Mercurial > SDL_sound_CoreAudio
diff SDL_sound.h @ 0:1078b3528e6f
Initial revision
author | Ryan C. Gordon <icculus@icculus.org> |
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date | Fri, 14 Sep 2001 23:41:11 +0000 |
parents | |
children | 508aac690b19 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/SDL_sound.h Fri Sep 14 23:41:11 2001 +0000 @@ -0,0 +1,337 @@ +/* + * SDL_sound -- An abstract sound format decoding API. + * Copyright (C) 2001 Ryan C. Gordon. + * + * This library 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. + * + * This library 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 this library; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +/** + * The basic gist of SDL_sound is that you use an SDL_RWops to get sound data + * into this library, and SDL_sound will take that data, in one of several + * popular formats, and decode it into raw waveform data in the format of + * your choice. This gives you a nice abstraction for getting sound into your + * game or application; just feed it to SDL_sound, and it will handle + * decoding and converting, so you can just pass it to your SDL audio + * callback (or whatever). Since it gets data from a SDL_RWops, you can get + * the initial sound data from any number of sources: file, memory buffer, + * network connection, etc. + * + * As the name implies, this library depends on SDL: Simple Directmedia Layer, + * which is a powerful, free, and cross-platform multimedia library. It can + * be found at http://www.libsdl.org/ + * + * Support is in place or planned for the following sound formats: + * - .WAV (Microsoft WAVfile RIFF data, internal.) + * - .VOC (Creative Labs' Voice format, internal.) + * - .MP3 (MPEG-1 layer 3 support, via the SMPEG library.) + * - .MID (MIDI music converted to Waveform data, via Timidity.) + * - .MOD (MOD files, via MikMod.) + * - .OGG (Ogg files, via Ogg Vorbis libraries.) + * - .RAWDATA (Raw sound data in any format, internal.) + * - .CDA (CD audio read into a sound buffer, internal.) + * + * (...and more to come...) + * + * Please see the file LICENSE in the source's root directory. + * + * This file written by Ryan C. Gordon. (icculus@clutteredmind.org) + */ + +#ifndef _INCLUDE_SDL_VOICE_H_ +#define _INCLUDE_SDL_VOICE_H_ + +#include "SDL.h" + +#ifdef __cplusplus +extern "C" { +#endif + +/* + * These are flags that are used in a Sound_Sample (below) to show various + * states. + * + * To use: "if (sample->flags & VOICE_SAMPLEFLAGS_ERROR) { dosomething(); }" + */ +typedef enum __VOICE_SAMPLEFLAGS__ +{ + VOICE_SAMPLEFLAG_NONE = 0, /* Null flag. */ + + /* these are set at sample creation time... */ + VOICE_SAMPLEFLAG_NEEDSEEK = 1, /* SDL_RWops must be able to seek. */ + VOICE_SAMPLEFLAG_STREAMING = 1 << 1, /* source is streaming (no EOF). */ + + /* these are set during decoding... */ + VOICE_SAMPLEFLAG_EOF = 1 << 29, /* end of input stream. */ + VOICE_SAMPLEFLAG_ERROR = 1 << 30, /* unrecoverable error. */ + VOICE_SAMPLEFLAG_AGAIN = 1 << 31 /* couldn't read without blocking. */ +} Sound_SampleFlags; + + +/* + * The Sound_Sample structure is the heart of SDL_sound. This holds + * information about a source of sound data as it is being decoded. + * EVERY FIELD IN THIS IS READ-ONLY. Please use the API functions to + * change them. + */ +typedef struct __VOICE_SAMPLE__ +{ + void *opaque; /* Internal use only. */ + Sound_DecoderInfo *decoder; /* Decoder used for this sample. */ + SDL_AudioSpec desired; /* Desired audio format for conversion. */ + SDL_AudioSpec actual; /* Actual audio format of sample. */ + void *buffer; /* Decoded sound data lands in here. */ + Uint32 buffer_size; /* Current size of (buffer), in bytes. */ + Sound_SampleFlags flags; /* Flags relating to this sample. */ +} Sound_Sample; + + +/* + * Each decoder sets up one of these structs, which can be retrieved via + * the Sound_AvailableDecoders() function. + */ +typedef struct __PHYSFS_ARCHIVEINFO__ +{ + const char *extension; /* Case sensitive standard file extension. */ + const char *description; /* Human readable description of decoder. */ + const char *author; /* "Name Of Author (email@emailhost.dom)" */ + const char *url; /* URL specific to this decoder. */ +} PHYSFS_ArchiveInfo; + + +/* + * Just what it says: a x.y.z style version number... + */ +typedef struct __VOICE_VERSION__ +{ + int major; + int minor; + int patch; +} Sound_Version; + + + +/* functions and macros... */ + +#define VOICE_VER_MAJOR 0 +#define VOICE_VER_MINOR 0 +#define VOICE_VER_PATCH 1 + +#define VOICE_VERSION(x) { \ + (x)->major = VOICE_VER_MAJOR; \ + (x)->minor = VOICE_VER_MINOR; \ + (x)->patch = VOICE_VER_PATCH; \ + } + +/** + * Get the version of SDL_sound that is linked against your program. If you + * are using a shared library (DLL) version of SDL_sound, then it is possible + * that it will be different than the version you compiled against. + * + * This is a real function; the macro VOICE_VERSION tells you what version + * of SDL_sound you compiled against: + * + * Sound_Version compiled; + * Sound_Version linked; + * + * VOICE_VERSION(&compiled); + * Sound_GetLinkedVersion(&linked); + * printf("We compiled against SDL_sound version %d.%d.%d ...\n", + * compiled.major, compiled.minor, compiled.patch); + * printf("But we linked against SDL_sound version %d.%d.%d.\n", + * linked.major, linked.minor, linked.patch); + * + * This function may be called safely at any time, even before Sound_Init(). + */ +extern DECLSPEC void Sound_GetLinkedVersion(Sound_Version *ver); + + +/** + * Initialize SDL_sound. This must be called before any other SDL_sound + * function (except perhaps Sound_GetLinkedVersion()). You should call + * SDL_Init() before calling this. Sound_Init() will attempt to call + * SDL_Init(SDL_INIT_AUDIO), just in case. This is a safe behaviour, but it + * may not configure SDL to your liking by itself. + * + * @return nonzero on success, zero on error. Specifics of the error can be + * gleaned from Sound_GetLastError(). + */ +extern DECLSPEC int Sound_Init(void); + + +/** + * Shutdown SDL_sound. This closes any SDL_RWops that were being used as + * sound sources, and frees any resources in use by SDL_sound. + * + * All Sound_Sample pointers you had prior to this call are INVALIDATED. + * + * Once successfully deinitialized, Sound_Init() can be called again to + * restart the subsystem. All defaults API states are restored at this + * point. + * + * You should call this BEFORE SDL_Quit(). This will NOT call SDL_Quit() + * for you! + * + * @return nonzero on success, zero on error. Specifics of the error can be + * gleaned from Sound_GetLastError(). If failure, state of SDL_sound + * is undefined, and probably badly screwed up. + */ +extern DECLSPEC int Sound_Quit(void); + + +/** + * Get a list of sound formats supported by this implementation of SDL_sound. + * This is for informational purposes only. Note that the extension listed is + * merely convention: if we list "MP3", you can open an MPEG Audio layer 3 + * file with an extension of "XYZ", if you like. The file extensions are + * informational, and only required as a hint to choosing the correct + * decoder, since the sound data may not be coming from a file at all, thanks + * to the abstraction that an SDL_RWops provides. + * + * The returned value is an array of pointers to Sound_DecoderInfo structures, + * with a NULL entry to signify the end of the list: + * + * Sound_DecoderInfo **i; + * + * for (i = Sound_AvailableDecoders(); *i != NULL; i++) + * { + * printf("Supported sound format: [%s], which is [%s].\n", + * i->extension, i->description); + * // ...and other fields... + * } + * + * The return values are pointers to static internal memory, and should + * be considered READ ONLY, and never freed. + * + * @return READ ONLY Null-terminated array of READ ONLY structures. + */ +extern DECLSPEC const Sound_DecoderInfo **Sound_AvailableDecoders(void); + + +/** + * Get the last SDL_sound error message as a null-terminated string. + * This will be NULL if there's been no error since the last call to this + * function. The pointer returned by this call points to an internal buffer. + * Each thread has a unique error state associated with it, but each time + * a new error message is set, it will overwrite the previous one associated + * with that thread. It is safe to call this function at anytime, even + * before Sound_Init(). + * + * @return READ ONLY string of last error message. + */ +extern DECLSPEC const char *Sound_GetLastError(void); + + +/** + * Start decoding a new sound sample. The data is read via an SDL_RWops + * structure (see SDL_rwops.h in the SDL include directory), so it may be + * coming from memory, disk, network stream, etc. The (ext) parameter is + * merely a hint to determining the correct decoder; if you specify, for + * example, "mp3" for an extension, and one of the decoders lists that + * (case sensitive) as a handled extension, then that decoder is given + * first shot at trying to claim the data for decoding. If none of the + * extensions match (or the extension is NULL), then every decoder examines + * the data to determine if it can handle it, until one accepts it. + * If no decoders can handle the data, a NULL value is returned, and a human + * readable error message can be fetched from Sound_GetLastError(). + * Optionally, a desired audio format can be specified. If the incoming data + * is in a different format, SDL_sound will convert it to the desired format + * on the fly. Note that this can be an expensive operation, so it may be + * wise to convert data before you need to play it back, if possible, or + * make sure your data is initially in the format that you need it in. + * If you don't want to convert the data, you can specify NULL for a desired + * format. The incoming format of the data, preconversion, can be found + * in the Sound_Sample structure. + * Note that the raw sound data "decoder" needs you to specify both the + * extension "RAWDATA" and a "desired" format, or it will refuse to handle + * the data. + * Finally, specify an initial buffer size; this is the number of bytes that + * will be allocated to store each read from the sound buffer. The more you + * can safely allocate, the more decoding can be done in one block, but the + * more resources you have to use up, and the longer each decoding call will + * take. Note that different data formats require more or less space to + * store. This buffer can be resized via Sound_SetBufferSize() ... + * + * When you are done with this Sound_Sample pointer, you can dispose of it + * via Sound_FreeSample(). + * + * @param rw SDL_RWops with sound data. + * @param ext File extension normally associated with a data format. + * Can usually be NULL. + * @param desired Format to convert sound data into. Can usually be NULL, + * if you don't need conversion. + * @return Sound_Sample pointer, which is used as a handle to several other + * SDL_sound APIs. NULL on error. If error, use + * Sound_GetLastError() to see what went wrong. + */ +extern DECLSPEC Sound_Sample *Sound_NewSample(SDL_RWops *rw, const char *ext, + SDL_AudioInfo *desired, + Uint32 bufferSize); + +/** + * Dispose of a Sound_Sample pointer that was returned from Sound_NewSample(). + * This will also close/dispose of the SDL_RWops that was used at creation + * time, so there's no need to keep a reference to that around. + * The Sound_Sample pointer is invalid after this call, and will almost + * certainly result in a crash if you attempt to keep using it. + * + * @param sample The Sound_Sample to delete. + */ +extern DECLSPEC void Sound_FreeSample(Sound_Sample *sample); + + +/** + * Decode more of the sound data in a Sound_Sample. It will decode at most + * sample->buffer_size bytes into sample->buffer in the desired format, and + * return the number of decoded bytes. + * If sample->buffer_size bytes could not be decoded, then please refer to + * sample->flags to determine if this was an End-of-stream or error condition. + * + * @param sample Do more decoding to this Sound_Sample. + * @return number of bytes decoded into sample->buffer. If it is less than + * sample->buffer_size, then you should check sample->flags to see + * what the current state of the sample is (EOF, error, read again). + */ +extern DECLSPEC Uint32 Sound_Decode(Sound_Sample *sample); + + +/** + * Decode the remainder of the sound data in a Sound_Sample. This will + * dynamically allocate memory for the ENTIRE remaining sample. + * sample->buffer_size and sample->buffer will be updated to reflect the + * new buffer. Please refer to sample->flags to determine if the decoding + * finished due to an End-of-stream or error condition. + * + * Be aware that sound data can take a large amount of memory, and that + * this function may block for quite awhile while processing. Also note + * that a streaming source (for example, from a SDL_RWops that is getting + * fed from an Internet radio feed that doesn't end) may fill all available + * memory before giving up...be sure to use this on finite sound sources + * only! + * + * @param sample Do all decoding for this Sound_Sample. + * @return number of bytes decoded into sample->buffer. If it is less than + * sample->buffer_size, then you should check sample->flags to see + * what the current state of the sample is (EOF, error, read again). + */ +extern DECLSPEC Uint32 Sound_DecodeAll(Sound_Sample *sample); + +#ifdef __cplusplus +} +#endif + +#endif /* !defined _INCLUDE_SDL_VOICE_H_ */ + +/* end of SDL_sound.h ... */ +