SDL_mixer: An audio mixer library based on the SDL library

Copyright (C) 1997, 1998, 1999, 2000, 2001 Sam Lantinga

This library is free software; you can redistribute it and/or

modify it under the terms of the GNU Library General Public

License as published by the Free Software Foundation; either

version 2 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

Library General Public License for more details.

You should have received a copy of the GNU Library General Public

License along with this library; if not, write to the Free

Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

Sam Lantinga

slouken@libsdl.org

*/

#include <stdlib.h>

#include <string.h>

#include "SDL_endian.h"

#include "SDL_audio.h"

/* The music command hack is UNIX specific */

#ifndef unix

#undef CMD_MUSIC

#endif

#ifdef CMD_MUSIC

#include "music_cmd.h"

#endif

#ifdef WAV_MUSIC

#include "wavestream.h"

#endif

#ifdef MOD_MUSIC

# include "mikmod.h"

# if defined(LIBMIKMOD_VERSION) /* libmikmod 3.1.8 */

# define UNIMOD MODULE

# define MikMod_Init() MikMod_Init(NULL)

# define MikMod_LoadSong(a,b) Player_Load(a,b,0)

# define MikMod_FreeSong Player_Free

extern int MikMod_errno;

# else /* old MikMod 3.0.3 */

# define MikMod_strerror(x) _mm_errmsg[x])

# define MikMod_errno _mm_errno

# endif

#endif

#ifdef MID_MUSIC

# ifdef USE_TIMIDITY_MIDI

# include "timidity.h"

# endif

# ifdef USE_NATIVE_MIDI

# include "native_midi.h"

# endif

# if defined(USE_TIMIDITY_MIDI) && defined(USE_NATIVE_MIDI)

# define MIDI_ELSE else

# else

# define MIDI_ELSE

# endif

#ifdef OGG_MUSIC

#include "music_ogg.h"

#endif

static SDL_AudioSpec used_mixer;

#endif

int volatile music_active = 1;

static int volatile music_stopped = 0;

static int music_loops = 0;

static char *music_cmd = NULL;

static int music_swap8;

static int music_swap16;

union {

#ifdef CMD_MUSIC

MusicCMD *cmd;

#endif

#ifdef WAV_MUSIC

WAVStream *wave;

#endif

#ifdef MOD_MUSIC

UNIMOD *module;

#endif

#ifdef MID_MUSIC

#ifdef USE_NATIVE_MIDI

NativeMidiSong *nativemidi;

#endif

#ifdef OGG_MUSIC

OGG_music *ogg;

#endif

#ifdef MP3_MUSIC

SMPEG *mp3;

#endif

} data;

int fade_step;

int fade_steps;

int error;

};

#ifdef USE_NATIVE_MIDI

static int native_midi_ok;

#endif

/* Used to calculate fading steps */

static int ms_per_step;

static void music_internal_volume(int volume);

static int music_internal_play(Mix_Music *music, double position);

static int music_internal_position(double position);

static int music_internal_playing();

static void music_internal_halt(void);

/* Support for hooking when the music has finished */

static void (*music_finished_hook)(void) = NULL;

void Mix_HookMusicFinished(void (*music_finished)(void))

{

SDL_LockAudio();

music_finished_hook = music_finished;

SDL_UnlockAudio();

}

/* Mixing function */

void music_mixer(void *udata, Uint8 *stream, int len)

{

if ( music_playing->fading != MIX_NO_FADING ) {

if ( music_playing->fade_step++ < music_playing->fade_steps ) {

int fade_step = music_playing->fade_step;

int fade_steps = music_playing->fade_steps;

} else {

if ( music_playing->fading == MIX_FADING_OUT ) {

music_internal_halt();

if ( music_finished_hook ) {

music_finished_hook();

}

}

}

if ( !music_internal_playing() ) {

/* Restart music if it has to loop at a high level */

} else {

music_internal_halt();

if ( music_finished_hook ) {

music_finished_hook();

switch (music_playing->type) {

#ifdef CMD_MUSIC

case MUS_CMD:

/* The playing is done externally */

break;

#endif

#ifdef WAV_MUSIC

case MUS_WAV:

break;

#endif

#ifdef MOD_MUSIC

case MUS_MOD:

VC_WriteBytes((SBYTE *)stream, len);

if ( music_swap8 ) {

Uint8 *dst;

dst = stream;

for ( i=len; i; --i ) {

*dst++ ^= 0x80;

}

} else

if ( music_swap16 ) {

Uint8 *dst, tmp;

dst = stream;

for ( i=(len/2); i; --i ) {

tmp = dst[0];

dst[0] = dst[1];

dst[1] = tmp;

dst += 2;

}

}

break;

#endif

#ifdef MID_MUSIC

if ( timidity_ok ) {

int samples = len / samplesize;

Timidity_PlaySome(stream, samples);

}

break;

#endif

#ifdef OGG_MUSIC

case MUS_OGG:

OGG_playAudio(music_playing->data.ogg, stream, len);

break;

#endif

case MUS_MP3:

SMPEG_playAudio(music_playing->data.mp3, stream, len);

break;

#endif

default:

/* Unknown music type?? */

break;

}

}

}

/* Initialize the music players with a certain desired audio format */

int open_music(SDL_AudioSpec *mixer)

{

int music_error;

music_error = 0;

#ifdef WAV_MUSIC

if ( WAVStream_Init(mixer) < 0 ) {

++music_error;

}

#endif

#ifdef MOD_MUSIC

/* Set the MikMod music format */

music_swap8 = 0;

music_swap16 = 0;

switch (mixer->format) {

case AUDIO_U8:

case AUDIO_S8: {

if ( mixer->format == AUDIO_S8 ) {

music_swap8 = 1;

}

md_mode = 0;

}

break;

case AUDIO_S16LSB:

case AUDIO_S16MSB: {

/* See if we need to correct MikMod mixing */

#if SDL_BYTEORDER == SDL_LIL_ENDIAN

if ( mixer->format == AUDIO_S16MSB ) {

#else

if ( mixer->format == AUDIO_S16LSB ) {

#endif

music_swap16 = 1;

}

md_mode = DMODE_16BITS;

}

break;

default: {

++music_error;

}

}

if ( mixer->channels > 1 ) {

if ( mixer->channels > 2 ) {

++music_error;

}

md_mode |= DMODE_STEREO;

}

md_mixfreq = mixer->freq;

md_device = 0;

md_volume = 96;

md_musicvolume = 128;

md_sndfxvolume = 128;

md_pansep = 128;

md_reverb = 0;

MikMod_RegisterAllLoaders();

MikMod_RegisterAllDrivers();

if ( MikMod_Init() ) {

++music_error;

}

#endif

#ifdef MID_MUSIC

} else {

timidity_ok = 0;

}

if ( native_midi_ok )

#endif

#ifdef OGG_MUSIC

if ( OGG_init(mixer) < 0 ) {

++music_error;

}

#endif

#ifdef MP3_MUSIC

/* Keep a copy of the mixer */

used_mixer = *mixer;

#endif

if ( music_error ) {

return(-1);

}

Mix_VolumeMusic(SDL_MIX_MAXVOLUME);

return(0);

}

/* Portable case-insensitive string compare function */

int MIX_string_equals(const char *str1, const char *str2)

{

while ( *str1 && *str2 ) {

if ( toupper((unsigned char)*str1) !=

toupper((unsigned char)*str2) )

break;

++str1;

++str2;

}

return (!*str1 && !*str2);

}

/* Load a music file */

Mix_Music *Mix_LoadMUS(const char *file)

{

FILE *fp;

Mix_Music *music;

/* Figure out what kind of file this is */

fp = fopen(file, "rb");

if ( (fp == NULL) || !fread(magic, 4, 1, fp) ) {

if ( fp != NULL ) {

fclose(fp);

}

return(NULL);

}

magic[4] = '\0';

fclose(fp);

/* Figure out the file extension, so we can determine the type */

ext = strrchr(file, '.');

if ( ext ) ++ext; /* skip the dot in the extension */

/* Allocate memory for the music structure */

music = (Mix_Music *)malloc(sizeof(Mix_Music));

if ( music == NULL ) {

return(NULL);

}

music->error = 0;

#ifdef CMD_MUSIC

if ( music_cmd ) {

music->type = MUS_CMD;

music->data.cmd = MusicCMD_LoadSong(music_cmd, file);

if ( music->data.cmd == NULL ) {

music->error = 1;

}

} else

#endif

#ifdef WAV_MUSIC

/* WAVE files have the magic four bytes "RIFF"

AIFF files have the magic 12 bytes "FORM" XXXX "AIFF"

*/

music->error = 1;

}

} else

#endif

#ifdef MID_MUSIC

/* MIDI files have the magic four bytes "MThd" */

if ( (ext && MIX_string_equals(ext, "MID")) ||

(ext && MIX_string_equals(ext, "MIDI")) ||

#ifdef USE_NATIVE_MIDI

if ( native_midi_ok ) {

music->data.nativemidi = native_midi_loadsong((char *)file);

if ( music->data.nativemidi == NULL ) {

Mix_SetError("%s", native_midi_error());

music->error = 1;

}

if ( timidity_ok ) {

music->data.midi = Timidity_LoadSong((char *)file);

if ( music->data.midi == NULL ) {

music->error = 1;

}

music->error = 1;

}

} else

#endif

#ifdef OGG_MUSIC

/* Ogg Vorbis files have the magic four bytes "OggS" */

music->type = MUS_OGG;

music->data.ogg = OGG_new(file);

if ( music->data.ogg == NULL ) {

music->error = 1;

}

} else

#endif

SMPEG_Info info;

music->type = MUS_MP3;

music->data.mp3 = SMPEG_new(file, &info, 0);

if(!info.has_audio){

music->error = 1;

}else{

SMPEG_actualSpec(music->data.mp3, &used_mixer);

}

} else

#endif

#ifdef MOD_MUSIC

if ( 1 ) {

music->type = MUS_MOD;

music->data.module = MikMod_LoadSong((char *)file, 64);

if ( music->data.module == NULL ) {

} else {

/* Stop implicit looping, fade out and other flags. */

music->data.module->extspd = 1;

music->data.module->panflag = 1;

music->data.module->wrap = 0;

music->data.module->loop = 0;

#if 0 /* Don't set fade out by default - unfortunately there's no real way

to query the status of the song or set trigger actions. Hum. */

}

} else

#endif

{

music->error = 1;

}

if ( music->error ) {

free(music);

music = NULL;

}

return(music);

}

/* Free a music chunk previously loaded */

void Mix_FreeMusic(Mix_Music *music)

{

if ( music ) {

/* Stop the music if it's currently playing */

SDL_LockAudio();

if ( music == music_playing ) {

/* Wait for any fade out to finish */

while ( music->fading == MIX_FADING_OUT ) {

SDL_UnlockAudio();

SDL_Delay(100);

SDL_LockAudio();

}

if ( music == music_playing ) {

music_internal_halt();

switch (music->type) {

#ifdef CMD_MUSIC

case MUS_CMD:

MusicCMD_FreeSong(music->data.cmd);

break;

#endif

#ifdef WAV_MUSIC

case MUS_WAV:

WAVStream_FreeSong(music->data.wave);

break;

#endif

#ifdef MOD_MUSIC

case MUS_MOD:

MikMod_FreeSong(music->data.module);

break;

#endif

#ifdef MID_MUSIC

case MUS_MID:

#ifdef USE_NATIVE_MIDI

if ( native_midi_ok ) {

native_midi_freesong(music->data.nativemidi);

if ( timidity_ok ) {

Timidity_FreeSong(music->data.midi);

}

break;

#endif

#ifdef OGG_MUSIC

case MUS_OGG:

OGG_delete(music->data.ogg);

break;

#endif

SMPEG_delete(music->data.mp3);

break;

#endif

default:

/* Unknown music type?? */

break;

}

free(music);

}

}

/* Find out the music format of a mixer music, or the currently playing

music, if 'music' is NULL.

*/

Mix_MusicType Mix_GetMusicType(const Mix_Music *music)

{

Mix_MusicType type = MUS_NONE;

if ( music ) {

type = music->type;

} else {

SDL_LockAudio();

if ( music_playing ) {

type = music_playing->type;

}

SDL_UnlockAudio();

}

return(type);

}

/* Play a music chunk. Returns 0, or -1 if there was an error.

*/

static int music_internal_play(Mix_Music *music, double position)

int retval = 0;

/* Note the music we're playing */

if ( music_playing ) {

music_internal_halt();

}

music_playing = music;

/* Set the initial volume */

if ( music->fading == MIX_FADING_IN ) {

music_internal_volume(0);

} else {

music_internal_volume(music_volume);

}

/* Set up for playback */

switch (music->type) {

#ifdef CMD_MUSIC

case MUS_CMD:

MusicCMD_Start(music->data.cmd);

break;

#endif

#ifdef WAV_MUSIC

case MUS_WAV:

WAVStream_Start(music->data.wave);

break;

#endif

#ifdef MOD_MUSIC

case MUS_MOD:

Player_Start(music->data.module);

break;

#endif

#ifdef MID_MUSIC

if ( native_midi_ok ) {

native_midi_start(music->data.nativemidi);

} MIDI_ELSE

if ( timidity_ok ) {

Timidity_Start(music->data.midi);

}