FFmpeg: libavcodec/mace.c Source File

00001 /*
00002  * MACE decoder
00003  * Copyright (c) 2002 Laszlo Torok <torokl@alpha.dfmk.hu>
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00027 #include "avcodec.h"
00028 
00029 /*
00030  * Adapted to ffmpeg by Francois Revol <revol@free.fr>
00031  * (removed 68k REG stuff, changed types, added some statics and consts,
00032  * libavcodec api, context stuff, interlaced stereo out).
00033  */
00034 
00035 static const int16_t MACEtab1[] = {-13, 8, 76, 222, 222, 76, 8, -13};
00036 
00037 static const int16_t MACEtab3[] = {-18, 140, 140, -18};
00038 
00039 static const int16_t MACEtab2[][4] = {
00040     {    37,    116,    206,    330}, {    39,    121,    216,    346},
00041     {    41,    127,    225,    361}, {    42,    132,    235,    377},
00042     {    44,    137,    245,    392}, {    46,    144,    256,    410},
00043     {    48,    150,    267,    428}, {    51,    157,    280,    449},
00044     {    53,    165,    293,    470}, {    55,    172,    306,    490},
00045     {    58,    179,    319,    511}, {    60,    187,    333,    534},
00046     {    63,    195,    348,    557}, {    66,    205,    364,    583},
00047     {    69,    214,    380,    609}, {    72,    223,    396,    635},
00048     {    75,    233,    414,    663}, {    79,    244,    433,    694},
00049     {    82,    254,    453,    725}, {    86,    265,    472,    756},
00050     {    90,    278,    495,    792}, {    94,    290,    516,    826},
00051     {    98,    303,    538,    862}, {   102,    316,    562,    901},
00052     {   107,    331,    588,    942}, {   112,    345,    614,    983},
00053     {   117,    361,    641,   1027}, {   122,    377,    670,   1074},
00054     {   127,    394,    701,   1123}, {   133,    411,    732,   1172},
00055     {   139,    430,    764,   1224}, {   145,    449,    799,   1280},
00056     {   152,    469,    835,   1337}, {   159,    490,    872,   1397},
00057     {   166,    512,    911,   1459}, {   173,    535,    951,   1523},
00058     {   181,    558,    993,   1590}, {   189,    584,   1038,   1663},
00059     {   197,    610,   1085,   1738}, {   206,    637,   1133,   1815},
00060     {   215,    665,   1183,   1895}, {   225,    695,   1237,   1980},
00061     {   235,    726,   1291,   2068}, {   246,    759,   1349,   2161},
00062     {   257,    792,   1409,   2257}, {   268,    828,   1472,   2357},
00063     {   280,    865,   1538,   2463}, {   293,    903,   1606,   2572},
00064     {   306,    944,   1678,   2688}, {   319,    986,   1753,   2807},
00065     {   334,   1030,   1832,   2933}, {   349,   1076,   1914,   3065},
00066     {   364,   1124,   1999,   3202}, {   380,   1174,   2088,   3344},
00067     {   398,   1227,   2182,   3494}, {   415,   1281,   2278,   3649},
00068     {   434,   1339,   2380,   3811}, {   453,   1398,   2486,   3982},
00069     {   473,   1461,   2598,   4160}, {   495,   1526,   2714,   4346},
00070     {   517,   1594,   2835,   4540}, {   540,   1665,   2961,   4741},
00071     {   564,   1740,   3093,   4953}, {   589,   1818,   3232,   5175},
00072     {   615,   1898,   3375,   5405}, {   643,   1984,   3527,   5647},
00073     {   671,   2072,   3683,   5898}, {   701,   2164,   3848,   6161},
00074     {   733,   2261,   4020,   6438}, {   766,   2362,   4199,   6724},
00075     {   800,   2467,   4386,   7024}, {   836,   2578,   4583,   7339},
00076     {   873,   2692,   4786,   7664}, {   912,   2813,   5001,   8008},
00077     {   952,   2938,   5223,   8364}, {   995,   3070,   5457,   8739},
00078     {  1039,   3207,   5701,   9129}, {  1086,   3350,   5956,   9537},
00079     {  1134,   3499,   6220,   9960}, {  1185,   3655,   6497,  10404},
00080     {  1238,   3818,   6788,  10869}, {  1293,   3989,   7091,  11355},
00081     {  1351,   4166,   7407,  11861}, {  1411,   4352,   7738,  12390},
00082     {  1474,   4547,   8084,  12946}, {  1540,   4750,   8444,  13522},
00083     {  1609,   4962,   8821,  14126}, {  1680,   5183,   9215,  14756},
00084     {  1756,   5415,   9626,  15415}, {  1834,   5657,  10057,  16104},
00085     {  1916,   5909,  10505,  16822}, {  2001,   6173,  10975,  17574},
00086     {  2091,   6448,  11463,  18356}, {  2184,   6736,  11974,  19175},
00087     {  2282,   7037,  12510,  20032}, {  2383,   7351,  13068,  20926},
00088     {  2490,   7679,  13652,  21861}, {  2601,   8021,  14260,  22834},
00089     {  2717,   8380,  14897,  23854}, {  2838,   8753,  15561,  24918},
00090     {  2965,   9144,  16256,  26031}, {  3097,   9553,  16982,  27193},
00091     {  3236,   9979,  17740,  28407}, {  3380,  10424,  18532,  29675},
00092     {  3531,  10890,  19359,  31000}, {  3688,  11375,  20222,  32382},
00093     {  3853,  11883,  21125,  32767}, {  4025,  12414,  22069,  32767},
00094     {  4205,  12967,  23053,  32767}, {  4392,  13546,  24082,  32767},
00095     {  4589,  14151,  25157,  32767}, {  4793,  14783,  26280,  32767},
00096     {  5007,  15442,  27452,  32767}, {  5231,  16132,  28678,  32767},
00097     {  5464,  16851,  29957,  32767}, {  5708,  17603,  31294,  32767},
00098     {  5963,  18389,  32691,  32767}, {  6229,  19210,  32767,  32767},
00099     {  6507,  20067,  32767,  32767}, {  6797,  20963,  32767,  32767},
00100     {  7101,  21899,  32767,  32767}, {  7418,  22876,  32767,  32767},
00101     {  7749,  23897,  32767,  32767}, {  8095,  24964,  32767,  32767},
00102     {  8456,  26078,  32767,  32767}, {  8833,  27242,  32767,  32767},
00103     {  9228,  28457,  32767,  32767}, {  9639,  29727,  32767,  32767}
00104 };
00105 
00106 static const int16_t MACEtab4[][2] = {
00107     {    64,    216}, {    67,    226}, {    70,    236}, {    74,    246},
00108     {    77,    257}, {    80,    268}, {    84,    280}, {    88,    294},
00109     {    92,    307}, {    96,    321}, {   100,    334}, {   104,    350},
00110     {   109,    365}, {   114,    382}, {   119,    399}, {   124,    416},
00111     {   130,    434}, {   136,    454}, {   142,    475}, {   148,    495},
00112     {   155,    519}, {   162,    541}, {   169,    564}, {   176,    590},
00113     {   185,    617}, {   193,    644}, {   201,    673}, {   210,    703},
00114     {   220,    735}, {   230,    767}, {   240,    801}, {   251,    838},
00115     {   262,    876}, {   274,    914}, {   286,    955}, {   299,    997},
00116     {   312,   1041}, {   326,   1089}, {   341,   1138}, {   356,   1188},
00117     {   372,   1241}, {   388,   1297}, {   406,   1354}, {   424,   1415},
00118     {   443,   1478}, {   462,   1544}, {   483,   1613}, {   505,   1684},
00119     {   527,   1760}, {   551,   1838}, {   576,   1921}, {   601,   2007},
00120     {   628,   2097}, {   656,   2190}, {   686,   2288}, {   716,   2389},
00121     {   748,   2496}, {   781,   2607}, {   816,   2724}, {   853,   2846},
00122     {   891,   2973}, {   930,   3104}, {   972,   3243}, {  1016,   3389},
00123     {  1061,   3539}, {  1108,   3698}, {  1158,   3862}, {  1209,   4035},
00124     {  1264,   4216}, {  1320,   4403}, {  1379,   4599}, {  1441,   4806},
00125     {  1505,   5019}, {  1572,   5244}, {  1642,   5477}, {  1715,   5722},
00126     {  1792,   5978}, {  1872,   6245}, {  1955,   6522}, {  2043,   6813},
00127     {  2134,   7118}, {  2229,   7436}, {  2329,   7767}, {  2432,   8114},
00128     {  2541,   8477}, {  2655,   8854}, {  2773,   9250}, {  2897,   9663},
00129     {  3026,  10094}, {  3162,  10546}, {  3303,  11016}, {  3450,  11508},
00130     {  3604,  12020}, {  3765,  12556}, {  3933,  13118}, {  4108,  13703},
00131     {  4292,  14315}, {  4483,  14953}, {  4683,  15621}, {  4892,  16318},
00132     {  5111,  17046}, {  5339,  17807}, {  5577,  18602}, {  5826,  19433},
00133     {  6086,  20300}, {  6358,  21205}, {  6642,  22152}, {  6938,  23141},
00134     {  7248,  24173}, {  7571,  25252}, {  7909,  26380}, {  8262,  27557},
00135     {  8631,  28786}, {  9016,  30072}, {  9419,  31413}, {  9839,  32767},
00136     { 10278,  32767}, { 10737,  32767}, { 11216,  32767}, { 11717,  32767},
00137     { 12240,  32767}, { 12786,  32767}, { 13356,  32767}, { 13953,  32767},
00138     { 14576,  32767}, { 15226,  32767}, { 15906,  32767}, { 16615,  32767}
00139 };
00140 
00141 static const struct {
00142     const int16_t *tab1; const int16_t *tab2; int stride;
00143 } tabs[] = {
00144     {MACEtab1, &MACEtab2[0][0], 4},
00145     {MACEtab3, &MACEtab4[0][0], 2},
00146     {MACEtab1, &MACEtab2[0][0], 4}
00147 };
00148 
00149 #define QT_8S_2_16S(x) (((x) & 0xFF00) | (((x) >> 8) & 0xFF))
00150 
00151 typedef struct ChannelData {
00152     int16_t index, factor, prev2, previous, level;
00153 } ChannelData;
00154 
00155 typedef struct MACEContext {
00156     ChannelData chd[2];
00157 } MACEContext;
00158 
00163 static inline int16_t mace_broken_clip_int16(int n)
00164 {
00165     if (n > 32767)
00166         return 32767;
00167     else if (n < -32768)
00168         return -32767;
00169     else
00170         return n;
00171 }
00172 
00173 static int16_t read_table(ChannelData *chd, uint8_t val, int tab_idx)
00174 {
00175     int16_t current;
00176 
00177     if (val < tabs[tab_idx].stride)
00178         current = tabs[tab_idx].tab2[((chd->index & 0x7f0) >> 4) * tabs[tab_idx].stride + val];
00179     else
00180         current = - 1 - tabs[tab_idx].tab2[((chd->index & 0x7f0) >> 4)*tabs[tab_idx].stride + 2*tabs[tab_idx].stride-val-1];
00181 
00182     if (( chd->index += tabs[tab_idx].tab1[val]-(chd->index >> 5) ) < 0)
00183       chd->index = 0;
00184 
00185     return current;
00186 }
00187 
00188 static void chomp3(ChannelData *chd, int16_t *output, uint8_t val,
00189                    int tab_idx,
00190                    uint32_t numChannels)
00191 {
00192 
00193     int16_t current = read_table(chd, val, tab_idx);
00194 
00195     current = mace_broken_clip_int16(current + chd->level);
00196 
00197     chd->level = current - (current >> 3);
00198     *output = QT_8S_2_16S(current);
00199 }
00200 
00201 static void chomp6(ChannelData *chd, int16_t *output, uint8_t val,
00202                    int tab_idx,
00203                    uint32_t numChannels)
00204 {
00205     int16_t current = read_table(chd, val, tab_idx);
00206 
00207     if ((chd->previous ^ current) >= 0) {
00208         chd->factor = FFMIN(chd->factor + 506, 32767);
00209     } else {
00210         if (chd->factor - 314 < -32768)
00211             chd->factor = -32767;
00212         else
00213             chd->factor -= 314;
00214     }
00215 
00216     current = mace_broken_clip_int16(current + chd->level);
00217 
00218     chd->level = (current*chd->factor) >> 15;
00219     current >>= 1;
00220 
00221     output[0] = QT_8S_2_16S(chd->previous + chd->prev2 -
00222                             ((chd->prev2-current) >> 2));
00223     output[numChannels] = QT_8S_2_16S(chd->previous + current +
00224                                       ((chd->prev2-current) >> 2));
00225     chd->prev2 = chd->previous;
00226     chd->previous = current;
00227 }
00228 
00229 static av_cold int mace_decode_init(AVCodecContext * avctx)
00230 {
00231     if (avctx->channels > 2)
00232         return -1;
00233     avctx->sample_fmt = AV_SAMPLE_FMT_S16;
00234     return 0;
00235 }
00236 
00237 static int mace_decode_frame(AVCodecContext *avctx,
00238                               void *data, int *data_size,
00239                               AVPacket *avpkt)
00240 {
00241     const uint8_t *buf = avpkt->data;
00242     int buf_size = avpkt->size;
00243     int16_t *samples = data;
00244     MACEContext *ctx = avctx->priv_data;
00245     int i, j, k, l;
00246     int is_mace3 = (avctx->codec_id == CODEC_ID_MACE3);
00247 
00248     if (*data_size < (3 * buf_size << (2-is_mace3))) {
00249         av_log(avctx, AV_LOG_ERROR, "Output buffer too small!\n");
00250         return -1;
00251     }
00252 
00253     for(i = 0; i < avctx->channels; i++) {
00254         int16_t *output = samples + i;
00255 
00256         for (j=0; j < buf_size / (avctx->channels << is_mace3); j++)
00257             for (k=0; k < (1 << is_mace3); k++) {
00258                 uint8_t pkt = buf[(i << is_mace3) +
00259                                   (j*avctx->channels << is_mace3) + k];
00260 
00261                 uint8_t val[2][3] = {{pkt >> 5, (pkt >> 3) & 3, pkt & 7 },
00262                                      {pkt & 7 , (pkt >> 3) & 3, pkt >> 5}};
00263 
00264                 for (l=0; l < 3; l++) {
00265                     if (is_mace3)
00266                         chomp3(&ctx->chd[i], output, val[1][l], l,
00267                                avctx->channels);
00268                     else
00269                         chomp6(&ctx->chd[i], output, val[0][l], l,
00270                                avctx->channels);
00271 
00272                     output += avctx->channels << (1-is_mace3);
00273                 }
00274             }
00275     }
00276 
00277     *data_size = 3 * buf_size << (2-is_mace3);
00278 
00279     return buf_size;
00280 }
00281 
00282 AVCodec ff_mace3_decoder = {
00283     "mace3",
00284     AVMEDIA_TYPE_AUDIO,
00285     CODEC_ID_MACE3,
00286     sizeof(MACEContext),
00287     mace_decode_init,
00288     NULL,
00289     NULL,
00290     mace_decode_frame,
00291     .long_name = NULL_IF_CONFIG_SMALL("MACE (Macintosh Audio Compression/Expansion) 3:1"),
00292 };
00293 
00294 AVCodec ff_mace6_decoder = {
00295     "mace6",
00296     AVMEDIA_TYPE_AUDIO,
00297     CODEC_ID_MACE6,
00298     sizeof(MACEContext),
00299     mace_decode_init,
00300     NULL,
00301     NULL,
00302     mace_decode_frame,
00303     .long_name = NULL_IF_CONFIG_SMALL("MACE (Macintosh Audio Compression/Expansion) 6:1"),
00304 };
00305