/*------------------------------------------------------------------------ * Copyright 2007-2010 (c) Jeff Brown * * 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 */ #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_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); /** request a preferred 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_video_open() * @since 0.7 */ extern int zbar_video_request_iomode(zbar_video_t *video, int iomode); /** retrieve current output image width. * @returns the width or 0 if the video device is not open */ extern int zbar_video_get_width(const zbar_video_t *video); /** retrieve current output image height. * @returns the height or 0 if the video device is not open */ extern int zbar_video_get_height(const zbar_video_t *video); /** initialize video using a specific format for debug. * use zbar_negotiate_format() to automatically select and initialize * the best available format */ extern int zbar_video_init(zbar_video_t *video, unsigned long format); /** start/stop video capture. * all buffered images are retired when capture is disabled. * @returns 0 if successful or -1 if an error occurs */ extern int zbar_video_enable(zbar_video_t *video, int enable); /** retrieve next captured image. blocks until an image is available. * @returns NULL if video is not enabled or an error occurs */ extern zbar_image_t *zbar_video_next_image(zbar_video_t *video); /** display detail for last video error to stderr. * @returns a non-zero value suitable for passing to exit() */ static inline int zbar_video_error_spew (const zbar_video_t *video, int verbosity) { return(_zbar_error_spew(video, verbosity)); } /** retrieve the detail string for the last video error. */ static inline const char *zbar_video_error_string (const zbar_video_t *video, int verbosity) { return(_zbar_error_string(video, verbosity)); } /** retrieve the type code for the last video error. */ static inline zbar_error_t zbar_video_get_error_code (const zbar_video_t *video) { return(_zbar_get_error_code(video)); } /*@}*/ /*------------------------------------------------------------*/ /** @name Window interface * @anchor c-window * mid-level output window abstraction. * displays images to user-specified platform specific output window */ /*@{*/ struct zbar_window_s; /** opaque window object. */ typedef struct zbar_window_s zbar_window_t; /** constructor. */ extern zbar_window_t *zbar_window_create(void); /** destructor. */ extern void zbar_window_destroy(zbar_window_t *window); /** associate reader with an existing platform window. * This can be any "Drawable" for X Windows or a "HWND" for windows. * input images will be scaled into the output window. * pass NULL to detach from the resource, further input will be * ignored */ extern int zbar_window_attach(zbar_window_t *window, void *x11_display_w32_hwnd, unsigned long x11_drawable); /** control content level of the reader overlay. * the overlay displays graphical data for informational or debug * purposes. higher values increase the level of annotation (possibly * decreasing performance). @verbatim 0 = disable overlay 1 = outline decoded symbols (default) 2 = also track and display input frame rate @endverbatim */ extern void zbar_window_set_overlay(zbar_window_t *window, int level); /** retrieve current content level of reader overlay. * @see zbar_window_set_overlay() * @since 0.10 */ extern int zbar_window_get_overlay(const zbar_window_t *window); /** draw a new image into the output window. */ extern int zbar_window_draw(zbar_window_t *window, zbar_image_t *image); /** redraw the last image (exposure handler). */ extern int zbar_window_redraw(zbar_window_t *window); /** resize the image window (reconfigure handler). * this does @em not update the contents of the window * @since 0.3, changed in 0.4 to not redraw window */ extern int zbar_window_resize(zbar_window_t *window, unsigned width, unsigned height); /** display detail for last window error to stderr. * @returns a non-zero value suitable for passing to exit() */ static inline int zbar_window_error_spew (const zbar_window_t *window, int verbosity) { return(_zbar_error_spew(window, verbosity)); } /** retrieve the detail string for the last window error. */ static inline const char* zbar_window_error_string (const zbar_window_t *window, int verbosity) { return(_zbar_error_string(window, verbosity)); } /** retrieve the type code for the last window error. */ static inline zbar_error_t zbar_window_get_error_code (const zbar_window_t *window) { return(_zbar_get_error_code(window)); } /** select a compatible format between video input and output window. * the selection algorithm attempts to use a format shared by * video input and window output which is also most useful for * barcode scanning. if a format conversion is necessary, it will * heuristically attempt to minimize the cost of the conversion */ extern int zbar_negotiate_format(zbar_video_t *video, zbar_window_t *window); /*@}*/ /*------------------------------------------------------------*/ /** @name Image Scanner interface * @anchor c-imagescanner * mid-level image scanner interface. * reads barcodes from 2-D images */ /*@{*/ struct zbar_image_scanner_s; /** opaque image scanner object. */ typedef struct zbar_image_scanner_s zbar_image_scanner_t; /** constructor. */ extern zbar_image_scanner_t *zbar_image_scanner_create(void); /** destructor. */ extern void zbar_image_scanner_destroy(zbar_image_scanner_t *scanner); /** setup result handler callback. * the specified function will be called by the scanner whenever * new results are available from a decoded image. * pass a NULL value to disable callbacks. * @returns the previously registered handler */ extern zbar_image_data_handler_t* zbar_image_scanner_set_data_handler(zbar_image_scanner_t *scanner, zbar_image_data_handler_t *handler, const void *userdata); /** 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_image_scanner_set_config(zbar_image_scanner_t *scanner, zbar_symbol_type_t symbology, zbar_config_t config, int value); /** parse configuration string using zbar_parse_config() * and apply to image scanner using zbar_image_scanner_set_config(). * @returns 0 for success, non-0 for failure * @see zbar_parse_config() * @see zbar_image_scanner_set_config() * @since 0.4 */ static inline int zbar_image_scanner_parse_config (zbar_image_scanner_t *scanner, 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_image_scanner_set_config(scanner, sym, cfg, val)); } /** enable or disable the inter-image result cache (default disabled). * mostly useful for scanning video frames, the cache filters * duplicate results from consecutive images, while adding some * consistency checking and hysteresis to the results. * this interface also clears the cache */ extern void zbar_image_scanner_enable_cache(zbar_image_scanner_t *scanner, int enable); /** remove any previously decoded results from the image scanner and the * specified image. somewhat more efficient version of * zbar_image_set_symbols(image, NULL) which may retain memory for * subsequent decodes * @since 0.10 */ extern void zbar_image_scanner_recycle_image(zbar_image_scanner_t *scanner, zbar_image_t *image); /** retrieve decode results for last scanned image. * @returns the symbol set result container or NULL if no results are * available * @note the symbol set does not have its reference count adjusted; * ensure that the count is incremented if the results may be kept * after the next image is scanned * @since 0.10 */ extern const zbar_symbol_set_t* zbar_image_scanner_get_results(const zbar_image_scanner_t *scanner); /** scan for symbols in provided image. The image format must be * "Y800" or "GRAY". * @returns >0 if symbols were successfully decoded from the image, * 0 if no symbols were found or -1 if an error occurs * @see zbar_image_convert() * @since 0.9 - changed to only accept grayscale images */ extern int zbar_scan_image(zbar_image_scanner_t *scanner, zbar_image_t *image); /*@}*/ /*------------------------------------------------------------*/ /** @name Decoder interface * @anchor c-decoder * low-level bar width stream decoder interface. * identifies symbols and extracts encoded data */ /*@{*/ struct zbar_decoder_s; /** opaque decoder object. */ typedef struct zbar_decoder_s zbar_decoder_t; /** decoder data handler callback function. * called by decoder when new data has just been decoded */ typedef void (zbar_decoder_handler_t)(zbar_decoder_t *decoder); /** constructor. */ extern zbar_decoder_t *zbar_decoder_create(void); /** destructor. */ extern void zbar_decoder_destroy(zbar_decoder_t *decoder); /** 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) * @since 0.4 */ extern int zbar_decoder_set_config(zbar_decoder_t *decoder, zbar_symbol_type_t symbology, zbar_config_t config, int value); /** parse configuration string using zbar_parse_config() * and apply to decoder using zbar_decoder_set_config(). * @returns 0 for success, non-0 for failure * @see zbar_parse_config() * @see zbar_decoder_set_config() * @since 0.4 */ static inline int zbar_decoder_parse_config (zbar_decoder_t *decoder, 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_decoder_set_config(decoder, sym, cfg, val)); } /** retrieve symbology boolean config settings. * @returns a bitmask indicating which configs are currently set for the * specified symbology. * @since 0.11 */ extern unsigned int zbar_decoder_get_configs(const zbar_decoder_t *decoder, zbar_symbol_type_t symbology); /** clear all decoder state. * any partial symbols are flushed */ extern void zbar_decoder_reset(zbar_decoder_t *decoder); /** mark start of a new scan pass. * clears any intra-symbol state and resets color to ::ZBAR_SPACE. * any partially decoded symbol state is retained */ extern void zbar_decoder_new_scan(zbar_decoder_t *decoder); /** process next bar/space width from input stream. * the width is in arbitrary relative units. first value of a scan * is ::ZBAR_SPACE width, alternating from there. * @returns appropriate symbol type if width completes * decode of a symbol (data is available for retrieval) * @returns ::ZBAR_PARTIAL as a hint if part of a symbol was decoded * @returns ::ZBAR_NONE (0) if no new symbol data is available */ extern zbar_symbol_type_t zbar_decode_width(zbar_decoder_t *decoder, unsigned width); /** retrieve color of @em next element passed to * zbar_decode_width(). */ extern zbar_color_t zbar_decoder_get_color(const zbar_decoder_t *decoder); /** retrieve last decoded data. * @returns the data string or NULL if no new data available. * the returned data buffer is owned by library, contents are only * valid between non-0 return from zbar_decode_width and next library * call */ extern const char *zbar_decoder_get_data(const zbar_decoder_t *decoder); /** retrieve length of binary data. * @returns the length of the decoded data or 0 if no new data * available. */ extern unsigned int zbar_decoder_get_data_length(const zbar_decoder_t *decoder); /** retrieve last decoded symbol type. * @returns the type or ::ZBAR_NONE if no new data available */ extern zbar_symbol_type_t zbar_decoder_get_type(const zbar_decoder_t *decoder); /** retrieve modifier flags for the last decoded symbol. * @returns a bitmask indicating which characteristics were detected * during decoding. * @since 0.11 */ extern unsigned int zbar_decoder_get_modifiers(const zbar_decoder_t *decoder); /** retrieve last decode direction. * @returns 1 for forward and -1 for reverse * @returns 0 if the decode direction is unknown or does not apply * @since 0.11 */ extern int zbar_decoder_get_direction(const zbar_decoder_t *decoder); /** setup data handler callback. * the registered function will be called by the decoder * just before zbar_decode_width() returns a non-zero value. * pass a NULL value to disable callbacks. * @returns the previously registered handler */ extern zbar_decoder_handler_t* zbar_decoder_set_handler(zbar_decoder_t *decoder, zbar_decoder_handler_t *handler); /** associate user specified data value with the decoder. */ extern void zbar_decoder_set_userdata(zbar_decoder_t *decoder, void *userdata); /** return user specified data value associated with the decoder. */ extern void *zbar_decoder_get_userdata(const zbar_decoder_t *decoder); /*@}*/ /*------------------------------------------------------------*/ /** @name Scanner interface * @anchor c-scanner * low-level linear intensity sample stream scanner interface. * identifies "bar" edges and measures width between them. * optionally passes to bar width decoder */ /*@{*/ struct zbar_scanner_s; /** opaque scanner object. */ typedef struct zbar_scanner_s zbar_scanner_t; /** constructor. * if decoder is non-NULL it will be attached to scanner * and called automatically at each new edge * current color is initialized to ::ZBAR_SPACE * (so an initial BAR->SPACE transition may be discarded) */ extern zbar_scanner_t *zbar_scanner_create(zbar_decoder_t *decoder); /** destructor. */ extern void zbar_scanner_destroy(zbar_scanner_t *scanner); /** clear all scanner state. * also resets an associated decoder */ extern zbar_symbol_type_t zbar_scanner_reset(zbar_scanner_t *scanner); /** mark start of a new scan pass. resets color to ::ZBAR_SPACE. * also updates an associated decoder. * @returns any decode results flushed from the pipeline * @note when not using callback handlers, the return value should * be checked the same as zbar_scan_y() * @note call zbar_scanner_flush() at least twice before calling this * method to ensure no decode results are lost */ extern zbar_symbol_type_t zbar_scanner_new_scan(zbar_scanner_t *scanner); /** flush scanner processing pipeline. * forces current scanner position to be a scan boundary. * call multiple times (max 3) to completely flush decoder. * @returns any decode/scan results flushed from the pipeline * @note when not using callback handlers, the return value should * be checked the same as zbar_scan_y() * @since 0.9 */ extern zbar_symbol_type_t zbar_scanner_flush(zbar_scanner_t *scanner); /** process next sample intensity value. * intensity (y) is in arbitrary relative units. * @returns result of zbar_decode_width() if a decoder is attached, * otherwise @returns (::ZBAR_PARTIAL) when new edge is detected * or 0 (::ZBAR_NONE) if no new edge is detected */ extern zbar_symbol_type_t zbar_scan_y(zbar_scanner_t *scanner, int y); /** process next sample from RGB (or BGR) triple. */ static inline zbar_symbol_type_t zbar_scan_rgb24 (zbar_scanner_t *scanner, unsigned char *rgb) { return(zbar_scan_y(scanner, rgb[0] + rgb[1] + rgb[2])); } /** retrieve last scanned width. */ extern unsigned zbar_scanner_get_width(const zbar_scanner_t *scanner); /** retrieve sample position of last edge. * @since 0.10 */ extern unsigned zbar_scanner_get_edge(const zbar_scanner_t *scn, unsigned offset, int prec); /** retrieve last scanned color. */ extern zbar_color_t zbar_scanner_get_color(const zbar_scanner_t *scanner); /*@}*/ #ifdef __cplusplus } } # include "zbar/Exception.h" # include "zbar/Decoder.h" # include "zbar/Scanner.h" # include "zbar/Symbol.h" # include "zbar/Image.h" # include "zbar/ImageScanner.h" # include "zbar/Video.h" # include "zbar/Window.h" # include "zbar/Processor.h" #endif #endif