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-rw-r--r--components/music/mp3head.c400
1 files changed, 0 insertions, 400 deletions
diff --git a/components/music/mp3head.c b/components/music/mp3head.c
deleted file mode 100644
index 32051fcf5..000000000
--- a/components/music/mp3head.c
+++ /dev/null
@@ -1,400 +0,0 @@
-/*
- * MPEG Layer3 header info extraction routines
- *
- * Author: Erik Gustavsson, <cyrano@algonet.se>
- *
- * This software is released under the GNU General Public License.
- * Please read the included file COPYING for more information.
- * This software comes with no warranty of any kind, use at you own risk!
- */
-
-#include "mp3head.h"
-
-int bitrates[2][16] = {
-{0,8,16,24,32,40,48,56,64,80,96,112,128,144,160,}, /* MPEG2 */
-{0,32,40,48, 56, 64, 80, 96,112,128,160,192,224,256,320,}}; /* MPEG1 */
-
-long samprates[2][3] = {
-{ 22050, 24000, 16000 }, /* MPEG2 */
-{ 44100, 48000, 32000 }}; /* MPEG1 */
-
-
-static int extractI4(unsigned char *buf)
-{
- int x;
- /* big endian extract */
-
- x = buf[0];
- x <<= 8;
- x |= buf[1];
- x <<= 8;
- x |= buf[2];
- x <<= 8;
- x |= buf[3];
-
- return(x);
-}
-
-/* check for valid MPEG header */
-static int is_mphead(unsigned char *buf)
-{
- if (buf[0] != 0xff) return(0);
- if ((buf[1] & 0xf0) != 0xf0) return(0); /* 12 bits framesync */
-
- return(1);
-}
-
-/* check for valid "Xing" VBR header */
-static int is_xhead(unsigned char *buf)
-{
- if (buf[0] != 'X') return(0);
- if (buf[1] != 'i') return(0);
- if (buf[2] != 'n') return(0);
- if (buf[3] != 'g') return(0);
-
- return(1);
-}
-
-/* return bitrate from MPEG header, average rate for VBR files or -1 on error */
-int get_bitrate (unsigned char *buf,int bufsize)
-{
- int i=0;
- int ver,srindex,brindex,xbytes,xframes;
- float br;
-
- while(!is_mphead(buf+i)) {
- i++;
- if (i>bufsize-4) return(-1); /* no valid header, give up */
- }
-
- ver = (buf[i+1] & 0x08) >> 3;
- brindex = (buf[i+2] & 0xf0) >> 4;
- srindex = (buf[i+2] & 0x0c) >> 2;
-
- /* but if there is a Xing header we'll use that instead... */
- i=0;
- while(!is_xhead(buf+i)) {
- i++;
- if (i>bufsize-16) return(bitrates[ver][brindex]);
- }
-
- xframes = extractI4(buf+i+8);
- xbytes = extractI4(buf+i+12);
-
- br = (float)samprates[ver][srindex]*xbytes/(576+ver*576)/xframes/125;
- return(br);
-}
-
-/* return sample rate from MPEG header */
-int get_samprate(unsigned char *buf, int bufsize)
-{
- int i=0;
- int ver,srindex;
-
- while(!is_mphead(buf+i))
- {
- i++;
- if (i>bufsize-4) return(-1); /* no valid header, give up */
- }
-
- ver = (buf[i+1] & 0x08) >> 3;
- srindex = (buf[i+2] & 0x0c) >> 2;
-
- return(samprates[ver][srindex]);
-}
-
-
-/* return 1 for MPEG1, 0 for MPEG2, -1 for error */
-int get_mpgver(unsigned char *buf,int bufsize)
-{
- int i=0;
- int ver;
-
- while(!is_mphead(buf+i))
- {
- i++;
- if (i>bufsize-4) return(-1); /* no valid header, give up */
- }
-
- ver = (buf[i+1] & 0x08) >> 3;
-
- return(ver);
-}
-
-/* return 0=mono, 1=dual ch, 2=joint stereo, 3=stereo */
-int get_stereo(unsigned char *buf,int bufsize)
-{
- int i=0;
- int st;
-
- while(!is_mphead(buf+i))
- {
- i++;
- if (i>bufsize-4) return(-1); /* no valid header, give up */
- }
-
- st = (buf[i+3] & 0xC0) >> 6;
-
- return(3-st);
-}
-
-
-static int mp_br_table[2][16] =
- {{0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0},
- {0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384, 0}};
-
-static int mp_sr20_table[2][4] =
- {{441, 480, 320, -999}, {882, 960, 640, -999}};
-
-/* mpeg2 */
-static int mp_br_tableL1[2][16] =
- {{0, 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 224, 256, 0},
- {0, 32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384, 416, 448, 0}};
-
-/* mpeg 2 */
-static int mp_br_tableL3[2][16] =
- {{0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0},
- {0, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 0}};
-
-
-static int
-compare(unsigned char *buf, unsigned char *buf2)
-{
- if (buf[0] != buf2[0]) {
- return 0;
- }
-
- if (buf[1] != buf2[1]) {
- return 0;
- }
-
- return 1;
-}
-
-
-
-/*------------------------------------------------------*/
-/*---- scan for next sync, assume start is valid -------*/
-/*---- return number bytes to next sync ----------------*/
-static int
-sync_scan (unsigned char *buf, int n, int i0)
-{
- int i;
-
- for (i = i0; i < n; i++) {
- if (compare (buf, buf + i)) {
- return i;
- }
- }
-
- return 0;
-}
-
-/*------------------------------------------------------*/
-/*- test consecutative syncs, input isync without pad --*/
-static int
-sync_test (unsigned char *buf, int n, int isync, int padbytes)
-{
- int i, nmatch, pad;
-
- nmatch = 0;
- for (i = 0;;) {
- pad = padbytes * ((buf[i + 2] & 0x02) >> 1);
- i += (pad + isync);
-
- if (i > n) {
- break;
- }
-
- if (!compare(buf, buf + i)) {
- return -nmatch;
- }
-
- nmatch++;
- }
-
- return nmatch;
-}
-
-
-static int
-find_sync (unsigned char *buf, int n)
-{
- int i0, isync, nmatch, pad;
- int padbytes, option;
-
- /* mod 4/12/95 i0 change from 72, allows as low as 8kbits for mpeg1 */
- i0 = 24;
- padbytes = 1;
- option = (buf[1] & 0x06) >> 1;
- if (option == 3) {
- padbytes = 4;
- i0 = 24; /* for shorter layer I frames */
- }
-
- pad = (buf[2] & 0x02) >> 1;
-
- n -= 3; /* need 3 bytes of header */
-
- while (i0 < 2000) {
- isync = sync_scan (buf, n, i0);
- i0 = isync + 1;
- isync -= pad;
- if (isync <= 0) {
- return 0;
- }
-
- nmatch = sync_test (buf, n, isync, padbytes);
- if (nmatch > 0) {
- return isync;
- }
- }
-
- return 0;
-}
-
-
-
-int
-get_header_info (unsigned char *buf, unsigned int n, MPEGHeader *h)
-{
- int framebytes;
- int mpeg25_flag;
-
- if (n > 10000) {
- /* limit scan for free format */
- n = 10000;
- }
-
- h->sync = 0;
-
- if ((buf[0] == 0xFF) && ((buf[0+1] & 0xF0) == 0xF0)) {
- /* mpeg 1 & 2 */
- mpeg25_flag = 0;
-
- } else if ((buf[0] == 0xFF) && ((buf[0+1] & 0xF0) == 0xE0)) {
- /* mpeg 2.5 */
- mpeg25_flag = 1;
- } else {
- /* sync fail */
- return 0;
- }
-
- h->sync = 1;
- if (mpeg25_flag) {
- /* low bit clear signals mpeg25 (as in 0xFFE) */
- h->sync = 2;
- }
-
- h->id = (buf[0+1] & 0x08) >> 3;
- h->option = (buf[0+1] & 0x06) >> 1;
- h->prot = (buf[0+1] & 0x01);
-
- h->br_index = (buf[0+2] & 0xf0) >> 4;
- h->sr_index = (buf[0+2] & 0x0c) >> 2;
- h->pad = (buf[0+2] & 0x02) >> 1;
- h->private_bit = (buf[0+2] & 0x01);
- h->mode = (buf[0+3] & 0xc0) >> 6;
- h->mode_ext = (buf[0+3] & 0x30) >> 4;
- h->cr = (buf[0+3] & 0x08) >> 3;
- h->original = (buf[0+3] & 0x04) >> 2;
- h->emphasis = (buf[0+3] & 0x03);
-
- /* compute framebytes for Layer I, II, III */
- if (h->option < 1) {
- return 0;
- }
-
- if (h->option > 3) {
- return 0;
- }
-
- framebytes = 0;
-
- if (h->br_index > 0) {
- if (h->option == 3) {
- /* layer I */
- framebytes = 240 * mp_br_tableL1[h->id][h->br_index] / mp_sr20_table[h->id][h->sr_index];
- framebytes = 4 * framebytes;
- } else if (h->option == 2) {
- /* layer II */
- framebytes = 2880 * mp_br_table[h->id][h->br_index] / mp_sr20_table[h->id][h->sr_index];
- } else if (h->option == 1) {
- /* layer III */
- if (h->id) {
- // mpeg1
- framebytes = 2880 * mp_br_tableL3[h->id][h->br_index] / mp_sr20_table[h->id][h->sr_index];
- } else {
- /* mpeg2 */
- if (mpeg25_flag) {
- /* mpeg2.2 */
- framebytes = 2880 * mp_br_tableL3[h->id][h->br_index] / mp_sr20_table[h->id][h->sr_index];
- } else {
- framebytes = 1440 * mp_br_tableL3[h->id][h->br_index] / mp_sr20_table[h->id][h->sr_index];
- }
- }
- } else {
- /* free format */
- framebytes = find_sync (buf, n);
- }
- }
-
- return framebytes;
-}
-
-int
-get_header_info_extended (unsigned char *buf, unsigned int n, MPEGHeader *h, int *bitrate)
-{
- int framebytes;
-
- /*--- return bitrate (in bits/sec) in addition to frame bytes ---*/
- *bitrate = 0;
-
- /*-- assume fail --*/
- framebytes = get_header_info (buf, n, h);
-
- if (framebytes == 0) {
- return 0;
- }
-
- /* layer III */
- if (h->option == 1) {
- if (h->br_index > 0) {
- *bitrate = 1000 * mp_br_tableL3[h->id][h->br_index];
- } else {
- if (h->id) {
- /* mpeg1 */
- *bitrate = 1000 * framebytes * mp_sr20_table[h->id][h->sr_index] / (144 * 20);
- } else {
- /* mpeg2 */
- if ((h->sync & 1) == 0) {
- /* flags mpeg25 */
- *bitrate = 500 * framebytes * mp_sr20_table[h->id][h->sr_index] / (72 * 20);
- } else {
- *bitrate = 1000 * framebytes * mp_sr20_table[h->id][h->sr_index] / (72 * 20);
- }
- }
- }
- }
-
- /* layer II */
- if (h->option == 2) {
- if (h->br_index > 0) {
- *bitrate = 1000 * mp_br_table[h->id][h->br_index];
- } else {
- *bitrate = 1000 * framebytes * mp_sr20_table[h->id][h->sr_index] / (144 * 20);
- }
- }
-
- /* layer I */
- if (h->option == 3) {
- if (h->br_index > 0) {
- *bitrate = 1000 * mp_br_tableL1[h->id][h->br_index];
- } else {
- *bitrate = 1000 * framebytes * mp_sr20_table[h->id][h->sr_index] / (48 * 20);
- }
- }
-
- return framebytes;
-}
-
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