calculate a destination rectangle for scaling.
GAVL_PUBLIC void	gavl_rectangle_i_dump (const gavl_rectangle_i_t *r)
	Dump a rectangle to stderr.
GAVL_PUBLIC void	gavl_rectangle_f_dump (const gavl_rectangle_f_t *r)
	Dump a floating point rectangle to stderr.

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Detailed Description

Define rectangular areas in a video frame

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Function Documentation

GAVL_PUBLIC void gavl_rectangle_i_crop_to_format	(	gavl_rectangle_i_t *	r,
		const gavl_video_format_t *	format
	)

Crop an integer rectangle so it fits into the image size of a video format.

Parameters:

	r	An integer rectangle
	format	The video format into which the rectangle must fit

GAVL_PUBLIC void gavl_rectangle_f_crop_to_format	(	gavl_rectangle_f_t *	r,
		const gavl_video_format_t *	format
	)

Crop a floating point rectangle so it fits into the image size of a video format.

Parameters:

	r	A floating point rectangle
	format	The video format into which the rectangle must fit

GAVL_PUBLIC void gavl_rectangle_crop_to_format_noscale	(	gavl_rectangle_i_t *	src_rect,
		gavl_rectangle_i_t *	dst_rect,
		const gavl_video_format_t *	src_format,
		const gavl_video_format_t *	dst_format
	)

Set 2 rectangles as source and destination when no scaling is available.

Parameters:

	src_rect	Source rectangle
	dst_rect	Destination rectangle
	src_format	Source format
	dst_format	Destination format

This shrinks src_rect and dest_rect that neither is outside the image boundaries of the format. Both rectangles will have the same dimensions.

This function can be used for fitting a video image into a window for the case, that no scaling is available.

GAVL_PUBLIC void gavl_rectangle_crop_to_format_scale	(	gavl_rectangle_f_t *	src_rect,
		gavl_rectangle_i_t *	dst_rect,
		const gavl_video_format_t *	src_format,
		const gavl_video_format_t *	dst_format
	)

Crop 2 rectangles to their formats when scaling is available.

Parameters:

	src_rect	Source rectangle
	dst_rect	Destination rectangle
	src_format	Source format
	dst_format	Destination format

This shrinks src_rect and dest_rect that neither is outside the image boundaries of the format.

GAVL_PUBLIC void gavl_rectangle_i_set_all	(	gavl_rectangle_i_t *	r,
		const gavl_video_format_t *	format
	)

Let an integer rectangle span the whole image size of a video format.

Parameters:

	r	An integer rectangle
	format	The video format into which the rectangle must fit

GAVL_PUBLIC void gavl_rectangle_f_set_all	(	gavl_rectangle_f_t *	r,
		const gavl_video_format_t *	format
	)

Let a float rectangle span the whole image size of a video format.

Parameters:

	r	A float rectangle
	format	The video format into which the rectangle must fit

GAVL_PUBLIC void gavl_rectangle_i_crop_left	(	gavl_rectangle_i_t *	r,
		int	num_pixels
	)

Crop an integer rectangle by some pixels from the left border.

Parameters:

	r	An integer rectangle
	num_pixels	The number of pixels by which the rectangle gets smaller

GAVL_PUBLIC void gavl_rectangle_i_crop_right	(	gavl_rectangle_i_t *	r,
		int	num_pixels
	)

Crop an integer rectangle by some pixels from the right border.

Parameters:

	r	An integer rectangle
	num_pixels	The number of pixels by which the rectangle gets smaller

GAVL_PUBLIC void gavl_rectangle_i_crop_top	(	gavl_rectangle_i_t *	r,
		int	num_pixels
	)

Crop an integer rectangle by some pixels from the top border.

Parameters:

	r	An integer rectangle
	num_pixels	The number of pixels by which the rectangle gets smaller

GAVL_PUBLIC void gavl_rectangle_i_crop_bottom	(	gavl_rectangle_i_t *	r,
		int	num_pixels
	)

Crop an integer rectangle by some pixels from the bottom border.

Parameters:

	r	An integer rectangle
	num_pixels	The number of pixels by which the rectangle gets smaller

GAVL_PUBLIC void gavl_rectangle_f_crop_left	(	gavl_rectangle_f_t *	r,
		double	num_pixels
	)

Crop a float rectangle by some pixels from the left border.

Parameters:

	r	A float rectangle
	num_pixels	The number of pixels by which the rectangle gets smaller

GAVL_PUBLIC void gavl_rectangle_f_crop_right	(	gavl_rectangle_f_t *	r,
		double	num_pixels
	)

Crop a float rectangle by some pixels from the right border.

Parameters:

	r	A float rectangle
	num_pixels	The number of pixels by which the rectangle gets smaller

GAVL_PUBLIC void gavl_rectangle_f_crop_top	(	gavl_rectangle_f_t *	r,
		double	num_pixels
	)

Crop a float rectangle by some pixels from the top border.

Parameters:

	r	A float rectangle
	num_pixels	The number of pixels by which the rectangle gets smaller

GAVL_PUBLIC void gavl_rectangle_f_crop_bottom	(	gavl_rectangle_f_t *	r,
		double	num_pixels
	)

Crop a float rectangle by some pixels from the bottom border.

Parameters:

	r	A float rectangle
	num_pixels	The number of pixels by which the rectangle gets smaller

GAVL_PUBLIC void gavl_rectangle_i_align	(	gavl_rectangle_i_t *	r,
		int	h_align,
		int	v_align
	)

Align a rectangle.

Parameters:

	r	An integer rectangle
	h_align	Horizontal alignment
	v_align	Vertical alignment

This aligns a rectangle such that the horizontal and vertical coordinates are multiples of h_align and v_align respectively. When dealing with chroma subsampled formats, you must call this function with the return values of gavl_pixelformat_chroma_sub before taking subframes from video frames.

GAVL_PUBLIC void gavl_rectangle_i_align_to_format	(	gavl_rectangle_i_t *	r,
		const gavl_video_format_t *	format
	)

Align a rectangle to a format.

Parameters:

	r	An integer rectangle
	format	A video format

The convenience function does the same as gavl_rectangle_i_align but takes a format as argument.

GAVL_PUBLIC void gavl_rectangle_i_copy	(	gavl_rectangle_i_t *	dst,
		const gavl_rectangle_i_t *	src
	)

Copy an integer rectangle.

Parameters:

	dst	Destination rectangle
	src	Source rectangle

GAVL_PUBLIC void gavl_rectangle_f_copy	(	gavl_rectangle_f_t *	dst,
		const gavl_rectangle_f_t *	src
	)

Copy a float rectangle.

Parameters:

	dst	Destination rectangle
	src	Source rectangle

GAVL_PUBLIC void gavl_rectangle_i_to_f	(	gavl_rectangle_f_t *	dst,
		const gavl_rectangle_i_t *	src
	)

Convert an integer rectangle to a floating point rectangle.

Parameters:

	dst	Destination rectangle
	src	Source rectangle

GAVL_PUBLIC void gavl_rectangle_f_to_i	(	gavl_rectangle_i_t *	dst,
		const gavl_rectangle_f_t *	src
	)

Convert a floating point rectangle to an integer rectangle.

Parameters:

	dst	Destination rectangle
	src	Source rectangle

GAVL_PUBLIC int gavl_rectangle_i_is_empty

(

const gavl_rectangle_i_t *

r

)

Check if an integer rectangle is empty.

Parameters:

r

Rectangle

Returns:

1 if the rectangle is empty, 0 else.

A rectangle is considered to be empty if the width or height are <= 0.

GAVL_PUBLIC int gavl_rectangle_f_is_empty

(

const gavl_rectangle_f_t *

r

)

Check if a float rectangle is empty.

Parameters:

r

Rectangle

Returns:

1 if the rectangle is empty, 0 else.

A rectangle is considered to be empty if the width or height are <= 0.

GAVL_PUBLIC void gavl_rectangle_fit_aspect	(	gavl_rectangle_i_t *	dst_rect,
		const gavl_video_format_t *	src_format,
		const gavl_rectangle_f_t *	src_rect,
		const gavl_video_format_t *	dst_format,
		float	zoom,
		float	squeeze
	)

Calculate a destination rectangle for scaling.

Parameters:

	dst_rect	Destination rectangle
	src_format	Source format
	src_rect	Source rectangle
	dst_format	Destination format
	zoom	Zoom factor
	squeeze	Squeeze factor

Assuming we take src_rect from a frame in src_format, calculate the optimal dst_rect in dst_format. The source and destination display aspect ratio will be preserved unless it is changed with the squeeze parameter.

Zoom is a zoom factor (1.0 = 100 %). Squeeze is a value between -1.0 and 1.0, which changes the apsect ratio in both directions. 0.0 means unchanged.

Note that dst_rect might be outside the image dimensions of dst_format. If you don't like this, call gavl_rectangle_crop_to_format_scale afterwards.

Furthermore, the chroma subsampling is ignored by this function. If you you use the rectangles to fire up a gavl_video_scaler_t, this is no problem (the scaler will align the rectangles internally). You can align the destination rectangle manually using gavl_rectangle_i_align or gavl_rectangle_i_align_to_format.

GAVL_PUBLIC void gavl_rectangle_i_dump

(

const gavl_rectangle_i_t *

r

)

Dump a rectangle to stderr.

Parameters:

r

Rectangle

GAVL_PUBLIC void gavl_rectangle_f_dump

(

const gavl_rectangle_f_t *

r

)

Dump a floating point rectangle to stderr.

Parameters:

r

Floating point rectangle