MythTV: gsm_implode.c Source File

00001 /*
00002  * Copyright 1992 by Jutta Degener and Carsten Bormann, Technische
00003  * Universitaet Berlin.  See the accompanying file "COPYRIGHT" for
00004  * details.  THERE IS ABSOLUTELY NO WARRANTY FOR THIS SOFTWARE.
00005  */
00006 
00007 /* $Header$ */
00008 
00009 #include "private.h"
00010 
00011 #include "gsm.h"
00012 #include "proto.h"
00013 
00014 void gsm_implode P3((s, source, c), gsm s, gsm_signal * source, gsm_byte * c)
00015 {
00016         /*      variable        size    index
00017 
00018                 GSM_MAGIC       4       -
00019 
00020                 LARc[0]         6       0
00021                 LARc[1]         6       1
00022                 LARc[2]         5       2
00023                 LARc[3]         5       3
00024                 LARc[4]         4       4
00025                 LARc[5]         4       5
00026                 LARc[6]         3       6
00027                 LARc[7]         3       7
00028 
00029                 Nc[0]           7       8
00030                 bc[0]           2       9
00031                 Mc[0]           2       10
00032                 xmaxc[0]        6       11
00033                 xmc[0]          3       12
00034                 xmc[1]          3       13
00035                 xmc[2]          3       14
00036                 xmc[3]          3       15
00037                 xmc[4]          3       16
00038                 xmc[5]          3       17
00039                 xmc[6]          3       18
00040                 xmc[7]          3       19
00041                 xmc[8]          3       20
00042                 xmc[9]          3       21
00043                 xmc[10]         3       22
00044                 xmc[11]         3       23
00045                 xmc[12]         3       24
00046 
00047                 Nc[1]           7       25
00048                 bc[1]           2       26
00049                 Mc[1]           2       27
00050                 xmaxc[1]        6       28
00051                 xmc[13]         3       29
00052                 xmc[14]         3       30
00053                 xmc[15]         3       31
00054                 xmc[16]         3       32
00055                 xmc[17]         3       33
00056                 xmc[18]         3       34
00057                 xmc[19]         3       35
00058                 xmc[20]         3       36
00059                 xmc[21]         3       37
00060                 xmc[22]         3       38
00061                 xmc[23]         3       39
00062                 xmc[24]         3       40
00063                 xmc[25]         3       41
00064 
00065                 Nc[2]           7       42
00066                 bc[2]           2       43
00067                 Mc[2]           2       44
00068                 xmaxc[2]        6       45
00069                 xmc[26]         3       46
00070                 xmc[27]         3       47
00071                 xmc[28]         3       48
00072                 xmc[29]         3       49
00073                 xmc[30]         3       50
00074                 xmc[31]         3       51
00075                 xmc[32]         3       52
00076                 xmc[33]         3       53
00077                 xmc[34]         3       54
00078                 xmc[35]         3       55
00079                 xmc[36]         3       56
00080                 xmc[37]         3       57
00081                 xmc[38]         3       58
00082 
00083                 Nc[3]           7       59
00084                 bc[3]           2       60
00085                 Mc[3]           2       61
00086                 xmaxc[3]        6       62
00087                 xmc[39]         3       63
00088                 xmc[40]         3       64
00089                 xmc[41]         3       65
00090                 xmc[42]         3       66
00091                 xmc[43]         3       67
00092                 xmc[44]         3       68
00093                 xmc[45]         3       69
00094                 xmc[46]         3       70
00095                 xmc[47]         3       71
00096                 xmc[48]         3       72
00097                 xmc[49]         3       73
00098                 xmc[50]         3       74
00099                 xmc[51]         3       75
00100         */
00101 
00102         /*      There are 76 parameters per frame.  The first eight are
00103          *      unique.  The remaining 68 are four identical subframes of
00104          *      17 parameters each.  gsm_implode converts from a representation
00105          *      of these parameters as values in one array of signed words
00106          *      to the "packed" version of a GSM frame.
00107          */
00108 
00109 #       define  LARc    source
00110 #       define  Nc      *((gsm_signal (*) [17])(source + 8))
00111 #       define  bc      *((gsm_signal (*) [17])(source + 9))
00112 #       define  Mc      *((gsm_signal (*) [17])(source + 10))
00113 #       define  xmaxc   *((gsm_signal (*) [17])(source + 11))
00114 
00115 #ifdef WAV49
00116         if (s->wav_fmt) {
00117 
00118                 uword sr = 0;
00119                 if (s->frame_index == 0) {
00120 
00121                         sr = *c++;
00122                         LARc[0] = sr & 0x3f;  sr >>= 6;
00123                         sr |= (uword)*c++ << 2;
00124                         LARc[1] = sr & 0x3f;  sr >>= 6;
00125                         sr |= (uword)*c++ << 4;
00126                         LARc[2] = sr & 0x1f;  sr >>= 5;
00127                         LARc[3] = sr & 0x1f;  sr >>= 5;
00128                         sr |= (uword)*c++ << 2;
00129                         LARc[4] = sr & 0xf;  sr >>= 4;
00130                         LARc[5] = sr & 0xf;  sr >>= 4;
00131                         sr |= (uword)*c++ << 2;                 /* 5 */
00132                         LARc[6] = sr & 0x7;  sr >>= 3;
00133                         LARc[7] = sr & 0x7;  sr >>= 3;
00134                         sr |= (uword)*c++ << 4;
00135                         Nc[0] = sr & 0x7f;  sr >>= 7;
00136                         bc[0] = sr & 0x3;  sr >>= 2;
00137                         Mc[0] = sr & 0x3;  sr >>= 2;
00138                         sr |= (uword)*c++ << 1;
00139                         xmaxc[0] = sr & 0x3f;  sr >>= 6;
00140 #undef  xmc
00141 #define xmc     (source + 12)
00142                         xmc[0] = sr & 0x7;  sr >>= 3;
00143                         sr = *c++;
00144                         xmc[1] = sr & 0x7;  sr >>= 3;
00145                         xmc[2] = sr & 0x7;  sr >>= 3;
00146                         sr |= (uword)*c++ << 2;
00147                         xmc[3] = sr & 0x7;  sr >>= 3;
00148                         xmc[4] = sr & 0x7;  sr >>= 3;
00149                         xmc[5] = sr & 0x7;  sr >>= 3;
00150                         sr |= (uword)*c++ << 1;                 /* 10 */
00151                         xmc[6] = sr & 0x7;  sr >>= 3;
00152                         xmc[7] = sr & 0x7;  sr >>= 3;
00153                         xmc[8] = sr & 0x7;  sr >>= 3;
00154                         sr = *c++;
00155                         xmc[9] = sr & 0x7;  sr >>= 3;
00156                         xmc[10] = sr & 0x7;  sr >>= 3;
00157                         sr |= (uword)*c++ << 2;
00158                         xmc[11] = sr & 0x7;  sr >>= 3;
00159                         xmc[12] = sr & 0x7;  sr >>= 3;
00160                         sr |= (uword)*c++ << 4;
00161                         Nc[1] = sr & 0x7f;  sr >>= 7;
00162                         bc[1] = sr & 0x3;  sr >>= 2;
00163                         Mc[1] = sr & 0x3;  sr >>= 2;
00164                         sr |= (uword)*c++ << 1;
00165                         xmaxc[1] = sr & 0x3f;  sr >>= 6;
00166 #undef  xmc
00167 #define xmc     (source + 29 - 13)
00168                         xmc[13] = sr & 0x7;  sr >>= 3;
00169                         sr = *c++;                              /* 15 */
00170                         xmc[14] = sr & 0x7;  sr >>= 3;
00171                         xmc[15] = sr & 0x7;  sr >>= 3;
00172                         sr |= (uword)*c++ << 2;
00173                         xmc[16] = sr & 0x7;  sr >>= 3;
00174                         xmc[17] = sr & 0x7;  sr >>= 3;
00175                         xmc[18] = sr & 0x7;  sr >>= 3;
00176                         sr |= (uword)*c++ << 1;
00177                         xmc[19] = sr & 0x7;  sr >>= 3;
00178                         xmc[20] = sr & 0x7;  sr >>= 3;
00179                         xmc[21] = sr & 0x7;  sr >>= 3;
00180                         sr = *c++;
00181                         xmc[22] = sr & 0x7;  sr >>= 3;
00182                         xmc[23] = sr & 0x7;  sr >>= 3;
00183                         sr |= (uword)*c++ << 2;
00184                         xmc[24] = sr & 0x7;  sr >>= 3;
00185                         xmc[25] = sr & 0x7;  sr >>= 3;
00186                         sr |= (uword)*c++ << 4;                 /* 20 */
00187                         Nc[2] = sr & 0x7f;  sr >>= 7;
00188                         bc[2] = sr & 0x3;  sr >>= 2;
00189                         Mc[2] = sr & 0x3;  sr >>= 2;
00190                         sr |= (uword)*c++ << 1;
00191                         xmaxc[2] = sr & 0x3f;  sr >>= 6;
00192 #undef  xmc
00193 #define xmc     (source + 46 - 26)
00194                         xmc[26] = sr & 0x7;  sr >>= 3;
00195                         sr = *c++;
00196                         xmc[27] = sr & 0x7;  sr >>= 3;
00197                         xmc[28] = sr & 0x7;  sr >>= 3;
00198                         sr |= (uword)*c++ << 2;
00199                         xmc[29] = sr & 0x7;  sr >>= 3;
00200                         xmc[30] = sr & 0x7;  sr >>= 3;
00201                         xmc[31] = sr & 0x7;  sr >>= 3;
00202                         sr |= (uword)*c++ << 1;
00203                         xmc[32] = sr & 0x7;  sr >>= 3;
00204                         xmc[33] = sr & 0x7;  sr >>= 3;
00205                         xmc[34] = sr & 0x7;  sr >>= 3;
00206                         sr = *c++;                              /* 25 */
00207                         xmc[35] = sr & 0x7;  sr >>= 3;
00208                         xmc[36] = sr & 0x7;  sr >>= 3;
00209                         sr |= (uword)*c++ << 2;
00210                         xmc[37] = sr & 0x7;  sr >>= 3;
00211                         xmc[38] = sr & 0x7;  sr >>= 3;
00212                         sr |= (uword)*c++ << 4;
00213                         Nc[3] = sr & 0x7f;  sr >>= 7;
00214                         bc[3] = sr & 0x3;  sr >>= 2;
00215                         Mc[3] = sr & 0x3;  sr >>= 2;
00216                         sr |= (uword)*c++ << 1;
00217                         xmaxc[3] = sr & 0x3f;  sr >>= 6;
00218 #undef  xmc
00219 #define xmc     (source + 63 - 39)
00220 
00221                         xmc[39] = sr & 0x7;  sr >>= 3;
00222                         sr = *c++;
00223                         xmc[40] = sr & 0x7;  sr >>= 3;
00224                         xmc[41] = sr & 0x7;  sr >>= 3;
00225                         sr |= (uword)*c++ << 2;                 /* 30 */
00226                         xmc[42] = sr & 0x7;  sr >>= 3;
00227                         xmc[43] = sr & 0x7;  sr >>= 3;
00228                         xmc[44] = sr & 0x7;  sr >>= 3;
00229                         sr |= (uword)*c++ << 1;
00230                         xmc[45] = sr & 0x7;  sr >>= 3;
00231                         xmc[46] = sr & 0x7;  sr >>= 3;
00232                         xmc[47] = sr & 0x7;  sr >>= 3;
00233                         sr = *c++;
00234                         xmc[48] = sr & 0x7;  sr >>= 3;
00235                         xmc[49] = sr & 0x7;  sr >>= 3;
00236                         sr |= (uword)*c++ << 2;
00237                         xmc[50] = sr & 0x7;  sr >>= 3;
00238                         xmc[51] = sr & 0x7;  sr >>= 3;
00239 
00240                         s->frame_chain = sr & 0xf;
00241                 }
00242                 else {
00243                         sr = s->frame_chain;
00244                         sr |= (uword)*c++ << 4;                 /* 1 */
00245                         LARc[0] = sr & 0x3f;  sr >>= 6;
00246                         LARc[1] = sr & 0x3f;  sr >>= 6;
00247                         sr = *c++;
00248                         LARc[2] = sr & 0x1f;  sr >>= 5;
00249                         sr |= (uword)*c++ << 3;
00250                         LARc[3] = sr & 0x1f;  sr >>= 5;
00251                         LARc[4] = sr & 0xf;  sr >>= 4;
00252                         sr |= (uword)*c++ << 2;
00253                         LARc[5] = sr & 0xf;  sr >>= 4;
00254                         LARc[6] = sr & 0x7;  sr >>= 3;
00255                         LARc[7] = sr & 0x7;  sr >>= 3;
00256                         sr = *c++;                              /* 5 */
00257                         Nc[0] = sr & 0x7f;  sr >>= 7;
00258                         sr |= (uword)*c++ << 1;
00259                         bc[0] = sr & 0x3;  sr >>= 2;
00260                         Mc[0] = sr & 0x3;  sr >>= 2;
00261                         sr |= (uword)*c++ << 5;
00262                         xmaxc[0] = sr & 0x3f;  sr >>= 6;
00263 #undef  xmc
00264 #define xmc     (source + 12)
00265                         xmc[0] = sr & 0x7;  sr >>= 3;
00266                         xmc[1] = sr & 0x7;  sr >>= 3;
00267                         sr |= (uword)*c++ << 1;
00268                         xmc[2] = sr & 0x7;  sr >>= 3;
00269                         xmc[3] = sr & 0x7;  sr >>= 3;
00270                         xmc[4] = sr & 0x7;  sr >>= 3;
00271                         sr = *c++;
00272                         xmc[5] = sr & 0x7;  sr >>= 3;
00273                         xmc[6] = sr & 0x7;  sr >>= 3;
00274                         sr |= (uword)*c++ << 2;                 /* 10 */
00275                         xmc[7] = sr & 0x7;  sr >>= 3;
00276                         xmc[8] = sr & 0x7;  sr >>= 3;
00277                         xmc[9] = sr & 0x7;  sr >>= 3;
00278                         sr |= (uword)*c++ << 1;
00279                         xmc[10] = sr & 0x7;  sr >>= 3;
00280                         xmc[11] = sr & 0x7;  sr >>= 3;
00281                         xmc[12] = sr & 0x7;  sr >>= 3;
00282                         sr = *c++;
00283                         Nc[1] = sr & 0x7f;  sr >>= 7;
00284                         sr |= (uword)*c++ << 1;
00285                         bc[1] = sr & 0x3;  sr >>= 2;
00286                         Mc[1] = sr & 0x3;  sr >>= 2;
00287                         sr |= (uword)*c++ << 5;
00288                         xmaxc[1] = sr & 0x3f;  sr >>= 6;
00289 #undef  xmc
00290 #define xmc     (source + 29 - 13)
00291                         xmc[13] = sr & 0x7;  sr >>= 3;
00292                         xmc[14] = sr & 0x7;  sr >>= 3;
00293                         sr |= (uword)*c++ << 1;                 /* 15 */
00294                         xmc[15] = sr & 0x7;  sr >>= 3;
00295                         xmc[16] = sr & 0x7;  sr >>= 3;
00296                         xmc[17] = sr & 0x7;  sr >>= 3;
00297                         sr = *c++;
00298                         xmc[18] = sr & 0x7;  sr >>= 3;
00299                         xmc[19] = sr & 0x7;  sr >>= 3;
00300                         sr |= (uword)*c++ << 2;
00301                         xmc[20] = sr & 0x7;  sr >>= 3;
00302                         xmc[21] = sr & 0x7;  sr >>= 3;
00303                         xmc[22] = sr & 0x7;  sr >>= 3;
00304                         sr |= (uword)*c++ << 1;
00305                         xmc[23] = sr & 0x7;  sr >>= 3;
00306                         xmc[24] = sr & 0x7;  sr >>= 3;
00307                         xmc[25] = sr & 0x7;  sr >>= 3;
00308                         sr = *c++;
00309                         Nc[2] = sr & 0x7f;  sr >>= 7;
00310                         sr |= (uword)*c++ << 1;                 /* 20 */
00311                         bc[2] = sr & 0x3;  sr >>= 2;
00312                         Mc[2] = sr & 0x3;  sr >>= 2;
00313                         sr |= (uword)*c++ << 5;
00314                         xmaxc[2] = sr & 0x3f;  sr >>= 6;
00315 #undef  xmc
00316 #define xmc     (source + 46 - 26)
00317                         xmc[26] = sr & 0x7;  sr >>= 3;
00318                         xmc[27] = sr & 0x7;  sr >>= 3;
00319                         sr |= (uword)*c++ << 1; 
00320                         xmc[28] = sr & 0x7;  sr >>= 3;
00321                         xmc[29] = sr & 0x7;  sr >>= 3;
00322                         xmc[30] = sr & 0x7;  sr >>= 3;
00323                         sr = *c++;
00324                         xmc[31] = sr & 0x7;  sr >>= 3;
00325                         xmc[32] = sr & 0x7;  sr >>= 3;
00326                         sr |= (uword)*c++ << 2;
00327                         xmc[33] = sr & 0x7;  sr >>= 3;
00328                         xmc[34] = sr & 0x7;  sr >>= 3;
00329                         xmc[35] = sr & 0x7;  sr >>= 3;
00330                         sr |= (uword)*c++ << 1;                 /* 25 */
00331                         xmc[36] = sr & 0x7;  sr >>= 3;
00332                         xmc[37] = sr & 0x7;  sr >>= 3;
00333                         xmc[38] = sr & 0x7;  sr >>= 3;
00334                         sr = *c++;
00335                         Nc[3] = sr & 0x7f;  sr >>= 7;
00336                         sr |= (uword)*c++ << 1;         
00337                         bc[3] = sr & 0x3;  sr >>= 2;
00338                         Mc[3] = sr & 0x3;  sr >>= 2;
00339                         sr |= (uword)*c++ << 5;
00340                         xmaxc[3] = sr & 0x3f;  sr >>= 6;
00341 #undef  xmc
00342 #define xmc     (source + 63 - 39)
00343 
00344                         xmc[39] = sr & 0x7;  sr >>= 3;
00345                         xmc[40] = sr & 0x7;  sr >>= 3;
00346                         sr |= (uword)*c++ << 1;
00347                         xmc[41] = sr & 0x7;  sr >>= 3;
00348                         xmc[42] = sr & 0x7;  sr >>= 3;
00349                         xmc[43] = sr & 0x7;  sr >>= 3;
00350                         sr = *c++;                              /* 30 */
00351                         xmc[44] = sr & 0x7;  sr >>= 3;
00352                         xmc[45] = sr & 0x7;  sr >>= 3;
00353                         sr |= (uword)*c++ << 2;
00354                         xmc[46] = sr & 0x7;  sr >>= 3;
00355                         xmc[47] = sr & 0x7;  sr >>= 3;
00356                         xmc[48] = sr & 0x7;  sr >>= 3;
00357                         sr |= (uword)*c++ << 1;
00358                         xmc[49] = sr & 0x7;  sr >>= 3;
00359                         xmc[50] = sr & 0x7;  sr >>= 3;
00360                         xmc[51] = sr & 0x7;  sr >>= 3;
00361                 }
00362         }
00363         else
00364 #endif 
00365         {
00366 
00367         *c++ =   ((GSM_MAGIC & 0xF) << 4)               /* 1 */
00368                | ((LARc[0] >> 2) & 0xF);
00369         *c++ =   ((LARc[0] & 0x3) << 6)
00370                | (LARc[1] & 0x3F);
00371         *c++ =   ((LARc[2] & 0x1F) << 3)
00372                | ((LARc[3] >> 2) & 0x7);
00373         *c++ =   ((LARc[3] & 0x3) << 6)
00374                | ((LARc[4] & 0xF) << 2)
00375                | ((LARc[5] >> 2) & 0x3);
00376         *c++ =   ((LARc[5] & 0x3) << 6)
00377                | ((LARc[6] & 0x7) << 3)
00378                | (LARc[7] & 0x7);
00379 
00380 
00381         *c++ =   ((Nc[0] & 0x7F) << 1)
00382 
00383 
00384                | ((bc[0] >> 1) & 0x1);
00385         *c++ =   ((bc[0] & 0x1) << 7)
00386 
00387 
00388                | ((Mc[0] & 0x3) << 5)
00389 
00390                | ((xmaxc[0] >> 1) & 0x1F);
00391         *c++ =   ((xmaxc[0] & 0x1) << 7)
00392 
00393 #undef xmc
00394 #define xmc     (source + 12)
00395 
00396                | ((xmc[0] & 0x7) << 4)
00397                | ((xmc[1] & 0x7) << 1)
00398                | ((xmc[2] >> 2) & 0x1);
00399         *c++ =   ((xmc[2] & 0x3) << 6)
00400                | ((xmc[3] & 0x7) << 3)
00401                | (xmc[4] & 0x7);
00402         *c++ =   ((xmc[5] & 0x7) << 5)                  /* 10 */
00403                | ((xmc[6] & 0x7) << 2)
00404                | ((xmc[7] >> 1) & 0x3);
00405         *c++ =   ((xmc[7] & 0x1) << 7)
00406                | ((xmc[8] & 0x7) << 4)
00407                | ((xmc[9] & 0x7) << 1)
00408                | ((xmc[10] >> 2) & 0x1);
00409         *c++ =   ((xmc[10] & 0x3) << 6)
00410                | ((xmc[11] & 0x7) << 3)
00411                | (xmc[12] & 0x7);
00412 
00413 
00414         *c++ =   ((Nc[1] & 0x7F) << 1)
00415 
00416 
00417                | ((bc[1] >> 1) & 0x1);
00418         *c++ =   ((bc[1] & 0x1) << 7)
00419 
00420 
00421                | ((Mc[1] & 0x3) << 5)
00422 
00423 
00424                | ((xmaxc[1] >> 1) & 0x1F);
00425         *c++ =   ((xmaxc[1] & 0x1) << 7)
00426 
00427 #undef  xmc
00428 #define xmc     (source + 29 - 13)
00429 
00430                | ((xmc[13] & 0x7) << 4)
00431                | ((xmc[14] & 0x7) << 1)
00432                | ((xmc[15] >> 2) & 0x1);
00433         *c++ =   ((xmc[15] & 0x3) << 6)
00434                | ((xmc[16] & 0x7) << 3)
00435                | (xmc[17] & 0x7);
00436         *c++ =   ((xmc[18] & 0x7) << 5)
00437                | ((xmc[19] & 0x7) << 2)
00438                | ((xmc[20] >> 1) & 0x3);
00439         *c++ =   ((xmc[20] & 0x1) << 7)
00440                | ((xmc[21] & 0x7) << 4)
00441                | ((xmc[22] & 0x7) << 1)
00442                | ((xmc[23] >> 2) & 0x1);
00443         *c++ =   ((xmc[23] & 0x3) << 6)
00444                | ((xmc[24] & 0x7) << 3)
00445                | (xmc[25] & 0x7);
00446 
00447 
00448         *c++ =   ((Nc[2] & 0x7F) << 1)                  /* 20 */
00449 
00450 
00451                | ((bc[2] >> 1) & 0x1);
00452         *c++ =   ((bc[2] & 0x1) << 7)
00453 
00454 
00455                | ((Mc[2] & 0x3) << 5)
00456 
00457 
00458                | ((xmaxc[2] >> 1) & 0x1F);
00459         *c++ =   ((xmaxc[2] & 0x1) << 7)
00460 
00461 #undef  xmc
00462 #define xmc     (source + 46 - 26)
00463 
00464                | ((xmc[26] & 0x7) << 4)
00465                | ((xmc[27] & 0x7) << 1)
00466                | ((xmc[28] >> 2) & 0x1);
00467         *c++ =   ((xmc[28] & 0x3) << 6)
00468                | ((xmc[29] & 0x7) << 3)
00469                | (xmc[30] & 0x7);
00470         *c++ =   ((xmc[31] & 0x7) << 5)
00471                | ((xmc[32] & 0x7) << 2)
00472                | ((xmc[33] >> 1) & 0x3);
00473         *c++ =   ((xmc[33] & 0x1) << 7)
00474                | ((xmc[34] & 0x7) << 4)
00475                | ((xmc[35] & 0x7) << 1)
00476                | ((xmc[36] >> 2) & 0x1);
00477         *c++ =   ((xmc[36] & 0x3) << 6)
00478                | ((xmc[37] & 0x7) << 3)
00479                | (xmc[38] & 0x7);
00480 
00481 
00482         *c++ =   ((Nc[3] & 0x7F) << 1)
00483 
00484 
00485                | ((bc[3] >> 1) & 0x1);
00486         *c++ =   ((bc[3] & 0x1) << 7)
00487 
00488 
00489                | ((Mc[3] & 0x3) << 5)
00490 
00491 
00492                | ((xmaxc[3] >> 1) & 0x1F);
00493         *c++ =   ((xmaxc[3] & 0x1) << 7)
00494 
00495 #undef  xmc
00496 #define xmc     (source + 63 - 39)
00497 
00498                | ((xmc[39] & 0x7) << 4)
00499                | ((xmc[40] & 0x7) << 1)
00500                | ((xmc[41] >> 2) & 0x1);
00501         *c++ =   ((xmc[41] & 0x3) << 6)                 /* 30 */
00502                | ((xmc[42] & 0x7) << 3)
00503                | (xmc[43] & 0x7);
00504         *c++ =   ((xmc[44] & 0x7) << 5)
00505                | ((xmc[45] & 0x7) << 2)
00506                | ((xmc[46] >> 1) & 0x3);
00507         *c++ =   ((xmc[46] & 0x1) << 7)
00508                | ((xmc[47] & 0x7) << 4)
00509                | ((xmc[48] & 0x7) << 1)
00510                | ((xmc[49] >> 2) & 0x1);
00511         *c++ =   ((xmc[49] & 0x3) << 6)
00512                | ((xmc[50] & 0x7) << 3)
00513                | (xmc[51] & 0x7);
00514         }
00515 }