1 /*
2 *
3 * Bluetooth low-complexity, subband codec (SBC) decoder
4 *
5 * Copyright (C) 2004-2009 Marcel Holtmann <marcel@holtmann.org>
6 *
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
21 *
22 */
23
24 #ifdef HAVE_CONFIG_H
25 #include <config.h>
26 #endif
27
28 #include <stdio.h>
29 #include <errno.h>
30 #include <fcntl.h>
31 #include <unistd.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include <getopt.h>
35 #include <sys/stat.h>
36 #include <sys/ioctl.h>
37 #include <sys/soundcard.h>
38
39 #include "sbc.h"
40 #include "formats.h"
41
42 #define BUF_SIZE 8192
43
44 static int verbose = 0;
45
decode(char * filename,char * output,int tofile)46 static void decode(char *filename, char *output, int tofile)
47 {
48 unsigned char buf[BUF_SIZE], *stream;
49 struct stat st;
50 sbc_t sbc;
51 int fd, ad, pos, streamlen, framelen, count;
52 size_t len;
53 int format = AFMT_S16_BE, frequency, channels;
54 ssize_t written;
55
56 if (stat(filename, &st) < 0) {
57 fprintf(stderr, "Can't get size of file %s: %s\n",
58 filename, strerror(errno));
59 return;
60 }
61
62 stream = malloc(st.st_size);
63
64 if (!stream) {
65 fprintf(stderr, "Can't allocate memory for %s: %s\n",
66 filename, strerror(errno));
67 return;
68 }
69
70 fd = open(filename, O_RDONLY);
71 if (fd < 0) {
72 fprintf(stderr, "Can't open file %s: %s\n",
73 filename, strerror(errno));
74 goto free;
75 }
76
77 if (read(fd, stream, st.st_size) != st.st_size) {
78 fprintf(stderr, "Can't read content of %s: %s\n",
79 filename, strerror(errno));
80 close(fd);
81 goto free;
82 }
83
84 close(fd);
85
86 pos = 0;
87 streamlen = st.st_size;
88
89 if (tofile)
90 ad = open(output, O_WRONLY | O_CREAT | O_TRUNC, 0644);
91 else
92 ad = open(output, O_WRONLY, 0);
93
94 if (ad < 0) {
95 fprintf(stderr, "Can't open output %s: %s\n",
96 output, strerror(errno));
97 goto free;
98 }
99
100 sbc_init(&sbc, 0L);
101 sbc.endian = SBC_BE;
102
103 framelen = sbc_decode(&sbc, stream, streamlen, buf, sizeof(buf), &len);
104 channels = sbc.mode == SBC_MODE_MONO ? 1 : 2;
105 switch (sbc.frequency) {
106 case SBC_FREQ_16000:
107 frequency = 16000;
108 break;
109
110 case SBC_FREQ_32000:
111 frequency = 32000;
112 break;
113
114 case SBC_FREQ_44100:
115 frequency = 44100;
116 break;
117
118 case SBC_FREQ_48000:
119 frequency = 48000;
120 break;
121 default:
122 frequency = 0;
123 }
124
125 if (verbose) {
126 fprintf(stderr,"decoding %s with rate %d, %d subbands, "
127 "%d bits, allocation method %s and mode %s\n",
128 filename, frequency, sbc.subbands * 4 + 4, sbc.bitpool,
129 sbc.allocation == SBC_AM_SNR ? "SNR" : "LOUDNESS",
130 sbc.mode == SBC_MODE_MONO ? "MONO" :
131 sbc.mode == SBC_MODE_STEREO ?
132 "STEREO" : "JOINTSTEREO");
133 }
134
135 if (tofile) {
136 struct au_header au_hdr;
137
138 au_hdr.magic = AU_MAGIC;
139 au_hdr.hdr_size = BE_INT(24);
140 au_hdr.data_size = BE_INT(0);
141 au_hdr.encoding = BE_INT(AU_FMT_LIN16);
142 au_hdr.sample_rate = BE_INT(frequency);
143 au_hdr.channels = BE_INT(channels);
144
145 written = write(ad, &au_hdr, sizeof(au_hdr));
146 if (written < (ssize_t) sizeof(au_hdr)) {
147 fprintf(stderr, "Failed to write header\n");
148 goto close;
149 }
150 } else {
151 if (ioctl(ad, SNDCTL_DSP_SETFMT, &format) < 0) {
152 fprintf(stderr, "Can't set audio format on %s: %s\n",
153 output, strerror(errno));
154 goto close;
155 }
156
157 if (ioctl(ad, SNDCTL_DSP_CHANNELS, &channels) < 0) {
158 fprintf(stderr, "Can't set number of channels on %s: %s\n",
159 output, strerror(errno));
160 goto close;
161 }
162
163 if (ioctl(ad, SNDCTL_DSP_SPEED, &frequency) < 0) {
164 fprintf(stderr, "Can't set audio rate on %s: %s\n",
165 output, strerror(errno));
166 goto close;
167 }
168 }
169
170 count = len;
171
172 while (framelen > 0) {
173 /* we have completed an sbc_decode at this point sbc.len is the
174 * length of the frame we just decoded count is the number of
175 * decoded bytes yet to be written */
176
177 if (count + len >= BUF_SIZE) {
178 /* buffer is too full to stuff decoded audio in so it
179 * must be written to the device */
180 written = write(ad, buf, count);
181 if (written > 0)
182 count -= written;
183 }
184
185 /* sanity check */
186 if (count + len >= BUF_SIZE) {
187 fprintf(stderr,
188 "buffer size of %d is too small for decoded"
189 " data (%lu)\n", BUF_SIZE, (unsigned long) (len + count));
190 exit(1);
191 }
192
193 /* push the pointer in the file forward to the next bit to be
194 * decoded tell the decoder to decode up to the remaining
195 * length of the file (!) */
196 pos += framelen;
197 framelen = sbc_decode(&sbc, stream + pos, streamlen - pos,
198 buf + count, sizeof(buf) - count, &len);
199
200 /* increase the count */
201 count += len;
202 }
203
204 if (count > 0) {
205 written = write(ad, buf, count);
206 if (written > 0)
207 count -= written;
208 }
209
210 close:
211 sbc_finish(&sbc);
212
213 close(ad);
214
215 free:
216 free(stream);
217 }
218
usage(void)219 static void usage(void)
220 {
221 printf("SBC decoder utility ver %s\n", VERSION);
222 printf("Copyright (c) 2004-2009 Marcel Holtmann\n\n");
223
224 printf("Usage:\n"
225 "\tsbcdec [options] file(s)\n"
226 "\n");
227
228 printf("Options:\n"
229 "\t-h, --help Display help\n"
230 "\t-v, --verbose Verbose mode\n"
231 "\t-d, --device <dsp> Sound device\n"
232 "\t-f, --file <file> Decode to a file\n"
233 "\n");
234 }
235
236 static struct option main_options[] = {
237 { "help", 0, 0, 'h' },
238 { "device", 1, 0, 'd' },
239 { "verbose", 0, 0, 'v' },
240 { "file", 1, 0, 'f' },
241 { 0, 0, 0, 0 }
242 };
243
main(int argc,char * argv[])244 int main(int argc, char *argv[])
245 {
246 char *output = NULL;
247 int i, opt, tofile = 0;
248
249 while ((opt = getopt_long(argc, argv, "+hvd:f:",
250 main_options, NULL)) != -1) {
251 switch(opt) {
252 case 'h':
253 usage();
254 exit(0);
255
256 case 'v':
257 verbose = 1;
258 break;
259
260 case 'd':
261 if (output)
262 free(output);
263 output = strdup(optarg);
264 tofile = 0;
265 break;
266
267 case 'f' :
268 if (output)
269 free(output);
270 output = strdup(optarg);
271 tofile = 1;
272 break;
273
274 default:
275 exit(1);
276 }
277 }
278
279 argc -= optind;
280 argv += optind;
281 optind = 0;
282
283 if (argc < 1) {
284 usage();
285 exit(1);
286 }
287
288 for (i = 0; i < argc; i++)
289 decode(argv[i], output ? output : "/dev/dsp", tofile);
290
291 if (output)
292 free(output);
293
294 return 0;
295 }
296