diff options
author | markster <markster@f38db490-d61c-443f-a65b-d21fe96a405b> | 1999-12-07 05:57:45 +0000 |
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committer | markster <markster@f38db490-d61c-443f-a65b-d21fe96a405b> | 1999-12-07 05:57:45 +0000 |
commit | 203a586f28972e48fdb9522afc9d8ac1d6106c3b (patch) | |
tree | 83146ef6a16d720b3ba3c8db0e34b5dcb92239e5 /codecs/mp3/src/cupL1.c | |
parent | 9bea3cc618bdaa5d09c433987d47f1532a31227c (diff) |
Version 0.1.1 from FTP
git-svn-id: http://svn.digium.com/svn/asterisk/trunk@118 f38db490-d61c-443f-a65b-d21fe96a405b
Diffstat (limited to 'codecs/mp3/src/cupL1.c')
-rwxr-xr-x | codecs/mp3/src/cupL1.c | 319 |
1 files changed, 319 insertions, 0 deletions
diff --git a/codecs/mp3/src/cupL1.c b/codecs/mp3/src/cupL1.c new file mode 100755 index 000000000..84b46d24d --- /dev/null +++ b/codecs/mp3/src/cupL1.c @@ -0,0 +1,319 @@ +/*____________________________________________________________________________ + + FreeAmp - The Free MP3 Player + + MP3 Decoder originally Copyright (C) 1995-1997 Xing Technology + Corp. http://www.xingtech.com + + Portions Copyright (C) 1998-1999 EMusic.com + + 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., 675 Mass Ave, Cambridge, MA 02139, USA. + + $Id$ +____________________________________________________________________________*/ + +/**** cupL1.c *************************************************** + +MPEG audio decoder Layer I mpeg1 and mpeg2 + +include to clup.c + + +******************************************************************/ +/*======================================================================*/ + + +/* Read Only */ +static int bat_bit_masterL1[] = +{ + 0, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16}; + +/*======================================================================*/ +static void unpack_baL1(MPEG *m) +{ + int j; + int nstereo; + + m->cup.bit_skip = 0; + nstereo = m->cup.stereo_sb; + + for (j = 0; j < m->cup.nbatL1; j++) + { + mac_load_check(4); + m->cup.ballo[j] = m->cup.samp_dispatch[j] = mac_load(4); + if (j >= m->cup.nsb_limit) + m->cup.bit_skip += bat_bit_masterL1[m->cup.samp_dispatch[j]]; + m->cup.c_value[j] = m->cup.look_c_valueL1[m->cup.samp_dispatch[j]]; + if (--nstereo < 0) + { + m->cup.ballo[j + 1] = m->cup.ballo[j]; + m->cup.samp_dispatch[j] += 15; /* flag as joint */ + m->cup.samp_dispatch[j + 1] = m->cup.samp_dispatch[j]; /* flag for sf */ + m->cup.c_value[j + 1] = m->cup.c_value[j]; + j++; + } + } +/*-- terminate with bit skip and end --*/ + m->cup.samp_dispatch[m->cup.nsb_limit] = 31; + m->cup.samp_dispatch[j] = 30; +} +/*-------------------------------------------------------------------------*/ +static void unpack_sfL1(MPEG *m) /* unpack scale factor */ +{ /* combine dequant and scale factors */ + int i; + + for (i = 0; i < m->cup.nbatL1; i++) + { + if (m->cup.ballo[i]) + { + mac_load_check(6); + m->cup.cs_factorL1[i] = m->cup.c_value[i] * m->cup.sf_table[mac_load(6)]; + } + } +/*-- done --*/ +} +/*-------------------------------------------------------------------------*/ +#define UNPACKL1_N(n) s[k] = m->cup.cs_factorL1[k]*(load(m,n)-((1 << (n-1)) -1)); \ + goto dispatch; +#define UNPACKL1J_N(n) tmp = (load(m,n)-((1 << (n-1)) -1)); \ + s[k] = m->cup.cs_factorL1[k]*tmp; \ + s[k+1] = m->cup.cs_factorL1[k+1]*tmp; \ + k++; \ + goto dispatch; +/*-------------------------------------------------------------------------*/ +static void unpack_sampL1(MPEG *m) /* unpack samples */ +{ + int j, k; + float *s; + long tmp; + + s = m->cup.sample; + for (j = 0; j < 12; j++) + { + k = -1; + dispatch:switch (m->cup.samp_dispatch[++k]) + { + case 0: + s[k] = 0.0F; + goto dispatch; + case 1: + UNPACKL1_N(2) /* 3 levels */ + case 2: + UNPACKL1_N(3) /* 7 levels */ + case 3: + UNPACKL1_N(4) /* 15 levels */ + case 4: + UNPACKL1_N(5) /* 31 levels */ + case 5: + UNPACKL1_N(6) /* 63 levels */ + case 6: + UNPACKL1_N(7) /* 127 levels */ + case 7: + UNPACKL1_N(8) /* 255 levels */ + case 8: + UNPACKL1_N(9) /* 511 levels */ + case 9: + UNPACKL1_N(10) /* 1023 levels */ + case 10: + UNPACKL1_N(11) /* 2047 levels */ + case 11: + UNPACKL1_N(12) /* 4095 levels */ + case 12: + UNPACKL1_N(13) /* 8191 levels */ + case 13: + UNPACKL1_N(14) /* 16383 levels */ + case 14: + UNPACKL1_N(15) /* 32767 levels */ +/* -- joint ---- */ + case 15 + 0: + s[k + 1] = s[k] = 0.0F; + k++; /* skip right chan dispatch */ + goto dispatch; +/* -- joint ---- */ + case 15 + 1: + UNPACKL1J_N(2) /* 3 levels */ + case 15 + 2: + UNPACKL1J_N(3) /* 7 levels */ + case 15 + 3: + UNPACKL1J_N(4) /* 15 levels */ + case 15 + 4: + UNPACKL1J_N(5) /* 31 levels */ + case 15 + 5: + UNPACKL1J_N(6) /* 63 levels */ + case 15 + 6: + UNPACKL1J_N(7) /* 127 levels */ + case 15 + 7: + UNPACKL1J_N(8) /* 255 levels */ + case 15 + 8: + UNPACKL1J_N(9) /* 511 levels */ + case 15 + 9: + UNPACKL1J_N(10) /* 1023 levels */ + case 15 + 10: + UNPACKL1J_N(11) /* 2047 levels */ + case 15 + 11: + UNPACKL1J_N(12) /* 4095 levels */ + case 15 + 12: + UNPACKL1J_N(13) /* 8191 levels */ + case 15 + 13: + UNPACKL1J_N(14) /* 16383 levels */ + case 15 + 14: + UNPACKL1J_N(15) /* 32767 levels */ + +/* -- end of dispatch -- */ + case 31: + skip(m,m->cup.bit_skip); + case 30: + s += 64; + } /* end switch */ + } /* end j loop */ + +/*-- done --*/ +} +/*-------------------------------------------------------------------*/ +IN_OUT L1audio_decode(void *mv, unsigned char *bs, signed short *pcm) +{ + MPEG *m = mv; + int sync, prot; + IN_OUT in_out; + + load_init(m, bs); /* initialize bit getter */ +/* test sync */ + in_out.in_bytes = 0; /* assume fail */ + in_out.out_bytes = 0; + sync = load(m,12); + if (sync != 0xFFF) + return in_out; /* sync fail */ + + + load(m,3); /* skip id and option (checked by init) */ + prot = load(m,1); /* load prot bit */ + load(m,6); /* skip to pad */ + m->cup.pad = (load(m,1)) << 2; + load(m,1); /* skip to mode */ + m->cup.stereo_sb = look_joint[load(m,4)]; + if (prot) + load(m,4); /* skip to data */ + else + load(m,20); /* skip crc */ + + unpack_baL1(m); /* unpack bit allocation */ + unpack_sfL1(m); /* unpack scale factor */ + unpack_sampL1(m); /* unpack samples */ + + m->cup.sbt(m, m->cup.sample, pcm, 12); +/*-----------*/ + in_out.in_bytes = m->cup.framebytes + m->cup.pad; + in_out.out_bytes = m->cup.outbytes; + + return in_out; +} +/*-------------------------------------------------------------------------*/ +int L1audio_decode_init(MPEG *m, MPEG_HEAD * h, int framebytes_arg, + int reduction_code, int transform_code, int convert_code, + int freq_limit) +{ + int i, k; + long samprate; + int limit; + long step; + int bit_code; + +/*--- sf init done by layer II init ---*/ + if (m->cup.first_pass_L1) + { + for (step = 4, i = 1; i < 16; i++, step <<= 1) + m->cup.look_c_valueL1[i] = (float) (2.0 / (step - 1)); + m->cup.first_pass_L1 = 0; + } + + transform_code = transform_code; /* not used, asm compatability */ + + bit_code = 0; + if (convert_code & 8) + bit_code = 1; + convert_code = convert_code & 3; /* higher bits used by dec8 freq cvt */ + if (reduction_code < 0) + reduction_code = 0; + if (reduction_code > 2) + reduction_code = 2; + if (freq_limit < 1000) + freq_limit = 1000; + + + m->cup.framebytes = framebytes_arg; +/* check if code handles */ + if (h->option != 3) + return 0; /* layer I only */ + + m->cup.nbatL1 = 32; + m->cup.max_sb = m->cup.nbatL1; +/*----- compute nsb_limit --------*/ + samprate = sr_table[4 * h->id + h->sr_index]; + m->cup.nsb_limit = (freq_limit * 64L + samprate / 2) / samprate; +/*- caller limit -*/ +/*---- limit = 0.94*(32>>reduction_code); ----*/ + limit = (32 >> reduction_code); + if (limit > 8) + limit--; + if (m->cup.nsb_limit > limit) + m->cup.nsb_limit = limit; + if (m->cup.nsb_limit > m->cup.max_sb) + m->cup.nsb_limit = m->cup.max_sb; + + m->cup.outvalues = 384 >> reduction_code; + if (h->mode != 3) + { /* adjust for 2 channel modes */ + m->cup.nbatL1 *= 2; + m->cup.max_sb *= 2; + m->cup.nsb_limit *= 2; + } + +/* set sbt function */ + k = 1 + convert_code; + if (h->mode == 3) + { + k = 0; + } + m->cup.sbt = sbt_table[bit_code][reduction_code][k]; + m->cup.outvalues *= out_chans[k]; + + if (bit_code) + m->cup.outbytes = m->cup.outvalues; + else + m->cup.outbytes = sizeof(short) * m->cup.outvalues; + + m->cup.decinfo.channels = out_chans[k]; + m->cup.decinfo.outvalues = m->cup.outvalues; + m->cup.decinfo.samprate = samprate >> reduction_code; + if (bit_code) + m->cup.decinfo.bits = 8; + else + m->cup.decinfo.bits = sizeof(short) * 8; + + m->cup.decinfo.framebytes = m->cup.framebytes; + m->cup.decinfo.type = 0; + + +/* clear sample buffer, unused sub bands must be 0 */ + for (i = 0; i < 768; i++) + m->cup.sample[i] = 0.0F; + + +/* init sub-band transform */ + sbt_init(); + + return 1; +} +/*---------------------------------------------------------*/ |