bluez/sbc/sbcinfo.c
2007-02-21 14:15:52 +00:00

301 lines
6.0 KiB
C

/*
*
* Bluetooth low-complexity, subband codec (SBC) library
*
* Copyright (C) 2004-2007 Marcel Holtmann <marcel@holtmann.org>
*
*
* This program 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.
*
* This program 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <libgen.h>
struct sbc_frame_hdr {
uint8_t syncword:8; /* Sync word */
uint8_t subbands:1; /* Subbands */
uint8_t allocation_method:1; /* Allocation method */
uint8_t channel_mode:2; /* Channel mode */
uint8_t blocks:2; /* Blocks */
uint8_t sampling_frequency:2; /* Sampling frequency */
uint8_t bitpool:8; /* Bitpool */
uint8_t crc_check:8; /* CRC check */
} __attribute__ ((packed));
static int calc_frame_len(struct sbc_frame_hdr *hdr)
{
int tmp, nrof_subbands, nrof_blocks;
nrof_subbands = (hdr->subbands + 1) * 4;
nrof_blocks = (hdr->blocks + 1) * 4;
switch (hdr->channel_mode) {
case 0x00:
nrof_subbands /= 2;
tmp = nrof_blocks * hdr->bitpool;
break;
case 0x01:
tmp = nrof_blocks * hdr->bitpool * 2;
break;
case 0x02:
tmp = nrof_blocks * hdr->bitpool;
break;
case 0x03:
tmp = nrof_blocks * hdr->bitpool + nrof_subbands;
break;
default:
return 0;
}
return (nrof_subbands + ((tmp + 7) / 8));
}
static double calc_bit_rate(struct sbc_frame_hdr *hdr)
{
int nrof_subbands, nrof_blocks;
double f;
nrof_subbands = (hdr->subbands + 1) * 4;
nrof_blocks = (hdr->blocks + 1) * 4;
switch (hdr->sampling_frequency) {
case 0:
f = 16;
break;
case 1:
f = 32;
break;
case 2:
f = 44.1;
break;
case 3:
f = 48;
break;
default:
return 0;
}
return ((8 * (calc_frame_len(hdr) + 4) * f) / (nrof_subbands * nrof_blocks));
}
static char *freq2str(uint8_t freq)
{
switch (freq) {
case 0:
return "16 kHz";
case 1:
return "32 kHz";
case 2:
return "44.1 kHz";
case 3:
return "48 kHz";
default:
return "Unknown";
}
}
static char *mode2str(uint8_t mode)
{
switch (mode) {
case 0:
return "Mono";
case 1:
return "Dual Channel";
case 2:
return "Stereo";
case 3:
return "Joint Stereo";
default:
return "Unknown";
}
}
static ssize_t __read(int fd, void *buf, size_t count)
{
ssize_t len, pos = 0;
while (count > 0) {
len = read(fd, buf + pos, count);
if (len <= 0)
return len;
count -= len;
pos += len;
}
return pos;
}
#define SIZE 32
static int analyze_file(char *filename)
{
struct sbc_frame_hdr hdr;
unsigned char buf[64];
double rate;
int bitpool[SIZE], frame_len[SIZE];
int subbands, blocks, freq, mode, method;
int n, p1, p2, fd, len, size, count, num;
if (strcmp(filename, "-")) {
printf("Filename\t\t%s\n", basename(filename));
fd = open(filename, O_RDONLY);
if (fd < 0) {
perror("Can't open file");
return -1;
}
} else
fd = fileno(stdin);
len = __read(fd, &hdr, sizeof(hdr));
if (len != sizeof(hdr) || hdr.syncword != 0x9c) {
fprintf(stderr, "Not a SBC audio file\n");
return -1;
}
subbands = (hdr.subbands + 1) * 4;
blocks = (hdr.blocks + 1) * 4;
freq = hdr.sampling_frequency;
mode = hdr.channel_mode;
method = hdr.allocation_method;
count = calc_frame_len(&hdr);
bitpool[0] = hdr.bitpool;
frame_len[0] = count + 4;
for (n = 1; n < SIZE; n++) {
bitpool[n] = 0;
frame_len[n] = 0;
}
if (lseek(fd, 0, SEEK_SET) < 0) {
num = 1;
rate = calc_bit_rate(&hdr);
while (count) {
size = count > sizeof(buf) ? sizeof(buf) : count;
len = __read(fd, buf, size);
if (len < 0)
break;
count -= len;
}
} else {
num = 0;
rate = 0;
}
while (1) {
len = __read(fd, &hdr, sizeof(hdr));
if (len < 0) {
fprintf(stderr, "Unable to read frame header (error %d)\n", errno);
break;
}
if (len == 0)
break;
if (len < sizeof(hdr) || hdr.syncword != 0x9c) {
fprintf(stderr, "Corrupted SBC stream (len %d syncword 0x%02x)\n",
len, hdr.syncword);
break;
}
count = calc_frame_len(&hdr);
len = count + 4;
p1 = -1;
p2 = -1;
for (n = 0; n < SIZE; n++) {
if (p1 < 0 && (bitpool[n] == 0 || bitpool[n] == hdr.bitpool))
p1 = n;
if (p2 < 0 && (frame_len[n] == 0 || frame_len[n] == len))
p2 = n;
}
if (p1 >= 0)
bitpool[p1] = hdr.bitpool;
if (p2 >= 0)
frame_len[p2] = len;
while (count) {
size = count > sizeof(buf) ? sizeof(buf) : count;
len = __read(fd, buf, size);
if (len != size) {
fprintf(stderr, "Unable to read frame data (error %d)\n", errno);
break;
}
count -= len;
}
rate += calc_bit_rate(&hdr);
num++;
}
printf("Subbands\t\t%d\n", subbands);
printf("Block length\t\t%d\n", blocks);
printf("Sampling frequency\t%s\n", freq2str(freq));
printf("Channel mode\t\t%s\n", mode2str(hdr.channel_mode));
printf("Allocation method\t%s\n", method ? "SNR" : "Loudness");
printf("Bitpool\t\t\t%d", bitpool[0]);
for (n = 1; n < SIZE; n++)
if (bitpool[n] > 0)
printf(", %d", bitpool[n]);
printf("\n");
printf("Number of frames\t%d\n", num);
printf("Frame length\t\t%d", frame_len[0]);
for (n = 1; n < SIZE; n++)
if (frame_len[n] > 0)
printf(", %d", frame_len[n]);
printf(" Bytes\n");
if (num > 0)
printf("Bit rate\t\t%.3f kbps\n", rate / num);
if (fd > fileno(stderr))
close(fd);
printf("\n");
return 0;
}
int main(int argc, char *argv[])
{
int i;
if (argc < 2) {
fprintf(stderr, "Usage: sbcinfo <file>\n");
exit(1);
}
for (i = 0; i < argc - 1; i++)
if (analyze_file(argv[i + 1]) < 0)
exit(1);
return 0;
}