lv_img_decoder.h File Reference

#include "../../../lv_conf.h"
#include <stdint.h>
#include "../lv_misc/lv_fs.h"
#include "../lv_misc/lv_types.h"
#include "../lv_misc/lv_area.h"
#include "../lv_core/lv_style.h"

Include dependency graph for lv_img_decoder.h:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Data Structures
struct	lv_img_header_t
struct	lv_img_dsc_t
struct	_lv_img_decoder
struct	_lv_img_decoder_dsc

Typedefs
typedef uint8_t	lv_img_src_t
typedef uint8_t	lv_img_cf_t
typedef lv_res_t(*	lv_img_decoder_info_f_t) (struct _lv_img_decoder *decoder, const void *src, lv_img_header_t *header)
typedef lv_res_t(*	lv_img_decoder_open_f_t) (struct _lv_img_decoder *decoder, struct _lv_img_decoder_dsc *dsc)
typedef lv_res_t(*	lv_img_decoder_read_line_f_t) (struct _lv_img_decoder *decoder, struct _lv_img_decoder_dsc *dsc, lv_coord_t x, lv_coord_t y, lv_coord_t len, uint8_t *buf)
typedef void(*	lv_img_decoder_close_f_t) (struct _lv_img_decoder *decoder, struct _lv_img_decoder_dsc *dsc)
typedef struct _lv_img_decoder	lv_img_decoder_t
typedef struct _lv_img_decoder_dsc	lv_img_decoder_dsc_t

Enumerations
enum	{ LV_IMG_SRC_VARIABLE, LV_IMG_SRC_FILE, LV_IMG_SRC_SYMBOL, LV_IMG_SRC_UNKNOWN }
enum	{   LV_IMG_CF_UNKNOWN = 0, LV_IMG_CF_RAW, LV_IMG_CF_RAW_ALPHA, LV_IMG_CF_RAW_CHROMA_KEYED,   LV_IMG_CF_TRUE_COLOR, LV_IMG_CF_TRUE_COLOR_ALPHA, LV_IMG_CF_TRUE_COLOR_CHROMA_KEYED, LV_IMG_CF_INDEXED_1BIT,   LV_IMG_CF_INDEXED_2BIT, LV_IMG_CF_INDEXED_4BIT, LV_IMG_CF_INDEXED_8BIT, LV_IMG_CF_ALPHA_1BIT,   LV_IMG_CF_ALPHA_2BIT, LV_IMG_CF_ALPHA_4BIT, LV_IMG_CF_ALPHA_8BIT, LV_IMG_CF_RESERVED_15,   LV_IMG_CF_RESERVED_16, LV_IMG_CF_RESERVED_17, LV_IMG_CF_RESERVED_18, LV_IMG_CF_RESERVED_19,   LV_IMG_CF_RESERVED_20, LV_IMG_CF_RESERVED_21, LV_IMG_CF_RESERVED_22, LV_IMG_CF_RESERVED_23,   LV_IMG_CF_USER_ENCODED_0, LV_IMG_CF_USER_ENCODED_1, LV_IMG_CF_USER_ENCODED_2, LV_IMG_CF_USER_ENCODED_3,   LV_IMG_CF_USER_ENCODED_4, LV_IMG_CF_USER_ENCODED_5, LV_IMG_CF_USER_ENCODED_6, LV_IMG_CF_USER_ENCODED_7 }

Functions
void	lv_img_decoder_init (void)
lv_res_t	lv_img_decoder_get_info (const char *src, lv_img_header_t *header)
lv_res_t	lv_img_decoder_open (lv_img_decoder_dsc_t *dsc, const void *src, const lv_style_t *style)
lv_res_t	lv_img_decoder_read_line (lv_img_decoder_dsc_t *dsc, lv_coord_t x, lv_coord_t y, lv_coord_t len, uint8_t *buf)
void	lv_img_decoder_close (lv_img_decoder_dsc_t *dsc)
lv_img_decoder_t *	lv_img_decoder_create (void)
void	lv_img_decoder_delete (lv_img_decoder_t *decoder)
void	lv_img_decoder_set_info_cb (lv_img_decoder_t *decoder, lv_img_decoder_info_f_t info_cb)
void	lv_img_decoder_set_open_cb (lv_img_decoder_t *decoder, lv_img_decoder_open_f_t open_cb)
void	lv_img_decoder_set_read_line_cb (lv_img_decoder_t *decoder, lv_img_decoder_read_line_f_t read_line_cb)
void	lv_img_decoder_set_close_cb (lv_img_decoder_t *decoder, lv_img_decoder_close_f_t close_cb)
lv_res_t	lv_img_decoder_built_in_info (lv_img_decoder_t *decoder, const void *src, lv_img_header_t *header)
lv_res_t	lv_img_decoder_built_in_open (lv_img_decoder_t *decoder, lv_img_decoder_dsc_t *dsc)
lv_res_t	lv_img_decoder_built_in_read_line (lv_img_decoder_t *decoder, lv_img_decoder_dsc_t *dsc, lv_coord_t x, lv_coord_t y, lv_coord_t len, uint8_t *buf)
void	lv_img_decoder_built_in_close (lv_img_decoder_t *decoder, lv_img_decoder_dsc_t *dsc)

Typedef Documentation

lv_img_src_t

typedef uint8_t lv_img_src_t

lv_img_cf_t

typedef uint8_t lv_img_cf_t

lv_img_decoder_info_f_t

typedef lv_res_t(* lv_img_decoder_info_f_t) (struct _lv_img_decoder *decoder, const void *src, lv_img_header_t *header)

Get info from an image and store in the header

Parameters

src	the image source. Can be a pointer to a C array or a file name (Use lv_img_src_get_type to determine the type)
header	store the info here

Returns

LV_RES_OK: info written correctly; LV_RES_INV: failed

lv_img_decoder_open_f_t

typedef lv_res_t(* lv_img_decoder_open_f_t) (struct _lv_img_decoder *decoder, struct _lv_img_decoder_dsc *dsc)

Open an image for decoding. Prepare it as it is required to read it later

Parameters

decoder	pointer to the decoder the function associated with
dsc	pointer to decoder descriptor. src, style are already initialized in it.

lv_img_decoder_read_line_f_t

typedef lv_res_t(* lv_img_decoder_read_line_f_t) (struct _lv_img_decoder *decoder, struct _lv_img_decoder_dsc *dsc, lv_coord_t x, lv_coord_t y, lv_coord_t len, uint8_t *buf)

Decode len pixels starting from the given x, y coordinates and store them in buf. Required only if the "open" function can't return with the whole decoded pixel array.

Parameters

decoder	pointer to the decoder the function associated with
dsc	pointer to decoder descriptor
x	start x coordinate
y	start y coordinate
len	number of pixels to decode
buf	a buffer to store the decoded pixels

Returns

LV_RES_OK: ok; LV_RES_INV: failed

lv_img_decoder_close_f_t

typedef void(* lv_img_decoder_close_f_t) (struct _lv_img_decoder *decoder, struct _lv_img_decoder_dsc *dsc)

Close the pending decoding. Free resources etc.

Parameters

decoder	pointer to the decoder the function associated with
dsc	pointer to decoder descriptor

lv_img_decoder_t

typedef struct _lv_img_decoder lv_img_decoder_t

lv_img_decoder_dsc_t

typedef struct _lv_img_decoder_dsc lv_img_decoder_dsc_t

Describe an image decoding session. Stores data about the decoding

Enumeration Type Documentation

anonymous enum

anonymous enum

Source of image.

Enumerator
LV_IMG_SRC_VARIABLE
LV_IMG_SRC_FILE	Binary/C variable
LV_IMG_SRC_SYMBOL	File in filesystem
LV_IMG_SRC_UNKNOWN	Symbol (lv_symbol_def.h)

anonymous enum

anonymous enum

Enumerator
LV_IMG_CF_UNKNOWN
LV_IMG_CF_RAW	Contains the file as it is. Needs custom decoder function
LV_IMG_CF_RAW_ALPHA	Contains the file as it is. The image has alpha. Needs custom decoder function
LV_IMG_CF_RAW_CHROMA_KEYED	Contains the file as it is. The image is chroma keyed. Needs custom decoder function
LV_IMG_CF_TRUE_COLOR	Color format and depth should match with LV_COLOR settings
LV_IMG_CF_TRUE_COLOR_ALPHA	Same as LV_IMG_CF_TRUE_COLOR but every pixel has an alpha byte
LV_IMG_CF_TRUE_COLOR_CHROMA_KEYED	Same as LV_IMG_CF_TRUE_COLOR but LV_COLOR_TRANSP pixels will be transparent
LV_IMG_CF_INDEXED_1BIT	Can have 2 different colors in a palette (always chroma keyed)
LV_IMG_CF_INDEXED_2BIT	Can have 4 different colors in a palette (always chroma keyed)
LV_IMG_CF_INDEXED_4BIT	Can have 16 different colors in a palette (always chroma keyed)
LV_IMG_CF_INDEXED_8BIT	Can have 256 different colors in a palette (always chroma keyed)
LV_IMG_CF_ALPHA_1BIT	Can have one color and it can be drawn or not
LV_IMG_CF_ALPHA_2BIT	Can have one color but 4 different alpha value
LV_IMG_CF_ALPHA_4BIT	Can have one color but 16 different alpha value
LV_IMG_CF_ALPHA_8BIT	Can have one color but 256 different alpha value
LV_IMG_CF_RESERVED_15	Reserved for further use.
LV_IMG_CF_RESERVED_16	Reserved for further use.
LV_IMG_CF_RESERVED_17	Reserved for further use.
LV_IMG_CF_RESERVED_18	Reserved for further use.
LV_IMG_CF_RESERVED_19	Reserved for further use.
LV_IMG_CF_RESERVED_20	Reserved for further use.
LV_IMG_CF_RESERVED_21	Reserved for further use.
LV_IMG_CF_RESERVED_22	Reserved for further use.
LV_IMG_CF_RESERVED_23	Reserved for further use.
LV_IMG_CF_USER_ENCODED_0	User holder encoding format.
LV_IMG_CF_USER_ENCODED_1	User holder encoding format.
LV_IMG_CF_USER_ENCODED_2	User holder encoding format.
LV_IMG_CF_USER_ENCODED_3	User holder encoding format.
LV_IMG_CF_USER_ENCODED_4	User holder encoding format.
LV_IMG_CF_USER_ENCODED_5	User holder encoding format.
LV_IMG_CF_USER_ENCODED_6	User holder encoding format.
LV_IMG_CF_USER_ENCODED_7	User holder encoding format.

Function Documentation

lv_img_decoder_init()

void lv_img_decoder_init

(

void

)

Initialize the image decoder module

lv_img_decoder_get_info()

lv_res_t lv_img_decoder_get_info	(	const char *	src,
		lv_img_header_t *	header
	)

Get information about an image. Try the created image decoder one by one. Once one is able to get info that info will be used.

Parameters

src	the image source. Can be 1) File name: E.g. "S:folder/img1.png" (The drivers needs to registered via lv_fs_add_drv()) 2) Variable: Pointer to an lv_img_dsc_t variable 3) Symbol: E.g. LV_SYMBOL_OK
header	the image info will be stored here

Returns

LV_RES_OK: success; LV_RES_INV: wasn't able to get info about the image

lv_img_decoder_open()

lv_res_t lv_img_decoder_open	(	lv_img_decoder_dsc_t *	dsc,
		const void *	src,
		const lv_style_t *	style
	)

Open an image. Try the created image decoder one by one. Once one is able to open the image that decoder is save in dsc

Parameters

dsc	describe a decoding session. Simply a pointer to an lv_img_decoder_dsc_t variable.
src	the image source. Can be 1) File name: E.g. "S:folder/img1.png" (The drivers needs to registered via lv_fs_add_drv()) 2) Variable: Pointer to an lv_img_dsc_t variable 3) Symbol: E.g. LV_SYMBOL_OK
style	the style of the image

Returns

LV_RES_OK: opened the image. dsc->img_data and dsc->header are set. LV_RES_INV: none of the registered image decoders were able to open the image.

lv_img_decoder_read_line()

lv_res_t lv_img_decoder_read_line	(	lv_img_decoder_dsc_t *	dsc,
		lv_coord_t	x,
		lv_coord_t	y,
		lv_coord_t	len,
		uint8_t *	buf
	)

Read a line from an opened image

Parameters

dsc	pointer to lv_img_decoder_dsc_t used in lv_img_decoder_open
x	start X coordinate (from left)
y	start Y coordinate (from top)
len	number of pixels to read
buf	store the data here

Returns

LV_RES_OK: success; LV_RES_INV: an error occurred

lv_img_decoder_close()

void lv_img_decoder_close

(

lv_img_decoder_dsc_t *

dsc

)

Close a decoding session

Parameters

dsc	pointer to lv_img_decoder_dsc_t used in lv_img_decoder_open

lv_img_decoder_create()

lv_img_decoder_t* lv_img_decoder_create

(

void

)

Create a new image decoder

Returns

pointer to the new image decoder

lv_img_decoder_delete()

void lv_img_decoder_delete

(

lv_img_decoder_t *

decoder

)

Delete an image decoder

Parameters

decoder

pointer to an image decoder

lv_img_decoder_set_info_cb()

void lv_img_decoder_set_info_cb	(	lv_img_decoder_t *	decoder,
		lv_img_decoder_info_f_t	info_cb
	)

Set a callback to get information about the image

Parameters

decoder	pointer to an image decoder
info_cb	a function to collect info about an image (fill an lv_img_header_t struct)

lv_img_decoder_set_open_cb()

void lv_img_decoder_set_open_cb	(	lv_img_decoder_t *	decoder,
		lv_img_decoder_open_f_t	open_cb
	)

Set a callback to open an image

Parameters

decoder	pointer to an image decoder
open_cb	a function to open an image

lv_img_decoder_set_read_line_cb()

void lv_img_decoder_set_read_line_cb	(	lv_img_decoder_t *	decoder,
		lv_img_decoder_read_line_f_t	read_line_cb
	)

Set a callback to a decoded line of an image

Parameters

decoder	pointer to an image decoder
read_line_cb	a function to read a line of an image

lv_img_decoder_set_close_cb()

void lv_img_decoder_set_close_cb	(	lv_img_decoder_t *	decoder,
		lv_img_decoder_close_f_t	close_cb
	)

Set a callback to close a decoding session. E.g. close files and free other resources.

Parameters

decoder	pointer to an image decoder
close_cb	a function to close a decoding session

lv_img_decoder_built_in_info()

lv_res_t lv_img_decoder_built_in_info	(	lv_img_decoder_t *	decoder,
		const void *	src,
		lv_img_header_t *	header
	)

Get info about a built-in image

Parameters

decoder	the decoder where this function belongs
src	the image source: pointer to an lv_img_dsc_t variable, a file path or a symbol
header	store the image data here

Returns

LV_RES_OK: the info is successfully stored in header; LV_RES_INV: unknown format or other error.

lv_img_decoder_built_in_open()

lv_res_t lv_img_decoder_built_in_open	(	lv_img_decoder_t *	decoder,
		lv_img_decoder_dsc_t *	dsc
	)

Open a built in image

Parameters

decoder	the decoder where this function belongs
dsc	pointer to decoder descriptor. src, style are already initialized in it.

Returns

LV_RES_OK: the info is successfully stored in header; LV_RES_INV: unknown format or other error.

lv_img_decoder_built_in_read_line()

lv_res_t lv_img_decoder_built_in_read_line	(	lv_img_decoder_t *	decoder,
		lv_img_decoder_dsc_t *	dsc,
		lv_coord_t	x,
		lv_coord_t	y,
		lv_coord_t	len,
		uint8_t *	buf
	)

Decode len pixels starting from the given x, y coordinates and store them in buf. Required only if the "open" function can't return with the whole decoded pixel array.

Parameters

decoder	pointer to the decoder the function associated with
dsc	pointer to decoder descriptor
x	start x coordinate
y	start y coordinate
len	number of pixels to decode
buf	a buffer to store the decoded pixels

Returns

LV_RES_OK: ok; LV_RES_INV: failed

lv_img_decoder_built_in_close()

void lv_img_decoder_built_in_close	(	lv_img_decoder_t *	decoder,
		lv_img_decoder_dsc_t *	dsc
	)

Close the pending decoding. Free resources etc.

Parameters

decoder	pointer to the decoder the function associated with
dsc	pointer to decoder descriptor