/
load_ogg.c
163 lines (128 loc) · 4.4 KB
1
/*
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
SDL_mixer: An audio mixer library based on the SDL library
Copyright (C) 1997-2012 Sam Lantinga <slouken@libsdl.org>
This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:
1. The origin of this software must not be misrepresented; you must not
claim that you wrote the original software. If you use this software
in a product, an acknowledgment in the product documentation would be
appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
This is the source needed to decode an Ogg Vorbis into a waveform.
This file by Vaclav Slavik (vaclav.slavik@matfyz.cz).
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
*/
/* $Id$ */
#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"
38
#include "dynamic_ogg.h"
39
40
41
42
43
44
45
46
47
#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)
{
48
return SDL_RWseek((SDL_RWops*)datasource, (int)offset, whence);
49
50
51
52
53
54
55
56
57
}
static int sdl_close_func_freesrc(void *datasource)
{
return SDL_RWclose((SDL_RWops*)datasource);
}
static int sdl_close_func_nofreesrc(void *datasource)
{
58
return SDL_RWseek((SDL_RWops*)datasource, 0, RW_SEEK_SET);
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
}
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;
85
if ( !Mix_Init(MIX_INIT_OGG) )
86
87
goto done;
88
89
90
91
92
93
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;
94
if (vorbis.ov_open_callbacks(src, &vf, NULL, 0, callbacks) != 0)
95
96
97
98
99
100
101
{
SDL_SetError("OGG bitstream is not valid Vorbis stream!");
goto done;
}
must_close = 0;
102
info = vorbis.ov_info(&vf, -1);
103
104
105
106
107
108
109
110
111
112
*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 */
113
samples = (long)vorbis.ov_pcm_total(&vf, -1);
114
115
*audio_len = spec->size = samples * spec->channels * 2;
116
*audio_buf = SDL_malloc(*audio_len);
117
118
119
120
121
if (*audio_buf == NULL)
goto done;
buf = *audio_buf;
to_read = *audio_len;
122
123
124
125
126
#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
127
for (read = vorbis.ov_read(&vf, (char *)buf, to_read, 0/*LE*/, 2/*16bit*/, 1/*signed*/, &bitstream);
128
read > 0;
129
read = vorbis.ov_read(&vf, (char *)buf, to_read, 0, 2, 1, &bitstream))
131
132
133
134
135
136
137
138
{
if (read == OV_HOLE || read == OV_EBADLINK)
break; /* error */
to_read -= read;
buf += read;
}
139
vorbis.ov_clear(&vf);
140
141
142
143
144
145
146
147
148
149
150
151
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
152
SDL_RWseek(src, 0, RW_SEEK_SET);
153
154
155
156
157
158
159
160
161
162
163
}
if ( was_error )
spec = NULL;
return(spec);
} /* Mix_LoadOGG_RW */
/* end of load_ogg.c ... */
#endif