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zbar.h
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/*------------------------------------------------------------------------
* Copyright 2007-2010 (c) Jeff Brown <[email protected]>
*
* This file is part of the ZBar Bar Code Reader.
*
* The ZBar Bar Code Reader is free software; you can redistribute it
* and/or modify it under the terms of the GNU Lesser Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* The ZBar Bar Code Reader is distributed in the hope that it will be
* useful, but WITHOUT ANY WARRANTY; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser Public License for more details.
*
* You should have received a copy of the GNU Lesser Public License
* along with the ZBar Bar Code Reader; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301 USA
*
* http://sourceforge.net/projects/zbar
*------------------------------------------------------------------------*/
#ifndef _ZBAR_H_
#define _ZBAR_H_
/** @file
* ZBar Barcode Reader C API definition
*/
/** @mainpage
*
* interface to the barcode reader is available at several levels.
* most applications will want to use the high-level interfaces:
*
* @section high-level High-Level Interfaces
*
* these interfaces wrap all library functionality into an easy-to-use
* package for a specific toolkit:
* - the "GTK+ 2.x widget" may be used with GTK GUI applications. a
* Python wrapper is included for PyGtk
* - the @ref zbar::QZBar "Qt4 widget" may be used with Qt GUI
* applications
* - the Processor interface (in @ref c-processor "C" or @ref
* zbar::Processor "C++") adds a scanning window to an application
* with no GUI.
*
* @section mid-level Intermediate Interfaces
*
* building blocks used to construct high-level interfaces:
* - the ImageScanner (in @ref c-imagescanner "C" or @ref
* zbar::ImageScanner "C++") looks for barcodes in a library defined
* image object
* - the Window abstraction (in @ref c-window "C" or @ref
* zbar::Window "C++") sinks library images, displaying them on the
* platform display
* - the Video abstraction (in @ref c-video "C" or @ref zbar::Video
* "C++") sources library images from a video device
*
* @section low-level Low-Level Interfaces
*
* direct interaction with barcode scanning and decoding:
* - the Scanner (in @ref c-scanner "C" or @ref zbar::Scanner "C++")
* looks for barcodes in a linear intensity sample stream
* - the Decoder (in @ref c-decoder "C" or @ref zbar::Decoder "C++")
* extracts barcodes from a stream of bar and space widths
*/
#define NUM_CFGS (ZBAR_CFG_MAX_LEN - ZBAR_CFG_MIN_LEN + 1)
#ifdef __cplusplus
/** C++ namespace for library interfaces */
namespace zbar {
extern "C" {
#endif
/** @name Global library interfaces */
/*@{*/
/** "color" of element: bar or space. */
typedef enum zbar_color_e {
ZBAR_SPACE = 0, /**< light area or space between bars */
ZBAR_BAR = 1, /**< dark area or colored bar segment */
} zbar_color_t;
/** decoded symbol type. */
typedef enum zbar_symbol_type_e {
ZBAR_NONE = 0, /**< no symbol decoded */
ZBAR_PARTIAL = 1, /**< intermediate status */
ZBAR_EAN2 = 2, /**< GS1 2-digit add-on */
ZBAR_EAN5 = 5, /**< GS1 5-digit add-on */
ZBAR_EAN8 = 8, /**< EAN-8 */
ZBAR_UPCE = 9, /**< UPC-E */
ZBAR_ISBN10 = 10, /**< ISBN-10 (from EAN-13). @since 0.4 */
ZBAR_UPCA = 12, /**< UPC-A */
ZBAR_EAN13 = 13, /**< EAN-13 */
ZBAR_ISBN13 = 14, /**< ISBN-13 (from EAN-13). @since 0.4 */
ZBAR_COMPOSITE = 15, /**< EAN/UPC composite */
ZBAR_I25 = 25, /**< Interleaved 2 of 5. @since 0.4 */
ZBAR_DATABAR = 34, /**< GS1 DataBar (RSS). @since 0.11 */
ZBAR_DATABAR_EXP = 35, /**< GS1 DataBar Expanded. @since 0.11 */
ZBAR_CODABAR = 38, /**< Codabar. @since 0.11 */
ZBAR_CODE39 = 39, /**< Code 39. @since 0.4 */
ZBAR_PDF417 = 57, /**< PDF417. @since 0.6 */
ZBAR_QRCODE = 64, /**< QR Code. @since 0.10 */
ZBAR_CODE93 = 93, /**< Code 93. @since 0.11 */
ZBAR_CODE128 = 128, /**< Code 128 */
/** mask for base symbol type.
* @deprecated in 0.11, remove this from existing code
*/
ZBAR_SYMBOL = 0x00ff,
/** 2-digit add-on flag.
* @deprecated in 0.11, a ::ZBAR_EAN2 component is used for
* 2-digit GS1 add-ons
*/
ZBAR_ADDON2 = 0x0200,
/** 5-digit add-on flag.
* @deprecated in 0.11, a ::ZBAR_EAN5 component is used for
* 5-digit GS1 add-ons
*/
ZBAR_ADDON5 = 0x0500,
/** add-on flag mask.
* @deprecated in 0.11, GS1 add-ons are represented using composite
* symbols of type ::ZBAR_COMPOSITE; add-on components use ::ZBAR_EAN2
* or ::ZBAR_EAN5
*/
ZBAR_ADDON = 0x0700,
} zbar_symbol_type_t;
/** decoded symbol coarse orientation.
* @since 0.11
*/
typedef enum zbar_orientation_e {
ZBAR_ORIENT_UNKNOWN = -1, /**< unable to determine orientation */
ZBAR_ORIENT_UP, /**< upright, read left to right */
ZBAR_ORIENT_RIGHT, /**< sideways, read top to bottom */
ZBAR_ORIENT_DOWN, /**< upside-down, read right to left */
ZBAR_ORIENT_LEFT, /**< sideways, read bottom to top */
} zbar_orientation_t;
/** error codes. */
typedef enum zbar_error_e {
ZBAR_OK = 0, /**< no error */
ZBAR_ERR_NOMEM, /**< out of memory */
ZBAR_ERR_INTERNAL, /**< internal library error */
ZBAR_ERR_UNSUPPORTED, /**< unsupported request */
ZBAR_ERR_INVALID, /**< invalid request */
ZBAR_ERR_SYSTEM, /**< system error */
ZBAR_ERR_LOCKING, /**< locking error */
ZBAR_ERR_BUSY, /**< all resources busy */
ZBAR_ERR_XDISPLAY, /**< X11 display error */
ZBAR_ERR_XPROTO, /**< X11 protocol error */
ZBAR_ERR_CLOSED, /**< output window is closed */
ZBAR_ERR_WINAPI, /**< windows system error */
ZBAR_ERR_NUM /**< number of error codes */
} zbar_error_t;
/** decoder configuration options.
* @since 0.4
*/
typedef enum zbar_config_e {
ZBAR_CFG_ENABLE = 0, /**< enable symbology/feature */
ZBAR_CFG_ADD_CHECK, /**< enable check digit when optional */
ZBAR_CFG_EMIT_CHECK, /**< return check digit when present */
ZBAR_CFG_ASCII, /**< enable full ASCII character set */
ZBAR_CFG_NUM, /**< number of boolean decoder configs */
ZBAR_CFG_MIN_LEN = 0x20, /**< minimum data length for valid decode */
ZBAR_CFG_MAX_LEN, /**< maximum data length for valid decode */
ZBAR_CFG_UNCERTAINTY = 0x40,/**< required video consistency frames */
ZBAR_CFG_POSITION = 0x80, /**< enable scanner to collect position data */
ZBAR_CFG_X_DENSITY = 0x100, /**< image scanner vertical scan density */
ZBAR_CFG_Y_DENSITY, /**< image scanner horizontal scan density */
} zbar_config_t;
/** decoder symbology modifier flags.
* @since 0.11
*/
typedef enum zbar_modifier_e {
/** barcode tagged as GS1 (EAN.UCC) reserved
* (eg, FNC1 before first data character).
* data may be parsed as a sequence of GS1 AIs
*/
ZBAR_MOD_GS1 = 0,
/** barcode tagged as AIM reserved
* (eg, FNC1 after first character or digit pair)
*/
ZBAR_MOD_AIM,
/** number of modifiers */
ZBAR_MOD_NUM,
} zbar_modifier_t;
/** retrieve runtime library version information.
* @param major set to the running major version (unless NULL)
* @param minor set to the running minor version (unless NULL)
* @returns 0
*/
extern int zbar_version(unsigned *major,
unsigned *minor);
/** set global library debug level.
* @param verbosity desired debug level. higher values create more spew
*/
extern void zbar_set_verbosity(int verbosity);
/** increase global library debug level.
* eg, for -vvvv
*/
extern void zbar_increase_verbosity(void);
/** retrieve string name for symbol encoding.
* @param sym symbol type encoding
* @returns the static string name for the specified symbol type,
* or "UNKNOWN" if the encoding is not recognized
*/
extern const char *zbar_get_symbol_name(zbar_symbol_type_t sym);
/** retrieve string name for addon encoding.
* @param sym symbol type encoding
* @returns static string name for any addon, or the empty string
* if no addons were decoded
* @deprecated in 0.11
*/
extern const char *zbar_get_addon_name(zbar_symbol_type_t sym);
/** retrieve string name for configuration setting.
* @param config setting to name
* @returns static string name for config,
* or the empty string if value is not a known config
*/
extern const char *zbar_get_config_name(zbar_config_t config);
/** retrieve string name for modifier.
* @param modifier flag to name
* @returns static string name for modifier,
* or the empty string if the value is not a known flag
*/
extern const char *zbar_get_modifier_name(zbar_modifier_t modifier);
/** retrieve string name for orientation.
* @param orientation orientation encoding
* @returns the static string name for the specified orientation,
* or "UNKNOWN" if the orientation is not recognized
* @since 0.11
*/
extern const char *zbar_get_orientation_name(zbar_orientation_t orientation);
/** parse a configuration string of the form "[symbology.]config[=value]".
* the config must match one of the recognized names.
* the symbology, if present, must match one of the recognized names.
* if symbology is unspecified, it will be set to 0.
* if value is unspecified it will be set to 1.
* @returns 0 if the config is parsed successfully, 1 otherwise
* @since 0.4
*/
extern int zbar_parse_config(const char *config_string,
zbar_symbol_type_t *symbology,
zbar_config_t *config,
int *value);
/** consistently compute fourcc values across architectures
* (adapted from v4l2 specification)
* @since 0.11
*/
#define zbar_fourcc(a, b, c, d) \
((unsigned long)(a) | \
((unsigned long)(b) << 8) | \
((unsigned long)(c) << 16) | \
((unsigned long)(d) << 24))
/** parse a fourcc string into its encoded integer value.
* @since 0.11
*/
static inline unsigned long zbar_fourcc_parse (const char *format)
{
unsigned long fourcc = 0;
if(format) {
int i;
for(i = 0; i < 4 && format[i]; i++)
fourcc |= ((unsigned long)format[i]) << (i * 8);
}
return(fourcc);
}
/** @internal type unsafe error API (don't use) */
extern int _zbar_error_spew(const void *object,
int verbosity);
extern const char *_zbar_error_string(const void *object,
int verbosity);
extern zbar_error_t _zbar_get_error_code(const void *object);
/*@}*/
struct zbar_symbol_s;
typedef struct zbar_symbol_s zbar_symbol_t;
struct zbar_symbol_set_s;
typedef struct zbar_symbol_set_s zbar_symbol_set_t;
/*------------------------------------------------------------*/
/** @name Symbol interface
* decoded barcode symbol result object. stores type, data, and image
* location of decoded symbol. all memory is owned by the library
*/
/*@{*/
/** @typedef zbar_symbol_t
* opaque decoded symbol object.
*/
/** symbol reference count manipulation.
* increment the reference count when you store a new reference to the
* symbol. decrement when the reference is no longer used. do not
* refer to the symbol once the count is decremented and the
* containing image has been recycled or destroyed.
* @note the containing image holds a reference to the symbol, so you
* only need to use this if you keep a symbol after the image has been
* destroyed or reused.
* @since 0.9
*/
extern void zbar_symbol_ref(const zbar_symbol_t *symbol,
int refs);
/** retrieve type of decoded symbol.
* @returns the symbol type
*/
extern zbar_symbol_type_t zbar_symbol_get_type(const zbar_symbol_t *symbol);
/** retrieve symbology boolean config settings.
* @returns a bitmask indicating which configs were set for the detected
* symbology during decoding.
* @since 0.11
*/
extern unsigned int zbar_symbol_get_configs(const zbar_symbol_t *symbol);
/** retrieve symbology modifier flag settings.
* @returns a bitmask indicating which characteristics were detected
* during decoding.
* @since 0.11
*/
extern unsigned int zbar_symbol_get_modifiers(const zbar_symbol_t *symbol);
/** retrieve data decoded from symbol.
* @returns the data string
*/
extern const char *zbar_symbol_get_data(const zbar_symbol_t *symbol);
/** retrieve length of binary data.
* @returns the length of the decoded data
*/
extern unsigned int zbar_symbol_get_data_length(const zbar_symbol_t *symbol);
/** retrieve a symbol confidence metric.
* @returns an unscaled, relative quantity: larger values are better
* than smaller values, where "large" and "small" are application
* dependent.
* @note expect the exact definition of this quantity to change as the
* metric is refined. currently, only the ordered relationship
* between two values is defined and will remain stable in the future
* @since 0.9
*/
extern int zbar_symbol_get_quality(const zbar_symbol_t *symbol);
/** retrieve current cache count. when the cache is enabled for the
* image_scanner this provides inter-frame reliability and redundancy
* information for video streams.
* @returns < 0 if symbol is still uncertain.
* @returns 0 if symbol is newly verified.
* @returns > 0 for duplicate symbols
*/
extern int zbar_symbol_get_count(const zbar_symbol_t *symbol);
/** retrieve the number of points in the location polygon. the
* location polygon defines the image area that the symbol was
* extracted from.
* @returns the number of points in the location polygon
* @note this is currently not a polygon, but the scan locations
* where the symbol was decoded
*/
extern unsigned zbar_symbol_get_loc_size(const zbar_symbol_t *symbol);
/** retrieve location polygon x-coordinates.
* points are specified by 0-based index.
* @returns the x-coordinate for a point in the location polygon.
* @returns -1 if index is out of range
*/
extern int zbar_symbol_get_loc_x(const zbar_symbol_t *symbol,
unsigned index);
/** retrieve location polygon y-coordinates.
* points are specified by 0-based index.
* @returns the y-coordinate for a point in the location polygon.
* @returns -1 if index is out of range
*/
extern int zbar_symbol_get_loc_y(const zbar_symbol_t *symbol,
unsigned index);
/** retrieve general orientation of decoded symbol.
* @returns a coarse, axis-aligned indication of symbol orientation or
* ::ZBAR_ORIENT_UNKNOWN if unknown
* @since 0.11
*/
extern zbar_orientation_t
zbar_symbol_get_orientation(const zbar_symbol_t *symbol);
/** iterate the set to which this symbol belongs (there can be only one).
* @returns the next symbol in the set, or
* @returns NULL when no more results are available
*/
extern const zbar_symbol_t *zbar_symbol_next(const zbar_symbol_t *symbol);
/** retrieve components of a composite result.
* @returns the symbol set containing the components
* @returns NULL if the symbol is already a physical symbol
* @since 0.10
*/
extern const zbar_symbol_set_t*
zbar_symbol_get_components(const zbar_symbol_t *symbol);
/** iterate components of a composite result.
* @returns the first physical component symbol of a composite result
* @returns NULL if the symbol is already a physical symbol
* @since 0.10
*/
extern const zbar_symbol_t*
zbar_symbol_first_component(const zbar_symbol_t *symbol);
/** print XML symbol element representation to user result buffer.
* @see http://zbar.sourceforge.net/2008/barcode.xsd for the schema.
* @param symbol is the symbol to print
* @param buffer is the inout result pointer, it will be reallocated
* with a larger size if necessary.
* @param buflen is inout length of the result buffer.
* @returns the buffer pointer
* @since 0.6
*/
extern char *zbar_symbol_xml(const zbar_symbol_t *symbol,
char **buffer,
unsigned *buflen);
/*@}*/
/*------------------------------------------------------------*/
/** @name Symbol Set interface
* container for decoded result symbols associated with an image
* or a composite symbol.
* @since 0.10
*/
/*@{*/
/** @typedef zbar_symbol_set_t
* opaque symbol iterator object.
* @since 0.10
*/
/** reference count manipulation.
* increment the reference count when you store a new reference.
* decrement when the reference is no longer used. do not refer to
* the object any longer once references have been released.
* @since 0.10
*/
extern void zbar_symbol_set_ref(const zbar_symbol_set_t *symbols,
int refs);
/** retrieve set size.
* @returns the number of symbols in the set.
* @since 0.10
*/
extern int zbar_symbol_set_get_size(const zbar_symbol_set_t *symbols);
/** set iterator.
* @returns the first decoded symbol result in a set
* @returns NULL if the set is empty
* @since 0.10
*/
extern const zbar_symbol_t*
zbar_symbol_set_first_symbol(const zbar_symbol_set_t *symbols);
/** raw result iterator.
* @returns the first decoded symbol result in a set, *before* filtering
* @returns NULL if the set is empty
* @since 0.11
*/
extern const zbar_symbol_t*
zbar_symbol_set_first_unfiltered(const zbar_symbol_set_t *symbols);
/*@}*/
/*------------------------------------------------------------*/
/** @name Image interface
* stores image data samples along with associated format and size
* metadata
*/
/*@{*/
struct zbar_image_s;
/** opaque image object. */
typedef struct zbar_image_s zbar_image_t;
/** cleanup handler callback function.
* called to free sample data when an image is destroyed.
*/
typedef void (zbar_image_cleanup_handler_t)(zbar_image_t *image);
/** data handler callback function.
* called when decoded symbol results are available for an image
*/
typedef void (zbar_image_data_handler_t)(zbar_image_t *image,
const void *userdata);
/** new image constructor.
* @returns a new image object with uninitialized data and format.
* this image should be destroyed (using zbar_image_destroy()) as
* soon as the application is finished with it
*/
extern zbar_image_t *zbar_image_create(void);
/** image destructor. all images created by or returned to the
* application should be destroyed using this function. when an image
* is destroyed, the associated data cleanup handler will be invoked
* if available
* @note make no assumptions about the image or the data buffer.
* they may not be destroyed/cleaned immediately if the library
* is still using them. if necessary, use the cleanup handler hook
* to keep track of image data buffers
*/
extern void zbar_image_destroy(zbar_image_t *image);
/** image reference count manipulation.
* increment the reference count when you store a new reference to the
* image. decrement when the reference is no longer used. do not
* refer to the image any longer once the count is decremented.
* zbar_image_ref(image, -1) is the same as zbar_image_destroy(image)
* @since 0.5
*/
extern void zbar_image_ref(zbar_image_t *image,
int refs);
/** image format conversion. refer to the documentation for supported
* image formats
* @returns a @em new image with the sample data from the original image
* converted to the requested format. the original image is
* unaffected.
* @note the converted image size may be rounded (up) due to format
* constraints
*/
extern zbar_image_t *zbar_image_convert(const zbar_image_t *image,
unsigned long format);
/** image format conversion with crop/pad.
* if the requested size is larger than the image, the last row/column
* are duplicated to cover the difference. if the requested size is
* smaller than the image, the extra rows/columns are dropped from the
* right/bottom.
* @returns a @em new image with the sample data from the original
* image converted to the requested format and size.
* @note the image is @em not scaled
* @see zbar_image_convert()
* @since 0.4
*/
extern zbar_image_t *zbar_image_convert_resize(const zbar_image_t *image,
unsigned long format,
unsigned width,
unsigned height);
/** retrieve the image format.
* @returns the fourcc describing the format of the image sample data
*/
extern unsigned long zbar_image_get_format(const zbar_image_t *image);
/** retrieve a "sequence" (page/frame) number associated with this image.
* @since 0.6
*/
extern unsigned zbar_image_get_sequence(const zbar_image_t *image);
/** retrieve the width of the image.
* @returns the width in sample columns
*/
extern unsigned zbar_image_get_width(const zbar_image_t *image);
/** retrieve the height of the image.
* @returns the height in sample rows
*/
extern unsigned zbar_image_get_height(const zbar_image_t *image);
/** retrieve both dimensions of the image.
* fills in the width and height in samples
*/
extern void zbar_image_get_size(const zbar_image_t *image,
unsigned *width,
unsigned *height);
/** retrieve the crop rectangle.
* fills in the image coordinates of the upper left corner and size
* of an axis-aligned rectangular area of the image that will be scanned.
* defaults to the full image
* @since 0.11
*/
extern void zbar_image_get_crop(const zbar_image_t *image,
unsigned *x,
unsigned *y,
unsigned *width,
unsigned *height);
/** return the image sample data. the returned data buffer is only
* valid until zbar_image_destroy() is called
*/
extern const void *zbar_image_get_data(const zbar_image_t *image);
/** return the size of image data.
* @since 0.6
*/
extern unsigned long zbar_image_get_data_length(const zbar_image_t *img);
/** retrieve the decoded results.
* @returns the (possibly empty) set of decoded symbols
* @returns NULL if the image has not been scanned
* @since 0.10
*/
extern const zbar_symbol_set_t*
zbar_image_get_symbols(const zbar_image_t *image);
/** associate the specified symbol set with the image, replacing any
* existing results. use NULL to release the current results from the
* image.
* @see zbar_image_scanner_recycle_image()
* @since 0.10
*/
extern void zbar_image_set_symbols(zbar_image_t *image,
const zbar_symbol_set_t *symbols);
/** image_scanner decode result iterator.
* @returns the first decoded symbol result for an image
* or NULL if no results are available
*/
extern const zbar_symbol_t*
zbar_image_first_symbol(const zbar_image_t *image);
/** specify the fourcc image format code for image sample data.
* refer to the documentation for supported formats.
* @note this does not convert the data!
* (see zbar_image_convert() for that)
*/
extern void zbar_image_set_format(zbar_image_t *image,
unsigned long format);
/** associate a "sequence" (page/frame) number with this image.
* @since 0.6
*/
extern void zbar_image_set_sequence(zbar_image_t *image,
unsigned sequence_num);
/** specify the pixel size of the image.
* @note this also resets the crop rectangle to the full image
* (0, 0, width, height)
* @note this does not affect the data!
*/
extern void zbar_image_set_size(zbar_image_t *image,
unsigned width,
unsigned height);
/** specify a rectangular region of the image to scan.
* the rectangle will be clipped to the image boundaries.
* defaults to the full image specified by zbar_image_set_size()
*/
extern void zbar_image_set_crop(zbar_image_t *image,
unsigned x,
unsigned y,
unsigned width,
unsigned height);
/** specify image sample data. when image data is no longer needed by
* the library the specific data cleanup handler will be called
* (unless NULL)
* @note application image data will not be modified by the library
*/
extern void zbar_image_set_data(zbar_image_t *image,
const void *data,
unsigned long data_byte_length,
zbar_image_cleanup_handler_t *cleanup_hndlr);
/** built-in cleanup handler.
* passes the image data buffer to free()
*/
extern void zbar_image_free_data(zbar_image_t *image);
/** associate user specified data value with an image.
* @since 0.5
*/
extern void zbar_image_set_userdata(zbar_image_t *image,
void *userdata);
/** return user specified data value associated with the image.
* @since 0.5
*/
extern void *zbar_image_get_userdata(const zbar_image_t *image);
/** dump raw image data to a file for debug.
* the data will be prefixed with a 16 byte header consisting of:
* - 4 bytes uint = 0x676d697a ("zimg")
* - 4 bytes format fourcc
* - 2 bytes width
* - 2 bytes height
* - 4 bytes size of following image data in bytes
* this header can be dumped w/eg:
* @verbatim
od -Ax -tx1z -N16 -w4 [file]
@endverbatim
* for some formats the image can be displayed/converted using
* ImageMagick, eg:
* @verbatim
display -size 640x480+16 [-depth ?] [-sampling-factor ?x?] \
{GRAY,RGB,UYVY,YUV}:[file]
@endverbatim
*
* @param image the image object to dump
* @param filebase base filename, appended with ".XXXX.zimg" where
* XXXX is the format fourcc
* @returns 0 on success or a system error code on failure
*/
extern int zbar_image_write(const zbar_image_t *image,
const char *filebase);
/** read back an image in the format written by zbar_image_write()
* @note TBD
*/
extern zbar_image_t *zbar_image_read(char *filename);
/*@}*/
/*------------------------------------------------------------*/
/** @name Processor interface
* @anchor c-processor
* high-level self-contained image processor.
* processes video and images for barcodes, optionally displaying
* images to a library owned output window
*/
/*@{*/
struct zbar_processor_s;
/** opaque standalone processor object. */
typedef struct zbar_processor_s zbar_processor_t;
/** constructor.
* if threaded is set and threading is available the processor
* will spawn threads where appropriate to avoid blocking and
* improve responsiveness
*/
extern zbar_processor_t *zbar_processor_create(int threaded);
/** destructor. cleans up all resources associated with the processor
*/
extern void zbar_processor_destroy(zbar_processor_t *processor);
/** (re)initialization.
* opens a video input device and/or prepares to display output
*/
extern int zbar_processor_init(zbar_processor_t *processor,
const char *video_device,
int enable_display);
/** request a preferred size for the video image from the device.
* the request may be adjusted or completely ignored by the driver.
* @note must be called before zbar_processor_init()
* @since 0.6
*/
extern int zbar_processor_request_size(zbar_processor_t *processor,
unsigned width,
unsigned height);
/** request a preferred video driver interface version for
* debug/testing.
* @note must be called before zbar_processor_init()
* @since 0.6
*/
extern int zbar_processor_request_interface(zbar_processor_t *processor,
int version);
/** request a preferred video I/O mode for debug/testing. You will
* get errors if the driver does not support the specified mode.
* @verbatim
0 = auto-detect
1 = force I/O using read()
2 = force memory mapped I/O using mmap()
3 = force USERPTR I/O (v4l2 only)
@endverbatim
* @note must be called before zbar_processor_init()
* @since 0.7
*/
extern int zbar_processor_request_iomode(zbar_processor_t *video,
int iomode);
/** force specific input and output formats for debug/testing.
* @note must be called before zbar_processor_init()
*/
extern int zbar_processor_force_format(zbar_processor_t *processor,
unsigned long input_format,
unsigned long output_format);
/** setup result handler callback.
* the specified function will be called by the processor whenever
* new results are available from the video stream or a static image.
* pass a NULL value to disable callbacks.
* @param processor the object on which to set the handler.
* @param handler the function to call when new results are available.
* @param userdata is set as with zbar_processor_set_userdata().
* @returns the previously registered handler
*/
extern zbar_image_data_handler_t*
zbar_processor_set_data_handler(zbar_processor_t *processor,
zbar_image_data_handler_t *handler,
const void *userdata);
/** associate user specified data value with the processor.
* @since 0.6
*/
extern void zbar_processor_set_userdata(zbar_processor_t *processor,
void *userdata);
/** return user specified data value associated with the processor.
* @since 0.6
*/
extern void *zbar_processor_get_userdata(const zbar_processor_t *processor);
/** set config for indicated symbology (0 for all) to specified value.
* @returns 0 for success, non-0 for failure (config does not apply to
* specified symbology, or value out of range)
* @see zbar_decoder_set_config()
* @since 0.4
*/
extern int zbar_processor_set_config(zbar_processor_t *processor,
zbar_symbol_type_t symbology,
zbar_config_t config,
int value);
/** parse configuration string using zbar_parse_config()
* and apply to processor using zbar_processor_set_config().
* @returns 0 for success, non-0 for failure
* @see zbar_parse_config()
* @see zbar_processor_set_config()
* @since 0.4
*/
static inline int zbar_processor_parse_config (zbar_processor_t *processor,
const char *config_string)
{
zbar_symbol_type_t sym;
zbar_config_t cfg;
int val;
return(zbar_parse_config(config_string, &sym, &cfg, &val) ||
zbar_processor_set_config(processor, sym, cfg, val));
}
/** retrieve the current state of the ouput window.
* @returns 1 if the output window is currently displayed, 0 if not.
* @returns -1 if an error occurs
*/
extern int zbar_processor_is_visible(zbar_processor_t *processor);
/** show or hide the display window owned by the library.
* the size will be adjusted to the input size
*/
extern int zbar_processor_set_visible(zbar_processor_t *processor,
int visible);
/** control the processor in free running video mode.
* only works if video input is initialized. if threading is in use,
* scanning will occur in the background, otherwise this is only
* useful wrapping calls to zbar_processor_user_wait(). if the
* library output window is visible, video display will be enabled.
*/
extern int zbar_processor_set_active(zbar_processor_t *processor,
int active);
/** retrieve decode results for last scanned image/frame.
* @returns the symbol set result container or NULL if no results are
* available
* @note the returned symbol set has its reference count incremented;
* ensure that the count is decremented after use
* @since 0.10
*/
extern const zbar_symbol_set_t*
zbar_processor_get_results(const zbar_processor_t *processor);
/** wait for input to the display window from the user
* (via mouse or keyboard).
* @returns >0 when input is received, 0 if timeout ms expired
* with no input or -1 in case of an error
*/
extern int zbar_processor_user_wait(zbar_processor_t *processor,
int timeout);
/** process from the video stream until a result is available,
* or the timeout (in milliseconds) expires.
* specify a timeout of -1 to scan indefinitely
* (zbar_processor_set_active() may still be used to abort the scan
* from another thread).
* if the library window is visible, video display will be enabled.
* @note that multiple results may still be returned (despite the
* name).
* @returns >0 if symbols were successfully decoded,
* 0 if no symbols were found (ie, the timeout expired)
* or -1 if an error occurs
*/
extern int zbar_process_one(zbar_processor_t *processor,
int timeout);
/** process the provided image for barcodes.
* if the library window is visible, the image will be displayed.
* @returns >0 if symbols were successfully decoded,
* 0 if no symbols were found or -1 if an error occurs
*/
extern int zbar_process_image(zbar_processor_t *processor,
zbar_image_t *image);
/** display detail for last processor error to stderr.
* @returns a non-zero value suitable for passing to exit()
*/
static inline int
zbar_processor_error_spew (const zbar_processor_t *processor,
int verbosity)
{
return(_zbar_error_spew(processor, verbosity));
}
/** retrieve the detail string for the last processor error. */
static inline const char*
zbar_processor_error_string (const zbar_processor_t *processor,
int verbosity)
{
return(_zbar_error_string(processor, verbosity));
}
/** retrieve the type code for the last processor error. */
static inline zbar_error_t
zbar_processor_get_error_code (const zbar_processor_t *processor)
{
return(_zbar_get_error_code(processor));
}
/*@}*/
/*------------------------------------------------------------*/
/** @name Video interface
* @anchor c-video
* mid-level video source abstraction.
* captures images from a video device
*/
/*@{*/
struct zbar_video_s;
/** opaque video object. */
typedef struct zbar_video_s zbar_video_t;
/** constructor. */
extern zbar_video_t *zbar_video_create(void);
/** destructor. */
extern void zbar_video_destroy(zbar_video_t *video);
/** open and probe a video device.
* the device specified by platform specific unique name
* (v4l device node path in *nix eg "/dev/video",
* DirectShow DevicePath property in windows).
* @returns 0 if successful or -1 if an error occurs
*/
extern int zbar_video_open(zbar_video_t *video,
const char *device);
/** retrieve file descriptor associated with open *nix video device
* useful for using select()/poll() to tell when new images are
* available (NB v4l2 only!!).
* @returns the file descriptor or -1 if the video device is not open
* or the driver only supports v4l1
*/
extern int zbar_video_get_fd(const zbar_video_t *video);
/** request a preferred size for the video image from the device.
* the request may be adjusted or completely ignored by the driver.
* @returns 0 if successful or -1 if the video device is already
* initialized
* @since 0.6
*/
extern int zbar_video_request_size(zbar_video_t *video,
unsigned width,
unsigned height);
/** request a preferred driver interface version for debug/testing.
* @note must be called before zbar_video_open()
* @since 0.6
*/
extern int zbar_video_request_interface(zbar_video_t *video,
int version);