Libswscale

Files
file	swscale.h
	external API header

Data Structures
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_CPU_CAPS_MMX   0x80000000
	CPU caps are autodetected now, those flags are only provided for API compatibility.
#define	SWS_CPU_CAPS_MMXEXT   0x20000000
#define	SWS_CPU_CAPS_MMX2   0x20000000
#define	SWS_CPU_CAPS_3DNOW   0x40000000
#define	SWS_CPU_CAPS_ALTIVEC   0x10000000
#define	SWS_CPU_CAPS_BFIN   0x01000000
#define	SWS_CPU_CAPS_SSE2   0x02000000
#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

Functions
unsigned	swscale_version (void)
	Return the LIBSWSCALE_VERSION_INT constant.
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().
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.
struct SwsContext *	sws_alloc_context (void)
	Allocate an empty SwsContext.
int	sws_init_context (struct SwsContext *sws_context, SwsFilter *srcFilter, SwsFilter *dstFilter)
	Initialize the swscaler context sws_context.
void	sws_freeContext (struct SwsContext *swsContext)
	Free the swscaler context swsContext.
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.
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.
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.
SwsVector *	sws_getConstVec (double c, int length)
	Allocate and return a vector with length coefficients, all with the same value c.
SwsVector *	sws_getIdentityVec (void)
	Allocate and return a vector with just one coefficient, with value 1.0.
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.
void	sws_convVec (SwsVector *a, SwsVector *b)
void	sws_addVec (SwsVector *a, SwsVector *b)
void	sws_subVec (SwsVector *a, SwsVector *b)
void	sws_shiftVec (SwsVector *a, int shift)
SwsVector *	sws_cloneVec (SwsVector *a)
	Allocate and return a clone of the vector a, that is a vector with the same coefficients as a.
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.
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.
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.
const AVClass *	sws_get_class (void)
	Get the AVClass for swsContext.

Detailed Description

Macro Definition Documentation

#define SWS_FAST_BILINEAR   1

Definition at line 58 of file swscale.h.

Referenced by ff_get_unscaled_swscale(), ff_sws_getFlagsAndFilterFromCmdLine(), initFilter(), selfTest(), sws_init_context(), sws_init_swScale_c(), and sws_init_swScale_TMPL().

#define SWS_BILINEAR   2

Examples:

doc/examples/scaling_video.c.

Definition at line 59 of file swscale.h.

Referenced by configure_input_video_filter(), doTest(), ff_scale_image(), ff_sws_getFlagsAndFilterFromCmdLine(), init(), initFilter(), main(), selfTest(), and sws_init_context().

#define SWS_BICUBIC   4

Examples:

doc/examples/muxing.c.

Definition at line 60 of file swscale.h.

Referenced by ff_sws_getFlagsAndFilterFromCmdLine(), init(), init_opts(), initFilter(), selfTest(), and sws_init_context().

#define SWS_X   8

Definition at line 61 of file swscale.h.

Referenced by ff_sws_getFlagsAndFilterFromCmdLine(), initFilter(), selfTest(), and sws_init_context().

#define SWS_POINT   0x10

Definition at line 62 of file swscale.h.

Referenced by allocStuff(), ff_get_unscaled_swscale(), ff_sws_getFlagsAndFilterFromCmdLine(), initFilter(), selfTest(), and sws_init_context().

#define SWS_AREA   0x20

Definition at line 63 of file swscale.h.

Referenced by ff_sws_getFlagsAndFilterFromCmdLine(), initFilter(), selfTest(), and sws_init_context().

#define SWS_BICUBLIN   0x40

Definition at line 64 of file swscale.h.

Referenced by ff_sws_getFlagsAndFilterFromCmdLine(), and sws_init_context().

#define SWS_GAUSS   0x80

Definition at line 65 of file swscale.h.

Referenced by ff_sws_getFlagsAndFilterFromCmdLine(), initFilter(), and sws_init_context().

#define SWS_SINC   0x100

Definition at line 66 of file swscale.h.

Referenced by ff_sws_getFlagsAndFilterFromCmdLine(), initFilter(), and sws_init_context().

#define SWS_LANCZOS   0x200

Definition at line 67 of file swscale.h.

Referenced by ff_sws_getFlagsAndFilterFromCmdLine(), initFilter(), and sws_init_context().

#define SWS_SPLINE   0x400

Definition at line 68 of file swscale.h.

Referenced by ff_sws_getFlagsAndFilterFromCmdLine(), initFilter(), and sws_init_context().

#define SWS_SRC_V_CHR_DROP_MASK   0x30000

Definition at line 70 of file swscale.h.

Referenced by sws_init_context().

#define SWS_SRC_V_CHR_DROP_SHIFT   16

Definition at line 71 of file swscale.h.

Referenced by sws_init_context().

#define SWS_PARAM_DEFAULT   123456

Definition at line 73 of file swscale.h.

Referenced by initFilter(), and sws_getCachedContext().

#define SWS_PRINT_INFO   0x1000

Definition at line 75 of file swscale.h.

Referenced by ff_sws_getFlagsAndFilterFromCmdLine(), initFilter(), sws_init_context(), and swScale().

#define SWS_FULL_CHR_H_INT   0x2000

Definition at line 79 of file swscale.h.

Referenced by ff_sws_init_output_funcs(), ff_sws_init_swScale_altivec(), sws_init_context(), and sws_init_swScale_TMPL().

#define SWS_FULL_CHR_H_INP   0x4000

Definition at line 81 of file swscale.h.

Referenced by sws_init_context().

#define SWS_DIRECT_BGR   0x8000

Definition at line 82 of file swscale.h.

#define SWS_ACCURATE_RND   0x40000

Definition at line 83 of file swscale.h.

Referenced by ff_get_unscaled_swscale(), initFilter(), and sws_init_swScale_TMPL().

#define SWS_BITEXACT   0x80000

Definition at line 84 of file swscale.h.

Referenced by configure_input_video_filter(), ff_get_unscaled_swscale(), ff_sws_init_swScale_altivec(), ff_swscale_get_unscaled_altivec(), initFilter(), sws_init_swScale_TMPL(), and sws_scale().

#define SWS_ERROR_DIFFUSION   0x800000

Definition at line 85 of file swscale.h.

Referenced by ff_get_unscaled_swscale(), sws_init_context(), sws_scale(), yuv2mono_1_c_template(), yuv2mono_2_c_template(), and yuv2mono_X_c_template().

#define SWS_CPU_CAPS_MMX   0x80000000

CPU caps are autodetected now, those flags are only provided for API compatibility.

Definition at line 92 of file swscale.h.

#define SWS_CPU_CAPS_MMXEXT   0x20000000

Definition at line 93 of file swscale.h.

#define SWS_CPU_CAPS_MMX2   0x20000000

Definition at line 94 of file swscale.h.

#define SWS_CPU_CAPS_3DNOW   0x40000000

Definition at line 95 of file swscale.h.

#define SWS_CPU_CAPS_ALTIVEC   0x10000000

Definition at line 96 of file swscale.h.

#define SWS_CPU_CAPS_BFIN   0x01000000

Definition at line 97 of file swscale.h.

#define SWS_CPU_CAPS_SSE2   0x02000000

Definition at line 98 of file swscale.h.

#define SWS_MAX_REDUCE_CUTOFF   0.002

Definition at line 101 of file swscale.h.

Referenced by initFilter().

#define SWS_CS_ITU709   1

Definition at line 103 of file swscale.h.

#define SWS_CS_FCC   4

Definition at line 104 of file swscale.h.

#define SWS_CS_ITU601   5

Definition at line 105 of file swscale.h.

#define SWS_CS_ITU624   5

Definition at line 106 of file swscale.h.

#define SWS_CS_SMPTE170M   5

Definition at line 107 of file swscale.h.

#define SWS_CS_SMPTE240M   7

Definition at line 108 of file swscale.h.

#define SWS_CS_DEFAULT   5

Definition at line 109 of file swscale.h.

Referenced by sws_getCachedContext(), sws_getCoefficients(), and sws_getContext().

Function Documentation

unsigned swscale_version

(

void

)

Return the LIBSWSCALE_VERSION_INT constant.

Definition at line 55 of file utils.c.

const char* swscale_configuration

(

void

)

Return the libswscale build-time configuration.

Definition at line 61 of file utils.c.

const char* swscale_license

(

void

)

Return the libswscale license.

Definition at line 66 of file utils.c.

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.

Definition at line 56 of file yuv2rgb.c.

int sws_isSupportedInput

(

enum AVPixelFormat

pix_fmt

)

Return a positive value if pix_fmt is a supported input format, 0 otherwise.

Definition at line 201 of file utils.c.

int sws_isSupportedOutput

(

enum AVPixelFormat

pix_fmt

)

Return a positive value if pix_fmt is a supported output format, 0 otherwise.

Definition at line 207 of file utils.c.

struct SwsContext* sws_alloc_context ( void  )

read

Allocate an empty SwsContext.

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

Definition at line 887 of file utils.c.

Referenced by sws_getCachedContext(), and sws_getContext().

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

Definition at line 899 of file utils.c.

Referenced by sws_getCachedContext(), and sws_getContext().

void sws_freeContext

(

struct SwsContext *

swsContext

)

Free the swscaler context swsContext.

If swsContext is NULL, then does nothing.

Examples:

doc/examples/scaling_video.c.

Definition at line 1761 of file utils.c.

Referenced by config_props(), doTest(), ff_scale_image(), freeBuffers(), main(), stream_close(), sws_getCachedContext(), sws_getContext(), uninit(), uninit_opts(), and uninit_parse_context().

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  )

read

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

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

Deprecated:

Use sws_getCachedContext() instead.

Examples:

doc/examples/muxing.c, and doc/examples/scaling_video.c.

Definition at line 1403 of file utils.c.

Referenced by allocStuff(), config_props(), doTest(), ff_scale_image(), ff_sws_getContextFromCmdLine(), init_opts(), main(), and write_video_frame().

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.

Definition at line 794 of file swscale.c.

Referenced by blur(), doTest(), ff_scale_image(), main(), queue_picture(), scale_slice(), wrap(), and write_video_frame().

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

Definition at line 802 of file utils.c.

Referenced by sws_getCachedContext(), and sws_getContext().

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

Definition at line 838 of file utils.c.

SwsVector* sws_allocVec

(

int

length

)

Allocate and return an uninitialized vector with length coefficients.

Definition at line 1504 of file utils.c.

Referenced by sws_cloneVec(), sws_getConstVec(), and sws_getGaussianVec().

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.

Definition at line 1521 of file utils.c.

Referenced by alloc_sws_context(), allocStuff(), and sws_getDefaultFilter().

SwsVector* sws_getConstVec	(	double	c,
		int	length
	)

Allocate and return a vector with length coefficients, all with the same value c.

Definition at line 1547 of file utils.c.

Referenced by sws_diffVec(), sws_getConvVec(), sws_getIdentityVec(), sws_getShiftedVec(), and sws_sumVec().

SwsVector* sws_getIdentityVec

(

void

)

Allocate and return a vector with just one coefficient, with value 1.0.

Definition at line 1561 of file utils.c.

Referenced by sws_getDefaultFilter().

void sws_scaleVec	(	SwsVector *	a,
		double	scalar
	)

Scale all the coefficients of a by the scalar value.

Definition at line 1577 of file utils.c.

Referenced by alloc_sws_context(), sws_getDefaultFilter(), and sws_normalizeVec().

void sws_normalizeVec	(	SwsVector *	a,
		double	height
	)

Scale all the coefficients of a so that their sum equals height.

Definition at line 1585 of file utils.c.

Referenced by sws_getDefaultFilter(), and sws_getGaussianVec().

void sws_convVec	(	SwsVector *	a,
		SwsVector *	b
	)

Definition at line 1687 of file utils.c.

void sws_addVec	(	SwsVector *	a,
		SwsVector *	b
	)

Definition at line 1669 of file utils.c.

Referenced by sws_getDefaultFilter().

void sws_subVec	(	SwsVector *	a,
		SwsVector *	b
	)

Definition at line 1678 of file utils.c.

void sws_shiftVec	(	SwsVector *	a,
		int	shift
	)

Definition at line 1660 of file utils.c.

Referenced by sws_getDefaultFilter().

SwsVector* sws_cloneVec

(

SwsVector *

a

)

Allocate and return a clone of the vector a, that is a vector with the same coefficients as a.

Definition at line 1696 of file utils.c.

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.

Definition at line 1710 of file utils.c.

Referenced by sws_getDefaultFilter().

void sws_freeVec

(

SwsVector *

a

)

Definition at line 1736 of file utils.c.

Referenced by alloc_sws_context(), allocStuff(), sws_freeFilter(), and sws_getDefaultFilter().

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

Definition at line 1442 of file utils.c.

void sws_freeFilter

(

SwsFilter *

filter

)

Definition at line 1745 of file utils.c.

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  )

read

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.

Definition at line 1828 of file utils.c.

Referenced by alloc_sws_context(), and queue_picture().

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

Definition at line 1124 of file swscale_unscaled.c.

Referenced by palToRgbWrapper().

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

Definition at line 1134 of file swscale_unscaled.c.

Referenced by palToRgbWrapper().

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().

Definition at line 78 of file options.c.

Referenced by init(), opt_default(), and show_help_default().