1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
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
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
|
/*
* Copyright (C) 2000-2001 the xine project
*
* This file is part of xine, a unix video player.
*
* xine is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* xine 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*
* $Id: xine_decoder.c,v 1.2 2001/08/21 19:39:50 jcdutton Exp $
*
* stuff needed to turn libmad into a xine decoder plugin
*/
#include <stdlib.h>
#include <string.h>
#include "audio_out.h"
#include "buffer.h"
#include "xine_internal.h"
#include "frame.h"
#include "synth.h"
#define MAX_NUM_SAMPLES 8192
#define INPUT_BUF_SIZE 16384
typedef struct mad_decoder_s {
audio_decoder_t audio_decoder;
uint32_t pts;
struct mad_synth synth;
struct mad_stream stream;
struct mad_frame frame;
ao_instance_t *audio_out;
int output_sampling_rate;
int output_open;
int16_t samples[MAX_NUM_SAMPLES];
uint8_t buffer[INPUT_BUF_SIZE];
int bytes_in_buffer;
} mad_decoder_t;
static int mad_can_handle (audio_decoder_t *this_gen, int buf_type) {
return ((buf_type & 0xFFFF0000) == BUF_AUDIO_MPEG) ;
}
static void mad_init (audio_decoder_t *this_gen, ao_instance_t *audio_out) {
mad_decoder_t *this = (mad_decoder_t *) this_gen;
this->audio_out = audio_out;
this->output_open = 0;
this->bytes_in_buffer = 0;
mad_synth_init (&this->synth);
mad_stream_init (&this->stream);
mad_frame_init (&this->frame);
}
/* utility to scale and round samples to 16 bits */
static inline
signed int scale(mad_fixed_t sample)
{
/* round */
sample += (1L << (MAD_F_FRACBITS - 16));
/* clip */
if (sample >= MAD_F_ONE)
sample = MAD_F_ONE - 1;
else if (sample < -MAD_F_ONE)
sample = -MAD_F_ONE;
/* quantize */
return sample >> (MAD_F_FRACBITS + 1 - 16);
}
/*
static int head_check(mad_decoder_t *this) {
if( (this->header & 0xffe00000) != 0xffe00000)
return 0;
if(!((this->header>>17)&3))
return 0;
if( ((this->header>>12)&0xf) == 0xf)
return 0;
if( ((this->header>>10)&0x3) == 0x3 )
return 0;
return 1;
}
*/
static void mad_decode_data (audio_decoder_t *this_gen, buf_element_t *buf) {
mad_decoder_t *this = (mad_decoder_t *) this_gen;
/* printf ("libmad: decode data\n");
fflush (stdout); */
if (buf->size>(INPUT_BUF_SIZE-this->bytes_in_buffer)) {
printf ("libmad: ALERT input buffer too small!\n");
}
if (buf->decoder_info[0] >0) {
memcpy (&this->buffer[this->bytes_in_buffer],
buf->content, buf->size);
this->bytes_in_buffer += buf->size;
/*
printf ("libmad: decode data - doing it\n");
fflush (stdout);
*/
mad_stream_buffer (&this->stream, this->buffer,
this->bytes_in_buffer);
while (1) {
if (mad_frame_decode (&this->frame, &this->stream) != 0) {
if (this->stream.next_frame) {
int num_bytes =
this->buffer + this->bytes_in_buffer - this->stream.next_frame;
/* printf("libmad: MAD_ERROR_BUFLEN\n"); */
memmove(this->buffer, this->stream.next_frame, num_bytes);
this->bytes_in_buffer = num_bytes;
}
switch (this->stream.error) {
case MAD_ERROR_BUFLEN:
return;
default:
mad_stream_buffer (&this->stream, this->buffer,
this->bytes_in_buffer);
}
} else {
if (!this->output_open) {
printf ("libmad: audio sample rate %d mode %d\n",
this->frame.header.samplerate,
this->frame.header.mode);
this->audio_out->open(this->audio_out,
16, this->frame.header.samplerate,
(this->frame.header.mode == MAD_MODE_SINGLE_CHANNEL) ? AO_CAP_MODE_MONO : AO_CAP_MODE_STEREO);
this->output_open = 1;
this->output_sampling_rate = this->frame.header.samplerate;
}
mad_synth_frame (&this->synth, &this->frame);
{
unsigned int nchannels, nsamples;
mad_fixed_t const *left_ch, *right_ch;
struct mad_pcm *pcm = &this->synth.pcm;
uint16_t *output = this->samples;
nchannels = pcm->channels;
nsamples = pcm->length;
left_ch = pcm->samples[0];
right_ch = pcm->samples[1];
while (nsamples--) {
/* output sample(s) in 16-bit signed little-endian PCM */
*output++ = scale(*left_ch++);
if (nchannels == 2)
*output++ = scale(*right_ch++);
}
this->audio_out->write (this->audio_out,
this->samples,
pcm->length,
buf->PTS);
buf->PTS = 0;
}
/* printf ("libmad: decode worked\n"); */
}
}
}
}
static void mad_close (audio_decoder_t *this_gen) {
mad_decoder_t *this = (mad_decoder_t *) this_gen;
mad_synth_finish (&this->synth);
mad_frame_finish (&this->frame);
mad_stream_finish(&this->stream);
if (this->output_open)
this->audio_out->close (this->audio_out);
}
static char *mad_get_id(void) {
return "mad";
}
audio_decoder_t *init_audio_decoder_plugin (int iface_version, config_values_t *cfg) {
mad_decoder_t *this ;
if (iface_version != 2) {
printf( "libmad: plugin doesn't support plugin API version %d.\n"
"libmad: this means there's a version mismatch between xine and this "
"libmad: decoder plugin.\nInstalling current plugins should help.\n",
iface_version);
return NULL;
}
this = (mad_decoder_t *) malloc (sizeof (mad_decoder_t));
this->audio_decoder.interface_version = 2;
this->audio_decoder.can_handle = mad_can_handle;
this->audio_decoder.init = mad_init;
this->audio_decoder.decode_data = mad_decode_data;
this->audio_decoder.close = mad_close;
this->audio_decoder.get_identifier = mad_get_id;
this->audio_decoder.priority = 5;
return (audio_decoder_t *) this;
}
|
