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| 1 : | edgomez | 1382 | /***************************************************************************** |
| 2 : | * | ||
| 3 : | * XviD VBR Library | ||
| 4 : | * - Fixed quantizer controller implementation / Deprecated code - | ||
| 5 : | * | ||
| 6 : | * Copyright (C) 2002-2003 Edouard Gomez <ed.gomez@free.fr> | ||
| 7 : | * | ||
| 8 : | * This program is free software; you can redistribute it and/or modify | ||
| 9 : | * it under the terms of the GNU General Public License as published by | ||
| 10 : | * the Free Software Foundation; either version 2 of the License, or | ||
| 11 : | * (at your option) any later version. | ||
| 12 : | * | ||
| 13 : | * This program is distributed in the hope that it will be useful, | ||
| 14 : | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
| 15 : | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
| 16 : | * GNU General Public License for more details. | ||
| 17 : | * | ||
| 18 : | * You should have received a copy of the GNU General Public License | ||
| 19 : | * along with this program; if not, write to the Free Software | ||
| 20 : | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | ||
| 21 : | * | ||
| 22 : | * $Id: plugin_fixed.c,v 1.2 2004-03-22 22:36:24 edgomez Exp $ | ||
| 23 : | * | ||
| 24 : | ****************************************************************************/ | ||
| 25 : | |||
| 26 : | |||
| 27 : | #include "../xvid.h" | ||
| 28 : | #include "../image/image.h" | ||
| 29 : | |||
| 30 : | |||
| 31 : | typedef struct | ||
| 32 : | { | ||
| 33 : | int32_t quant_increment; | ||
| 34 : | int32_t quant_base; | ||
| 35 : | |||
| 36 : | /* Number of quantizers in the *quant distribution */ | ||
| 37 : | int nquant; | ||
| 38 : | |||
| 39 : | /* Quantizer distribution */ | ||
| 40 : | int *quant; | ||
| 41 : | } rc_fixed_t; | ||
| 42 : | |||
| 43 : | |||
| 44 : | static int gcd(int a, int b) | ||
| 45 : | { | ||
| 46 : | int r; | ||
| 47 : | |||
| 48 : | while(b) { | ||
| 49 : | r = a % b; | ||
| 50 : | a = b; | ||
| 51 : | b = r; | ||
| 52 : | } | ||
| 53 : | |||
| 54 : | return(a); | ||
| 55 : | } | ||
| 56 : | |||
| 57 : | |||
| 58 : | static int | ||
| 59 : | distribute_quants(int **quants, int lquant, int n_lquant, int n_hquant) | ||
| 60 : | { | ||
| 61 : | |||
| 62 : | int i, n, _gcd; | ||
| 63 : | int nlow, nhigh; | ||
| 64 : | int low, high; | ||
| 65 : | int q, r; | ||
| 66 : | int a,b,min, max; | ||
| 67 : | int m, M; | ||
| 68 : | int *dist; | ||
| 69 : | |||
| 70 : | /* Low quant */ | ||
| 71 : | low = lquant; | ||
| 72 : | |||
| 73 : | /* High quant is just low quant + 1 */ | ||
| 74 : | high = low + 1; | ||
| 75 : | |||
| 76 : | /* How much low quants we have to distribute */ | ||
| 77 : | nlow = n_lquant; | ||
| 78 : | |||
| 79 : | /* How much high quants we have to distribute */ | ||
| 80 : | nhigh = n_hquant; | ||
| 81 : | |||
| 82 : | /* Simplify the pattern, respecting the current ratio nhigh/nlow */ | ||
| 83 : | _gcd = gcd( nlow, nhigh); | ||
| 84 : | nlow = nlow / _gcd; | ||
| 85 : | nhigh = nhigh / _gcd; | ||
| 86 : | |||
| 87 : | /* Allocate the distributuion array */ | ||
| 88 : | if((*quants = (int*)malloc((nhigh + nlow)*sizeof(int))) == NULL) | ||
| 89 : | return (-1); | ||
| 90 : | |||
| 91 : | /* Validate distribution size */ | ||
| 92 : | n = nlow + nhigh; | ||
| 93 : | |||
| 94 : | /* | ||
| 95 : | * Our goal now is to find packet length so we distribute the quants | ||
| 96 : | * the best we can. The solution i chose is quite simple. | ||
| 97 : | * | ||
| 98 : | * Let's 'max' be max(nlow, nhigh) | ||
| 99 : | * Let's 'min' be min(nlow, nhigh) | ||
| 100 : | * | ||
| 101 : | * Then if we compute the euclidian division of 'max' by 'min', the | ||
| 102 : | * quotient 'q' represents the length of 'max type quant' packets | ||
| 103 : | * length. Let's call 'r' the remaining part of the euclidian division. | ||
| 104 : | * | ||
| 105 : | * We could stop there and have something like this: | ||
| 106 : | * M == quant type of the quantity 'max' | ||
| 107 : | * m == quant type of the quantity 'min' | ||
| 108 : | * | ||
| 109 : | * (MM.........Mm)*(MMMMMM...M) | ||
| 110 : | * '----------' '--------' | ||
| 111 : | * '----|------' |-> repeated 'r' times | ||
| 112 : | * || | ||
| 113 : | * ||--> repeated 'min' times | ||
| 114 : | * |---> repeated 'q' times' | ||
| 115 : | * | ||
| 116 : | * | ||
| 117 : | * Let's look if we have precision quants. | ||
| 118 : | * | ||
| 119 : | * We have 'min' packets of (q+1) length | ||
| 120 : | * We have also a packet of length 'r' | ||
| 121 : | * So : min*(q+1) + r == (min*q + r) + min == max + min == n | ||
| 122 : | * | ||
| 123 : | * Ok this is good :-) | ||
| 124 : | * | ||
| 125 : | * Now let's complicate things a bit :-))) | ||
| 126 : | * | ||
| 127 : | * We will distribute the last M quantizers all over the distribution | ||
| 128 : | * array. To achieve that, we build packets of (q+2) quantizers containing | ||
| 129 : | * qM + 1m as usual plus 1M from the last remaining M quantizer packet and | ||
| 130 : | * usual packets of (q+1) with qM and 1m. | ||
| 131 : | * | ||
| 132 : | * So we will have this kind of distribution: | ||
| 133 : | * | ||
| 134 : | * (MM.........Mm)*(MMMM...Mm) | ||
| 135 : | * '----------' '------' | ||
| 136 : | * '----|------' '---|---' | ||
| 137 : | * || ||--> repeated 'min-r' times | ||
| 138 : | * || |---> repeated 'q' times | ||
| 139 : | * ||--> repeated 'r' times | ||
| 140 : | * |---> repeated 'q+1' times | ||
| 141 : | * | ||
| 142 : | * | ||
| 143 : | * Let's check if it's still right: | ||
| 144 : | * | ||
| 145 : | * We'll have ((q+1)*r + q*(min-r))M quants == (q*r + r + q*min - q*r)M | ||
| 146 : | * == (q*min + r)M | ||
| 147 : | * == (max)M it's good | ||
| 148 : | * And: (r + min - r)m quantizers == (min)m it's good too) | ||
| 149 : | * | ||
| 150 : | * NB: if the fixed quantizer is an integer then we have min == 0, so we | ||
| 151 : | * must take care of it apart (else the euclidian division leads to | ||
| 152 : | * an arithmetic signal - division by zero) | ||
| 153 : | * | ||
| 154 : | */ | ||
| 155 : | |||
| 156 : | |||
| 157 : | max = MAX(nlow, nhigh); | ||
| 158 : | min = MIN(nlow, nhigh); | ||
| 159 : | |||
| 160 : | /* Euclidian division */ | ||
| 161 : | if(min == 0) { | ||
| 162 : | q = 0; | ||
| 163 : | r = max; | ||
| 164 : | } else { | ||
| 165 : | q = max/min; | ||
| 166 : | r = max%min; | ||
| 167 : | } | ||
| 168 : | |||
| 169 : | /* How much packets of (q+1)M quantizers + 1m quantizer */ | ||
| 170 : | a = r; | ||
| 171 : | |||
| 172 : | /* How much packets of (q)M quantizers + 1m quantizer */ | ||
| 173 : | b = min - r; | ||
| 174 : | |||
| 175 : | /* First we set M */ | ||
| 176 : | M = (max==nhigh)?high:low; | ||
| 177 : | |||
| 178 : | /* | ||
| 179 : | * Then as we can't guarantee that max != min, we are forced to set | ||
| 180 : | * the other one according to the first value. We can't use the first | ||
| 181 : | * formula with s/max/min/ | ||
| 182 : | */ | ||
| 183 : | m = (M==high)?low:high; | ||
| 184 : | |||
| 185 : | /* | ||
| 186 : | * Ok now we know everything we have to know to distribute those funny | ||
| 187 : | * quantizers. What about just doing it ? | ||
| 188 : | */ | ||
| 189 : | |||
| 190 : | dist = *quants; | ||
| 191 : | |||
| 192 : | /* Distribute big packets */ | ||
| 193 : | for(i=0; i<a; i++) { | ||
| 194 : | |||
| 195 : | int j; | ||
| 196 : | |||
| 197 : | /* Repeat q+1 times the M quantizer */ | ||
| 198 : | for(j=0; j<(q+1); j++) *(dist++) = M; | ||
| 199 : | |||
| 200 : | /* Put a m quantizer */ | ||
| 201 : | *(dist++) = m; | ||
| 202 : | |||
| 203 : | } | ||
| 204 : | |||
| 205 : | /* Distribute the little packets */ | ||
| 206 : | for(i=0; i<b; i++) { | ||
| 207 : | |||
| 208 : | int j; | ||
| 209 : | |||
| 210 : | /* Repeat q times the M quantizer */ | ||
| 211 : | for(j=0; j<q; j++) *(dist++) = M; | ||
| 212 : | |||
| 213 : | /* Put a m quantizer */ | ||
| 214 : | *(dist++) = m; | ||
| 215 : | |||
| 216 : | } | ||
| 217 : | |||
| 218 : | return(n); | ||
| 219 : | } | ||
| 220 : | |||
| 221 : | |||
| 222 : | |||
| 223 : | |||
| 224 : | static int rc_fixed_create(xvid_plg_create_t * create, rc_fixed_t ** handle) | ||
| 225 : | { | ||
| 226 : | xvid_plugin_fixed_t * param = (xvid_plugin_fixed_t *)create->param; | ||
| 227 : | rc_fixed_t * rc; | ||
| 228 : | int quant_low; | ||
| 229 : | int nquant_low, nquant_high; | ||
| 230 : | |||
| 231 : | /* allocate context struct */ | ||
| 232 : | if((rc = malloc(sizeof(rc_fixed_t))) == NULL) | ||
| 233 : | return(XVID_ERR_MEMORY); | ||
| 234 : | |||
| 235 : | /* Copy data to private area */ | ||
| 236 : | rc->quant_increment = param->quant_increment; | ||
| 237 : | rc->quant_base = param->quant_base; | ||
| 238 : | |||
| 239 : | /* Cut down the precision up to 1/precision */ | ||
| 240 : | quant_low = rc->quant_increment/rc->quant_base; | ||
| 241 : | |||
| 242 : | /* Force [1..31] range */ | ||
| 243 : | if(quant_low < 1) { | ||
| 244 : | quant_low = 1; | ||
| 245 : | rc->quant_base = 1; | ||
| 246 : | rc->quant_increment = quant_low; | ||
| 247 : | } else if(quant_low > 30) { | ||
| 248 : | quant_low = 31; | ||
| 249 : | rc->quant_base = 1; | ||
| 250 : | rc->quant_increment = quant_low; | ||
| 251 : | } | ||
| 252 : | |||
| 253 : | /* How much low quants we have to distribute) */ | ||
| 254 : | nquant_low = rc->quant_base*(quant_low+1) - rc->quant_increment; | ||
| 255 : | nquant_high = rc->quant_base - nquant_low; | ||
| 256 : | |||
| 257 : | /* Distribute the quantizers */ | ||
| 258 : | rc->nquant = distribute_quants(&rc->quant, | ||
| 259 : | quant_low, | ||
| 260 : | nquant_low, | ||
| 261 : | nquant_high); | ||
| 262 : | |||
| 263 : | if(rc->quant == NULL) { | ||
| 264 : | free(rc); | ||
| 265 : | return(XVID_ERR_MEMORY); | ||
| 266 : | } | ||
| 267 : | |||
| 268 : | *handle = rc; | ||
| 269 : | return(0); | ||
| 270 : | } | ||
| 271 : | |||
| 272 : | |||
| 273 : | static int rc_fixed_destroy(rc_fixed_t * rc, xvid_plg_destroy_t * destroy) | ||
| 274 : | { | ||
| 275 : | free(rc); | ||
| 276 : | return(0); | ||
| 277 : | } | ||
| 278 : | |||
| 279 : | |||
| 280 : | static int rc_fixed_before(rc_fixed_t * rc, xvid_plg_data_t * data) | ||
| 281 : | { | ||
| 282 : | data->quant = rc->quant[data->frame_num%rc->nquant]; | ||
| 283 : | data->type = XVID_TYPE_AUTO; | ||
| 284 : | return 0; | ||
| 285 : | } | ||
| 286 : | |||
| 287 : | |||
| 288 : | int xvid_plugin_fixed(void * handle, int opt, void * param1, void * param2) | ||
| 289 : | { | ||
| 290 : | switch(opt) | ||
| 291 : | { | ||
| 292 : | case XVID_PLG_INFO : | ||
| 293 : | return 0; | ||
| 294 : | |||
| 295 : | case XVID_PLG_CREATE : | ||
| 296 : | return rc_fixed_create((xvid_plg_create_t*)param1, param2); | ||
| 297 : | |||
| 298 : | case XVID_PLG_DESTROY : | ||
| 299 : | return rc_fixed_destroy((rc_fixed_t*)handle, (xvid_plg_destroy_t*)param1); | ||
| 300 : | |||
| 301 : | case XVID_PLG_BEFORE : | ||
| 302 : | return rc_fixed_before((rc_fixed_t*)handle, (xvid_plg_data_t*)param1); | ||
| 303 : | |||
| 304 : | case XVID_PLG_AFTER : | ||
| 305 : | return 0; | ||
| 306 : | } | ||
| 307 : | |||
| 308 : | return XVID_ERR_FAIL; | ||
| 309 : | } |
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