1/* 2 * 3 * Bluetooth low-complexity, subband codec (SBC) library 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 <stdint.h> 34#include <string.h> 35#include <libgen.h> 36 37#if __BYTE_ORDER == __LITTLE_ENDIAN 38struct sbc_frame_hdr { 39 uint8_t syncword:8; /* Sync word */ 40 uint8_t subbands:1; /* Subbands */ 41 uint8_t allocation_method:1; /* Allocation method */ 42 uint8_t channel_mode:2; /* Channel mode */ 43 uint8_t blocks:2; /* Blocks */ 44 uint8_t sampling_frequency:2; /* Sampling frequency */ 45 uint8_t bitpool:8; /* Bitpool */ 46 uint8_t crc_check:8; /* CRC check */ 47} __attribute__ ((packed)); 48#elif __BYTE_ORDER == __BIG_ENDIAN 49struct sbc_frame_hdr { 50 uint8_t syncword:8; /* Sync word */ 51 uint8_t sampling_frequency:2; /* Sampling frequency */ 52 uint8_t blocks:2; /* Blocks */ 53 uint8_t channel_mode:2; /* Channel mode */ 54 uint8_t allocation_method:1; /* Allocation method */ 55 uint8_t subbands:1; /* Subbands */ 56 uint8_t bitpool:8; /* Bitpool */ 57 uint8_t crc_check:8; /* CRC check */ 58} __attribute__ ((packed)); 59#else 60#error "Unknown byte order" 61#endif 62 63static int calc_frame_len(struct sbc_frame_hdr *hdr) 64{ 65 int tmp, nrof_subbands, nrof_blocks; 66 67 nrof_subbands = (hdr->subbands + 1) * 4; 68 nrof_blocks = (hdr->blocks + 1) * 4; 69 70 switch (hdr->channel_mode) { 71 case 0x00: 72 nrof_subbands /= 2; 73 tmp = nrof_blocks * hdr->bitpool; 74 break; 75 case 0x01: 76 tmp = nrof_blocks * hdr->bitpool * 2; 77 break; 78 case 0x02: 79 tmp = nrof_blocks * hdr->bitpool; 80 break; 81 case 0x03: 82 tmp = nrof_blocks * hdr->bitpool + nrof_subbands; 83 break; 84 default: 85 return 0; 86 } 87 88 return (nrof_subbands + ((tmp + 7) / 8)); 89} 90 91static double calc_bit_rate(struct sbc_frame_hdr *hdr) 92{ 93 int nrof_subbands, nrof_blocks; 94 double f; 95 96 nrof_subbands = (hdr->subbands + 1) * 4; 97 nrof_blocks = (hdr->blocks + 1) * 4; 98 99 switch (hdr->sampling_frequency) { 100 case 0: 101 f = 16; 102 break; 103 case 1: 104 f = 32; 105 break; 106 case 2: 107 f = 44.1; 108 break; 109 case 3: 110 f = 48; 111 break; 112 default: 113 return 0; 114 } 115 116 return ((8 * (calc_frame_len(hdr) + 4) * f) / 117 (nrof_subbands * nrof_blocks)); 118} 119 120static char *freq2str(uint8_t freq) 121{ 122 switch (freq) { 123 case 0: 124 return "16 kHz"; 125 case 1: 126 return "32 kHz"; 127 case 2: 128 return "44.1 kHz"; 129 case 3: 130 return "48 kHz"; 131 default: 132 return "Unknown"; 133 } 134} 135 136static char *mode2str(uint8_t mode) 137{ 138 switch (mode) { 139 case 0: 140 return "Mono"; 141 case 1: 142 return "Dual Channel"; 143 case 2: 144 return "Stereo"; 145 case 3: 146 return "Joint Stereo"; 147 default: 148 return "Unknown"; 149 } 150} 151 152static ssize_t __read(int fd, void *buf, size_t count) 153{ 154 ssize_t len, pos = 0; 155 156 while (count > 0) { 157 len = read(fd, buf + pos, count); 158 if (len <= 0) 159 return len; 160 161 count -= len; 162 pos += len; 163 } 164 165 return pos; 166} 167 168#define SIZE 32 169 170static int analyze_file(char *filename) 171{ 172 struct sbc_frame_hdr hdr; 173 unsigned char buf[64]; 174 double rate; 175 int bitpool[SIZE], frame_len[SIZE]; 176 int subbands, blocks, freq, mode, method; 177 int n, p1, p2, fd, size, num; 178 ssize_t len; 179 unsigned int count; 180 181 if (strcmp(filename, "-")) { 182 printf("Filename\t\t%s\n", basename(filename)); 183 184 fd = open(filename, O_RDONLY); 185 if (fd < 0) { 186 perror("Can't open file"); 187 return -1; 188 } 189 } else 190 fd = fileno(stdin); 191 192 len = __read(fd, &hdr, sizeof(hdr)); 193 if (len != sizeof(hdr) || hdr.syncword != 0x9c) { 194 fprintf(stderr, "Not a SBC audio file\n"); 195 return -1; 196 } 197 198 subbands = (hdr.subbands + 1) * 4; 199 blocks = (hdr.blocks + 1) * 4; 200 freq = hdr.sampling_frequency; 201 mode = hdr.channel_mode; 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 307int 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