Image related

AVPicture types, pixel formats and basic image planes manipulation. Подробнее...

Граф связей класса Image related:

Перечисления
enum	AVPictureType {   AV_PICTURE_TYPE_NONE = 0, AV_PICTURE_TYPE_I, AV_PICTURE_TYPE_P, AV_PICTURE_TYPE_B,   AV_PICTURE_TYPE_S, AV_PICTURE_TYPE_SI, AV_PICTURE_TYPE_SP, AV_PICTURE_TYPE_BI }

Функции
char	av_get_picture_type_char (enum AVPictureType pict_type)
void	av_image_fill_max_pixsteps (int max_pixsteps[4], int max_pixstep_comps[4], const AVPixFmtDescriptor *pixdesc)
int	av_image_get_linesize (enum AVPixelFormat pix_fmt, int width, int plane)
int	av_image_fill_linesizes (int linesizes[4], enum AVPixelFormat pix_fmt, int width)
int	av_image_fill_pointers (uint8_t *data[4], enum AVPixelFormat pix_fmt, int height, uint8_t *ptr, const int linesizes[4])
int	av_image_alloc (uint8_t *pointers[4], int linesizes[4], int w, int h, enum AVPixelFormat pix_fmt, int align)
void	av_image_copy_plane (uint8_t *dst, int dst_linesize, const uint8_t *src, int src_linesize, int bytewidth, int height)
void	av_image_copy (uint8_t *dst_data[4], int dst_linesizes[4], const uint8_t *src_data[4], const int src_linesizes[4], enum AVPixelFormat pix_fmt, int width, int height)
void	av_image_copy_uc_from (uint8_t *dst_data[4], const ptrdiff_t dst_linesizes[4], const uint8_t *src_data[4], const ptrdiff_t src_linesizes[4], enum AVPixelFormat pix_fmt, int width, int height)
int	av_image_fill_arrays (uint8_t *dst_data[4], int dst_linesize[4], const uint8_t *src, enum AVPixelFormat pix_fmt, int width, int height, int align)
int	av_image_get_buffer_size (enum AVPixelFormat pix_fmt, int width, int height, int align)
int	av_image_copy_to_buffer (uint8_t *dst, int dst_size, const uint8_t *const src_data[4], const int src_linesize[4], enum AVPixelFormat pix_fmt, int width, int height, int align)
int	av_image_check_size (unsigned int w, unsigned int h, int log_offset, void *log_ctx)
int	av_image_check_size2 (unsigned int w, unsigned int h, int64_t max_pixels, enum AVPixelFormat pix_fmt, int log_offset, void *log_ctx)
int	av_image_check_sar (unsigned int w, unsigned int h, AVRational sar)
int	av_image_fill_black (uint8_t *dst_data[4], const ptrdiff_t dst_linesize[4], enum AVPixelFormat pix_fmt, enum AVColorRange range, int width, int height)

Подробное описание

AVPicture types, pixel formats and basic image planes manipulation.

Перечисления

AVPictureType

enum AVPictureType

#include <C:/git/world-of-might-and-magic/lib/win32/x86/ffmpeg-4.2.2/include/libavutil/avutil.h>

Элементы перечислений
AV_PICTURE_TYPE_NONE	Undefined.
AV_PICTURE_TYPE_I	Intra.
AV_PICTURE_TYPE_P	Predicted.
AV_PICTURE_TYPE_B	Bi-dir predicted.
AV_PICTURE_TYPE_S	S(GMC)-VOP MPEG-4.
AV_PICTURE_TYPE_SI	Switching Intra.
AV_PICTURE_TYPE_SP	Switching Predicted.
AV_PICTURE_TYPE_BI	BI type.

См. определение в файле avutil.h строка 272

                   {
    AV_PICTURE_TYPE_NONE = 0, 
    AV_PICTURE_TYPE_I,     
    AV_PICTURE_TYPE_P,     
    AV_PICTURE_TYPE_B,     
    AV_PICTURE_TYPE_S,     
    AV_PICTURE_TYPE_SI,    
    AV_PICTURE_TYPE_SP,    
    AV_PICTURE_TYPE_BI,    
};

Функции

av_get_picture_type_char()

char av_get_picture_type_char

(

enum AVPictureType

pict_type

)

#include <C:/git/world-of-might-and-magic/lib/win32/x86/ffmpeg-4.2.2/include/libavutil/avutil.h>

Return a single letter to describe the given picture type pict_type.

Аргументы

[in]

pict_type

the picture type

Возвращает

a single character representing the picture type, '?' if pict_type is unknown

av_image_fill_max_pixsteps()

void av_image_fill_max_pixsteps	(	int	max_pixsteps[4],
		int	max_pixstep_comps[4],
		const AVPixFmtDescriptor *	pixdesc
	)

#include <C:/git/world-of-might-and-magic/lib/win32/x86/ffmpeg-4.2.2/include/libavutil/imgutils.h>

Compute the max pixel step for each plane of an image with a format described by pixdesc.

The pixel step is the distance in bytes between the first byte of the group of bytes which describe a pixel component and the first byte of the successive group in the same plane for the same component.

Аргументы

max_pixsteps	an array which is filled with the max pixel step for each plane. Since a plane may contain different pixel components, the computed max_pixsteps[plane] is relative to the component in the plane with the max pixel step.
max_pixstep_comps	an array which is filled with the component for each plane which has the max pixel step. May be NULL.

av_image_get_linesize()

int av_image_get_linesize	(	enum AVPixelFormat	pix_fmt,
		int	width,
		int	plane
	)

#include <C:/git/world-of-might-and-magic/lib/win32/x86/ffmpeg-4.2.2/include/libavutil/imgutils.h>

Compute the size of an image line with format pix_fmt and width width for the plane plane.

Возвращает

the computed size in bytes

av_image_fill_linesizes()

int av_image_fill_linesizes	(	int	linesizes[4],
		enum AVPixelFormat	pix_fmt,
		int	width
	)

#include <C:/git/world-of-might-and-magic/lib/win32/x86/ffmpeg-4.2.2/include/libavutil/imgutils.h>

Fill plane linesizes for an image with pixel format pix_fmt and width width.

Аргументы

linesizes

array to be filled with the linesize for each plane

Возвращает

>= 0 in case of success, a negative error code otherwise

Используется в AVVideoStream::decode_frame().

Граф вызова функции:

av_image_fill_pointers()

int av_image_fill_pointers	(	uint8_t *	data[4],
		enum AVPixelFormat	pix_fmt,
		int	height,
		uint8_t *	ptr,
		const int	linesizes[4]
	)

#include <C:/git/world-of-might-and-magic/lib/win32/x86/ffmpeg-4.2.2/include/libavutil/imgutils.h>

Fill plane data pointers for an image with pixel format pix_fmt and height height.

Аргументы

data	pointers array to be filled with the pointer for each image plane
ptr	the pointer to a buffer which will contain the image
linesizes	the array containing the linesize for each plane, should be filled by av_image_fill_linesizes()

Возвращает

the size in bytes required for the image buffer, a negative error code in case of failure

av_image_alloc()

int av_image_alloc	(	uint8_t *	pointers[4],
		int	linesizes[4],
		int	w,
		int	h,
		enum AVPixelFormat	pix_fmt,
		int	align
	)

#include <C:/git/world-of-might-and-magic/lib/win32/x86/ffmpeg-4.2.2/include/libavutil/imgutils.h>

Allocate an image with size w and h and pixel format pix_fmt, and fill pointers and linesizes accordingly. The allocated image buffer has to be freed by using av_freep(&pointers[0]).

Аргументы

align

the value to use for buffer size alignment

Возвращает

the size in bytes required for the image buffer, a negative error code in case of failure

av_image_copy_plane()

void av_image_copy_plane	(	uint8_t *	dst,
		int	dst_linesize,
		const uint8_t *	src,
		int	src_linesize,
		int	bytewidth,
		int	height
	)

#include <C:/git/world-of-might-and-magic/lib/win32/x86/ffmpeg-4.2.2/include/libavutil/imgutils.h>

Copy image plane from src to dst. That is, copy "height" number of lines of "bytewidth" bytes each. The first byte of each successive line is separated by *_linesize bytes.

bytewidth must be contained by both absolute values of dst_linesize and src_linesize, otherwise the function behavior is undefined.

Аргументы

dst_linesize	linesize for the image plane in dst
src_linesize	linesize for the image plane in src

av_image_copy()

void av_image_copy	(	uint8_t *	dst_data[4],
		int	dst_linesizes[4],
		const uint8_t *	src_data[4],
		const int	src_linesizes[4],
		enum AVPixelFormat	pix_fmt,
		int	width,
		int	height
	)

#include <C:/git/world-of-might-and-magic/lib/win32/x86/ffmpeg-4.2.2/include/libavutil/imgutils.h>

Copy image in src_data to dst_data.

Аргументы

dst_linesizes	linesizes for the image in dst_data
src_linesizes	linesizes for the image in src_data

av_image_copy_uc_from()

void av_image_copy_uc_from	(	uint8_t *	dst_data[4],
		const ptrdiff_t	dst_linesizes[4],
		const uint8_t *	src_data[4],
		const ptrdiff_t	src_linesizes[4],
		enum AVPixelFormat	pix_fmt,
		int	width,
		int	height
	)

#include <C:/git/world-of-might-and-magic/lib/win32/x86/ffmpeg-4.2.2/include/libavutil/imgutils.h>

Copy image data located in uncacheable (e.g. GPU mapped) memory. Where available, this function will use special functionality for reading from such memory, which may result in greatly improved performance compared to plain av_image_copy().

The data pointers and the linesizes must be aligned to the maximum required by the CPU architecture.

Заметки

The linesize parameters have the type ptrdiff_t here, while they are int for av_image_copy().

On x86, the linesizes currently need to be aligned to the cacheline size (i.e. 64) to get improved performance.

av_image_fill_arrays()

int av_image_fill_arrays	(	uint8_t *	dst_data[4],
		int	dst_linesize[4],
		const uint8_t *	src,
		enum AVPixelFormat	pix_fmt,
		int	width,
		int	height,
		int	align
	)

#include <C:/git/world-of-might-and-magic/lib/win32/x86/ffmpeg-4.2.2/include/libavutil/imgutils.h>

Setup the data pointers and linesizes based on the specified image parameters and the provided array.

The fields of the given image are filled in by using the src address which points to the image data buffer. Depending on the specified pixel format, one or multiple image data pointers and line sizes will be set. If a planar format is specified, several pointers will be set pointing to the different picture planes and the line sizes of the different planes will be stored in the lines_sizes array. Call with src == NULL to get the required size for the src buffer.

To allocate the buffer and fill in the dst_data and dst_linesize in one call, use av_image_alloc().

Аргументы

dst_data	data pointers to be filled in
dst_linesize	linesizes for the image in dst_data to be filled in
src	buffer which will contain or contains the actual image data, can be NULL
pix_fmt	the pixel format of the image
width	the width of the image in pixels
height	the height of the image in pixels
align	the value used in src for linesize alignment

Возвращает

the size in bytes required for src, a negative error code in case of failure

av_image_get_buffer_size()

int av_image_get_buffer_size	(	enum AVPixelFormat	pix_fmt,
		int	width,
		int	height,
		int	align
	)

#include <C:/git/world-of-might-and-magic/lib/win32/x86/ffmpeg-4.2.2/include/libavutil/imgutils.h>

Return the size in bytes of the amount of data required to store an image with the given parameters.

Аргументы

pix_fmt	the pixel format of the image
width	the width of the image in pixels
height	the height of the image in pixels
align	the assumed linesize alignment

Возвращает

the buffer size in bytes, a negative error code in case of failure

av_image_copy_to_buffer()

int av_image_copy_to_buffer	(	uint8_t *	dst,
		int	dst_size,
		const uint8_t *const	src_data[4],
		const int	src_linesize[4],
		enum AVPixelFormat	pix_fmt,
		int	width,
		int	height,
		int	align
	)

#include <C:/git/world-of-might-and-magic/lib/win32/x86/ffmpeg-4.2.2/include/libavutil/imgutils.h>

Copy image data from an image into a buffer.

av_image_get_buffer_size() can be used to compute the required size for the buffer to fill.

Аргументы

dst	a buffer into which picture data will be copied
dst_size	the size in bytes of dst
src_data	pointers containing the source image data
src_linesize	linesizes for the image in src_data
pix_fmt	the pixel format of the source image
width	the width of the source image in pixels
height	the height of the source image in pixels
align	the assumed linesize alignment for dst

Возвращает

the number of bytes written to dst, or a negative value (error code) on error

av_image_check_size()

int av_image_check_size	(	unsigned int	w,
		unsigned int	h,
		int	log_offset,
		void *	log_ctx
	)

#include <C:/git/world-of-might-and-magic/lib/win32/x86/ffmpeg-4.2.2/include/libavutil/imgutils.h>

Check if the given dimension of an image is valid, meaning that all bytes of the image can be addressed with a signed int.

Аргументы

w	the width of the picture
h	the height of the picture
log_offset	the offset to sum to the log level for logging with log_ctx
log_ctx	the parent logging context, it may be NULL

Возвращает

>= 0 if valid, a negative error code otherwise

av_image_check_size2()

int av_image_check_size2	(	unsigned int	w,
		unsigned int	h,
		int64_t	max_pixels,
		enum AVPixelFormat	pix_fmt,
		int	log_offset,
		void *	log_ctx
	)

#include <C:/git/world-of-might-and-magic/lib/win32/x86/ffmpeg-4.2.2/include/libavutil/imgutils.h>

Check if the given dimension of an image is valid, meaning that all bytes of a plane of an image with the specified pix_fmt can be addressed with a signed int.

Аргументы

w	the width of the picture
h	the height of the picture
max_pixels	the maximum number of pixels the user wants to accept
pix_fmt	the pixel format, can be AV_PIX_FMT_NONE if unknown.
log_offset	the offset to sum to the log level for logging with log_ctx
log_ctx	the parent logging context, it may be NULL

Возвращает

>= 0 if valid, a negative error code otherwise

av_image_check_sar()

int av_image_check_sar	(	unsigned int	w,
		unsigned int	h,
		AVRational	sar
	)

#include <C:/git/world-of-might-and-magic/lib/win32/x86/ffmpeg-4.2.2/include/libavutil/imgutils.h>

Check if the given sample aspect ratio of an image is valid.

It is considered invalid if the denominator is 0 or if applying the ratio to the image size would make the smaller dimension less than 1. If the sar numerator is 0, it is considered unknown and will return as valid.

Аргументы

w	width of the image
h	height of the image
sar	sample aspect ratio of the image

Возвращает

0 if valid, a negative AVERROR code otherwise

av_image_fill_black()

int av_image_fill_black	(	uint8_t *	dst_data[4],
		const ptrdiff_t	dst_linesize[4],
		enum AVPixelFormat	pix_fmt,
		enum AVColorRange	range,
		int	width,
		int	height
	)

#include <C:/git/world-of-might-and-magic/lib/win32/x86/ffmpeg-4.2.2/include/libavutil/imgutils.h>

Overwrite the image data with black. This is suitable for filling a sub-rectangle of an image, meaning the padding between the right most pixel and the left most pixel on the next line will not be overwritten. For some formats, the image size might be rounded up due to inherent alignment.

If the pixel format has alpha, the alpha is cleared to opaque.

This can return an error if the pixel format is not supported. Normally, all non-hwaccel pixel formats should be supported.

Passing NULL for dst_data is allowed. Then the function returns whether the operation would have succeeded. (It can return an error if the pix_fmt is not supported.)

Аргументы

dst_data	data pointers to destination image
dst_linesize	linesizes for the destination image
pix_fmt	the pixel format of the image
range	the color range of the image (important for colorspaces such as YUV)
width	the width of the image in pixels
height	the height of the image in pixels

Возвращает

0 if the image data was cleared, a negative AVERROR code otherwise