Revision 45e3c163 libavutil/crc.c
libavutil/crc.c | ||
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* Inits a crc table. |
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* @param ctx must be an array of sizeof(AVCRC)*257 or sizeof(AVCRC)*1024 |
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* @param cts_size size of ctx in bytes |
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* @param le if 1, lowest bit represents coefficient for highest exponent |
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* of corresponding polynomial (both for poly and actual CRC). |
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* If 0, you must swap the crc parameter and the result of av_crc |
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* if you need the standard representation (can be simplified in |
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* most cases to e.g. bswap16): |
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* bswap_32(crc << (32-bits)) |
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* @param bits number of bits for the CRC |
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* @param poly generator polynomial without the x**bits coefficient, in the |
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* representation as specified by le |
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* @return <0 on failure |
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*/ |
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int av_crc_init(AVCRC *ctx, int le, int bits, uint32_t poly, int ctx_size){ |
... | ... | |
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return 0; |
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} |
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/** |
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* Calculate the CRC of a block |
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* @param crc CRC of previous blocks if any or initial value for CRC. |
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* @return CRC updated with the data from the given block |
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* |
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* @see av_crc_init() "le" parameter |
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*/ |
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uint32_t av_crc(const AVCRC *ctx, uint32_t crc, const uint8_t *buffer, size_t length){ |
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const uint8_t *end= buffer+length; |
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