/*

SDL_mixer: An audio mixer library based on the SDL library

Copyright (C) 1997-2009 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

This is the source needed to decode an Ogg Vorbis into a waveform.

This file by Vaclav Slavik (vaclav.slavik@matfyz.cz).

*/

/* $Id$ */

#ifdef OGG_MUSIC

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include "SDL_mutex.h"

#include "SDL_endian.h"

#include "SDL_timer.h"

#include "SDL_mixer.h"

#include "dynamic_ogg.h"

#include "load_ogg.h"

static size_t sdl_read_func(void *ptr, size_t size, size_t nmemb, void *datasource)

{

return SDL_RWread((SDL_RWops*)datasource, ptr, size, nmemb);

}

static int sdl_seek_func(void *datasource, ogg_int64_t offset, int whence)

{

return SDL_RWseek((SDL_RWops*)datasource, (int)offset, whence);

}

static int sdl_close_func_freesrc(void *datasource)

{

return SDL_RWclose((SDL_RWops*)datasource);

}

static int sdl_close_func_nofreesrc(void *datasource)

{

return SDL_RWseek((SDL_RWops*)datasource, 0, SEEK_SET);

}

static long sdl_tell_func(void *datasource)

{

return SDL_RWtell((SDL_RWops*)datasource);

}

/* don't call this directly; use Mix_LoadWAV_RW() for now. */

SDL_AudioSpec *Mix_LoadOGG_RW (SDL_RWops *src, int freesrc,

SDL_AudioSpec *spec, Uint8 **audio_buf, Uint32 *audio_len)

{

OggVorbis_File vf;

ov_callbacks callbacks;

vorbis_info *info;

Uint8 *buf;

int bitstream = -1;

long samplesize;

long samples;

int read, to_read;

int must_close = 1;

int was_error = 1;

if ( (!src) || (!audio_buf) || (!audio_len) ) /* sanity checks. */

goto done;

if ( Mix_InitOgg() < 0 )

goto done;

callbacks.read_func = sdl_read_func;

callbacks.seek_func = sdl_seek_func;

callbacks.tell_func = sdl_tell_func;

callbacks.close_func = freesrc ?

sdl_close_func_freesrc : sdl_close_func_nofreesrc;

if (vorbis.ov_open_callbacks(src, &vf, NULL, 0, callbacks) != 0)

{

SDL_SetError("OGG bitstream is not valid Vorbis stream!");

goto done;

}

must_close = 0;

info = vorbis.ov_info(&vf, -1);

*audio_buf = NULL;

*audio_len = 0;

memset(spec, '\0', sizeof (SDL_AudioSpec));

spec->format = AUDIO_S16;

spec->channels = info->channels;

spec->freq = info->rate;

spec->samples = 4096; /* buffer size */

samples = (long)vorbis.ov_pcm_total(&vf, -1);

*audio_len = spec->size = samples * spec->channels * 2;

*audio_buf = malloc(*audio_len);

if (*audio_buf == NULL)

goto done;

buf = *audio_buf;

to_read = *audio_len;

#ifdef OGG_USE_TREMOR

for (read = vorbis.ov_read(&vf, (char *)buf, to_read, &bitstream);

read > 0;

read = vorbis.ov_read(&vf, (char *)buf, to_read, &bitstream))

#else

for (read = vorbis.ov_read(&vf, (char *)buf, to_read, 0/*LE*/, 2/*16bit*/, 1/*signed*/, &bitstream);

read > 0;

read = vorbis.ov_read(&vf, (char *)buf, to_read, 0, 2, 1, &bitstream))

#endif

{

if (read == OV_HOLE || read == OV_EBADLINK)

break; /* error */

to_read -= read;

buf += read;

}

vorbis.ov_clear(&vf);

was_error = 0;

/* Don't return a buffer that isn't a multiple of samplesize */

samplesize = ((spec->format & 0xFF)/8)*spec->channels;

*audio_len &= ~(samplesize-1);

done:

if (src && must_close)

{

if (freesrc)

SDL_RWclose(src);

else

SDL_RWseek(src, 0, SEEK_SET);

}

if ( was_error )

spec = NULL;

Mix_QuitOgg();

return(spec);

} /* Mix_LoadOGG_RW */

/* end of load_ogg.c ... */

#endif