aarch64: Add assembly support for -fsanitize=hwaddress tagged globals.
[libav.git] / libavutil / crc.h
1 /*
2 * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
3 *
4 * This file is part of Libav.
5 *
6 * Libav is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * Libav is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with Libav; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21 #ifndef AVUTIL_CRC_H
22 #define AVUTIL_CRC_H
23
24 #include <stdint.h>
25 #include <stddef.h>
26 #include "attributes.h"
27
28 typedef uint32_t AVCRC;
29
30 typedef enum {
31 AV_CRC_8_ATM,
32 AV_CRC_16_ANSI,
33 AV_CRC_16_CCITT,
34 AV_CRC_32_IEEE,
35 AV_CRC_32_IEEE_LE, /*< reversed bitorder version of AV_CRC_32_IEEE */
36 AV_CRC_16_ANSI_LE, /*< reversed bitorder version of AV_CRC_16_ANSI */
37 AV_CRC_MAX, /*< Not part of public API! Do not use outside libavutil. */
38 }AVCRCId;
39
40 /**
41 * Initialize a CRC table.
42 * @param ctx must be an array of size sizeof(AVCRC)*257 or sizeof(AVCRC)*1024
43 * @param le If 1, the lowest bit represents the coefficient for the highest
44 * exponent of the corresponding polynomial (both for poly and
45 * actual CRC).
46 * If 0, you must swap the CRC parameter and the result of av_crc
47 * if you need the standard representation (can be simplified in
48 * most cases to e.g. bswap16):
49 * av_bswap32(crc << (32-bits))
50 * @param bits number of bits for the CRC
51 * @param poly generator polynomial without the x**bits coefficient, in the
52 * representation as specified by le
53 * @param ctx_size size of ctx in bytes
54 * @return <0 on failure
55 */
56 int av_crc_init(AVCRC *ctx, int le, int bits, uint32_t poly, int ctx_size);
57
58 /**
59 * Get an initialized standard CRC table.
60 * @param crc_id ID of a standard CRC
61 * @return a pointer to the CRC table or NULL on failure
62 */
63 const AVCRC *av_crc_get_table(AVCRCId crc_id);
64
65 /**
66 * Calculate the CRC of a block.
67 * @param crc CRC of previous blocks if any or initial value for CRC
68 * @return CRC updated with the data from the given block
69 *
70 * @see av_crc_init() "le" parameter
71 */
72 uint32_t av_crc(const AVCRC *ctx, uint32_t crc,
73 const uint8_t *buffer, size_t length) av_pure;
74
75 #endif /* AVUTIL_CRC_H */