Color conversion and scaling library. More...

Files
file	swscale.h
	external API header

Classes
struct	SwsVector

struct	SwsFilter

Macros
#define	SWS_FAST_BILINEAR 1

#define	SWS_BILINEAR 2

#define	SWS_BICUBIC 4

#define	SWS_X 8

#define	SWS_POINT 0x10

#define	SWS_AREA 0x20

#define	SWS_BICUBLIN 0x40

#define	SWS_GAUSS 0x80

#define	SWS_SINC 0x100

#define	SWS_LANCZOS 0x200

#define	SWS_SPLINE 0x400

#define	SWS_SRC_V_CHR_DROP_MASK 0x30000

#define	SWS_SRC_V_CHR_DROP_SHIFT 16

#define	SWS_PARAM_DEFAULT 123456

#define	SWS_PRINT_INFO 0x1000

#define	SWS_FULL_CHR_H_INT 0x2000

#define	SWS_FULL_CHR_H_INP 0x4000

#define	SWS_DIRECT_BGR 0x8000

#define	SWS_ACCURATE_RND 0x40000

#define	SWS_BITEXACT 0x80000

#define	SWS_ERROR_DIFFUSION 0x800000

#define	SWS_MAX_REDUCE_CUTOFF 0.002

#define	SWS_CS_ITU709 1

#define	SWS_CS_FCC 4

#define	SWS_CS_ITU601 5

#define	SWS_CS_ITU624 5

#define	SWS_CS_SMPTE170M 5

#define	SWS_CS_SMPTE240M 7

#define	SWS_CS_DEFAULT 5

#define	SWS_CS_BT2020 9

Typedefs
typedef struct SwsVector	SwsVector

typedef struct SwsFilter	SwsFilter

Functions
unsigned	swscale_version (void)

const char *	swscale_configuration (void)
	Return the libswscale build-time configuration.

const char *	swscale_license (void)
	Return the libswscale license.

const int *	sws_getCoefficients (int colorspace)
	Return a pointer to yuv<->rgb coefficients for the given colorspace suitable for sws_setColorspaceDetails(). More...

int	sws_isSupportedInput (enum AVPixelFormat pix_fmt)
	Return a positive value if pix_fmt is a supported input format, 0 otherwise.

int	sws_isSupportedOutput (enum AVPixelFormat pix_fmt)
	Return a positive value if pix_fmt is a supported output format, 0 otherwise.

int	sws_isSupportedEndiannessConversion (enum AVPixelFormat pix_fmt)

struct SwsContext *	sws_alloc_context (void)
	Allocate an empty SwsContext. More...

av_warn_unused_result int	sws_init_context (struct SwsContext sws_context, SwsFilter srcFilter, SwsFilter *dstFilter)
	Initialize the swscaler context sws_context. More...

void	sws_freeContext (struct SwsContext *swsContext)
	Free the swscaler context swsContext. More...

struct SwsContext *	sws_getContext (int srcW, int srcH, enum AVPixelFormat srcFormat, int dstW, int dstH, enum AVPixelFormat dstFormat, int flags, SwsFilter srcFilter, SwsFilter dstFilter, const double *param)
	Allocate and return an SwsContext. More...

int	sws_scale (struct SwsContext c, const uint8_t const srcSlice[], const int srcStride[], int srcSliceY, int srcSliceH, uint8_t *const dst[], const int dstStride[])
	Scale the image slice in srcSlice and put the resulting scaled slice in the image in dst. More...

int	sws_setColorspaceDetails (struct SwsContext *c, const int inv_table[4], int srcRange, const int table[4], int dstRange, int brightness, int contrast, int saturation)

int	sws_getColorspaceDetails (struct SwsContext c, int inv_table, int srcRange, int *table, int dstRange, int brightness, int contrast, int *saturation)

SwsVector *	sws_allocVec (int length)
	Allocate and return an uninitialized vector with length coefficients.

SwsVector *	sws_getGaussianVec (double variance, double quality)
	Return a normalized Gaussian curve used to filter stuff quality = 3 is high quality, lower is lower quality.

void	sws_scaleVec (SwsVector *a, double scalar)
	Scale all the coefficients of a by the scalar value.

void	sws_normalizeVec (SwsVector *a, double height)
	Scale all the coefficients of a so that their sum equals height.

attribute_deprecated SwsVector *	sws_getConstVec (double c, int length)
	Allocate and return a vector with length coefficients, all with the same value c.

attribute_deprecated SwsVector *	sws_getIdentityVec (void)
	Allocate and return a vector with just one coefficient, with value 1.0.

attribute_deprecated void	sws_convVec (SwsVector a, SwsVector b)

attribute_deprecated void	sws_addVec (SwsVector a, SwsVector b)

attribute_deprecated void	sws_subVec (SwsVector a, SwsVector b)

attribute_deprecated void	sws_shiftVec (SwsVector *a, int shift)

attribute_deprecated SwsVector *	sws_cloneVec (SwsVector *a)

attribute_deprecated void	sws_printVec2 (SwsVector a, AVClass log_ctx, int log_level)
	Print with av_log() a textual representation of the vector a if log_level <= av_log_level.

void	sws_freeVec (SwsVector *a)

SwsFilter *	sws_getDefaultFilter (float lumaGBlur, float chromaGBlur, float lumaSharpen, float chromaSharpen, float chromaHShift, float chromaVShift, int verbose)

void	sws_freeFilter (SwsFilter *filter)

struct SwsContext *	sws_getCachedContext (struct SwsContext context, int srcW, int srcH, enum AVPixelFormat srcFormat, int dstW, int dstH, enum AVPixelFormat dstFormat, int flags, SwsFilter srcFilter, SwsFilter dstFilter, const double param)
	Check if context can be reused, otherwise reallocate a new one. More...

void	sws_convertPalette8ToPacked32 (const uint8_t src, uint8_t dst, int num_pixels, const uint8_t *palette)
	Convert an 8-bit paletted frame into a frame with a color depth of 32 bits. More...

void	sws_convertPalette8ToPacked24 (const uint8_t src, uint8_t dst, int num_pixels, const uint8_t *palette)
	Convert an 8-bit paletted frame into a frame with a color depth of 24 bits. More...

const AVClass *	sws_get_class (void)
	Get the AVClass for swsContext. More...

Detailed Description

Color conversion and scaling library.

Return the LIBSWSCALE_VERSION_INT constant.

Function Documentation

§ sws_alloc_context()

struct SwsContext* sws_alloc_context ( void )

Allocate an empty SwsContext.

This must be filled and passed to sws_init_context(). For filling see AVOptions, options.c and sws_setColorspaceDetails().

§ sws_convertPalette8ToPacked24()

void sws_convertPalette8ToPacked24	(	const uint8_t *	src,
		uint8_t *	dst,
		int	num_pixels,
		const uint8_t *	palette
	)

Convert an 8-bit paletted frame into a frame with a color depth of 24 bits.

With the palette format "ABCD", the destination frame ends up with the format "ABC".

Parameters

src	source frame buffer
dst	destination frame buffer
num_pixels	number of pixels to convert
palette	array with [256] entries, which must match color arrangement (RGB or BGR) of src

§ sws_convertPalette8ToPacked32()

void sws_convertPalette8ToPacked32	(	const uint8_t *	src,
		uint8_t *	dst,
		int	num_pixels,
		const uint8_t *	palette
	)

Convert an 8-bit paletted frame into a frame with a color depth of 32 bits.

The output frame will have the same packed format as the palette.

Parameters

src	source frame buffer
dst	destination frame buffer
num_pixels	number of pixels to convert
palette	array with [256] entries, which must match color arrangement (RGB or BGR) of src

§ sws_freeContext()

void sws_freeContext ( struct SwsContext * swsContext )

Free the swscaler context swsContext.

If swsContext is NULL, then does nothing.

§ sws_get_class()

const AVClass* sws_get_class ( void )

Get the AVClass for swsContext.

It can be used in combination with AV_OPT_SEARCH_FAKE_OBJ for examining options.

See also: av_opt_find().

§ sws_getCachedContext()

struct SwsContext* sws_getCachedContext	(	struct SwsContext *	context,
		int	srcW,
		int	srcH,
		enum AVPixelFormat	srcFormat,
		int	dstW,
		int	dstH,
		enum AVPixelFormat	dstFormat,
		int	flags,
		SwsFilter *	srcFilter,
		SwsFilter *	dstFilter,
		const double *	param
	)

Check if context can be reused, otherwise reallocate a new one.

If context is NULL, just calls sws_getContext() to get a new context. Otherwise, checks if the parameters are the ones already saved in context. If that is the case, returns the current context. Otherwise, frees context and gets a new context with the new parameters.

Be warned that srcFilter and dstFilter are not checked, they are assumed to remain the same.

§ sws_getCoefficients()

const int* sws_getCoefficients ( int colorspace )

Return a pointer to yuv<->rgb coefficients for the given colorspace suitable for sws_setColorspaceDetails().

Parameters

colorspace One of the SWS_CS_* macros. If invalid, SWS_CS_DEFAULT is used.

§ sws_getColorspaceDetails()

int sws_getColorspaceDetails	(	struct SwsContext *	c,
		int **	inv_table,
		int *	srcRange,
		int **	table,
		int *	dstRange,
		int *	brightness,
		int *	contrast,
		int *	saturation
	)

Returns: -1 if not supported

§ sws_getContext()

struct SwsContext* sws_getContext	(	int	srcW,
		int	srcH,
		enum AVPixelFormat	srcFormat,
		int	dstW,
		int	dstH,
		enum AVPixelFormat	dstFormat,
		int	flags,
		SwsFilter *	srcFilter,
		SwsFilter *	dstFilter,
		const double *	param
	)

Allocate and return an SwsContext.

You need it to perform scaling/conversion operations using sws_scale().

Parameters

srcW	the width of the source image
srcH	the height of the source image
srcFormat	the source image format
dstW	the width of the destination image
dstH	the height of the destination image
dstFormat	the destination image format
flags	specify which algorithm and options to use for rescaling
param	extra parameters to tune the used scaler For SWS_BICUBIC param[0] and [1] tune the shape of the basis function, param[0] tunes f(1) and param[1] f´(1) For SWS_GAUSS param[0] tunes the exponent and thus cutoff frequency For SWS_LANCZOS param[0] tunes the width of the window function

Returns: a pointer to an allocated context, or NULL in case of error

Note: this function is to be removed after a saner alternative is written

§ sws_init_context()

av_warn_unused_result int sws_init_context	(	struct SwsContext *	sws_context,
		SwsFilter *	srcFilter,
		SwsFilter *	dstFilter
	)

Initialize the swscaler context sws_context.

Returns: zero or positive value on success, a negative value on error

§ sws_isSupportedEndiannessConversion()

int sws_isSupportedEndiannessConversion ( enum AVPixelFormat pix_fmt )

Parameters

[in] pix_fmt the pixel format

Returns: a positive value if an endianness conversion for pix_fmt is supported, 0 otherwise.

§ sws_scale()

int sws_scale	(	struct SwsContext *	c,
		const uint8_t *const	srcSlice[],
		const int	srcStride[],
		int	srcSliceY,
		int	srcSliceH,
		uint8_t *const	dst[],
		const int	dstStride[]
	)

Scale the image slice in srcSlice and put the resulting scaled slice in the image in dst.

A slice is a sequence of consecutive rows in an image.

Slices have to be provided in sequential order, either in top-bottom or bottom-top order. If slices are provided in non-sequential order the behavior of the function is undefined.

Parameters

c	the scaling context previously created with sws_getContext()
srcSlice	the array containing the pointers to the planes of the source slice
srcStride	the array containing the strides for each plane of the source image
srcSliceY	the position in the source image of the slice to process, that is the number (counted starting from zero) in the image of the first row of the slice
srcSliceH	the height of the source slice, that is the number of rows in the slice
dst	the array containing the pointers to the planes of the destination image
dstStride	the array containing the strides for each plane of the destination image

Returns: the height of the output slice

Scale the image slice in srcSlice and put the resulting scaled slice in the image in dst.

Assumes planar YUV to be in YUV order instead of YVU.

§ sws_setColorspaceDetails()

int sws_setColorspaceDetails	(	struct SwsContext *	c,
		const int	inv_table[4],
		int	srcRange,
		const int	table[4],
		int	dstRange,
		int	brightness,
		int	contrast,
		int	saturation
	)

Parameters

dstRange	flag indicating the while-black range of the output (1=jpeg / 0=mpeg)
srcRange	flag indicating the while-black range of the input (1=jpeg / 0=mpeg)
table	the yuv2rgb coefficients describing the output yuv space, normally ff_yuv2rgb_coeffs[x]
inv_table	the yuv2rgb coefficients describing the input yuv space, normally ff_yuv2rgb_coeffs[x]
brightness	16.16 fixed point brightness correction
contrast	16.16 fixed point contrast correction
saturation	16.16 fixed point saturation correction

Returns: -1 if not supported

Files

Classes

Macros

Typedefs

Functions

Detailed Description

Function Documentation

§ sws_alloc_context()

§ sws_convertPalette8ToPacked24()

§ sws_convertPalette8ToPacked32()

§ sws_freeContext()

§ sws_get_class()

§ sws_getCachedContext()

§ sws_getCoefficients()

§ sws_getColorspaceDetails()

§ sws_getContext()

§ sws_init_context()

§ sws_isSupportedEndiannessConversion()

§ sws_scale()

§ sws_setColorspaceDetails()