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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 17:32:43 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 17:32:43 +0000 |
commit | 6bf0a5cb5034a7e684dcc3500e841785237ce2dd (patch) | |
tree | a68f146d7fa01f0134297619fbe7e33db084e0aa /media/ffvpx/libavutil/crc.h | |
parent | Initial commit. (diff) | |
download | thunderbird-6bf0a5cb5034a7e684dcc3500e841785237ce2dd.tar.xz thunderbird-6bf0a5cb5034a7e684dcc3500e841785237ce2dd.zip |
Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | media/ffvpx/libavutil/crc.h | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/media/ffvpx/libavutil/crc.h b/media/ffvpx/libavutil/crc.h new file mode 100644 index 0000000000..7f59812a18 --- /dev/null +++ b/media/ffvpx/libavutil/crc.h @@ -0,0 +1,102 @@ +/* + * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at> + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg 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 General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +/** + * @file + * @ingroup lavu_crc32 + * Public header for CRC hash function implementation. + */ + +#ifndef AVUTIL_CRC_H +#define AVUTIL_CRC_H + +#include <stdint.h> +#include <stddef.h> +#include "attributes.h" + +/** + * @defgroup lavu_crc32 CRC + * @ingroup lavu_hash + * CRC (Cyclic Redundancy Check) hash function implementation. + * + * This module supports numerous CRC polynomials, in addition to the most + * widely used CRC-32-IEEE. See @ref AVCRCId for a list of available + * polynomials. + * + * @{ + */ + +typedef uint32_t AVCRC; + +typedef enum { + AV_CRC_8_ATM, + AV_CRC_16_ANSI, + AV_CRC_16_CCITT, + AV_CRC_32_IEEE, + AV_CRC_32_IEEE_LE, /*< reversed bitorder version of AV_CRC_32_IEEE */ + AV_CRC_16_ANSI_LE, /*< reversed bitorder version of AV_CRC_16_ANSI */ + AV_CRC_24_IEEE, + AV_CRC_8_EBU, + AV_CRC_MAX, /*< Not part of public API! Do not use outside libavutil. */ +}AVCRCId; + +/** + * Initialize a CRC table. + * @param ctx must be an array of size sizeof(AVCRC)*257 or sizeof(AVCRC)*1024 + * @param le If 1, the lowest bit represents the coefficient for the highest + * exponent of the corresponding polynomial (both for poly and + * actual CRC). + * If 0, you must swap the CRC parameter and the result of av_crc + * if you need the standard representation (can be simplified in + * most cases to e.g. bswap16): + * av_bswap32(crc << (32-bits)) + * @param bits number of bits for the CRC + * @param poly generator polynomial without the x**bits coefficient, in the + * representation as specified by le + * @param ctx_size size of ctx in bytes + * @return <0 on failure + */ +int av_crc_init(AVCRC *ctx, int le, int bits, uint32_t poly, int ctx_size); + +/** + * Get an initialized standard CRC table. + * @param crc_id ID of a standard CRC + * @return a pointer to the CRC table or NULL on failure + */ +const AVCRC *av_crc_get_table(AVCRCId crc_id); + +/** + * Calculate the CRC of a block. + * @param ctx initialized AVCRC array (see av_crc_init()) + * @param crc CRC of previous blocks if any or initial value for CRC + * @param buffer buffer whose CRC to calculate + * @param length length of the buffer + * @return CRC updated with the data from the given block + * + * @see av_crc_init() "le" parameter + */ +uint32_t av_crc(const AVCRC *ctx, uint32_t crc, + const uint8_t *buffer, size_t length) av_pure; + +/** + * @} + */ + +#endif /* AVUTIL_CRC_H */ |