diff options
Diffstat (limited to 'debian/transcode/transcode-1.1.7/tools/aud_scan.c')
| -rw-r--r-- | debian/transcode/transcode-1.1.7/tools/aud_scan.c | 364 |
1 files changed, 364 insertions, 0 deletions
diff --git a/debian/transcode/transcode-1.1.7/tools/aud_scan.c b/debian/transcode/transcode-1.1.7/tools/aud_scan.c new file mode 100644 index 00000000..68c8c1cb --- /dev/null +++ b/debian/transcode/transcode-1.1.7/tools/aud_scan.c @@ -0,0 +1,364 @@ +/* + * aud_scan.c + * + * Scans the audio track + * + * Copyright (C) Tilmann Bitterberg - June 2003 + * + * This file is part of transcode, a video stream processing tool + * + * transcode 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, or (at your option) + * any later version. + * + * transcode 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 GNU Make; see the file COPYING. If not, write to + * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. + * + */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include <stdint.h> +#include <stdio.h> +#include <string.h> +#include <unistd.h> + +#include "aud_scan.h" + +// MP3 + +// from mencoder +//----------------------- mp3 audio frame header parser ----------------------- + +static int tabsel_123[2][3][16] = { + { {0,32,64,96,128,160,192,224,256,288,320,352,384,416,448,0}, + {0,32,48,56, 64, 80, 96,112,128,160,192,224,256,320,384,0}, + {0,32,40,48, 56, 64, 80, 96,112,128,160,192,224,256,320,0} }, + + { {0,32,48,56,64,80,96,112,128,144,160,176,192,224,256,0}, + {0,8,16,24,32,40,48,56,64,80,96,112,128,144,160,0}, + {0,8,16,24,32,40,48,56,64,80,96,112,128,144,160,0} } +}; +static long freqs[9] = { 44100, 48000, 32000, 22050, 24000, 16000 , 11025 , 12000 , 8000 }; + +/* + * return frame size or -1 (bad frame) + */ +int tc_get_mp3_header(uint8_t* hbuf, int* chans, int* srate, int *bitrate){ + int stereo, ssize, crc, lsf, mpeg25, framesize; + int padding, bitrate_index, sampling_frequency; + uint32_t newhead = + hbuf[0] << 24 | + hbuf[1] << 16 | + hbuf[2] << 8 | + hbuf[3]; + + // head_check: + if ( (newhead & 0xffe00000) != 0xffe00000 + || (newhead & 0x0000fc00) == 0x0000fc00) { + // fprintf( stderr, "[%s] head_check failed\n", __FILE__); + return -1; + } + + if ((4 - ((newhead >> 17) & 3)) != 3) { + return -1; + } + + if (newhead & ((long)1 << 20)) { + lsf = (newhead & ((long)1 << 19)) ?0x0 :0x1; + mpeg25 = 0; + } else { + lsf = 1; + mpeg25 = 1; + } + + if (mpeg25) { + sampling_frequency = 6 + ((newhead>>10)&0x3); + } else { + sampling_frequency = ((newhead>>10)&0x3) + (lsf*3); + } + + if (sampling_frequency > 8) { + return -1; // valid: 0..8 + } + + crc = ((newhead >> 16) & 0x1) ^ 0x1; + bitrate_index = ((newhead >> 12) & 0xf); + padding = ((newhead >> 9) & 0x1); + + stereo = ((((newhead >> 6) & 0x3)) == 3) ?1 :2; + + if (!bitrate_index) { + return -1; + } + + if (lsf) { + ssize = (stereo == 1) ?9 :17; + } else { + ssize = (stereo == 1) ?17 :32; + } + if(crc) { + ssize += 2; + } + + framesize = tabsel_123[lsf][2][bitrate_index] * 144000; + if (bitrate) { + *bitrate = tabsel_123[lsf][2][bitrate_index]; + } + + if (!framesize){ + return -1; // valid: 1..14 + } + + framesize /= freqs[sampling_frequency]<<lsf; + framesize += padding; + + if (srate) { + *srate = freqs[sampling_frequency]; + } + if (chans) { + *chans = stereo; + } + return framesize; +} + +static const uint8_t nfchans[] = { + 2, 1, 2, 3, 3, 4, 4, 5, 1, 1, 2 +}; + +struct frmsize_s { + uint16_t bit_rate; + uint16_t frm_size[3]; +} frmsize_t; + +static const struct frmsize_s frmsizecod_tbl[] = { + { 32 ,{64 ,69 ,96 } }, + { 32 ,{64 ,70 ,96 } }, + { 40 ,{80 ,87 ,120 } }, + { 40 ,{80 ,88 ,120 } }, + { 48 ,{96 ,104 ,144 } }, + { 48 ,{96 ,105 ,144 } }, + { 56 ,{112 ,121 ,168 } }, + { 56 ,{112 ,122 ,168 } }, + { 64 ,{128 ,139 ,192 } }, + { 64 ,{128 ,140 ,192 } }, + { 80 ,{160 ,174 ,240 } }, + { 80 ,{160 ,175 ,240 } }, + { 96 ,{192 ,208 ,288 } }, + { 96 ,{192 ,209 ,288 } }, + { 112 ,{224 ,243 ,336 } }, + { 112 ,{224 ,244 ,336 } }, + { 128 ,{256 ,278 ,384 } }, + { 128 ,{256 ,279 ,384 } }, + { 160 ,{320 ,348 ,480 } }, + { 160 ,{320 ,349 ,480 } }, + { 192 ,{384 ,417 ,576 } }, + { 192 ,{384 ,418 ,576 } }, + { 224 ,{448 ,487 ,672 } }, + { 224 ,{448 ,488 ,672 } }, + { 256 ,{512 ,557 ,768 } }, + { 256 ,{512 ,558 ,768 } }, + { 320 ,{640 ,696 ,960 } }, + { 320 ,{640 ,697 ,960 } }, + { 384 ,{768 ,835 ,1152 } }, + { 384 ,{768 ,836 ,1152 } }, + { 448 ,{896 ,975 ,1344 } }, + { 448 ,{896 ,976 ,1344 } }, + { 512 ,{1024 ,1114 ,1536 } }, + { 512 ,{1024 ,1115 ,1536 } }, + { 576 ,{1152 ,1253 ,1728 } }, + { 576 ,{1152 ,1254 ,1728 } }, + { 640 ,{1280 ,1393 ,1920 } }, + { 640 ,{1280 ,1394 ,1920 } } +}; + +#define fscd_tbl_entries (sizeof(frmsizecod_tbl)/sizeof(frmsize_t)) + +static uint32_t get_ac3_header(uint8_t *buf) +{ + int i = 0; + uint32_t tmp = 0; + + tmp = (tmp << 8) + (buf[i++] & 0xff); + tmp = (tmp << 8) + (buf[i++] & 0xff); + tmp = (tmp << 8) + (buf[i++] & 0xff); + + return tmp; +} + +static int get_ac3_framesize(uint8_t *buf) +{ + int fscod, frmsizecod; + uint32_t tmp = get_ac3_header(buf); + + if (tmp < 0) { + return -1; + } + + fscod = (tmp >> 6) & 0x3; + frmsizecod = tmp & 0x3f; + + if (frmsizecod >= fscd_tbl_entries || fscod > 2) { + return -1; + } + return frmsizecod_tbl[frmsizecod].frm_size[fscod]; +} + +// FIXME: recheck me up, 1.0.x is reference +// We try to find the number of chans in the ac3 header (BSI) +static int get_ac3_nfchans(uint8_t *buf) +{ + /* skip syncinfo (size = 5bytes) */ + /* skip to acmod */ + int acmod = buf[6]>>5; + /* LFE flags is on, we have one more channel */ + int lfe = ((buf[2] & 0x40) == 0x40); + + if (acmod < 0 || acmod > 11) + return -1; + return (nfchans[acmod] + lfe); +} + + +static int get_ac3_bitrate(uint8_t *buf) +{ + int frmsizecod = 0; + uint32_t tmp = get_ac3_header(buf); + + frmsizecod = tmp & 0x3f; + + if (frmsizecod >= fscd_tbl_entries) { + return -1; + } + return frmsizecod_tbl[frmsizecod].bit_rate; +} + + +static int get_ac3_samplerate(uint8_t *buf) +{ + int fscod, sampling_rate; + uint32_t tmp = get_ac3_header(buf); + + // Get the sampling rate + fscod = (tmp >> 6) & 0x3; + + if (fscod == 3) { + return -1; //invalid sampling rate code + } else if (fscod == 2) { + sampling_rate = 32000; + } else if (fscod == 1) { + sampling_rate = 44100; + } else { + sampling_rate = 48000; + } + return sampling_rate; +} + + +int tc_get_ac3_header(uint8_t *_buf, int len, int *chans, int *srate, int *bitrate ) +{ + int j = 0, i = 0; + uint8_t *buffer = _buf; + uint16_t sync_word = 0; + + // need to find syncframe: + + for (i = 0; i < len-4; i++) { + sync_word = (sync_word << 8) + (uint8_t) buffer[i]; + if (sync_word == 0x0b77) { + break; + } + } + + if (sync_word != 0x0b77) { + return -1; + } + + if (srate) { + *srate = get_ac3_samplerate(&buffer[i+1]); + } + if (bitrate) { + *bitrate = get_ac3_bitrate(&buffer[i+1]); + } + if (chans) { + *chans = get_ac3_nfchans(&buffer[i+1]); + } + + if (j < 0 || bitrate < 0) { + return -1; + } + return 2 * get_ac3_framesize(&buffer[i+1]); +} + + +int tc_get_audio_header(uint8_t *buf, int buflen, int format, int *chans, int *srate, int *bitrate ) +{ + switch (format) { + case 0x55: // MP3 + return tc_get_mp3_header(buf, chans, srate, bitrate); + break; + case 0x2000: // AC3 + return tc_get_ac3_header(buf, buflen, chans, srate, bitrate); + break; + default: + return -1; + } + return -1; +} + +int tc_probe_audio_header(uint8_t *buf, int buflen) +{ + if (tc_get_mp3_header(buf, NULL, NULL, NULL) > 0) { + return 0x55; + } + if (tc_get_ac3_header(buf, buflen, NULL, NULL, NULL) > 0) { + return 0x2000; + } + return -1; +} + +int tc_format_ms_supported(int format) +{ + return (format == 0x55 /* MP3 */ + || format == 0x2000 /* AC3 */ + || format == 0x1); /* PCM */ +} + +void tc_format_mute(uint8_t *buf, int buflen, int format) +{ + switch (format) { + case 0x1: + memset(buf + 0, 0, buflen - 0); + break; + case 0x55: + memset(buf + 4, 0, buflen - 4); + break; + case 0x2000: + // check me! + memset(buf + 5, 0, buflen - 5); + break; + default: /* we're already fine */ + break; + } +} + +/*************************************************************************/ + +/* + * Local variables: + * c-file-style: "stroustrup" + * c-file-offsets: ((case-label . *) (statement-case-intro . *)) + * indent-tabs-mode: nil + * End: + * + * vim: expandtab shiftwidth=4: + */ |