1 /* 2 * 3 * Bluetooth low-complexity, subband codec (SBC) library 4 * 5 * Copyright (C) 2008-2010 Nokia Corporation 6 * Copyright (C) 2004-2010 Marcel Holtmann <marcel (at) holtmann.org> 7 * 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License as published by 11 * the Free Software Foundation; either version 2 of the License, or 12 * (at your option) any later version. 13 * 14 * This program is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 * GNU General Public License for more details. 18 * 19 * You should have received a copy of the GNU General Public License 20 * along with this program; if not, write to the Free Software 21 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 22 * 23 */ 24 25 #ifdef HAVE_CONFIG_H 26 #include <config.h> 27 #endif 28 29 #include <stdio.h> 30 #include <errno.h> 31 #include <fcntl.h> 32 #include <unistd.h> 33 #include <stdlib.h> 34 #include <stdint.h> 35 #include <string.h> 36 #include <libgen.h> 37 38 #if __BYTE_ORDER == __LITTLE_ENDIAN 39 struct sbc_frame_hdr { 40 uint8_t syncword:8; /* Sync word */ 41 uint8_t subbands:1; /* Subbands */ 42 uint8_t allocation_method:1; /* Allocation method */ 43 uint8_t channel_mode:2; /* Channel mode */ 44 uint8_t blocks:2; /* Blocks */ 45 uint8_t sampling_frequency:2; /* Sampling frequency */ 46 uint8_t bitpool:8; /* Bitpool */ 47 uint8_t crc_check:8; /* CRC check */ 48 } __attribute__ ((packed)); 49 #elif __BYTE_ORDER == __BIG_ENDIAN 50 struct sbc_frame_hdr { 51 uint8_t syncword:8; /* Sync word */ 52 uint8_t sampling_frequency:2; /* Sampling frequency */ 53 uint8_t blocks:2; /* Blocks */ 54 uint8_t channel_mode:2; /* Channel mode */ 55 uint8_t allocation_method:1; /* Allocation method */ 56 uint8_t subbands:1; /* Subbands */ 57 uint8_t bitpool:8; /* Bitpool */ 58 uint8_t crc_check:8; /* CRC check */ 59 } __attribute__ ((packed)); 60 #else 61 #error "Unknown byte order" 62 #endif 63 64 static int calc_frame_len(struct sbc_frame_hdr *hdr) 65 { 66 int tmp, nrof_subbands, nrof_blocks; 67 68 nrof_subbands = (hdr->subbands + 1) * 4; 69 nrof_blocks = (hdr->blocks + 1) * 4; 70 71 switch (hdr->channel_mode) { 72 case 0x00: 73 nrof_subbands /= 2; 74 tmp = nrof_blocks * hdr->bitpool; 75 break; 76 case 0x01: 77 tmp = nrof_blocks * hdr->bitpool * 2; 78 break; 79 case 0x02: 80 tmp = nrof_blocks * hdr->bitpool; 81 break; 82 case 0x03: 83 tmp = nrof_blocks * hdr->bitpool + nrof_subbands; 84 break; 85 default: 86 return 0; 87 } 88 89 return (nrof_subbands + ((tmp + 7) / 8)); 90 } 91 92 static double calc_bit_rate(struct sbc_frame_hdr *hdr) 93 { 94 int nrof_subbands, nrof_blocks; 95 double f; 96 97 nrof_subbands = (hdr->subbands + 1) * 4; 98 nrof_blocks = (hdr->blocks + 1) * 4; 99 100 switch (hdr->sampling_frequency) { 101 case 0: 102 f = 16; 103 break; 104 case 1: 105 f = 32; 106 break; 107 case 2: 108 f = 44.1; 109 break; 110 case 3: 111 f = 48; 112 break; 113 default: 114 return 0; 115 } 116 117 return ((8 * (calc_frame_len(hdr) + 4) * f) / 118 (nrof_subbands * nrof_blocks)); 119 } 120 121 static char *freq2str(uint8_t freq) 122 { 123 switch (freq) { 124 case 0: 125 return "16 kHz"; 126 case 1: 127 return "32 kHz"; 128 case 2: 129 return "44.1 kHz"; 130 case 3: 131 return "48 kHz"; 132 default: 133 return "Unknown"; 134 } 135 } 136 137 static char *mode2str(uint8_t mode) 138 { 139 switch (mode) { 140 case 0: 141 return "Mono"; 142 case 1: 143 return "Dual Channel"; 144 case 2: 145 return "Stereo"; 146 case 3: 147 return "Joint Stereo"; 148 default: 149 return "Unknown"; 150 } 151 } 152 153 static ssize_t __read(int fd, void *buf, size_t count) 154 { 155 ssize_t len, pos = 0; 156 157 while (count > 0) { 158 len = read(fd, buf + pos, count); 159 if (len <= 0) 160 return len; 161 162 count -= len; 163 pos += len; 164 } 165 166 return pos; 167 } 168 169 #define SIZE 32 170 171 static int analyze_file(char *filename) 172 { 173 struct sbc_frame_hdr hdr; 174 unsigned char buf[64]; 175 double rate; 176 int bitpool[SIZE], frame_len[SIZE]; 177 int subbands, blocks, freq, method; 178 int n, p1, p2, fd, size, num; 179 ssize_t len; 180 unsigned int count; 181 182 if (strcmp(filename, "-")) { 183 printf("Filename\t\t%s\n", basename(filename)); 184 185 fd = open(filename, O_RDONLY); 186 if (fd < 0) { 187 perror("Can't open file"); 188 return -1; 189 } 190 } else 191 fd = fileno(stdin); 192 193 len = __read(fd, &hdr, sizeof(hdr)); 194 if (len != sizeof(hdr) || hdr.syncword != 0x9c) { 195 fprintf(stderr, "Not a SBC audio file\n"); 196 return -1; 197 } 198 199 subbands = (hdr.subbands + 1) * 4; 200 blocks = (hdr.blocks + 1) * 4; 201 freq = hdr.sampling_frequency; 202 method = hdr.allocation_method; 203 204 count = calc_frame_len(&hdr); 205 206 bitpool[0] = hdr.bitpool; 207 frame_len[0] = count + 4; 208 209 for (n = 1; n < SIZE; n++) { 210 bitpool[n] = 0; 211 frame_len[n] = 0; 212 } 213 214 if (lseek(fd, 0, SEEK_SET) < 0) { 215 num = 1; 216 rate = calc_bit_rate(&hdr); 217 while (count) { 218 size = count > sizeof(buf) ? sizeof(buf) : count; 219 len = __read(fd, buf, size); 220 if (len < 0) 221 break; 222 count -= len; 223 } 224 } else { 225 num = 0; 226 rate = 0; 227 } 228 229 while (1) { 230 len = __read(fd, &hdr, sizeof(hdr)); 231 if (len < 0) { 232 fprintf(stderr, "Unable to read frame header" 233 " (error %d)\n", errno); 234 break; 235 } 236 237 if (len == 0) 238 break; 239 240 if ((size_t) len < sizeof(hdr) || hdr.syncword != 0x9c) { 241 fprintf(stderr, "Corrupted SBC stream " 242 "(len %zd syncword 0x%02x)\n", 243 len, hdr.syncword); 244 break; 245 } 246 247 count = calc_frame_len(&hdr); 248 len = count + 4; 249 250 p1 = -1; 251 p2 = -1; 252 for (n = 0; n < SIZE; n++) { 253 if (p1 < 0 && (bitpool[n] == 0 || bitpool[n] == hdr.bitpool)) 254 p1 = n; 255 if (p2 < 0 && (frame_len[n] == 0 || frame_len[n] == len)) 256 p2 = n; 257 } 258 if (p1 >= 0) 259 bitpool[p1] = hdr.bitpool; 260 if (p2 >= 0) 261 frame_len[p2] = len; 262 263 while (count) { 264 size = count > sizeof(buf) ? sizeof(buf) : count; 265 266 len = __read(fd, buf, size); 267 if (len != size) { 268 fprintf(stderr, "Unable to read frame data " 269 "(error %d)\n", errno); 270 break; 271 } 272 273 count -= len; 274 } 275 276 rate += calc_bit_rate(&hdr); 277 num++; 278 } 279 280 printf("Subbands\t\t%d\n", subbands); 281 printf("Block length\t\t%d\n", blocks); 282 printf("Sampling frequency\t%s\n", freq2str(freq)); 283 printf("Channel mode\t\t%s\n", mode2str(hdr.channel_mode)); 284 printf("Allocation method\t%s\n", method ? "SNR" : "Loudness"); 285 printf("Bitpool\t\t\t%d", bitpool[0]); 286 for (n = 1; n < SIZE; n++) 287 if (bitpool[n] > 0) 288 printf(", %d", bitpool[n]); 289 printf("\n"); 290 printf("Number of frames\t%d\n", num); 291 printf("Frame length\t\t%d", frame_len[0]); 292 for (n = 1; n < SIZE; n++) 293 if (frame_len[n] > 0) 294 printf(", %d", frame_len[n]); 295 printf(" Bytes\n"); 296 if (num > 0) 297 printf("Bit rate\t\t%.3f kbps\n", rate / num); 298 299 if (fd > fileno(stderr)) 300 close(fd); 301 302 printf("\n"); 303 304 return 0; 305 } 306 307 int main(int argc, char *argv[]) 308 { 309 int i; 310 311 if (argc < 2) { 312 fprintf(stderr, "Usage: sbcinfo <file>\n"); 313 exit(1); 314 } 315 316 for (i = 0; i < argc - 1; i++) 317 if (analyze_file(argv[i + 1]) < 0) 318 exit(1); 319 320 return 0; 321 } 322
