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Diffstat (limited to 'make/stub_includes/ffmpeg/v0400/libavutil/hash.h')
| -rw-r--r-- | make/stub_includes/ffmpeg/v0400/libavutil/hash.h | 269 |
1 files changed, 269 insertions, 0 deletions
diff --git a/make/stub_includes/ffmpeg/v0400/libavutil/hash.h b/make/stub_includes/ffmpeg/v0400/libavutil/hash.h new file mode 100644 index 000000000..7693e6bf0 --- /dev/null +++ b/make/stub_includes/ffmpeg/v0400/libavutil/hash.h @@ -0,0 +1,269 @@ +/* + * Copyright (C) 2013 Reimar Döffinger <[email protected]> + * + * 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_hash_generic + * Generic hashing API + */ + +#ifndef AVUTIL_HASH_H +#define AVUTIL_HASH_H + +#include <stdint.h> + +#include "version.h" + +/** + * @defgroup lavu_hash Hash Functions + * @ingroup lavu_crypto + * Hash functions useful in multimedia. + * + * Hash functions are widely used in multimedia, from error checking and + * concealment to internal regression testing. libavutil has efficient + * implementations of a variety of hash functions that may be useful for + * FFmpeg and other multimedia applications. + * + * @{ + * + * @defgroup lavu_hash_generic Generic Hashing API + * An abstraction layer for all hash functions supported by libavutil. + * + * If your application needs to support a wide range of different hash + * functions, then the Generic Hashing API is for you. It provides a generic, + * reusable API for @ref lavu_hash "all hash functions" implemented in libavutil. + * If you just need to use one particular hash function, use the @ref lavu_hash + * "individual hash" directly. + * + * @section Sample Code + * + * A basic template for using the Generic Hashing API follows: + * + * @code + * struct AVHashContext *ctx = NULL; + * const char *hash_name = NULL; + * uint8_t *output_buf = NULL; + * + * // Select from a string returned by av_hash_names() + * hash_name = ...; + * + * // Allocate a hash context + * ret = av_hash_alloc(&ctx, hash_name); + * if (ret < 0) + * return ret; + * + * // Initialize the hash context + * av_hash_init(ctx); + * + * // Update the hash context with data + * while (data_left) { + * av_hash_update(ctx, data, size); + * } + * + * // Now we have no more data, so it is time to finalize the hash and get the + * // output. But we need to first allocate an output buffer. Note that you can + * // use any memory allocation function, including malloc(), not just + * // av_malloc(). + * output_buf = av_malloc(av_hash_get_size(ctx)); + * if (!output_buf) + * return AVERROR(ENOMEM); + * + * // Finalize the hash context. + * // You can use any of the av_hash_final*() functions provided, for other + * // output formats. If you do so, be sure to adjust the memory allocation + * // above. See the function documentation below for the exact amount of extra + * // memory needed. + * av_hash_final(ctx, output_buffer); + * + * // Free the context + * av_hash_freep(&ctx); + * @endcode + * + * @section Hash Function-Specific Information + * If the CRC32 hash is selected, the #AV_CRC_32_IEEE polynomial will be + * used. + * + * If the Murmur3 hash is selected, the default seed will be used. See @ref + * lavu_murmur3_seedinfo "Murmur3" for more information. + * + * @{ + */ + +/** + * @example ffhash.c + * This example is a simple command line application that takes one or more + * arguments. It demonstrates a typical use of the hashing API with allocation, + * initialization, updating, and finalizing. + */ + +struct AVHashContext; + +/** + * Allocate a hash context for the algorithm specified by name. + * + * @return >= 0 for success, a negative error code for failure + * + * @note The context is not initialized after a call to this function; you must + * call av_hash_init() to do so. + */ +int av_hash_alloc(struct AVHashContext **ctx, const char *name); + +/** + * Get the names of available hash algorithms. + * + * This function can be used to enumerate the algorithms. + * + * @param[in] i Index of the hash algorithm, starting from 0 + * @return Pointer to a static string or `NULL` if `i` is out of range + */ +const char *av_hash_names(int i); + +/** + * Get the name of the algorithm corresponding to the given hash context. + */ +const char *av_hash_get_name(const struct AVHashContext *ctx); + +/** + * Maximum value that av_hash_get_size() will currently return. + * + * You can use this if you absolutely want or need to use static allocation for + * the output buffer and are fine with not supporting hashes newly added to + * libavutil without recompilation. + * + * @warning + * Adding new hashes with larger sizes, and increasing the macro while doing + * so, will not be considered an ABI change. To prevent your code from + * overflowing a buffer, either dynamically allocate the output buffer with + * av_hash_get_size(), or limit your use of the Hashing API to hashes that are + * already in FFmpeg during the time of compilation. + */ +#define AV_HASH_MAX_SIZE 64 + +/** + * Get the size of the resulting hash value in bytes. + * + * The maximum value this function will currently return is available as macro + * #AV_HASH_MAX_SIZE. + * + * @param[in] ctx Hash context + * @return Size of the hash value in bytes + */ +int av_hash_get_size(const struct AVHashContext *ctx); + +/** + * Initialize or reset a hash context. + * + * @param[in,out] ctx Hash context + */ +void av_hash_init(struct AVHashContext *ctx); + +/** + * Update a hash context with additional data. + * + * @param[in,out] ctx Hash context + * @param[in] src Data to be added to the hash context + * @param[in] len Size of the additional data + */ +#if FF_API_CRYPTO_SIZE_T +void av_hash_update(struct AVHashContext *ctx, const uint8_t *src, int len); +#else +void av_hash_update(struct AVHashContext *ctx, const uint8_t *src, size_t len); +#endif + +/** + * Finalize a hash context and compute the actual hash value. + * + * The minimum size of `dst` buffer is given by av_hash_get_size() or + * #AV_HASH_MAX_SIZE. The use of the latter macro is discouraged. + * + * It is not safe to update or finalize a hash context again, if it has already + * been finalized. + * + * @param[in,out] ctx Hash context + * @param[out] dst Where the final hash value will be stored + * + * @see av_hash_final_bin() provides an alternative API + */ +void av_hash_final(struct AVHashContext *ctx, uint8_t *dst); + +/** + * Finalize a hash context and store the actual hash value in a buffer. + * + * It is not safe to update or finalize a hash context again, if it has already + * been finalized. + * + * If `size` is smaller than the hash size (given by av_hash_get_size()), the + * hash is truncated; if size is larger, the buffer is padded with 0. + * + * @param[in,out] ctx Hash context + * @param[out] dst Where the final hash value will be stored + * @param[in] size Number of bytes to write to `dst` + */ +void av_hash_final_bin(struct AVHashContext *ctx, uint8_t *dst, int size); + +/** + * Finalize a hash context and store the hexadecimal representation of the + * actual hash value as a string. + * + * It is not safe to update or finalize a hash context again, if it has already + * been finalized. + * + * The string is always 0-terminated. + * + * If `size` is smaller than `2 * hash_size + 1`, where `hash_size` is the + * value returned by av_hash_get_size(), the string will be truncated. + * + * @param[in,out] ctx Hash context + * @param[out] dst Where the string will be stored + * @param[in] size Maximum number of bytes to write to `dst` + */ +void av_hash_final_hex(struct AVHashContext *ctx, uint8_t *dst, int size); + +/** + * Finalize a hash context and store the Base64 representation of the + * actual hash value as a string. + * + * It is not safe to update or finalize a hash context again, if it has already + * been finalized. + * + * The string is always 0-terminated. + * + * If `size` is smaller than AV_BASE64_SIZE(hash_size), where `hash_size` is + * the value returned by av_hash_get_size(), the string will be truncated. + * + * @param[in,out] ctx Hash context + * @param[out] dst Where the final hash value will be stored + * @param[in] size Maximum number of bytes to write to `dst` + */ +void av_hash_final_b64(struct AVHashContext *ctx, uint8_t *dst, int size); + +/** + * Free hash context and set hash context pointer to `NULL`. + * + * @param[in,out] ctx Pointer to hash context + */ +void av_hash_freep(struct AVHashContext **ctx); + +/** + * @} + * @} + */ + +#endif /* AVUTIL_HASH_H */ |