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