diff options
author | markster <markster@f38db490-d61c-443f-a65b-d21fe96a405b> | 1999-12-07 05:45:48 +0000 |
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committer | markster <markster@f38db490-d61c-443f-a65b-d21fe96a405b> | 1999-12-07 05:45:48 +0000 |
commit | 878dd470f235a2c945f2410927175a45f052b234 (patch) | |
tree | 4fc09f73bccf2e5017fd2dab7019e076351cab9b /codecs/mp3/src/iupL1.c | |
parent | 070e10a75492938462eeac565c78c8c16a02fc74 (diff) |
Version 0.1.1 from FTP
git-svn-id: http://svn.digium.com/svn/asterisk/trunk@95 f38db490-d61c-443f-a65b-d21fe96a405b
Diffstat (limited to 'codecs/mp3/src/iupL1.c')
-rwxr-xr-x | codecs/mp3/src/iupL1.c | 330 |
1 files changed, 330 insertions, 0 deletions
diff --git a/codecs/mp3/src/iupL1.c b/codecs/mp3/src/iupL1.c new file mode 100755 index 000000000..041c2a00b --- /dev/null +++ b/codecs/mp3/src/iupL1.c @@ -0,0 +1,330 @@ +/*____________________________________________________________________________ + + 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. + + $Id$ +____________________________________________________________________________*/ + +/**** iupL1.c *************************************************** + +MPEG audio decoder Layer I mpeg1 and mpeg2 +should be portable ANSI C, should be endian independent + +icupL1 integer version of cupL1.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(MPEGI *m) +{ + int k; + int nstereo; + int n; + + m->iup.bit_skip = 0; + nstereo = m->iup.stereo_sb; + for (k = 0; k < m->iup.nbatL1; k++) + { + mac_load_check(4); + n = m->iup.ballo[k] = m->iup.samp_dispatch[k] = mac_load(4); + if (k >= m->iup.nsb_limit) + m->iup.bit_skip += bat_bit_masterL1[m->iup.samp_dispatch[k]]; + m->iup.c_value[k] = m->iup.look_c_valueL1[n]; + m->iup.c_shift[k] = m->iup.look_c_shiftL1[n]; + if (--nstereo < 0) + { + m->iup.ballo[k + 1] = m->iup.ballo[k]; + m->iup.samp_dispatch[k] += 15; /* flag as joint */ + m->iup.samp_dispatch[k + 1] = m->iup.samp_dispatch[k]; /* flag for sf */ + m->iup.c_value[k + 1] = m->iup.c_value[k]; + m->iup.c_shift[k + 1] = m->iup.c_shift[k]; + k++; + } + } + m->iup.samp_dispatch[m->iup.nsb_limit] = 31; /* terminate the dispatcher with skip */ + m->iup.samp_dispatch[k] = 30; /* terminate the dispatcher */ + +} +/*-------------------------------------------------------------------------*/ +static void unpack_sfL1(MPEGI *m) /* unpack scale factor */ +{ /* combine dequant and scale factors */ + int i, n; + INT32 tmp; /* only reason tmp is 32 bit is to get 32 bit mult result */ + + for (i = 0; i < m->iup.nbatL1; i++) + { + if (m->iup.ballo[i]) + { + mac_load_check(6); + tmp = m->iup.c_value[i]; + n = m->iup.c_shift[i]; + m->iup.cs_factorL1[i] = (tmp * m->iup.sf_table[mac_load(6)]) >> n; + } + } + +/*-- done --*/ +} +/*-------------------------------------------------------------------------*/ +#define UNPACKL1_N(n) s[k] = (m->iup.cs_factorL1[k]*(load(m,n)-((1 << (n-1)) -1)))>>(n-1); \ + goto dispatch; +#define UNPACKL1J_N(n) tmp = (load(m,n)-((1 << (n-1)) -1)); \ + s[k] = (m->iup.cs_factorL1[k]*tmp)>>(n-1); \ + s[k+1] = (m->iup.cs_factorL1[k+1]*tmp)>>(n-1); \ + k++; /* skip right chan dispatch */ \ + goto dispatch; +/*-------------------------------------------------------------------------*/ +static void unpack_sampL1(MPEGI *m) /* unpack samples */ +{ + int j, k; + SAMPLEINT *s; + INT32 tmp; + + s = m->iup.sample; + for (j = 0; j < 12; j++) + { + k = -1; + dispatch:switch (m->iup.samp_dispatch[++k]) + { + case 0: + s[k] = 0; + 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; + 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->iup.bit_skip); + case 30: + s += 64; + } /* end switch */ + } /* end j loop */ + +/*-- done --*/ +} +/*-------------------------------------------------------------------------*/ +static void unpackL1(MPEGI *m) +{ + int prot; + +/* at entry bit getter points at id, sync skipped by caller */ + + load(m,3); /* skip id and option (checked by init) */ + prot = load(m,1); /* load prot bit */ + load(m,6); /* skip to pad */ + m->iup.pad = load(m,1) << 2; + load(m,1); /* skip to mode */ + m->iup.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 */ + + +} +/*-------------------------------------------------------------------------*/ + +#ifdef _MSC_VER +#pragma warning(disable: 4056) +#endif + +int i_audio_decode_initL1(MPEGI *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; + int stepbit; + long step; + int bit_code; + +/*--- sf table built by Layer II init ---*/ + + if (m->iup.first_pass_L1) + { + stepbit = 2; + step = 4; + for (i = 1; i < 16; i++) + { + m->iup.look_c_valueL1[i] = (int) (32768.0 * 2.0 / (step - 1)); + m->iup.look_c_shiftL1[i] = 16 - stepbit; + stepbit++; + step <<= 1; + } + m->iup.first_pass_L1 = 0; + } + + m->iup.unpack_routine = unpackL1; + + + 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->iup.framebytes = framebytes_arg; +/* check if code handles */ + if (h->option != 3) + return 0; /* layer I only */ + + m->iup.nbatL1 = 32; + m->iup.max_sb = m->iup.nbatL1; +/*----- compute nsb_limit --------*/ + samprate = sr_table[4 * h->id + h->sr_index]; + m->iup.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->iup.nsb_limit > limit) + m->iup.nsb_limit = limit; + if (m->iup.nsb_limit > m->iup.max_sb) + m->iup.nsb_limit = m->iup.max_sb; + + m->iup.outvalues = 384 >> reduction_code; + if (h->mode != 3) + { /* adjust for 2 channel modes */ + m->iup.nbatL1 *= 2; + m->iup.max_sb *= 2; + m->iup.nsb_limit *= 2; + } + +/* set sbt function */ + m->iup.nsbt = 12; + k = 1 + convert_code; + if (h->mode == 3) + { + k = 0; + } + m->iup.sbt = sbt_table[bit_code][reduction_code][k]; + m->iup.outvalues *= out_chans[k]; + if (bit_code != 0) + m->iup.outbytes = m->iup.outvalues; + else + m->iup.outbytes = sizeof(short) * m->iup.outvalues; + + m->iup.decinfo.channels = out_chans[k]; + m->iup.decinfo.outvalues = m->iup.outvalues; + m->iup.decinfo.samprate = samprate >> reduction_code; + if (bit_code != 0) + m->iup.decinfo.bits = 8; + else + m->iup.decinfo.bits = sizeof(short) * 8; + + m->iup.decinfo.framebytes = m->iup.framebytes; + m->iup.decinfo.type = 0; + + +/* clear sample buffer, unused sub bands must be 0 */ + for (i = 0; i < 768; i++) + m->iup.sample[i] = 0; + + +/* init sub-band transform */ + i_sbt_init(); + + return 1; +} + +#ifdef _MSC_VER +#pragma warning(default: 4056) +#endif + +/*---------------------------------------------------------*/ |