1/* 2 libmpg123: MPEG Audio Decoder library (version @PACKAGE_VERSION@) 3 4 copyright 1995-2015 by the mpg123 project 5 free software under the terms of the LGPL 2.1 6 see COPYING and AUTHORS files in distribution or http://mpg123.org 7*/ 8 9#ifndef MPG123_LIB_H 10#define MPG123_LIB_H 11 12#include <fmt123.h> 13 14/** \file mpg123.h The header file for the libmpg123 MPEG Audio decoder */ 15 16/** A macro to check at compile time which set of API functions to expect. 17 * This should be incremented at least each time a new symbol is added 18 * to the header. 19 */ 20#define MPG123_API_VERSION @API_VERSION@ 21 22#ifndef MPG123_EXPORT 23/** Defines needed for MS Visual Studio(tm) DLL builds. 24 * Every public function must be prefixed with MPG123_EXPORT. When building 25 * the DLL ensure to define BUILD_MPG123_DLL. This makes the function accessible 26 * for clients and includes it in the import library which is created together 27 * with the DLL. When consuming the DLL ensure to define LINK_MPG123_DLL which 28 * imports the functions from the DLL. 29 */ 30#ifdef BUILD_MPG123_DLL 31/* The dll exports. */ 32#define MPG123_EXPORT __declspec(dllexport) 33#else 34#ifdef LINK_MPG123_DLL 35/* The exe imports. */ 36#define MPG123_EXPORT __declspec(dllimport) 37#else 38/* Nothing on normal/UNIX builds */ 39#define MPG123_EXPORT 40#endif 41#endif 42#endif 43 44/* This is for Visual Studio, so this header works as distributed in the binary downloads */ 45#if defined(_MSC_VER) && !defined(MPG123_DEF_SSIZE_T) 46#define MPG123_DEF_SSIZE_T 47#include <stddef.h> 48typedef ptrdiff_t ssize_t; 49#endif 50 51#ifndef MPG123_NO_CONFIGURE /* Enable use of this file without configure. */ 52@INCLUDE_STDLIB_H@ 53@INCLUDE_SYS_TYPE_H@ 54 55/* Simplified large file handling. 56 I used to have a check here that prevents building for a library with conflicting large file setup 57 (application that uses 32 bit offsets with library that uses 64 bits). 58 While that was perfectly fine in an environment where there is one incarnation of the library, 59 it hurt GNU/Linux and Solaris systems with multilib where the distribution fails to provide the 60 correct header matching the 32 bit library (where large files need explicit support) or 61 the 64 bit library (where there is no distinction). 62 63 New approach: When the app defines _FILE_OFFSET_BITS, it wants non-default large file support, 64 and thus functions with added suffix (mpg123_open_64). 65 Any mismatch will be caught at link time because of the _FILE_OFFSET_BITS setting used when 66 building libmpg123. Plus, there's dual mode large file support in mpg123 since 1.12 now. 67 Link failure is not the expected outcome of any half-sane usage anymore. 68 69 More complication: What about client code defining _LARGEFILE64_SOURCE? It might want direct access to the _64 functions, along with the ones without suffix. Well, that's possible now via defining MPG123_NO_LARGENAME and MPG123_LARGESUFFIX, respectively, for disabling or enforcing the suffix names. 70*/ 71 72/* 73 Now, the renaming of large file aware functions. 74 By default, it appends underscore _FILE_OFFSET_BITS (so, mpg123_seek_64 for mpg123_seek), if _FILE_OFFSET_BITS is defined. You can force a different suffix via MPG123_LARGESUFFIX (that must include the underscore), or you can just disable the whole mess by defining MPG123_NO_LARGENAME. 75*/ 76#if (!defined MPG123_NO_LARGENAME) && ((defined _FILE_OFFSET_BITS) || (defined MPG123_LARGESUFFIX)) 77 78/* Need some trickery to concatenate the value(s) of the given macro(s). */ 79#define MPG123_MACROCAT_REALLY(a, b) a ## b 80#define MPG123_MACROCAT(a, b) MPG123_MACROCAT_REALLY(a, b) 81#ifndef MPG123_LARGESUFFIX 82#define MPG123_LARGESUFFIX MPG123_MACROCAT(_, _FILE_OFFSET_BITS) 83#endif 84#define MPG123_LARGENAME(func) MPG123_MACROCAT(func, MPG123_LARGESUFFIX) 85 86#define mpg123_open MPG123_LARGENAME(mpg123_open) 87#define mpg123_open_fd MPG123_LARGENAME(mpg123_open_fd) 88#define mpg123_open_handle MPG123_LARGENAME(mpg123_open_handle) 89#define mpg123_framebyframe_decode MPG123_LARGENAME(mpg123_framebyframe_decode) 90#define mpg123_decode_frame MPG123_LARGENAME(mpg123_decode_frame) 91#define mpg123_tell MPG123_LARGENAME(mpg123_tell) 92#define mpg123_tellframe MPG123_LARGENAME(mpg123_tellframe) 93#define mpg123_tell_stream MPG123_LARGENAME(mpg123_tell_stream) 94#define mpg123_seek MPG123_LARGENAME(mpg123_seek) 95#define mpg123_feedseek MPG123_LARGENAME(mpg123_feedseek) 96#define mpg123_seek_frame MPG123_LARGENAME(mpg123_seek_frame) 97#define mpg123_timeframe MPG123_LARGENAME(mpg123_timeframe) 98#define mpg123_index MPG123_LARGENAME(mpg123_index) 99#define mpg123_set_index MPG123_LARGENAME(mpg123_set_index) 100#define mpg123_position MPG123_LARGENAME(mpg123_position) 101#define mpg123_length MPG123_LARGENAME(mpg123_length) 102#define mpg123_framelength MPG123_LARGENAME(mpg123_framelength) 103#define mpg123_set_filesize MPG123_LARGENAME(mpg123_set_filesize) 104#define mpg123_replace_reader MPG123_LARGENAME(mpg123_replace_reader) 105#define mpg123_replace_reader_handle MPG123_LARGENAME(mpg123_replace_reader_handle) 106#define mpg123_framepos MPG123_LARGENAME(mpg123_framepos) 107 108#endif /* largefile hackery */ 109 110#endif /* MPG123_NO_CONFIGURE */ 111 112#ifdef __cplusplus 113extern "C" { 114#endif 115 116/** \defgroup mpg123_init mpg123 library and handle setup 117 * 118 * Functions to initialise and shutdown the mpg123 library and handles. 119 * The parameters of handles have workable defaults, you only have to tune them when you want to tune something;-) 120 * Tip: Use a RVA setting... 121 * 122 * @{ 123 */ 124 125/** Opaque structure for the libmpg123 decoder handle. */ 126struct mpg123_handle_struct; 127 128/** Opaque structure for the libmpg123 decoder handle. 129 * Most functions take a pointer to a mpg123_handle as first argument and operate on its data in an object-oriented manner. 130 */ 131typedef struct mpg123_handle_struct mpg123_handle; 132 133/** Function to initialise the mpg123 library. 134 * This function is not thread-safe. Call it exactly once per process, before any other (possibly threaded) work with the library. 135 * 136 * \return MPG123_OK if successful, otherwise an error number. 137 */ 138MPG123_EXPORT int mpg123_init(void); 139 140/** Function to close down the mpg123 library. 141 * This function is not thread-safe. Call it exactly once per process, before any other (possibly threaded) work with the library. */ 142MPG123_EXPORT void mpg123_exit(void); 143 144/** Create a handle with optional choice of decoder (named by a string, see mpg123_decoders() or mpg123_supported_decoders()). 145 * and optional retrieval of an error code to feed to mpg123_plain_strerror(). 146 * Optional means: Any of or both the parameters may be NULL. 147 * 148 * \param decoder optional choice of decoder variant (NULL for default) 149 * \param error optional address to store error codes 150 * \return Non-NULL pointer to fresh handle when successful. 151 */ 152MPG123_EXPORT mpg123_handle *mpg123_new(const char* decoder, int *error); 153 154/** Delete handle, mh is either a valid mpg123 handle or NULL. 155 * \param mh handle 156 */ 157MPG123_EXPORT void mpg123_delete(mpg123_handle *mh); 158 159/** Enumeration of the parameters types that it is possible to set/get. */ 160enum mpg123_parms 161{ 162 MPG123_VERBOSE = 0, /**< set verbosity value for enabling messages to stderr, >= 0 makes sense (integer) */ 163 MPG123_FLAGS, /**< set all flags, p.ex val = MPG123_GAPLESS|MPG123_MONO_MIX (integer) */ 164 MPG123_ADD_FLAGS, /**< add some flags (integer) */ 165 MPG123_FORCE_RATE, /**< when value > 0, force output rate to that value (integer) */ 166 MPG123_DOWN_SAMPLE, /**< 0=native rate, 1=half rate, 2=quarter rate (integer) */ 167 MPG123_RVA, /**< one of the RVA choices above (integer) */ 168 MPG123_DOWNSPEED, /**< play a frame N times (integer) */ 169 MPG123_UPSPEED, /**< play every Nth frame (integer) */ 170 MPG123_START_FRAME, /**< start with this frame (skip frames before that, integer) */ 171 MPG123_DECODE_FRAMES, /**< decode only this number of frames (integer) */ 172 MPG123_ICY_INTERVAL, /**< stream contains ICY metadata with this interval (integer) */ 173 MPG123_OUTSCALE, /**< the scale for output samples (amplitude - integer or float according to mpg123 output format, normally integer) */ 174 MPG123_TIMEOUT, /**< timeout for reading from a stream (not supported on win32, integer) */ 175 MPG123_REMOVE_FLAGS, /**< remove some flags (inverse of MPG123_ADD_FLAGS, integer) */ 176 MPG123_RESYNC_LIMIT, /**< Try resync on frame parsing for that many bytes or until end of stream (<0 ... integer). This can enlarge the limit for skipping junk on beginning, too (but not reduce it). */ 177 MPG123_INDEX_SIZE /**< Set the frame index size (if supported). Values <0 mean that the index is allowed to grow dynamically in these steps (in positive direction, of course) -- Use this when you really want a full index with every individual frame. */ 178 ,MPG123_PREFRAMES /**< Decode/ignore that many frames in advance for layer 3. This is needed to fill bit reservoir after seeking, for example (but also at least one frame in advance is needed to have all "normal" data for layer 3). Give a positive integer value, please.*/ 179 ,MPG123_FEEDPOOL /**< For feeder mode, keep that many buffers in a pool to avoid frequent malloc/free. The pool is allocated on mpg123_open_feed(). If you change this parameter afterwards, you can trigger growth and shrinkage during decoding. The default value could change any time. If you care about this, then set it. (integer) */ 180 ,MPG123_FEEDBUFFER /**< Minimal size of one internal feeder buffer, again, the default value is subject to change. (integer) */ 181}; 182 183/** Flag bits for MPG123_FLAGS, use the usual binary or to combine. */ 184enum mpg123_param_flags 185{ 186 MPG123_FORCE_MONO = 0x7 /**< 0111 Force some mono mode: This is a test bitmask for seeing if any mono forcing is active. */ 187 ,MPG123_MONO_LEFT = 0x1 /**< 0001 Force playback of left channel only. */ 188 ,MPG123_MONO_RIGHT = 0x2 /**< 0010 Force playback of right channel only. */ 189 ,MPG123_MONO_MIX = 0x4 /**< 0100 Force playback of mixed mono. */ 190 ,MPG123_FORCE_STEREO = 0x8 /**< 1000 Force stereo output. */ 191 ,MPG123_FORCE_8BIT = 0x10 /**< 00010000 Force 8bit formats. */ 192 ,MPG123_QUIET = 0x20 /**< 00100000 Suppress any printouts (overrules verbose). */ 193 ,MPG123_GAPLESS = 0x40 /**< 01000000 Enable gapless decoding (default on if libmpg123 has support). */ 194 ,MPG123_NO_RESYNC = 0x80 /**< 10000000 Disable resync stream after error. */ 195 ,MPG123_SEEKBUFFER = 0x100 /**< 000100000000 Enable small buffer on non-seekable streams to allow some peek-ahead (for better MPEG sync). */ 196 ,MPG123_FUZZY = 0x200 /**< 001000000000 Enable fuzzy seeks (guessing byte offsets or using approximate seek points from Xing TOC) */ 197 ,MPG123_FORCE_FLOAT = 0x400 /**< 010000000000 Force floating point output (32 or 64 bits depends on mpg123 internal precision). */ 198 ,MPG123_PLAIN_ID3TEXT = 0x800 /**< 100000000000 Do not translate ID3 text data to UTF-8. ID3 strings will contain the raw text data, with the first byte containing the ID3 encoding code. */ 199 ,MPG123_IGNORE_STREAMLENGTH = 0x1000 /**< 1000000000000 Ignore any stream length information contained in the stream, which can be contained in a 'TLEN' frame of an ID3v2 tag or a Xing tag */ 200 ,MPG123_SKIP_ID3V2 = 0x2000 /**< 10 0000 0000 0000 Do not parse ID3v2 tags, just skip them. */ 201 ,MPG123_IGNORE_INFOFRAME = 0x4000 /**< 100 0000 0000 0000 Do not parse the LAME/Xing info frame, treat it as normal MPEG data. */ 202 ,MPG123_AUTO_RESAMPLE = 0x8000 /**< 1000 0000 0000 0000 Allow automatic internal resampling of any kind (default on if supported). Especially when going lowlevel with replacing output buffer, you might want to unset this flag. Setting MPG123_DOWNSAMPLE or MPG123_FORCE_RATE will override this. */ 203 ,MPG123_PICTURE = 0x10000 /**< 17th bit: Enable storage of pictures from tags (ID3v2 APIC). */ 204 ,MPG123_NO_PEEK_END = 0x20000 /**< 18th bit: Do not seek to the end of 205 * the stream in order to probe 206 * the stream length and search for the id3v1 field. This also means 207 * the file size is unknown unless set using mpg123_set_filesize() and 208 * the stream is assumed as non-seekable unless overridden. 209 */ 210 ,MPG123_FORCE_SEEKABLE = 0x40000 /**< 19th bit: Force the stream to be seekable. */ 211}; 212 213/** choices for MPG123_RVA */ 214enum mpg123_param_rva 215{ 216 MPG123_RVA_OFF = 0 /**< RVA disabled (default). */ 217 ,MPG123_RVA_MIX = 1 /**< Use mix/track/radio gain. */ 218 ,MPG123_RVA_ALBUM = 2 /**< Use album/audiophile gain */ 219 ,MPG123_RVA_MAX = MPG123_RVA_ALBUM /**< The maximum RVA code, may increase in future. */ 220}; 221 222/** Set a specific parameter, for a specific mpg123_handle, using a parameter 223 * type key chosen from the mpg123_parms enumeration, to the specified value. 224 * \param mh handle 225 * \param type parameter choice 226 * \param value integer value 227 * \param fvalue floating point value 228 * \return MPG123_OK on success 229 */ 230MPG123_EXPORT int mpg123_param( mpg123_handle *mh 231, enum mpg123_parms type, long value, double fvalue ); 232 233/** Get a specific parameter, for a specific mpg123_handle. 234 * See the mpg123_parms enumeration for a list of available parameters. 235 * \param mh handle 236 * \param type parameter choice 237 * \param value integer value return address 238 * \param fvalue floating point value return address 239 * \return MPG123_OK on success 240 */ 241MPG123_EXPORT int mpg123_getparam( mpg123_handle *mh 242, enum mpg123_parms type, long *value, double *fvalue ); 243 244/** Feature set available for query with mpg123_feature. */ 245enum mpg123_feature_set 246{ 247 MPG123_FEATURE_ABI_UTF8OPEN = 0 /**< mpg123 expects path names to be given in UTF-8 encoding instead of plain native. */ 248 ,MPG123_FEATURE_OUTPUT_8BIT /**< 8bit output */ 249 ,MPG123_FEATURE_OUTPUT_16BIT /**< 16bit output */ 250 ,MPG123_FEATURE_OUTPUT_32BIT /**< 32bit output */ 251 ,MPG123_FEATURE_INDEX /**< support for building a frame index for accurate seeking */ 252 ,MPG123_FEATURE_PARSE_ID3V2 /**< id3v2 parsing */ 253 ,MPG123_FEATURE_DECODE_LAYER1 /**< mpeg layer-1 decoder enabled */ 254 ,MPG123_FEATURE_DECODE_LAYER2 /**< mpeg layer-2 decoder enabled */ 255 ,MPG123_FEATURE_DECODE_LAYER3 /**< mpeg layer-3 decoder enabled */ 256 ,MPG123_FEATURE_DECODE_ACCURATE /**< accurate decoder rounding */ 257 ,MPG123_FEATURE_DECODE_DOWNSAMPLE /**< downsample (sample omit) */ 258 ,MPG123_FEATURE_DECODE_NTOM /**< flexible rate decoding */ 259 ,MPG123_FEATURE_PARSE_ICY /**< ICY support */ 260 ,MPG123_FEATURE_TIMEOUT_READ /**< Reader with timeout (network). */ 261 ,MPG123_FEATURE_EQUALIZER /**< tunable equalizer */ 262}; 263 264/** Query libmpg123 features. 265 * \param key feature selection 266 * \return 1 for success, 0 for unimplemented functions 267 */ 268MPG123_EXPORT int mpg123_feature(const enum mpg123_feature_set key); 269 270/* @} */ 271 272 273/** \defgroup mpg123_error mpg123 error handling 274 * 275 * Functions to get text version of the error numbers and an enumeration 276 * of the error codes returned by libmpg123. 277 * 278 * Most functions operating on a mpg123_handle simply return MPG123_OK (0) 279 * on success and MPG123_ERR (-1) on failure, setting the internal error 280 * variable of the handle to the specific error code. If there was not a valid 281 * (non-NULL) handle provided to a function operating on one, MPG123_BAD_HANDLE 282 * may be returned if this can not be confused with a valid positive return 283 * value. 284 * Meaning: A function expected to return positive integers on success will 285 * always indicate error or a special condition by returning a negative one. 286 * 287 * Decoding/seek functions may also return message codes MPG123_DONE, 288 * MPG123_NEW_FORMAT and MPG123_NEED_MORE (all negative, see below on how to 289 * react). Note that calls to those can be nested, so generally watch out 290 * for these codes after initial handle setup. 291 * Especially any function that needs information about the current stream 292 * to work will try to at least parse the beginning if that did not happen 293 * yet. 294 * 295 * On a function that is supposed to return MPG123_OK on success and 296 * MPG123_ERR on failure, make sure you check for != MPG123_OK, not 297 * == MPG123_ERR, as the error code could get more specific in future, 298 * or there is just a special message from a decoding routine as indicated 299 * above. 300 * 301 * @{ 302 */ 303 304/** Enumeration of the message and error codes and returned by libmpg123 functions. */ 305enum mpg123_errors 306{ 307 MPG123_DONE=-12, /**< Message: Track ended. Stop decoding. */ 308 MPG123_NEW_FORMAT=-11, /**< Message: Output format will be different on next call. Note that some libmpg123 versions between 1.4.3 and 1.8.0 insist on you calling mpg123_getformat() after getting this message code. Newer verisons behave like advertised: You have the chance to call mpg123_getformat(), but you can also just continue decoding and get your data. */ 309 MPG123_NEED_MORE=-10, /**< Message: For feed reader: "Feed me more!" (call mpg123_feed() or mpg123_decode() with some new input data). */ 310 MPG123_ERR=-1, /**< Generic Error */ 311 MPG123_OK=0, /**< Success */ 312 MPG123_BAD_OUTFORMAT, /**< Unable to set up output format! */ 313 MPG123_BAD_CHANNEL, /**< Invalid channel number specified. */ 314 MPG123_BAD_RATE, /**< Invalid sample rate specified. */ 315 MPG123_ERR_16TO8TABLE, /**< Unable to allocate memory for 16 to 8 converter table! */ 316 MPG123_BAD_PARAM, /**< Bad parameter id! */ 317 MPG123_BAD_BUFFER, /**< Bad buffer given -- invalid pointer or too small size. */ 318 MPG123_OUT_OF_MEM, /**< Out of memory -- some malloc() failed. */ 319 MPG123_NOT_INITIALIZED, /**< You didn't initialize the library! */ 320 MPG123_BAD_DECODER, /**< Invalid decoder choice. */ 321 MPG123_BAD_HANDLE, /**< Invalid mpg123 handle. */ 322 MPG123_NO_BUFFERS, /**< Unable to initialize frame buffers (out of memory?). */ 323 MPG123_BAD_RVA, /**< Invalid RVA mode. */ 324 MPG123_NO_GAPLESS, /**< This build doesn't support gapless decoding. */ 325 MPG123_NO_SPACE, /**< Not enough buffer space. */ 326 MPG123_BAD_TYPES, /**< Incompatible numeric data types. */ 327 MPG123_BAD_BAND, /**< Bad equalizer band. */ 328 MPG123_ERR_NULL, /**< Null pointer given where valid storage address needed. */ 329 MPG123_ERR_READER, /**< Error reading the stream. */ 330 MPG123_NO_SEEK_FROM_END,/**< Cannot seek from end (end is not known). */ 331 MPG123_BAD_WHENCE, /**< Invalid 'whence' for seek function.*/ 332 MPG123_NO_TIMEOUT, /**< Build does not support stream timeouts. */ 333 MPG123_BAD_FILE, /**< File access error. */ 334 MPG123_NO_SEEK, /**< Seek not supported by stream. */ 335 MPG123_NO_READER, /**< No stream opened. */ 336 MPG123_BAD_PARS, /**< Bad parameter handle. */ 337 MPG123_BAD_INDEX_PAR, /**< Bad parameters to mpg123_index() and mpg123_set_index() */ 338 MPG123_OUT_OF_SYNC, /**< Lost track in bytestream and did not try to resync. */ 339 MPG123_RESYNC_FAIL, /**< Resync failed to find valid MPEG data. */ 340 MPG123_NO_8BIT, /**< No 8bit encoding possible. */ 341 MPG123_BAD_ALIGN, /**< Stack aligmnent error */ 342 MPG123_NULL_BUFFER, /**< NULL input buffer with non-zero size... */ 343 MPG123_NO_RELSEEK, /**< Relative seek not possible (screwed up file offset) */ 344 MPG123_NULL_POINTER, /**< You gave a null pointer somewhere where you shouldn't have. */ 345 MPG123_BAD_KEY, /**< Bad key value given. */ 346 MPG123_NO_INDEX, /**< No frame index in this build. */ 347 MPG123_INDEX_FAIL, /**< Something with frame index went wrong. */ 348 MPG123_BAD_DECODER_SETUP, /**< Something prevents a proper decoder setup */ 349 MPG123_MISSING_FEATURE /**< This feature has not been built into libmpg123. */ 350 ,MPG123_BAD_VALUE /**< A bad value has been given, somewhere. */ 351 ,MPG123_LSEEK_FAILED /**< Low-level seek failed. */ 352 ,MPG123_BAD_CUSTOM_IO /**< Custom I/O not prepared. */ 353 ,MPG123_LFS_OVERFLOW /**< Offset value overflow during translation of large file API calls -- your client program cannot handle that large file. */ 354 ,MPG123_INT_OVERFLOW /**< Some integer overflow. */ 355}; 356 357/** Look up error strings given integer code. 358 * \param errcode integer error code 359 * \return string describing what that error error code means 360 */ 361MPG123_EXPORT const char* mpg123_plain_strerror(int errcode); 362 363/** Give string describing what error has occured in the context of handle mh. 364 * When a function operating on an mpg123 handle returns MPG123_ERR, you should check for the actual reason via 365 * char *errmsg = mpg123_strerror(mh) 366 * This function will catch mh == NULL and return the message for MPG123_BAD_HANDLE. 367 * \param mh handle 368 * \return error message 369 */ 370MPG123_EXPORT const char* mpg123_strerror(mpg123_handle *mh); 371 372/** Return the plain errcode intead of a string. 373 * \param mh handle 374 * \return error code recorded in handle or MPG123_BAD_HANDLE 375 */ 376MPG123_EXPORT int mpg123_errcode(mpg123_handle *mh); 377 378/*@}*/ 379 380 381/** \defgroup mpg123_decoder mpg123 decoder selection 382 * 383 * Functions to list and select the available decoders. 384 * Perhaps the most prominent feature of mpg123: You have several (optimized) decoders to choose from (on x86 and PPC (MacOS) systems, that is). 385 * 386 * @{ 387 */ 388 389/** Get available decoder list. 390 * \return NULL-terminated array of generally available decoder names (plain 8bit ASCII) 391 */ 392MPG123_EXPORT const char **mpg123_decoders(void); 393 394/** Get supported decoder list. 395 * \return NULL-terminated array of the decoders supported by the CPU (plain 8bit ASCII) 396 */ 397MPG123_EXPORT const char **mpg123_supported_decoders(void); 398 399/** Set the active decoder. 400 * \param mh handle 401 * \param decoder_name name of decoder 402 * \return MPG123_OK on success 403 */ 404MPG123_EXPORT int mpg123_decoder(mpg123_handle *mh, const char* decoder_name); 405 406/** Get the currently active decoder name. 407 * The active decoder engine can vary depening on output constraints, 408 * mostly non-resampling, integer output is accelerated via 3DNow & Co. but for 409 * other modes a fallback engine kicks in. 410 * Note that this can return a decoder that is only active in the hidden and not 411 * available as decoder choice from the outside. 412 * \param mh handle 413 * \return The decoder name or NULL on error. 414 */ 415MPG123_EXPORT const char* mpg123_current_decoder(mpg123_handle *mh); 416 417/*@}*/ 418 419 420/** \defgroup mpg123_output mpg123 output audio format 421 * 422 * Functions to get and select the format of the decoded audio. 423 * 424 * Before you dive in, please be warned that you might get confused by this. This seems to happen a lot, therefore I am trying to explain in advance. 425 * 426 * The mpg123 library decides what output format to use when encountering the first frame in a stream, or actually any frame that is still valid but differs from the frames before in the prompted output format. At such a deciding point, an internal table of allowed encodings, sampling rates and channel setups is consulted. According to this table, an output format is chosen and the decoding engine set up accordingly (including optimized routines for different output formats). This might seem unusual but it just follows from the non-existence of "MPEG audio files" with defined overall properties. There are streams, streams are concatenations of (semi) independent frames. We store streams on disk and call them "MPEG audio files", but that does not change their nature as the decoder is concerned (the LAME/Xing header for gapless decoding makes things interesting again). 427 * 428 * To get to the point: What you do with mpg123_format() and friends is to fill the internal table of allowed formats before it is used. That includes removing support for some formats or adding your forced sample rate (see MPG123_FORCE_RATE) that will be used with the crude internal resampler. Also keep in mind that the sample encoding is just a question of choice -- the MPEG frames do only indicate their native sampling rate and channel count. If you want to decode to integer or float samples, 8 or 16 bit ... that is your decision. In a "clean" world, libmpg123 would always decode to 32 bit float and let you handle any sample conversion. But there are optimized routines that work faster by directly decoding to the desired encoding / accuracy. We prefer efficiency over conceptual tidyness. 429 * 430 * People often start out thinking that mpg123_format() should change the actual decoding format on the fly. That is wrong. It only has effect on the next natural change of output format, when libmpg123 will consult its format table again. To make life easier, you might want to call mpg123_format_none() before any thing else and then just allow one desired encoding and a limited set of sample rates / channel choices that you actually intend to deal with. You can force libmpg123 to decode everything to 44100 KHz, stereo, 16 bit integer ... it will duplicate mono channels and even do resampling if needed (unless that feature is disabled in the build, same with some encodings). But I have to stress that the resampling of libmpg123 is very crude and doesn't even contain any kind of "proper" interpolation. 431 * 432 * In any case, watch out for MPG123_NEW_FORMAT as return message from decoding routines and call mpg123_getformat() to get the currently active output format. 433 * 434 * @{ 435 */ 436 437/** They can be combined into one number (3) to indicate mono and stereo... */ 438enum mpg123_channelcount 439{ 440 MPG123_MONO = 1 /**< mono */ 441 ,MPG123_STEREO = 2 /**< stereo */ 442}; 443 444/** An array of supported standard sample rates 445 * These are possible native sample rates of MPEG audio files. 446 * You can still force mpg123 to resample to a different one, but by default you will only get audio in one of these samplings. 447 * \param list Store a pointer to the sample rates array there. 448 * \param number Store the number of sample rates there. */ 449MPG123_EXPORT void mpg123_rates(const long **list, size_t *number); 450 451/** An array of supported audio encodings. 452 * An audio encoding is one of the fully qualified members of mpg123_enc_enum (MPG123_ENC_SIGNED_16, not MPG123_SIGNED). 453 * \param list Store a pointer to the encodings array there. 454 * \param number Store the number of encodings there. */ 455MPG123_EXPORT void mpg123_encodings(const int **list, size_t *number); 456 457/** Return the size (in bytes) of one mono sample of the named encoding. 458 * \param encoding The encoding value to analyze. 459 * \return positive size of encoding in bytes, 0 on invalid encoding. */ 460MPG123_EXPORT int mpg123_encsize(int encoding); 461 462/** Configure a mpg123 handle to accept no output format at all, 463 * use before specifying supported formats with mpg123_format 464 * \param mh handle 465 * \return MPG123_OK on success 466 */ 467MPG123_EXPORT int mpg123_format_none(mpg123_handle *mh); 468 469/** Configure mpg123 handle to accept all formats 470 * (also any custom rate you may set) -- this is default. 471 * \param mh handle 472 * \return MPG123_OK on success 473 */ 474MPG123_EXPORT int mpg123_format_all(mpg123_handle *mh); 475 476/** Set the audio format support of a mpg123_handle in detail: 477 * \param mh handle 478 * \param rate The sample rate value (in Hertz). 479 * \param channels A combination of MPG123_STEREO and MPG123_MONO. 480 * \param encodings A combination of accepted encodings for rate and channels, p.ex MPG123_ENC_SIGNED16 | MPG123_ENC_ULAW_8 (or 0 for no support). Please note that some encodings may not be supported in the library build and thus will be ignored here. 481 * \return MPG123_OK on success, MPG123_ERR if there was an error. */ 482MPG123_EXPORT int mpg123_format( mpg123_handle *mh 483, long rate, int channels, int encodings ); 484 485/** Check to see if a specific format at a specific rate is supported 486 * by mpg123_handle. 487 * \param mh handle 488 * \param rate sampling rate 489 * \param encoding encoding 490 * \return 0 for no support (that includes invalid parameters), MPG123_STEREO, 491 * MPG123_MONO or MPG123_STEREO|MPG123_MONO. */ 492MPG123_EXPORT int mpg123_format_support( mpg123_handle *mh 493, long rate, int encoding ); 494 495/** Get the current output format written to the addresses given. 496 * If the stream is freshly loaded, this will try to parse enough 497 * of it to give you the format to come. This clears the flag that 498 * would otherwise make the first decoding call return 499 * MPG123_NEW_FORMAT. 500 * \param mh handle 501 * \param rate sampling rate return address 502 * \param channels channel count return address 503 * \param encoding encoding return address 504 * \return MPG123_OK on success 505 */ 506MPG123_EXPORT int mpg123_getformat( mpg123_handle *mh 507, long *rate, int *channels, int *encoding ); 508 509/** Get the current output format written to the addresses given. 510 * This differs from plain mpg123_getformat() in that you can choose 511 * _not_ to clear the flag that would trigger the next decoding call 512 * to return MPG123_NEW_FORMAT in case of a new format arriving. 513 * \param mh handle 514 * \param rate sampling rate return address 515 * \param channels channel count return address 516 * \param encoding encoding return address 517 * \param clear_flag if true, clear internal format flag 518 * \return MPG123_OK on success 519 */ 520MPG123_EXPORT int mpg123_getformat2( mpg123_handle *mh 521, long *rate, int *channels, int *encoding, int clear_flag ); 522 523/*@}*/ 524 525 526/** \defgroup mpg123_input mpg123 file input and decoding 527 * 528 * Functions for input bitstream and decoding operations. 529 * Decoding/seek functions may also return message codes MPG123_DONE, MPG123_NEW_FORMAT and MPG123_NEED_MORE (please read up on these on how to react!). 530 * @{ 531 */ 532 533/* reading samples / triggering decoding, possible return values: */ 534/** Enumeration of the error codes returned by libmpg123 functions. */ 535 536/** Open and prepare to decode the specified file by filesystem path. 537 * This does not open HTTP urls; libmpg123 contains no networking code. 538 * If you want to decode internet streams, use mpg123_open_fd() or mpg123_open_feed(). 539 * \param mh handle 540 * \param path filesystem path 541 * \return MPG123_OK on success 542 */ 543MPG123_EXPORT int mpg123_open(mpg123_handle *mh, const char *path); 544 545/** Use an already opened file descriptor as the bitstream input 546 * mpg123_close() will _not_ close the file descriptor. 547 * \param mh handle 548 * \param fd file descriptor 549 * \return MPG123_OK on success 550 */ 551MPG123_EXPORT int mpg123_open_fd(mpg123_handle *mh, int fd); 552 553/** Use an opaque handle as bitstream input. This works only with the 554 * replaced I/O from mpg123_replace_reader_handle()! 555 * mpg123_close() will call the cleanup callback for your handle (if you gave one). 556 * \param mh handle 557 * \param iohandle your handle 558 * \return MPG123_OK on success 559 */ 560MPG123_EXPORT int mpg123_open_handle(mpg123_handle *mh, void *iohandle); 561 562/** Open a new bitstream and prepare for direct feeding 563 * This works together with mpg123_decode(); you are responsible for reading and feeding the input bitstream. 564 * \param mh handle 565 * \return MPG123_OK on success 566 */ 567MPG123_EXPORT int mpg123_open_feed(mpg123_handle *mh); 568 569/** Closes the source, if libmpg123 opened it. 570 * \param mh handle 571 * \return MPG123_OK on success 572 */ 573MPG123_EXPORT int mpg123_close(mpg123_handle *mh); 574 575/** Read from stream and decode up to outmemsize bytes. 576 * \param mh handle 577 * \param outmemory address of output buffer to write to 578 * \param outmemsize maximum number of bytes to write 579 * \param done address to store the number of actually decoded bytes to 580 * \return MPG123_OK or error/message code 581 */ 582MPG123_EXPORT int mpg123_read(mpg123_handle *mh 583, unsigned char *outmemory, size_t outmemsize, size_t *done ); 584 585/** Feed data for a stream that has been opened with mpg123_open_feed(). 586 * It's give and take: You provide the bytestream, mpg123 gives you the decoded samples. 587 * \param mh handle 588 * \param in input buffer 589 * \param size number of input bytes 590 * \return MPG123_OK or error/message code. 591 */ 592MPG123_EXPORT int mpg123_feed( mpg123_handle *mh 593, const unsigned char *in, size_t size ); 594 595/** Decode MPEG Audio from inmemory to outmemory. 596 * This is very close to a drop-in replacement for old mpglib. 597 * When you give zero-sized output buffer the input will be parsed until 598 * decoded data is available. This enables you to get MPG123_NEW_FORMAT (and query it) 599 * without taking decoded data. 600 * Think of this function being the union of mpg123_read() and mpg123_feed() (which it actually is, sort of;-). 601 * You can actually always decide if you want those specialized functions in separate steps or one call this one here. 602 * \param mh handle 603 * \param inmemory input buffer 604 * \param inmemsize number of input bytes 605 * \param outmemory output buffer 606 * \param outmemsize maximum number of output bytes 607 * \param done address to store the number of actually decoded bytes to 608 * \return error/message code (watch out especially for MPG123_NEED_MORE) 609 */ 610MPG123_EXPORT int mpg123_decode( mpg123_handle *mh 611, const unsigned char *inmemory, size_t inmemsize 612, unsigned char *outmemory, size_t outmemsize, size_t *done ); 613 614/** Decode next MPEG frame to internal buffer 615 * or read a frame and return after setting a new format. 616 * \param mh handle 617 * \param num current frame offset gets stored there 618 * \param audio This pointer is set to the internal buffer to read the decoded audio from. 619 * \param bytes number of output bytes ready in the buffer 620 * \return MPG123_OK or error/message code 621 */ 622MPG123_EXPORT int mpg123_decode_frame( mpg123_handle *mh 623, off_t *num, unsigned char **audio, size_t *bytes ); 624 625/** Decode current MPEG frame to internal buffer. 626 * Warning: This is experimental API that might change in future releases! 627 * Please watch mpg123 development closely when using it. 628 * \param mh handle 629 * \param num last frame offset gets stored there 630 * \param audio this pointer is set to the internal buffer to read the decoded audio from. 631 * \param bytes number of output bytes ready in the buffer 632 * \return MPG123_OK or error/message code 633 */ 634MPG123_EXPORT int mpg123_framebyframe_decode( mpg123_handle *mh 635, off_t *num, unsigned char **audio, size_t *bytes ); 636 637/** Find, read and parse the next mp3 frame 638 * Warning: This is experimental API that might change in future releases! 639 * Please watch mpg123 development closely when using it. 640 * \param mh handle 641 * \return MPG123_OK or error/message code 642 */ 643MPG123_EXPORT int mpg123_framebyframe_next(mpg123_handle *mh); 644 645/** Get access to the raw input data for the last parsed frame. 646 * This gives you a direct look (and write access) to the frame body data. 647 * Together with the raw header, you can reconstruct the whole raw MPEG stream without junk and meta data, or play games by actually modifying the frame body data before decoding this frame (mpg123_framebyframe_decode()). 648 * A more sane use would be to use this for CRC checking (see mpg123_info() and MPG123_CRC), the first two bytes of the body make up the CRC16 checksum, if present. 649 * You can provide NULL for a parameter pointer when you are not interested in the value. 650 * 651 * \param mh handle 652 * \param header the 4-byte MPEG header 653 * \param bodydata pointer to the frame body stored in the handle (without the header) 654 * \param bodybytes size of frame body in bytes (without the header) 655 * \return MPG123_OK if there was a yet un-decoded frame to get the 656 * data from, MPG123_BAD_HANDLE or MPG123_ERR otherwise (without further 657 * explanation, the error state of the mpg123_handle is not modified by 658 * this function). 659 */ 660MPG123_EXPORT int mpg123_framedata( mpg123_handle *mh 661, unsigned long *header, unsigned char **bodydata, size_t *bodybytes ); 662 663/** Get the input position (byte offset in stream) of the last parsed frame. 664 * This can be used for external seek index building, for example. 665 * It just returns the internally stored offset, regardless of validity -- 666 * you ensure that a valid frame has been parsed before! 667 * \param mh handle 668 * \return byte offset in stream 669 */ 670MPG123_EXPORT off_t mpg123_framepos(mpg123_handle *mh); 671 672/*@}*/ 673 674 675/** \defgroup mpg123_seek mpg123 position and seeking 676 * 677 * Functions querying and manipulating position in the decoded audio bitstream. 678 * The position is measured in decoded audio samples, or MPEG frame offset for the specific functions. 679 * If gapless code is in effect, the positions are adjusted to compensate the skipped padding/delay - meaning, you should not care about that at all and just use the position defined for the samples you get out of the decoder;-) 680 * The general usage is modelled after stdlib's ftell() and fseek(). 681 * Especially, the whence parameter for the seek functions has the same meaning as the one for fseek() and needs the same constants from stdlib.h: 682 * - SEEK_SET: set position to (or near to) specified offset 683 * - SEEK_CUR: change position by offset from now 684 * - SEEK_END: set position to offset from end 685 * 686 * Note that sample-accurate seek only works when gapless support has been enabled at compile time; seek is frame-accurate otherwise. 687 * Also, really sample-accurate seeking (meaning that you get the identical sample value after seeking compared to plain decoding up to the position) is only guaranteed when you do not mess with the position code by using MPG123_UPSPEED, MPG123_DOWNSPEED or MPG123_START_FRAME. The first two mainly should cause trouble with NtoM resampling, but in any case with these options in effect, you have to keep in mind that the sample offset is not the same as counting the samples you get from decoding since mpg123 counts the skipped samples, too (or the samples played twice only once)! 688 * Short: When you care about the sample position, don't mess with those parameters;-) 689 * Also, seeking is not guaranteed to work for all streams (underlying stream may not support it). 690 * And yet another caveat: If the stream is concatenated out of differing pieces (Frankenstein stream), seeking may suffer, too. 691 * 692 * @{ 693 */ 694 695/** Returns the current position in samples. 696 * On the next successful read, you'd get that sample. 697 * \param mh handle 698 * \return sample offset or MPG123_ERR (null handle) 699 */ 700MPG123_EXPORT off_t mpg123_tell(mpg123_handle *mh); 701 702/** Returns the frame number that the next read will give you data from. 703 * \param mh handle 704 * \return frame offset or MPG123_ERR (null handle) 705 */ 706MPG123_EXPORT off_t mpg123_tellframe(mpg123_handle *mh); 707 708/** Returns the current byte offset in the input stream. 709 * \param mh handle 710 * \return byte offset or MPG123_ERR (null handle) 711 */ 712MPG123_EXPORT off_t mpg123_tell_stream(mpg123_handle *mh); 713 714/** Seek to a desired sample offset. 715 * Usage is modelled afer the standard lseek(). 716 * \param mh handle 717 * \param sampleoff offset in PCM samples 718 * \param whence one of SEEK_SET, SEEK_CUR or SEEK_END 719 * \return The resulting offset >= 0 or error/message code 720 */ 721MPG123_EXPORT off_t mpg123_seek( mpg123_handle *mh 722, off_t sampleoff, int whence ); 723 724/** Seek to a desired sample offset in data feeding mode. 725 * This just prepares things to be right only if you ensure that the next chunk of input data will be from input_offset byte position. 726 * \param mh handle 727 * \param sampleoff offset in PCM samples 728 * \param whence one of SEEK_SET, SEEK_CUR or SEEK_END 729 * \param input_offset The position it expects to be at the 730 * next time data is fed to mpg123_decode(). 731 * \return The resulting offset >= 0 or error/message code */ 732MPG123_EXPORT off_t mpg123_feedseek( mpg123_handle *mh 733, off_t sampleoff, int whence, off_t *input_offset ); 734 735/** Seek to a desired MPEG frame offset. 736 * Usage is modelled afer the standard lseek(). 737 * \param mh handle 738 * \param frameoff offset in MPEG frames 739 * \param whence one of SEEK_SET, SEEK_CUR or SEEK_END 740 * \return The resulting offset >= 0 or error/message code */ 741MPG123_EXPORT off_t mpg123_seek_frame( mpg123_handle *mh 742, off_t frameoff, int whence ); 743 744/** Return a MPEG frame offset corresponding to an offset in seconds. 745 * This assumes that the samples per frame do not change in the file/stream, which is a good assumption for any sane file/stream only. 746 * \return frame offset >= 0 or error/message code */ 747MPG123_EXPORT off_t mpg123_timeframe(mpg123_handle *mh, double sec); 748 749/** Give access to the frame index table that is managed for seeking. 750 * You are asked not to modify the values... Use mpg123_set_index to set the 751 * seek index 752 * \param mh handle 753 * \param offsets pointer to the index array 754 * \param step one index byte offset advances this many MPEG frames 755 * \param fill number of recorded index offsets; size of the array 756 * \return MPG123_OK on success 757 */ 758MPG123_EXPORT int mpg123_index( mpg123_handle *mh 759, off_t **offsets, off_t *step, size_t *fill ); 760 761/** Set the frame index table 762 * Setting offsets to NULL and fill > 0 will allocate fill entries. Setting offsets 763 * to NULL and fill to 0 will clear the index and free the allocated memory used by the index. 764 * \param mh handle 765 * \param offsets pointer to the index array 766 * \param step one index byte offset advances this many MPEG frames 767 * \param fill number of recorded index offsets; size of the array 768 * \return MPG123_OK on success 769 */ 770MPG123_EXPORT int mpg123_set_index( mpg123_handle *mh 771, off_t *offsets, off_t step, size_t fill ); 772 773/** An old crutch to keep old mpg123 binaries happy. 774 * WARNING: This function is there only to avoid runtime linking errors with 775 * standalone mpg123 before version 1.23.0 (if you strangely update the 776 * library but not the end-user program) and actually is broken 777 * for various cases (p.ex. 24 bit output). Do never use. It might eventually 778 * be purged from the library. 779 */ 780MPG123_EXPORT int mpg123_position( mpg123_handle *mh, off_t frame_offset, off_t buffered_bytes, off_t *current_frame, off_t *frames_left, double *current_seconds, double *seconds_left); 781 782/*@}*/ 783 784 785/** \defgroup mpg123_voleq mpg123 volume and equalizer 786 * 787 * @{ 788 */ 789 790/** another channel enumeration, for left/right choice */ 791enum mpg123_channels 792{ 793 MPG123_LEFT=0x1 /**< The Left Channel. */ 794 ,MPG123_RIGHT=0x2 /**< The Right Channel. */ 795 ,MPG123_LR=0x3 /**< Both left and right channel; same as MPG123_LEFT|MPG123_RIGHT */ 796}; 797 798/** Set the 32 Band Audio Equalizer settings. 799 * \param mh handle 800 * \param channel Can be MPG123_LEFT, MPG123_RIGHT or MPG123_LEFT|MPG123_RIGHT for both. 801 * \param band The equaliser band to change (from 0 to 31) 802 * \param val The (linear) adjustment factor. 803 * \return MPG123_OK on success 804 */ 805MPG123_EXPORT int mpg123_eq( mpg123_handle *mh 806, enum mpg123_channels channel, int band, double val ); 807 808/** Get the 32 Band Audio Equalizer settings. 809 * \param mh handle 810 * \param channel Can be MPG123_LEFT, MPG123_RIGHT or MPG123_LEFT|MPG123_RIGHT for (arithmetic mean of) both. 811 * \param band The equaliser band to change (from 0 to 31) 812 * \return The (linear) adjustment factor (zero for pad parameters) */ 813MPG123_EXPORT double mpg123_geteq(mpg123_handle *mh 814 , enum mpg123_channels channel, int band); 815 816/** Reset the 32 Band Audio Equalizer settings to flat 817 * \param mh handle 818 * \return MPG123_OK on success 819 */ 820MPG123_EXPORT int mpg123_reset_eq(mpg123_handle *mh); 821 822/** Set the absolute output volume including the RVA setting, 823 * vol<0 just applies (a possibly changed) RVA setting. 824 * \param mh handle 825 * \param vol volume value (linear factor) 826 * \return MPG123_OK on success 827 */ 828MPG123_EXPORT int mpg123_volume(mpg123_handle *mh, double vol); 829 830/** Adjust output volume including the RVA setting by chosen amount 831 * \param mh handle 832 * \param change volume value (linear factor increment) 833 * \return MPG123_OK on success 834 */ 835MPG123_EXPORT int mpg123_volume_change(mpg123_handle *mh, double change); 836 837/** Return current volume setting, the actual value due to RVA, and the RVA 838 * adjustment itself. It's all as double float value to abstract the sample 839 * format. The volume values are linear factors / amplitudes (not percent) 840 * and the RVA value is in decibels. 841 * \param mh handle 842 * \param base return address for base volume (linear factor) 843 * \param really return address for actual volume (linear factor) 844 * \param rva_db return address for RVA value (decibels) 845 * \return MPG123_OK on success 846 */ 847MPG123_EXPORT int mpg123_getvolume(mpg123_handle *mh, double *base, double *really, double *rva_db); 848 849/* TODO: Set some preamp in addition / to replace internal RVA handling? */ 850 851/*@}*/ 852 853 854/** \defgroup mpg123_status mpg123 status and information 855 * 856 * @{ 857 */ 858 859/** Enumeration of the mode types of Variable Bitrate */ 860enum mpg123_vbr { 861 MPG123_CBR=0, /**< Constant Bitrate Mode (default) */ 862 MPG123_VBR, /**< Variable Bitrate Mode */ 863 MPG123_ABR /**< Average Bitrate Mode */ 864}; 865 866/** Enumeration of the MPEG Versions */ 867enum mpg123_version { 868 MPG123_1_0=0, /**< MPEG Version 1.0 */ 869 MPG123_2_0, /**< MPEG Version 2.0 */ 870 MPG123_2_5 /**< MPEG Version 2.5 */ 871}; 872 873 874/** Enumeration of the MPEG Audio mode. 875 * Only the mono mode has 1 channel, the others have 2 channels. */ 876enum mpg123_mode { 877 MPG123_M_STEREO=0, /**< Standard Stereo. */ 878 MPG123_M_JOINT, /**< Joint Stereo. */ 879 MPG123_M_DUAL, /**< Dual Channel. */ 880 MPG123_M_MONO /**< Single Channel. */ 881}; 882 883 884/** Enumeration of the MPEG Audio flag bits */ 885enum mpg123_flags { 886 MPG123_CRC=0x1, /**< The bitstream is error protected using 16-bit CRC. */ 887 MPG123_COPYRIGHT=0x2, /**< The bitstream is copyrighted. */ 888 MPG123_PRIVATE=0x4, /**< The private bit has been set. */ 889 MPG123_ORIGINAL=0x8 /**< The bitstream is an original, not a copy. */ 890}; 891 892/** Data structure for storing information about a frame of MPEG Audio */ 893struct mpg123_frameinfo 894{ 895 enum mpg123_version version; /**< The MPEG version (1.0/2.0/2.5). */ 896 int layer; /**< The MPEG Audio Layer (MP1/MP2/MP3). */ 897 long rate; /**< The sampling rate in Hz. */ 898 enum mpg123_mode mode; /**< The audio mode (Mono, Stereo, Joint-stero, Dual Channel). */ 899 int mode_ext; /**< The mode extension bit flag. */ 900 int framesize; /**< The size of the frame (in bytes, including header). */ 901 enum mpg123_flags flags; /**< MPEG Audio flag bits. Just now I realize that it should be declared as int, not enum. It's a bitwise combination of the enum values. */ 902 int emphasis; /**< The emphasis type. */ 903 int bitrate; /**< Bitrate of the frame (kbps). */ 904 int abr_rate; /**< The target average bitrate. */ 905 enum mpg123_vbr vbr; /**< The VBR mode. */ 906}; 907 908/** Get frame information about the MPEG audio bitstream and store it in a mpg123_frameinfo structure. 909 * \param mh handle 910 * \param mi address of existing frameinfo structure to write to 911 * \return MPG123_OK on success 912 */ 913MPG123_EXPORT int mpg123_info(mpg123_handle *mh, struct mpg123_frameinfo *mi); 914 915/** Get the safe output buffer size for all cases 916 * (when you want to replace the internal buffer) 917 * \return safe buffer size 918 */ 919MPG123_EXPORT size_t mpg123_safe_buffer(void); 920 921/** Make a full parsing scan of each frame in the file. ID3 tags are found. An 922 * accurate length value is stored. Seek index will be filled. A seek back to 923 * current position is performed. At all, this function refuses work when 924 * stream is not seekable. 925 * \param mh handle 926 * \return MPG123_OK on success 927 */ 928MPG123_EXPORT int mpg123_scan(mpg123_handle *mh); 929 930/** Return, if possible, the full (expected) length of current track in frames. 931 * \param mh handle 932 * \return length >= 0 or MPG123_ERR if there is no length guess possible. 933 */ 934MPG123_EXPORT off_t mpg123_framelength(mpg123_handle *mh); 935 936/** Return, if possible, the full (expected) length of current track in samples. 937 * \param mh handle 938 * \return length >= 0 or MPG123_ERR if there is no length guess possible. 939 */ 940MPG123_EXPORT off_t mpg123_length(mpg123_handle *mh); 941 942/** Override the value for file size in bytes. 943 * Useful for getting sensible track length values in feed mode or for HTTP streams. 944 * \param mh handle 945 * \param size file size in bytes 946 * \return MPG123_OK on success 947 */ 948MPG123_EXPORT int mpg123_set_filesize(mpg123_handle *mh, off_t size); 949 950/** Get MPEG frame duration in seconds. 951 * \param mh handle 952 * \return frame duration in seconds, <0 on error 953 */ 954MPG123_EXPORT double mpg123_tpf(mpg123_handle *mh); 955 956/** Get MPEG frame duration in samples. 957 * \param mh handle 958 * \return samples per frame for the most recently parsed frame; <0 on errors 959 */ 960MPG123_EXPORT int mpg123_spf(mpg123_handle *mh); 961 962/** Get and reset the clip count. 963 * \param mh handle 964 * \return count of clipped samples 965 */ 966MPG123_EXPORT long mpg123_clip(mpg123_handle *mh); 967 968 969/** The key values for state information from mpg123_getstate(). */ 970enum mpg123_state 971{ 972 MPG123_ACCURATE = 1 /**< Query if positons are currently accurate (integer value, 0 if false, 1 if true). */ 973 ,MPG123_BUFFERFILL /**< Get fill of internal (feed) input buffer as integer byte count returned as long and as double. An error is returned on integer overflow while converting to (signed) long, but the returned floating point value shold still be fine. */ 974 ,MPG123_FRANKENSTEIN /**< Stream consists of carelessly stitched together files. Seeking may yield unexpected results (also with MPG123_ACCURATE, it may be confused). */ 975 ,MPG123_FRESH_DECODER /**< Decoder structure has been updated, possibly indicating changed stream (integer value, 0 if false, 1 if true). Flag is cleared after retrieval. */ 976}; 977 978/** Get various current decoder/stream state information. 979 * \param mh handle 980 * \param key the key to identify the information to give. 981 * \param val the address to return (long) integer values to 982 * \param fval the address to return floating point values to 983 * \return MPG123_OK on success 984 */ 985MPG123_EXPORT int mpg123_getstate( mpg123_handle *mh 986, enum mpg123_state key, long *val, double *fval ); 987 988/*@}*/ 989 990 991/** \defgroup mpg123_metadata mpg123 metadata handling 992 * 993 * Functions to retrieve the metadata from MPEG Audio files and streams. 994 * Also includes string handling functions. 995 * 996 * @{ 997 */ 998 999/** Data structure for storing strings in a safer way than a standard C-String. 1000 * Can also hold a number of null-terminated strings. */ 1001typedef struct 1002{ 1003 char* p; /**< pointer to the string data */ 1004 size_t size; /**< raw number of bytes allocated */ 1005 size_t fill; /**< number of used bytes (including closing zero byte) */ 1006} mpg123_string; 1007 1008/** Create and allocate memory for a new mpg123_string 1009 * \param sb string handle (address of existing structure on your side) 1010 */ 1011MPG123_EXPORT void mpg123_init_string(mpg123_string* sb); 1012 1013/** Free-up mempory for an existing mpg123_string 1014 * \param sb string handle 1015 */ 1016MPG123_EXPORT void mpg123_free_string(mpg123_string* sb); 1017 1018/** Change the size of a mpg123_string 1019 * \param sb string handle 1020 * \param news new size in bytes 1021 * \return 0 on error, 1 on success 1022 */ 1023MPG123_EXPORT int mpg123_resize_string(mpg123_string* sb, size_t news); 1024 1025/** Increase size of a mpg123_string if necessary (it may stay larger). 1026 * Note that the functions for adding and setting in current libmpg123 1027 * use this instead of mpg123_resize_string(). 1028 * That way, you can preallocate memory and safely work afterwards with 1029 * pieces. 1030 * \param sb string handle 1031 * \param news new minimum size 1032 * \return 0 on error, 1 on success 1033 */ 1034MPG123_EXPORT int mpg123_grow_string(mpg123_string* sb, size_t news); 1035 1036/** Copy the contents of one mpg123_string string to another. 1037 * Yes the order of arguments is reversed compated to memcpy(). 1038 * \param from string handle 1039 * \param to string handle 1040 * \return 0 on error, 1 on success 1041 */ 1042MPG123_EXPORT int mpg123_copy_string(mpg123_string* from, mpg123_string* to); 1043 1044/** Append a C-String to an mpg123_string 1045 * \param sb string handle 1046 * \param stuff to append 1047 * \return 0 on error, 1 on success 1048 */ 1049MPG123_EXPORT int mpg123_add_string(mpg123_string* sb, const char* stuff); 1050 1051/** Append a C-substring to an mpg123 string 1052 * \param sb string handle 1053 * \param stuff content to copy 1054 * \param from offset to copy from 1055 * \param count number of characters to copy (a null-byte is always appended) 1056 * \return 0 on error, 1 on success 1057 */ 1058MPG123_EXPORT int mpg123_add_substring( mpg123_string *sb 1059, const char *stuff, size_t from, size_t count ); 1060 1061/** Set the content of a mpg123_string to a C-string 1062 * \param sb string handle 1063 * \param stuff content to copy 1064 * \return 0 on error, 1 on success 1065 */ 1066MPG123_EXPORT int mpg123_set_string(mpg123_string* sb, const char* stuff); 1067 1068/** Set the content of a mpg123_string to a C-substring 1069 * \param sb string handle 1070 * \param stuff the future content 1071 * \param from offset to copy from 1072 * \param count number of characters to copy (a null-byte is always appended) 1073 * \return 0 on error, 1 on success 1074 */ 1075MPG123_EXPORT int mpg123_set_substring( mpg123_string *sb 1076, const char *stuff, size_t from, size_t count ); 1077 1078/** Count characters in a mpg123 string (non-null bytes or UTF-8 characters). 1079 * Even with the fill property, the character count is not obvious as there could be multiple trailing null bytes. 1080 * \param sb string handle 1081 * \param utf8 a flag to tell if the string is in utf8 encoding 1082 * \return character count 1083*/ 1084MPG123_EXPORT size_t mpg123_strlen(mpg123_string *sb, int utf8); 1085 1086/** Remove trailing \\r and \\n, if present. 1087 * \param sb string handle 1088 * \return 0 on error, 1 on success 1089 */ 1090MPG123_EXPORT int mpg123_chomp_string(mpg123_string *sb); 1091 1092/** The mpg123 text encodings. This contains encodings we encounter in ID3 tags or ICY meta info. */ 1093enum mpg123_text_encoding 1094{ 1095 mpg123_text_unknown = 0 /**< Unkown encoding... mpg123_id3_encoding can return that on invalid codes. */ 1096 ,mpg123_text_utf8 = 1 /**< UTF-8 */ 1097 ,mpg123_text_latin1 = 2 /**< ISO-8859-1. Note that sometimes latin1 in ID3 is abused for totally different encodings. */ 1098 ,mpg123_text_icy = 3 /**< ICY metadata encoding, usually CP-1252 but we take it as UTF-8 if it qualifies as such. */ 1099 ,mpg123_text_cp1252 = 4 /**< Really CP-1252 without any guessing. */ 1100 ,mpg123_text_utf16 = 5 /**< Some UTF-16 encoding. The last of a set of leading BOMs (byte order mark) rules. 1101 * When there is no BOM, big endian ordering is used. Note that UCS-2 qualifies as UTF-8 when 1102 * you don't mess with the reserved code points. If you want to decode little endian data 1103 * without BOM you need to prepend 0xff 0xfe yourself. */ 1104 ,mpg123_text_utf16bom = 6 /**< Just an alias for UTF-16, ID3v2 has this as distinct code. */ 1105 ,mpg123_text_utf16be = 7 /**< Another alias for UTF16 from ID3v2. Note, that, because of the mess that is reality, 1106 * BOMs are used if encountered. There really is not much distinction between the UTF16 types for mpg123 1107 * One exception: Since this is seen in ID3v2 tags, leading null bytes are skipped for all other UTF16 1108 * types (we expect a BOM before real data there), not so for utf16be!*/ 1109 ,mpg123_text_max = 7 /**< Placeholder for the maximum encoding value. */ 1110}; 1111 1112/** The encoding byte values from ID3v2. */ 1113enum mpg123_id3_enc 1114{ 1115 mpg123_id3_latin1 = 0 /**< Note: This sometimes can mean anything in practice... */ 1116 ,mpg123_id3_utf16bom = 1 /**< UTF16, UCS-2 ... it's all the same for practical purposes. */ 1117 ,mpg123_id3_utf16be = 2 /**< Big-endian UTF-16, BOM see note for mpg123_text_utf16be. */ 1118 ,mpg123_id3_utf8 = 3 /**< Our lovely overly ASCII-compatible 8 byte encoding for the world. */ 1119 ,mpg123_id3_enc_max = 3 /**< Placeholder to check valid range of encoding byte. */ 1120}; 1121 1122/** Convert ID3 encoding byte to mpg123 encoding index. 1123 * \param id3_enc_byte the ID3 encoding code 1124 * \return the mpg123 encoding index 1125 */ 1126 1127MPG123_EXPORT enum mpg123_text_encoding mpg123_enc_from_id3(unsigned char id3_enc_byte); 1128 1129/** Store text data in string, after converting to UTF-8 from indicated encoding 1130 * A prominent error can be that you provided an unknown encoding value, or this build of libmpg123 lacks support for certain encodings (ID3 or ICY stuff missing). 1131 * Also, you might want to take a bit of care with preparing the data; for example, strip leading zeroes (I have seen that). 1132 * \param sb target string 1133 * \param enc mpg123 text encoding value 1134 * \param source source buffer with plain unsigned bytes (you might need to cast from signed char) 1135 * \param source_size number of bytes in the source buffer 1136 * \return 0 on error, 1 on success (on error, mpg123_free_string is called on sb) 1137 */ 1138MPG123_EXPORT int mpg123_store_utf8(mpg123_string *sb, enum mpg123_text_encoding enc, const unsigned char *source, size_t source_size); 1139 1140/** Sub data structure for ID3v2, for storing various text fields (including comments). 1141 * This is for ID3v2 COMM, TXXX and all the other text fields. 1142 * Only COMM and TXXX have a description, only COMM and USLT have a language. 1143 * You should consult the ID3v2 specification for the use of the various text fields ("frames" in ID3v2 documentation, I use "fields" here to separate from MPEG frames). */ 1144typedef struct 1145{ 1146 char lang[3]; /**< Three-letter language code (not terminated). */ 1147 char id[4]; /**< The ID3v2 text field id, like TALB, TPE2, ... (4 characters, no string termination). */ 1148 mpg123_string description; /**< Empty for the generic comment... */ 1149 mpg123_string text; /**< ... */ 1150} mpg123_text; 1151 1152/** The picture type values from ID3v2. */ 1153enum mpg123_id3_pic_type 1154{ 1155 mpg123_id3_pic_other = 0 /**< see ID3v2 docs */ 1156 ,mpg123_id3_pic_icon = 1 /**< see ID3v2 docs */ 1157 ,mpg123_id3_pic_other_icon = 2 /**< see ID3v2 docs */ 1158 ,mpg123_id3_pic_front_cover = 3 /**< see ID3v2 docs */ 1159 ,mpg123_id3_pic_back_cover = 4 /**< see ID3v2 docs */ 1160 ,mpg123_id3_pic_leaflet = 5 /**< see ID3v2 docs */ 1161 ,mpg123_id3_pic_media = 6 /**< see ID3v2 docs */ 1162 ,mpg123_id3_pic_lead = 7 /**< see ID3v2 docs */ 1163 ,mpg123_id3_pic_artist = 8 /**< see ID3v2 docs */ 1164 ,mpg123_id3_pic_conductor = 9 /**< see ID3v2 docs */ 1165 ,mpg123_id3_pic_orchestra = 10 /**< see ID3v2 docs */ 1166 ,mpg123_id3_pic_composer = 11 /**< see ID3v2 docs */ 1167 ,mpg123_id3_pic_lyricist = 12 /**< see ID3v2 docs */ 1168 ,mpg123_id3_pic_location = 13 /**< see ID3v2 docs */ 1169 ,mpg123_id3_pic_recording = 14 /**< see ID3v2 docs */ 1170 ,mpg123_id3_pic_performance = 15 /**< see ID3v2 docs */ 1171 ,mpg123_id3_pic_video = 16 /**< see ID3v2 docs */ 1172 ,mpg123_id3_pic_fish = 17 /**< see ID3v2 docs */ 1173 ,mpg123_id3_pic_illustration = 18 /**< see ID3v2 docs */ 1174 ,mpg123_id3_pic_artist_logo = 19 /**< see ID3v2 docs */ 1175 ,mpg123_id3_pic_publisher_logo = 20 /**< see ID3v2 docs */ 1176}; 1177 1178/** Sub data structure for ID3v2, for storing picture data including comment. 1179 * This is for the ID3v2 APIC field. You should consult the ID3v2 specification 1180 * for the use of the APIC field ("frames" in ID3v2 documentation, I use "fields" 1181 * here to separate from MPEG frames). */ 1182typedef struct 1183{ 1184 char type; /**< mpg123_id3_pic_type value */ 1185 mpg123_string description; /**< description string */ 1186 mpg123_string mime_type; /**< MIME type */ 1187 size_t size; /**< size in bytes */ 1188 unsigned char* data; /**< pointer to the image data */ 1189} mpg123_picture; 1190 1191/** Data structure for storing IDV3v2 tags. 1192 * This structure is not a direct binary mapping with the file contents. 1193 * The ID3v2 text frames are allowed to contain multiple strings. 1194 * So check for null bytes until you reach the mpg123_string fill. 1195 * All text is encoded in UTF-8. */ 1196typedef struct 1197{ 1198 unsigned char version; /**< 3 or 4 for ID3v2.3 or ID3v2.4. */ 1199 mpg123_string *title; /**< Title string (pointer into text_list). */ 1200 mpg123_string *artist; /**< Artist string (pointer into text_list). */ 1201 mpg123_string *album; /**< Album string (pointer into text_list). */ 1202 mpg123_string *year; /**< The year as a string (pointer into text_list). */ 1203 mpg123_string *genre; /**< Genre String (pointer into text_list). The genre string(s) may very well need postprocessing, esp. for ID3v2.3. */ 1204 mpg123_string *comment; /**< Pointer to last encountered comment text with empty description. */ 1205 /* Encountered ID3v2 fields are appended to these lists. 1206 There can be multiple occurences, the pointers above always point to the last encountered data. */ 1207 mpg123_text *comment_list; /**< Array of comments. */ 1208 size_t comments; /**< Number of comments. */ 1209 mpg123_text *text; /**< Array of ID3v2 text fields (including USLT) */ 1210 size_t texts; /**< Numer of text fields. */ 1211 mpg123_text *extra; /**< The array of extra (TXXX) fields. */ 1212 size_t extras; /**< Number of extra text (TXXX) fields. */ 1213 mpg123_picture *picture; /**< Array of ID3v2 pictures fields (APIC). */ 1214 size_t pictures; /**< Number of picture (APIC) fields. */ 1215} mpg123_id3v2; 1216 1217/** Data structure for ID3v1 tags (the last 128 bytes of a file). 1218 * Don't take anything for granted (like string termination)! 1219 * Also note the change ID3v1.1 did: comment[28] = 0; comment[29] = track_number 1220 * It is your task to support ID3v1 only or ID3v1.1 ...*/ 1221typedef struct 1222{ 1223 char tag[3]; /**< Always the string "TAG", the classic intro. */ 1224 char title[30]; /**< Title string. */ 1225 char artist[30]; /**< Artist string. */ 1226 char album[30]; /**< Album string. */ 1227 char year[4]; /**< Year string. */ 1228 char comment[30]; /**< Comment string. */ 1229 unsigned char genre; /**< Genre index. */ 1230} mpg123_id3v1; 1231 1232#define MPG123_ID3 0x3 /**< 0011 There is some ID3 info. Also matches 0010 or NEW_ID3. */ 1233#define MPG123_NEW_ID3 0x1 /**< 0001 There is ID3 info that changed since last call to mpg123_id3. */ 1234#define MPG123_ICY 0xc /**< 1100 There is some ICY info. Also matches 0100 or NEW_ICY.*/ 1235#define MPG123_NEW_ICY 0x4 /**< 0100 There is ICY info that changed since last call to mpg123_icy. */ 1236 1237/** Query if there is (new) meta info, be it ID3 or ICY (or something new in future). 1238 * \param mh handle 1239 * \return combination of flags, 0 on error (same as "nothing new") 1240 */ 1241MPG123_EXPORT int mpg123_meta_check(mpg123_handle *mh); 1242 1243/** Clean up meta data storage (ID3v2 and ICY), freeing memory. 1244 * \param mh handle 1245 */ 1246MPG123_EXPORT void mpg123_meta_free(mpg123_handle *mh); 1247 1248/** Point v1 and v2 to existing data structures wich may change on any next read/decode function call. 1249 * v1 and/or v2 can be set to NULL when there is no corresponding data. 1250 * \return MPG123_OK on success 1251 */ 1252MPG123_EXPORT int mpg123_id3( mpg123_handle *mh 1253, mpg123_id3v1 **v1, mpg123_id3v2 **v2 ); 1254 1255/** Point icy_meta to existing data structure wich may change on any next read/decode function call. 1256 * \param mh handle 1257 * \param icy_meta return address for ICY meta string (set to NULL if nothing there) 1258 * \return MPG123_OK on success 1259 */ 1260MPG123_EXPORT int mpg123_icy(mpg123_handle *mh, char **icy_meta); 1261 1262/** Decode from windows-1252 (the encoding ICY metainfo used) to UTF-8. 1263 * Note that this is very similar to mpg123_store_utf8(&sb, mpg123_text_icy, icy_text, strlen(icy_text+1)) . 1264 * \param icy_text The input data in ICY encoding 1265 * \return pointer to newly allocated buffer with UTF-8 data (You free() it!) */ 1266MPG123_EXPORT char* mpg123_icy2utf8(const char* icy_text); 1267 1268 1269/* @} */ 1270 1271 1272/** \defgroup mpg123_advpar mpg123 advanced parameter API 1273 * 1274 * Direct access to a parameter set without full handle around it. 1275 * Possible uses: 1276 * - Influence behaviour of library _during_ initialization of handle (MPG123_VERBOSE). 1277 * - Use one set of parameters for multiple handles. 1278 * 1279 * The functions for handling mpg123_pars (mpg123_par() and mpg123_fmt() 1280 * family) directly return a fully qualified mpg123 error code, the ones 1281 * operating on full handles normally MPG123_OK or MPG123_ERR, storing the 1282 * specific error code itseld inside the handle. 1283 * 1284 * @{ 1285 */ 1286 1287/** Opaque structure for the libmpg123 decoder parameters. */ 1288struct mpg123_pars_struct; 1289 1290/** Opaque structure for the libmpg123 decoder parameters. */ 1291typedef struct mpg123_pars_struct mpg123_pars; 1292 1293/** Create a handle with preset parameters. 1294 * \param mp parameter handle 1295 * \param decoder decoder choice 1296 * \param error error code return address 1297 * \return mpg123 handle 1298 */ 1299MPG123_EXPORT mpg123_handle *mpg123_parnew( mpg123_pars *mp 1300, const char* decoder, int *error ); 1301 1302/** Allocate memory for and return a pointer to a new mpg123_pars 1303 * \param error error code return address 1304 * \return new parameter handle 1305 */ 1306MPG123_EXPORT mpg123_pars *mpg123_new_pars(int *error); 1307 1308/** Delete and free up memory used by a mpg123_pars data structure 1309 * \param mp parameter handle 1310 */ 1311MPG123_EXPORT void mpg123_delete_pars(mpg123_pars* mp); 1312 1313/** Configure mpg123 parameters to accept no output format at all, 1314 * use before specifying supported formats with mpg123_format 1315 * \param mp parameter handle 1316 * \return MPG123_OK on success 1317 */ 1318MPG123_EXPORT int mpg123_fmt_none(mpg123_pars *mp); 1319 1320/** Configure mpg123 parameters to accept all formats 1321 * (also any custom rate you may set) -- this is default. 1322 * \param mp parameter handle 1323 * \return MPG123_OK on success 1324 */ 1325MPG123_EXPORT int mpg123_fmt_all(mpg123_pars *mp); 1326 1327/** Set the audio format support of a mpg123_pars in detail: 1328 * \param mp parameter handle 1329 * \param rate The sample rate value (in Hertz). 1330 * \param channels A combination of MPG123_STEREO and MPG123_MONO. 1331 * \param encodings A combination of accepted encodings for rate and channels, 1332 * p.ex MPG123_ENC_SIGNED16|MPG123_ENC_ULAW_8 (or 0 for no 1333 * support). 1334 * \return MPG123_OK on success 1335*/ 1336MPG123_EXPORT int mpg123_fmt(mpg123_pars *mp 1337, long rate, int channels, int encodings); 1338 1339/** Check to see if a specific format at a specific rate is supported 1340 * by mpg123_pars. 1341 * \param mp parameter handle 1342 * \param rate sampling rate 1343 * \param encoding encoding 1344 * \return 0 for no support (that includes invalid parameters), MPG123_STEREO, 1345 * MPG123_MONO or MPG123_STEREO|MPG123_MONO. */ 1346MPG123_EXPORT int mpg123_fmt_support(mpg123_pars *mp, long rate, int encoding); 1347 1348/** Set a specific parameter, for a specific mpg123_pars, using a parameter 1349 * type key chosen from the mpg123_parms enumeration, to the specified value. 1350 * \param mp parameter handle 1351 * \param type parameter choice 1352 * \param value integer value 1353 * \param fvalue floating point value 1354 * \return MPG123_OK on success 1355 */ 1356MPG123_EXPORT int mpg123_par( mpg123_pars *mp 1357, enum mpg123_parms type, long value, double fvalue ); 1358 1359/** Get a specific parameter, for a specific mpg123_pars. 1360 * See the mpg123_parms enumeration for a list of available parameters. 1361 * \param mp parameter handle 1362 * \param type parameter choice 1363 * \param value integer value return address 1364 * \param fvalue floating point value return address 1365 * \return MPG123_OK on success 1366 */ 1367MPG123_EXPORT int mpg123_getpar( mpg123_pars *mp 1368, enum mpg123_parms type, long *value, double *fvalue); 1369 1370/* @} */ 1371 1372 1373/** \defgroup mpg123_lowio mpg123 low level I/O 1374 * You may want to do tricky stuff with I/O that does not work with mpg123's default file access or you want to make it decode into your own pocket... 1375 * 1376 * @{ */ 1377 1378/** Replace default internal buffer with user-supplied buffer. 1379 * Instead of working on it's own private buffer, mpg123 will directly use the one you provide for storing decoded audio. 1380 * Note that the required buffer size could be bigger than expected from output 1381 * encoding if libmpg123 has to convert from primary decoder output (p.ex. 32 bit 1382 * storage for 24 bit output). 1383 * \param mh handle 1384 * \param data pointer to user buffer 1385 * \param size of buffer in bytes 1386 * \return MPG123_OK on success 1387 */ 1388MPG123_EXPORT int mpg123_replace_buffer(mpg123_handle *mh 1389, unsigned char *data, size_t size); 1390 1391/** The max size of one frame's decoded output with current settings. 1392 * Use that to determine an appropriate minimum buffer size for decoding one frame. 1393 * \param mh handle 1394 * \return maximum decoded data size in bytes 1395 */ 1396MPG123_EXPORT size_t mpg123_outblock(mpg123_handle *mh); 1397 1398/** Replace low-level stream access functions; read and lseek as known in POSIX. 1399 * You can use this to make any fancy file opening/closing yourself, 1400 * using mpg123_open_fd() to set the file descriptor for your read/lseek 1401 * (doesn't need to be a "real" file descriptor...). 1402 * Setting a function to NULL means that the default internal read is 1403 * used (active from next mpg123_open call on). 1404 * Note: As it would be troublesome to mess with this while having a file open, 1405 * this implies mpg123_close(). 1406 * \param mh handle 1407 * \param r_read callback for reading (behaviour like POSIX read) 1408 * \param r_lseek callback for seeking (like POSIX lseek) 1409 * \return MPG123_OK on success 1410 */ 1411MPG123_EXPORT int mpg123_replace_reader( mpg123_handle *mh 1412, ssize_t (*r_read) (int, void *, size_t) 1413, off_t (*r_lseek)(int, off_t, int) 1414); 1415 1416/** Replace I/O functions with your own ones operating on some kind of 1417 * handle instead of integer descriptors. 1418 * The handle is a void pointer, so you can pass any data you want... 1419 * mpg123_open_handle() is the call you make to use the I/O defined here. 1420 * There is no fallback to internal read/seek here. 1421 * Note: As it would be troublesome to mess with this while having a file open, 1422 * this mpg123_close() is implied here. 1423 * \param mh handle 1424 * \param r_read callback for reading (behaviour like POSIX read) 1425 * \param r_lseek callback for seeking (like POSIX lseek) 1426 * \param cleanup A callback to clean up an I/O handle on mpg123_close, 1427 * can be NULL for none (you take care of cleaning your handles). 1428 * \return MPG123_OK on success 1429 */ 1430MPG123_EXPORT int mpg123_replace_reader_handle( mpg123_handle *mh 1431, ssize_t (*r_read) (void *, void *, size_t) 1432, off_t (*r_lseek)(void *, off_t, int) 1433, void (*cleanup)(void*) ); 1434 1435/* @} */ 1436 1437#ifdef __cplusplus 1438} 1439#endif 1440 1441#endif 1442