141 lines
4.3 KiB
C
141 lines
4.3 KiB
C
/* quirc -- QR-code recognition library
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* Copyright (C) 2010-2012 Daniel Beer <dlbeer@gmail.com>
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*
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* Permission to use, copy, modify, and/or distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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#ifndef QUIRC_H_
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#define QUIRC_H_
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#include <stdint.h>
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struct quirc;
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/* Obtain the library version string. */
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const char *quirc_version(void);
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/* Construct a new QR-code recognizer. This function will return NULL
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* if sufficient memory could not be allocated.
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*/
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struct quirc *quirc_new(void);
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/* Destroy a QR-code recognizer. */
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void quirc_destroy(struct quirc *q);
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/* Resize the QR-code recognizer. The size of an image must be
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* specified before codes can be analyzed.
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*
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* This function returns 0 on success, or -1 if sufficient memory could
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* not be allocated.
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*/
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int quirc_resize(struct quirc *q, int w, int h);
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/* These functions are used to process images for QR-code recognition.
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* quirc_begin() must first be called to obtain access to a buffer into
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* which the input image should be placed. Optionally, the current
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* width and height may be returned.
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*
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* After filling the buffer, quirc_end() should be called to process
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* the image for QR-code recognition. The locations and content of each
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* code may be obtained using accessor functions described below.
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*/
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uint8_t *quirc_begin(struct quirc *q, int *w, int *h);
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void quirc_end(struct quirc *q);
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/* This structure describes a location in the input image buffer. */
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struct quirc_point {
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int x;
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int y;
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};
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/* This enum describes the various decoder errors which may occur. */
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typedef enum {
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QUIRC_SUCCESS = 0,
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QUIRC_ERROR_INVALID_GRID_SIZE,
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QUIRC_ERROR_INVALID_VERSION,
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QUIRC_ERROR_FORMAT_ECC,
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QUIRC_ERROR_DATA_ECC,
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QUIRC_ERROR_UNKNOWN_DATA_TYPE,
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QUIRC_ERROR_DATA_OVERFLOW,
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QUIRC_ERROR_DATA_UNDERFLOW
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} quirc_decode_error_t;
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/* Return a string error message for an error code. */
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const char *quirc_strerror(quirc_decode_error_t err);
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/* Limits on the maximum size of QR-codes and their content. */
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#define QUIRC_MAX_BITMAP 3917
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#define QUIRC_MAX_PAYLOAD 8896
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/* QR-code ECC types. */
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#define QUIRC_ECC_LEVEL_M 0
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#define QUIRC_ECC_LEVEL_L 1
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#define QUIRC_ECC_LEVEL_H 2
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#define QUIRC_ECC_LEVEL_Q 3
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/* QR-code data types. */
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#define QUIRC_DATA_TYPE_NUMERIC 1
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#define QUIRC_DATA_TYPE_ALPHA 2
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#define QUIRC_DATA_TYPE_BYTE 4
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#define QUIRC_DATA_TYPE_KANJI 8
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/* This structure is used to return information about detected QR codes
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* in the input image.
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*/
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struct quirc_code {
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/* The four corners of the QR-code, from top left, clockwise */
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struct quirc_point corners[4];
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/* The number of cells across in the QR-code. The cell bitmap
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* is a bitmask giving the actual values of cells. If the cell
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* at (x, y) is black, then the following bit is set:
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*
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* cell_bitmap[i << 3] & (1 << (i & 7))
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*
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* where i = (y * size) + x.
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*/
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int size;
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uint8_t cell_bitmap[QUIRC_MAX_BITMAP];
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};
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/* This structure holds the decoded QR-code data */
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struct quirc_data {
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/* Various parameters of the QR-code. These can mostly be
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* ignored if you only care about the data.
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*/
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int version;
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int ecc_level;
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int mask;
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int data_type;
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/* Data payload. For the Kanji datatype, payload is encoded as
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* Shift-JIS. For all other datatypes, payload is ASCII text.
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*/
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uint8_t payload[QUIRC_MAX_PAYLOAD];
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int payload_len;
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};
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/* Return the number of QR-codes identified in the last processed
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* image.
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*/
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int quirc_count(const struct quirc *q);
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/* Extract the QR-code specified by the given index. */
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void quirc_extract(const struct quirc *q, int index,
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struct quirc_code *code);
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/* Decode a QR-code, returning the payload data. */
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quirc_decode_error_t quirc_decode(const struct quirc_code *code,
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struct quirc_data *data);
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#endif
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