vp8/common/loopfilter_filters.c

   1 /*
   2  *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
   3  *
   4  *  Use of this source code is governed by a BSD-style license
   5  *  that can be found in the LICENSE file in the root of the source
   6  *  tree. An additional intellectual property rights grant can be found
   7  *  in the file PATENTS.  All contributing project authors may
   8  *  be found in the AUTHORS file in the root of the source tree.
   9  */
  10
  11
  12 #include <stdlib.h>
  13 #include "loopfilter.h"
  14 #include "onyxc_int.h"
  15
  16 typedef unsigned char uc;
  17
  18 static __inline signed char vp8_signed_char_clamp(int t)
  19 {
  20     t = (t < -128 ? -128 : t);
  21     t = (t > 127 ? 127 : t);
  22     return (signed char) t;
  23 }
  24
  25
  26 /* should we apply any filter at all ( 11111111 yes, 00000000 no) */
  27 static __inline signed char vp8_filter_mask(signed char limit, signed char flimit,
  28                                      uc p3, uc p2, uc p1, uc p0, uc q0, uc q1, uc q2, uc q3)
  29 {
  30     signed char mask = 0;
  31     mask |= (abs(p3 - p2) > limit) * -1;
  32     mask |= (abs(p2 - p1) > limit) * -1;
  33     mask |= (abs(p1 - p0) > limit) * -1;
  34     mask |= (abs(q1 - q0) > limit) * -1;
  35     mask |= (abs(q2 - q1) > limit) * -1;
  36     mask |= (abs(q3 - q2) > limit) * -1;
  37     mask |= (abs(p0 - q0) * 2 + abs(p1 - q1) / 2  > flimit * 2 + limit) * -1;
  38     mask = ~mask;
  39     return mask;
  40 }
  41
  42 /* is there high variance internal edge ( 11111111 yes, 00000000 no) */
  43 static __inline signed char vp8_hevmask(signed char thresh, uc p1, uc p0, uc q0, uc q1)
  44 {
  45     signed char hev = 0;
  46     hev  |= (abs(p1 - p0) > thresh) * -1;
  47     hev  |= (abs(q1 - q0) > thresh) * -1;
  48     return hev;
  49 }
  50
  51 static __inline void vp8_filter(signed char mask, signed char hev, uc *op1, uc *op0, uc *oq0, uc *oq1)
  52
  53 {
  54     signed char ps0, qs0;
  55     signed char ps1, qs1;
  56     signed char vp8_filter, Filter1, Filter2;
  57     signed char u;
  58
  59     ps1 = (signed char) * op1 ^ 0x80;
  60     ps0 = (signed char) * op0 ^ 0x80;
  61     qs0 = (signed char) * oq0 ^ 0x80;
  62     qs1 = (signed char) * oq1 ^ 0x80;
  63
  64     /* add outer taps if we have high edge variance */
  65     vp8_filter = vp8_signed_char_clamp(ps1 - qs1);
  66     vp8_filter &= hev;
  67
  68     /* inner taps */
  69     vp8_filter = vp8_signed_char_clamp(vp8_filter + 3 * (qs0 - ps0));
  70     vp8_filter &= mask;
  71
  72     /* save bottom 3 bits so that we round one side +4 and the other +3
  73      * if it equals 4 we'll set to adjust by -1 to account for the fact
  74      * we'd round 3 the other way
  75      */
  76     Filter1 = vp8_signed_char_clamp(vp8_filter + 4);
  77     Filter2 = vp8_signed_char_clamp(vp8_filter + 3);
  78     Filter1 >>= 3;
  79     Filter2 >>= 3;
  80     u = vp8_signed_char_clamp(qs0 - Filter1);
  81     *oq0 = u ^ 0x80;
  82     u = vp8_signed_char_clamp(ps0 + Filter2);
  83     *op0 = u ^ 0x80;
  84     vp8_filter = Filter1;
  85
  86     /* outer tap adjustments */
  87     vp8_filter += 1;
  88     vp8_filter >>= 1;
  89     vp8_filter &= ~hev;
  90
  91     u = vp8_signed_char_clamp(qs1 - vp8_filter);
  92     *oq1 = u ^ 0x80;
  93     u = vp8_signed_char_clamp(ps1 + vp8_filter);
  94     *op1 = u ^ 0x80;
  95
  96 }
  97 void vp8_loop_filter_horizontal_edge_c
  98 (
  99     unsigned char *s,
 100     int p, /* pitch */
 101     const signed char *flimit,
 102     const signed char *limit,
 103     const signed char *thresh,
 104     int count
 105 )
 106 {
 107     int  hev = 0; /* high edge variance */
 108     signed char mask = 0;
 109     int i = 0;
 110
 111     /* loop filter designed to work using chars so that we can make maximum use
 112      * of 8 bit simd instructions.
 113      */
 114     do
 115     {
 116         mask = vp8_filter_mask(limit[i], flimit[i],
 117                                s[-4*p], s[-3*p], s[-2*p], s[-1*p],
 118                                s[0*p], s[1*p], s[2*p], s[3*p]);
 119
 120         hev = vp8_hevmask(thresh[i], s[-2*p], s[-1*p], s[0*p], s[1*p]);
 121
 122         vp8_filter(mask, hev, s - 2 * p, s - 1 * p, s, s + 1 * p);
 123
 124         ++s;
 125     }
 126     while (++i < count * 8);
 127 }
 128
 129 void vp8_loop_filter_vertical_edge_c
 130 (
 131     unsigned char *s,
 132     int p,
 133     const signed char *flimit,
 134     const signed char *limit,
 135     const signed char *thresh,
 136     int count
 137 )
 138 {
 139     int  hev = 0; /* high edge variance */
 140     signed char mask = 0;
 141     int i = 0;
 142
 143     /* loop filter designed to work using chars so that we can make maximum use
 144      * of 8 bit simd instructions.
 145      */
 146     do
 147     {
 148         mask = vp8_filter_mask(limit[i], flimit[i],
 149                                s[-4], s[-3], s[-2], s[-1], s[0], s[1], s[2], s[3]);
 150
 151         hev = vp8_hevmask(thresh[i], s[-2], s[-1], s[0], s[1]);
 152
 153         vp8_filter(mask, hev, s - 2, s - 1, s, s + 1);
 154
 155         s += p;
 156     }
 157     while (++i < count * 8);
 158 }
 159
 160 static __inline void vp8_mbfilter(signed char mask, signed char hev,
 161                            uc *op2, uc *op1, uc *op0, uc *oq0, uc *oq1, uc *oq2)
 162 {
 163     signed char s, u;
 164     signed char vp8_filter, Filter1, Filter2;
 165     signed char ps2 = (signed char) * op2 ^ 0x80;
 166     signed char ps1 = (signed char) * op1 ^ 0x80;
 167     signed char ps0 = (signed char) * op0 ^ 0x80;
 168     signed char qs0 = (signed char) * oq0 ^ 0x80;
 169     signed char qs1 = (signed char) * oq1 ^ 0x80;
 170     signed char qs2 = (signed char) * oq2 ^ 0x80;
 171
 172     /* add outer taps if we have high edge variance */
 173     vp8_filter = vp8_signed_char_clamp(ps1 - qs1);
 174     vp8_filter = vp8_signed_char_clamp(vp8_filter + 3 * (qs0 - ps0));
 175     vp8_filter &= mask;
 176
 177     Filter2 = vp8_filter;
 178     Filter2 &= hev;
 179
 180     /* save bottom 3 bits so that we round one side +4 and the other +3 */
 181     Filter1 = vp8_signed_char_clamp(Filter2 + 4);
 182     Filter2 = vp8_signed_char_clamp(Filter2 + 3);
 183     Filter1 >>= 3;
 184     Filter2 >>= 3;
 185     qs0 = vp8_signed_char_clamp(qs0 - Filter1);
 186     ps0 = vp8_signed_char_clamp(ps0 + Filter2);
 187
 188
 189     /* only apply wider filter if not high edge variance */
 190     vp8_filter &= ~hev;
 191     Filter2 = vp8_filter;
 192
 193     /* roughly 3/7th difference across boundary */
 194     u = vp8_signed_char_clamp((63 + Filter2 * 27) >> 7);
 195     s = vp8_signed_char_clamp(qs0 - u);
 196     *oq0 = s ^ 0x80;
 197     s = vp8_signed_char_clamp(ps0 + u);
 198     *op0 = s ^ 0x80;
 199
 200     /* roughly 2/7th difference across boundary */
 201     u = vp8_signed_char_clamp((63 + Filter2 * 18) >> 7);
 202     s = vp8_signed_char_clamp(qs1 - u);
 203     *oq1 = s ^ 0x80;
 204     s = vp8_signed_char_clamp(ps1 + u);
 205     *op1 = s ^ 0x80;
 206
 207     /* roughly 1/7th difference across boundary */
 208     u = vp8_signed_char_clamp((63 + Filter2 * 9) >> 7);
 209     s = vp8_signed_char_clamp(qs2 - u);
 210     *oq2 = s ^ 0x80;
 211     s = vp8_signed_char_clamp(ps2 + u);
 212     *op2 = s ^ 0x80;
 213 }
 214
 215 void vp8_mbloop_filter_horizontal_edge_c
 216 (
 217     unsigned char *s,
 218     int p,
 219     const signed char *flimit,
 220     const signed char *limit,
 221     const signed char *thresh,
 222     int count
 223 )
 224 {
 225     signed char hev = 0; /* high edge variance */
 226     signed char mask = 0;
 227     int i = 0;
 228
 229     /* loop filter designed to work using chars so that we can make maximum use
 230      * of 8 bit simd instructions.
 231      */
 232     do
 233     {
 234
 235         mask = vp8_filter_mask(limit[i], flimit[i],
 236                                s[-4*p], s[-3*p], s[-2*p], s[-1*p],
 237                                s[0*p], s[1*p], s[2*p], s[3*p]);
 238
 239         hev = vp8_hevmask(thresh[i], s[-2*p], s[-1*p], s[0*p], s[1*p]);
 240
 241         vp8_mbfilter(mask, hev, s - 3 * p, s - 2 * p, s - 1 * p, s, s + 1 * p, s + 2 * p);
 242
 243         ++s;
 244     }
 245     while (++i < count * 8);
 246
 247 }
 248
 249
 250 void vp8_mbloop_filter_vertical_edge_c
 251 (
 252     unsigned char *s,
 253     int p,
 254     const signed char *flimit,
 255     const signed char *limit,
 256     const signed char *thresh,
 257     int count
 258 )
 259 {
 260     signed char hev = 0; /* high edge variance */
 261     signed char mask = 0;
 262     int i = 0;
 263
 264     do
 265     {
 266
 267         mask = vp8_filter_mask(limit[i], flimit[i],
 268                                s[-4], s[-3], s[-2], s[-1], s[0], s[1], s[2], s[3]);
 269
 270         hev = vp8_hevmask(thresh[i], s[-2], s[-1], s[0], s[1]);
 271
 272         vp8_mbfilter(mask, hev, s - 3, s - 2, s - 1, s, s + 1, s + 2);
 273
 274         s += p;
 275     }
 276     while (++i < count * 8);
 277
 278 }
 279
 280 /* should we apply any filter at all ( 11111111 yes, 00000000 no) */
 281 static __inline signed char vp8_simple_filter_mask(signed char limit, signed char flimit, uc p1, uc p0, uc q0, uc q1)
 282 {
 283 /* Why does this cause problems for win32?
 284  * error C2143: syntax error : missing ';' before 'type'
 285  *  (void) limit;
 286  */
 287     signed char mask = (abs(p0 - q0) * 2 + abs(p1 - q1) / 2  <= flimit * 2 + limit) * -1;
 288     return mask;
 289 }
 290
 291 static __inline void vp8_simple_filter(signed char mask, uc *op1, uc *op0, uc *oq0, uc *oq1)
 292 {
 293     signed char vp8_filter, Filter1, Filter2;
 294     signed char p1 = (signed char) * op1 ^ 0x80;
 295     signed char p0 = (signed char) * op0 ^ 0x80;
 296     signed char q0 = (signed char) * oq0 ^ 0x80;
 297     signed char q1 = (signed char) * oq1 ^ 0x80;
 298     signed char u;
 299
 300     vp8_filter = vp8_signed_char_clamp(p1 - q1);
 301     vp8_filter = vp8_signed_char_clamp(vp8_filter + 3 * (q0 - p0));
 302     vp8_filter &= mask;
 303
 304     /* save bottom 3 bits so that we round one side +4 and the other +3 */
 305     Filter1 = vp8_signed_char_clamp(vp8_filter + 4);
 306     Filter1 >>= 3;
 307     u = vp8_signed_char_clamp(q0 - Filter1);
 308     *oq0  = u ^ 0x80;
 309
 310     Filter2 = vp8_signed_char_clamp(vp8_filter + 3);
 311     Filter2 >>= 3;
 312     u = vp8_signed_char_clamp(p0 + Filter2);
 313     *op0 = u ^ 0x80;
 314 }
 315
 316 void vp8_loop_filter_simple_horizontal_edge_c
 317 (
 318     unsigned char *s,
 319     int p,
 320     const signed char *flimit,
 321     const signed char *limit,
 322     const signed char *thresh,
 323     int count
 324 )
 325 {
 326     signed char mask = 0;
 327     int i = 0;
 328     (void) thresh;
 329
 330     do
 331     {
 332         /*mask = vp8_simple_filter_mask( limit[i], flimit[i],s[-1*p],s[0*p]);*/
 333         mask = vp8_simple_filter_mask(limit[i], flimit[i], s[-2*p], s[-1*p], s[0*p], s[1*p]);
 334         vp8_simple_filter(mask, s - 2 * p, s - 1 * p, s, s + 1 * p);
 335         ++s;
 336     }
 337     while (++i < count * 8);
 338 }
 339
 340 void vp8_loop_filter_simple_vertical_edge_c
 341 (
 342     unsigned char *s,
 343     int p,
 344     const signed char *flimit,
 345     const signed char *limit,
 346     const signed char *thresh,
 347     int count
 348 )
 349 {
 350     signed char mask = 0;
 351     int i = 0;
 352     (void) thresh;
 353
 354     do
 355     {
 356         /*mask = vp8_simple_filter_mask( limit[i], flimit[i],s[-1],s[0]);*/
 357         mask = vp8_simple_filter_mask(limit[i], flimit[i], s[-2], s[-1], s[0], s[1]);
 358         vp8_simple_filter(mask, s - 2, s - 1, s, s + 1);
 359         s += p;
 360     }
 361     while (++i < count * 8);
 362
 363 }