1 /* libFLAC - Free Lossless Audio Codec library 2 * Copyright (C) 2004-2009 Josh Coalson 3 * Copyright (C) 2011-2014 Xiph.Org Foundation 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 9 * - Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 12 * - Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * - Neither the name of the Xiph.org Foundation nor the names of its 17 * contributors may be used to endorse or promote products derived from 18 * this software without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 23 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR 24 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 25 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 26 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 27 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 28 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 29 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 30 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 #ifndef FLAC__CALLBACK_H 34 #define FLAC__CALLBACK_H 35 36 #include "ordinals.h" 37 38 // JUCE: removed as JUCE already includes this and including stdlib 39 // in FlacNamespace will cause problems 40 //#include <stdlib.h> 41 42 /** \file include/FLAC/callback.h 43 * 44 * \brief 45 * This module defines the structures for describing I/O callbacks 46 * to the other FLAC interfaces. 47 * 48 * See the detailed documentation for callbacks in the 49 * \link flac_callbacks callbacks \endlink module. 50 */ 51 52 /** \defgroup flac_callbacks FLAC/callback.h: I/O callback structures 53 * \ingroup flac 54 * 55 * \brief 56 * This module defines the structures for describing I/O callbacks 57 * to the other FLAC interfaces. 58 * 59 * The purpose of the I/O callback functions is to create a common way 60 * for the metadata interfaces to handle I/O. 61 * 62 * Originally the metadata interfaces required filenames as the way of 63 * specifying FLAC files to operate on. This is problematic in some 64 * environments so there is an additional option to specify a set of 65 * callbacks for doing I/O on the FLAC file, instead of the filename. 66 * 67 * In addition to the callbacks, a FLAC__IOHandle type is defined as an 68 * opaque structure for a data source. 69 * 70 * The callback function prototypes are similar (but not identical) to the 71 * stdio functions fread, fwrite, fseek, ftell, feof, and fclose. If you use 72 * stdio streams to implement the callbacks, you can pass fread, fwrite, and 73 * fclose anywhere a FLAC__IOCallback_Read, FLAC__IOCallback_Write, or 74 * FLAC__IOCallback_Close is required, and a FILE* anywhere a FLAC__IOHandle 75 * is required. \warning You generally CANNOT directly use fseek or ftell 76 * for FLAC__IOCallback_Seek or FLAC__IOCallback_Tell since on most systems 77 * these use 32-bit offsets and FLAC requires 64-bit offsets to deal with 78 * large files. You will have to find an equivalent function (e.g. ftello), 79 * or write a wrapper. The same is true for feof() since this is usually 80 * implemented as a macro, not as a function whose address can be taken. 81 * 82 * \{ 83 */ 84 85 #ifdef __cplusplus 86 extern "C" { 87 #endif 88 89 /** This is the opaque handle type used by the callbacks. Typically 90 * this is a \c FILE* or address of a file descriptor. 91 */ 92 typedef void* FLAC__IOHandle; 93 94 /** Signature for the read callback. 95 * The signature and semantics match POSIX fread() implementations 96 * and can generally be used interchangeably. 97 * 98 * \param ptr The address of the read buffer. 99 * \param size The size of the records to be read. 100 * \param nmemb The number of records to be read. 101 * \param handle The handle to the data source. 102 * \retval size_t 103 * The number of records read. 104 */ 105 typedef size_t (*FLAC__IOCallback_Read) (void *ptr, size_t size, size_t nmemb, FLAC__IOHandle handle); 106 107 /** Signature for the write callback. 108 * The signature and semantics match POSIX fwrite() implementations 109 * and can generally be used interchangeably. 110 * 111 * \param ptr The address of the write buffer. 112 * \param size The size of the records to be written. 113 * \param nmemb The number of records to be written. 114 * \param handle The handle to the data source. 115 * \retval size_t 116 * The number of records written. 117 */ 118 typedef size_t (*FLAC__IOCallback_Write) (const void *ptr, size_t size, size_t nmemb, FLAC__IOHandle handle); 119 120 /** Signature for the seek callback. 121 * The signature and semantics mostly match POSIX fseek() WITH ONE IMPORTANT 122 * EXCEPTION: the offset is a 64-bit type whereas fseek() is generally 'long' 123 * and 32-bits wide. 124 * 125 * \param handle The handle to the data source. 126 * \param offset The new position, relative to \a whence 127 * \param whence \c SEEK_SET, \c SEEK_CUR, or \c SEEK_END 128 * \retval int 129 * \c 0 on success, \c -1 on error. 130 */ 131 typedef int (*FLAC__IOCallback_Seek) (FLAC__IOHandle handle, FLAC__int64 offset, int whence); 132 133 /** Signature for the tell callback. 134 * The signature and semantics mostly match POSIX ftell() WITH ONE IMPORTANT 135 * EXCEPTION: the offset is a 64-bit type whereas ftell() is generally 'long' 136 * and 32-bits wide. 137 * 138 * \param handle The handle to the data source. 139 * \retval FLAC__int64 140 * The current position on success, \c -1 on error. 141 */ 142 typedef FLAC__int64 (*FLAC__IOCallback_Tell) (FLAC__IOHandle handle); 143 144 /** Signature for the EOF callback. 145 * The signature and semantics mostly match POSIX feof() but WATCHOUT: 146 * on many systems, feof() is a macro, so in this case a wrapper function 147 * must be provided instead. 148 * 149 * \param handle The handle to the data source. 150 * \retval int 151 * \c 0 if not at end of file, nonzero if at end of file. 152 */ 153 typedef int (*FLAC__IOCallback_Eof) (FLAC__IOHandle handle); 154 155 /** Signature for the close callback. 156 * The signature and semantics match POSIX fclose() implementations 157 * and can generally be used interchangeably. 158 * 159 * \param handle The handle to the data source. 160 * \retval int 161 * \c 0 on success, \c EOF on error. 162 */ 163 typedef int (*FLAC__IOCallback_Close) (FLAC__IOHandle handle); 164 165 /** A structure for holding a set of callbacks. 166 * Each FLAC interface that requires a FLAC__IOCallbacks structure will 167 * describe which of the callbacks are required. The ones that are not 168 * required may be set to NULL. 169 * 170 * If the seek requirement for an interface is optional, you can signify that 171 * a data sorce is not seekable by setting the \a seek field to \c NULL. 172 */ 173 typedef struct { 174 FLAC__IOCallback_Read read; 175 FLAC__IOCallback_Write write; 176 FLAC__IOCallback_Seek seek; 177 FLAC__IOCallback_Tell tell; 178 FLAC__IOCallback_Eof eof; 179 FLAC__IOCallback_Close close; 180 } FLAC__IOCallbacks; 181 182 /* \} */ 183 184 #ifdef __cplusplus 185 } 186 #endif 187 188 #endif 189