1// Copyright 2010 Google Inc. All Rights Reserved.
2//
3// Use of this source code is governed by a BSD-style license
4// that can be found in the COPYING file in the root of the source
5// tree. An additional intellectual property rights grant can be found
6// in the file PATENTS. All contributing project authors may
7// be found in the AUTHORS file in the root of the source tree.
8// -----------------------------------------------------------------------------
9//
10// Speed-critical decoding functions, default plain-C implementations.
11//
12// Author: Skal (pascal.massimino@gmail.com)
13
14#include "./dsp.h"
15#include "../dec/vp8i_dec.h"
16#include "../utils/utils.h"
17
18//------------------------------------------------------------------------------
19
20static WEBP_INLINE uint8_t clip_8b(int v) {
21  return (!(v & ~0xff)) ? v : (v < 0) ? 0 : 255;
22}
23
24//------------------------------------------------------------------------------
25// Transforms (Paragraph 14.4)
26
27#define STORE(x, y, v) \
28  dst[x + y * BPS] = clip_8b(dst[x + y * BPS] + ((v) >> 3))
29
30#define STORE2(y, dc, d, c) do {    \
31  const int DC = (dc);              \
32  STORE(0, y, DC + (d));            \
33  STORE(1, y, DC + (c));            \
34  STORE(2, y, DC - (c));            \
35  STORE(3, y, DC - (d));            \
36} while (0)
37
38#define MUL1(a) ((((a) * 20091) >> 16) + (a))
39#define MUL2(a) (((a) * 35468) >> 16)
40
41static void TransformOne(const int16_t* in, uint8_t* dst) {
42  int C[4 * 4], *tmp;
43  int i;
44  tmp = C;
45  for (i = 0; i < 4; ++i) {    // vertical pass
46    const int a = in[0] + in[8];    // [-4096, 4094]
47    const int b = in[0] - in[8];    // [-4095, 4095]
48    const int c = MUL2(in[4]) - MUL1(in[12]);   // [-3783, 3783]
49    const int d = MUL1(in[4]) + MUL2(in[12]);   // [-3785, 3781]
50    tmp[0] = a + d;   // [-7881, 7875]
51    tmp[1] = b + c;   // [-7878, 7878]
52    tmp[2] = b - c;   // [-7878, 7878]
53    tmp[3] = a - d;   // [-7877, 7879]
54    tmp += 4;
55    in++;
56  }
57  // Each pass is expanding the dynamic range by ~3.85 (upper bound).
58  // The exact value is (2. + (20091 + 35468) / 65536).
59  // After the second pass, maximum interval is [-3794, 3794], assuming
60  // an input in [-2048, 2047] interval. We then need to add a dst value
61  // in the [0, 255] range.
62  // In the worst case scenario, the input to clip_8b() can be as large as
63  // [-60713, 60968].
64  tmp = C;
65  for (i = 0; i < 4; ++i) {    // horizontal pass
66    const int dc = tmp[0] + 4;
67    const int a =  dc +  tmp[8];
68    const int b =  dc -  tmp[8];
69    const int c = MUL2(tmp[4]) - MUL1(tmp[12]);
70    const int d = MUL1(tmp[4]) + MUL2(tmp[12]);
71    STORE(0, 0, a + d);
72    STORE(1, 0, b + c);
73    STORE(2, 0, b - c);
74    STORE(3, 0, a - d);
75    tmp++;
76    dst += BPS;
77  }
78}
79
80// Simplified transform when only in[0], in[1] and in[4] are non-zero
81static void TransformAC3(const int16_t* in, uint8_t* dst) {
82  const int a = in[0] + 4;
83  const int c4 = MUL2(in[4]);
84  const int d4 = MUL1(in[4]);
85  const int c1 = MUL2(in[1]);
86  const int d1 = MUL1(in[1]);
87  STORE2(0, a + d4, d1, c1);
88  STORE2(1, a + c4, d1, c1);
89  STORE2(2, a - c4, d1, c1);
90  STORE2(3, a - d4, d1, c1);
91}
92#undef MUL1
93#undef MUL2
94#undef STORE2
95
96static void TransformTwo(const int16_t* in, uint8_t* dst, int do_two) {
97  TransformOne(in, dst);
98  if (do_two) {
99    TransformOne(in + 16, dst + 4);
100  }
101}
102
103static void TransformUV(const int16_t* in, uint8_t* dst) {
104  VP8Transform(in + 0 * 16, dst, 1);
105  VP8Transform(in + 2 * 16, dst + 4 * BPS, 1);
106}
107
108static void TransformDC(const int16_t* in, uint8_t* dst) {
109  const int DC = in[0] + 4;
110  int i, j;
111  for (j = 0; j < 4; ++j) {
112    for (i = 0; i < 4; ++i) {
113      STORE(i, j, DC);
114    }
115  }
116}
117
118static void TransformDCUV(const int16_t* in, uint8_t* dst) {
119  if (in[0 * 16]) VP8TransformDC(in + 0 * 16, dst);
120  if (in[1 * 16]) VP8TransformDC(in + 1 * 16, dst + 4);
121  if (in[2 * 16]) VP8TransformDC(in + 2 * 16, dst + 4 * BPS);
122  if (in[3 * 16]) VP8TransformDC(in + 3 * 16, dst + 4 * BPS + 4);
123}
124
125#undef STORE
126
127//------------------------------------------------------------------------------
128// Paragraph 14.3
129
130static void TransformWHT(const int16_t* in, int16_t* out) {
131  int tmp[16];
132  int i;
133  for (i = 0; i < 4; ++i) {
134    const int a0 = in[0 + i] + in[12 + i];
135    const int a1 = in[4 + i] + in[ 8 + i];
136    const int a2 = in[4 + i] - in[ 8 + i];
137    const int a3 = in[0 + i] - in[12 + i];
138    tmp[0  + i] = a0 + a1;
139    tmp[8  + i] = a0 - a1;
140    tmp[4  + i] = a3 + a2;
141    tmp[12 + i] = a3 - a2;
142  }
143  for (i = 0; i < 4; ++i) {
144    const int dc = tmp[0 + i * 4] + 3;    // w/ rounder
145    const int a0 = dc             + tmp[3 + i * 4];
146    const int a1 = tmp[1 + i * 4] + tmp[2 + i * 4];
147    const int a2 = tmp[1 + i * 4] - tmp[2 + i * 4];
148    const int a3 = dc             - tmp[3 + i * 4];
149    out[ 0] = (a0 + a1) >> 3;
150    out[16] = (a3 + a2) >> 3;
151    out[32] = (a0 - a1) >> 3;
152    out[48] = (a3 - a2) >> 3;
153    out += 64;
154  }
155}
156
157void (*VP8TransformWHT)(const int16_t* in, int16_t* out);
158
159//------------------------------------------------------------------------------
160// Intra predictions
161
162#define DST(x, y) dst[(x) + (y) * BPS]
163
164static WEBP_INLINE void TrueMotion(uint8_t* dst, int size) {
165  const uint8_t* top = dst - BPS;
166  const uint8_t* const clip0 = VP8kclip1 - top[-1];
167  int y;
168  for (y = 0; y < size; ++y) {
169    const uint8_t* const clip = clip0 + dst[-1];
170    int x;
171    for (x = 0; x < size; ++x) {
172      dst[x] = clip[top[x]];
173    }
174    dst += BPS;
175  }
176}
177static void TM4(uint8_t* dst)   { TrueMotion(dst, 4); }
178static void TM8uv(uint8_t* dst) { TrueMotion(dst, 8); }
179static void TM16(uint8_t* dst)  { TrueMotion(dst, 16); }
180
181//------------------------------------------------------------------------------
182// 16x16
183
184static void VE16(uint8_t* dst) {     // vertical
185  int j;
186  for (j = 0; j < 16; ++j) {
187    memcpy(dst + j * BPS, dst - BPS, 16);
188  }
189}
190
191static void HE16(uint8_t* dst) {     // horizontal
192  int j;
193  for (j = 16; j > 0; --j) {
194    memset(dst, dst[-1], 16);
195    dst += BPS;
196  }
197}
198
199static WEBP_INLINE void Put16(int v, uint8_t* dst) {
200  int j;
201  for (j = 0; j < 16; ++j) {
202    memset(dst + j * BPS, v, 16);
203  }
204}
205
206static void DC16(uint8_t* dst) {    // DC
207  int DC = 16;
208  int j;
209  for (j = 0; j < 16; ++j) {
210    DC += dst[-1 + j * BPS] + dst[j - BPS];
211  }
212  Put16(DC >> 5, dst);
213}
214
215static void DC16NoTop(uint8_t* dst) {   // DC with top samples not available
216  int DC = 8;
217  int j;
218  for (j = 0; j < 16; ++j) {
219    DC += dst[-1 + j * BPS];
220  }
221  Put16(DC >> 4, dst);
222}
223
224static void DC16NoLeft(uint8_t* dst) {  // DC with left samples not available
225  int DC = 8;
226  int i;
227  for (i = 0; i < 16; ++i) {
228    DC += dst[i - BPS];
229  }
230  Put16(DC >> 4, dst);
231}
232
233static void DC16NoTopLeft(uint8_t* dst) {  // DC with no top and left samples
234  Put16(0x80, dst);
235}
236
237VP8PredFunc VP8PredLuma16[NUM_B_DC_MODES];
238
239//------------------------------------------------------------------------------
240// 4x4
241
242#define AVG3(a, b, c) ((uint8_t)(((a) + 2 * (b) + (c) + 2) >> 2))
243#define AVG2(a, b) (((a) + (b) + 1) >> 1)
244
245static void VE4(uint8_t* dst) {    // vertical
246  const uint8_t* top = dst - BPS;
247  const uint8_t vals[4] = {
248    AVG3(top[-1], top[0], top[1]),
249    AVG3(top[ 0], top[1], top[2]),
250    AVG3(top[ 1], top[2], top[3]),
251    AVG3(top[ 2], top[3], top[4])
252  };
253  int i;
254  for (i = 0; i < 4; ++i) {
255    memcpy(dst + i * BPS, vals, sizeof(vals));
256  }
257}
258
259static void HE4(uint8_t* dst) {    // horizontal
260  const int A = dst[-1 - BPS];
261  const int B = dst[-1];
262  const int C = dst[-1 + BPS];
263  const int D = dst[-1 + 2 * BPS];
264  const int E = dst[-1 + 3 * BPS];
265  WebPUint32ToMem(dst + 0 * BPS, 0x01010101U * AVG3(A, B, C));
266  WebPUint32ToMem(dst + 1 * BPS, 0x01010101U * AVG3(B, C, D));
267  WebPUint32ToMem(dst + 2 * BPS, 0x01010101U * AVG3(C, D, E));
268  WebPUint32ToMem(dst + 3 * BPS, 0x01010101U * AVG3(D, E, E));
269}
270
271static void DC4(uint8_t* dst) {   // DC
272  uint32_t dc = 4;
273  int i;
274  for (i = 0; i < 4; ++i) dc += dst[i - BPS] + dst[-1 + i * BPS];
275  dc >>= 3;
276  for (i = 0; i < 4; ++i) memset(dst + i * BPS, dc, 4);
277}
278
279static void RD4(uint8_t* dst) {   // Down-right
280  const int I = dst[-1 + 0 * BPS];
281  const int J = dst[-1 + 1 * BPS];
282  const int K = dst[-1 + 2 * BPS];
283  const int L = dst[-1 + 3 * BPS];
284  const int X = dst[-1 - BPS];
285  const int A = dst[0 - BPS];
286  const int B = dst[1 - BPS];
287  const int C = dst[2 - BPS];
288  const int D = dst[3 - BPS];
289  DST(0, 3)                                     = AVG3(J, K, L);
290  DST(1, 3) = DST(0, 2)                         = AVG3(I, J, K);
291  DST(2, 3) = DST(1, 2) = DST(0, 1)             = AVG3(X, I, J);
292  DST(3, 3) = DST(2, 2) = DST(1, 1) = DST(0, 0) = AVG3(A, X, I);
293              DST(3, 2) = DST(2, 1) = DST(1, 0) = AVG3(B, A, X);
294                          DST(3, 1) = DST(2, 0) = AVG3(C, B, A);
295                                      DST(3, 0) = AVG3(D, C, B);
296}
297
298static void LD4(uint8_t* dst) {   // Down-Left
299  const int A = dst[0 - BPS];
300  const int B = dst[1 - BPS];
301  const int C = dst[2 - BPS];
302  const int D = dst[3 - BPS];
303  const int E = dst[4 - BPS];
304  const int F = dst[5 - BPS];
305  const int G = dst[6 - BPS];
306  const int H = dst[7 - BPS];
307  DST(0, 0)                                     = AVG3(A, B, C);
308  DST(1, 0) = DST(0, 1)                         = AVG3(B, C, D);
309  DST(2, 0) = DST(1, 1) = DST(0, 2)             = AVG3(C, D, E);
310  DST(3, 0) = DST(2, 1) = DST(1, 2) = DST(0, 3) = AVG3(D, E, F);
311              DST(3, 1) = DST(2, 2) = DST(1, 3) = AVG3(E, F, G);
312                          DST(3, 2) = DST(2, 3) = AVG3(F, G, H);
313                                      DST(3, 3) = AVG3(G, H, H);
314}
315
316static void VR4(uint8_t* dst) {   // Vertical-Right
317  const int I = dst[-1 + 0 * BPS];
318  const int J = dst[-1 + 1 * BPS];
319  const int K = dst[-1 + 2 * BPS];
320  const int X = dst[-1 - BPS];
321  const int A = dst[0 - BPS];
322  const int B = dst[1 - BPS];
323  const int C = dst[2 - BPS];
324  const int D = dst[3 - BPS];
325  DST(0, 0) = DST(1, 2) = AVG2(X, A);
326  DST(1, 0) = DST(2, 2) = AVG2(A, B);
327  DST(2, 0) = DST(3, 2) = AVG2(B, C);
328  DST(3, 0)             = AVG2(C, D);
329
330  DST(0, 3) =             AVG3(K, J, I);
331  DST(0, 2) =             AVG3(J, I, X);
332  DST(0, 1) = DST(1, 3) = AVG3(I, X, A);
333  DST(1, 1) = DST(2, 3) = AVG3(X, A, B);
334  DST(2, 1) = DST(3, 3) = AVG3(A, B, C);
335  DST(3, 1) =             AVG3(B, C, D);
336}
337
338static void VL4(uint8_t* dst) {   // Vertical-Left
339  const int A = dst[0 - BPS];
340  const int B = dst[1 - BPS];
341  const int C = dst[2 - BPS];
342  const int D = dst[3 - BPS];
343  const int E = dst[4 - BPS];
344  const int F = dst[5 - BPS];
345  const int G = dst[6 - BPS];
346  const int H = dst[7 - BPS];
347  DST(0, 0) =             AVG2(A, B);
348  DST(1, 0) = DST(0, 2) = AVG2(B, C);
349  DST(2, 0) = DST(1, 2) = AVG2(C, D);
350  DST(3, 0) = DST(2, 2) = AVG2(D, E);
351
352  DST(0, 1) =             AVG3(A, B, C);
353  DST(1, 1) = DST(0, 3) = AVG3(B, C, D);
354  DST(2, 1) = DST(1, 3) = AVG3(C, D, E);
355  DST(3, 1) = DST(2, 3) = AVG3(D, E, F);
356              DST(3, 2) = AVG3(E, F, G);
357              DST(3, 3) = AVG3(F, G, H);
358}
359
360static void HU4(uint8_t* dst) {   // Horizontal-Up
361  const int I = dst[-1 + 0 * BPS];
362  const int J = dst[-1 + 1 * BPS];
363  const int K = dst[-1 + 2 * BPS];
364  const int L = dst[-1 + 3 * BPS];
365  DST(0, 0) =             AVG2(I, J);
366  DST(2, 0) = DST(0, 1) = AVG2(J, K);
367  DST(2, 1) = DST(0, 2) = AVG2(K, L);
368  DST(1, 0) =             AVG3(I, J, K);
369  DST(3, 0) = DST(1, 1) = AVG3(J, K, L);
370  DST(3, 1) = DST(1, 2) = AVG3(K, L, L);
371  DST(3, 2) = DST(2, 2) =
372    DST(0, 3) = DST(1, 3) = DST(2, 3) = DST(3, 3) = L;
373}
374
375static void HD4(uint8_t* dst) {  // Horizontal-Down
376  const int I = dst[-1 + 0 * BPS];
377  const int J = dst[-1 + 1 * BPS];
378  const int K = dst[-1 + 2 * BPS];
379  const int L = dst[-1 + 3 * BPS];
380  const int X = dst[-1 - BPS];
381  const int A = dst[0 - BPS];
382  const int B = dst[1 - BPS];
383  const int C = dst[2 - BPS];
384
385  DST(0, 0) = DST(2, 1) = AVG2(I, X);
386  DST(0, 1) = DST(2, 2) = AVG2(J, I);
387  DST(0, 2) = DST(2, 3) = AVG2(K, J);
388  DST(0, 3)             = AVG2(L, K);
389
390  DST(3, 0)             = AVG3(A, B, C);
391  DST(2, 0)             = AVG3(X, A, B);
392  DST(1, 0) = DST(3, 1) = AVG3(I, X, A);
393  DST(1, 1) = DST(3, 2) = AVG3(J, I, X);
394  DST(1, 2) = DST(3, 3) = AVG3(K, J, I);
395  DST(1, 3)             = AVG3(L, K, J);
396}
397
398#undef DST
399#undef AVG3
400#undef AVG2
401
402VP8PredFunc VP8PredLuma4[NUM_BMODES];
403
404//------------------------------------------------------------------------------
405// Chroma
406
407static void VE8uv(uint8_t* dst) {    // vertical
408  int j;
409  for (j = 0; j < 8; ++j) {
410    memcpy(dst + j * BPS, dst - BPS, 8);
411  }
412}
413
414static void HE8uv(uint8_t* dst) {    // horizontal
415  int j;
416  for (j = 0; j < 8; ++j) {
417    memset(dst, dst[-1], 8);
418    dst += BPS;
419  }
420}
421
422// helper for chroma-DC predictions
423static WEBP_INLINE void Put8x8uv(uint8_t value, uint8_t* dst) {
424  int j;
425  for (j = 0; j < 8; ++j) {
426    memset(dst + j * BPS, value, 8);
427  }
428}
429
430static void DC8uv(uint8_t* dst) {     // DC
431  int dc0 = 8;
432  int i;
433  for (i = 0; i < 8; ++i) {
434    dc0 += dst[i - BPS] + dst[-1 + i * BPS];
435  }
436  Put8x8uv(dc0 >> 4, dst);
437}
438
439static void DC8uvNoLeft(uint8_t* dst) {   // DC with no left samples
440  int dc0 = 4;
441  int i;
442  for (i = 0; i < 8; ++i) {
443    dc0 += dst[i - BPS];
444  }
445  Put8x8uv(dc0 >> 3, dst);
446}
447
448static void DC8uvNoTop(uint8_t* dst) {  // DC with no top samples
449  int dc0 = 4;
450  int i;
451  for (i = 0; i < 8; ++i) {
452    dc0 += dst[-1 + i * BPS];
453  }
454  Put8x8uv(dc0 >> 3, dst);
455}
456
457static void DC8uvNoTopLeft(uint8_t* dst) {    // DC with nothing
458  Put8x8uv(0x80, dst);
459}
460
461VP8PredFunc VP8PredChroma8[NUM_B_DC_MODES];
462
463//------------------------------------------------------------------------------
464// Edge filtering functions
465
466// 4 pixels in, 2 pixels out
467static WEBP_INLINE void do_filter2(uint8_t* p, int step) {
468  const int p1 = p[-2*step], p0 = p[-step], q0 = p[0], q1 = p[step];
469  const int a = 3 * (q0 - p0) + VP8ksclip1[p1 - q1];  // in [-893,892]
470  const int a1 = VP8ksclip2[(a + 4) >> 3];            // in [-16,15]
471  const int a2 = VP8ksclip2[(a + 3) >> 3];
472  p[-step] = VP8kclip1[p0 + a2];
473  p[    0] = VP8kclip1[q0 - a1];
474}
475
476// 4 pixels in, 4 pixels out
477static WEBP_INLINE void do_filter4(uint8_t* p, int step) {
478  const int p1 = p[-2*step], p0 = p[-step], q0 = p[0], q1 = p[step];
479  const int a = 3 * (q0 - p0);
480  const int a1 = VP8ksclip2[(a + 4) >> 3];
481  const int a2 = VP8ksclip2[(a + 3) >> 3];
482  const int a3 = (a1 + 1) >> 1;
483  p[-2*step] = VP8kclip1[p1 + a3];
484  p[-  step] = VP8kclip1[p0 + a2];
485  p[      0] = VP8kclip1[q0 - a1];
486  p[   step] = VP8kclip1[q1 - a3];
487}
488
489// 6 pixels in, 6 pixels out
490static WEBP_INLINE void do_filter6(uint8_t* p, int step) {
491  const int p2 = p[-3*step], p1 = p[-2*step], p0 = p[-step];
492  const int q0 = p[0], q1 = p[step], q2 = p[2*step];
493  const int a = VP8ksclip1[3 * (q0 - p0) + VP8ksclip1[p1 - q1]];
494  // a is in [-128,127], a1 in [-27,27], a2 in [-18,18] and a3 in [-9,9]
495  const int a1 = (27 * a + 63) >> 7;  // eq. to ((3 * a + 7) * 9) >> 7
496  const int a2 = (18 * a + 63) >> 7;  // eq. to ((2 * a + 7) * 9) >> 7
497  const int a3 = (9  * a + 63) >> 7;  // eq. to ((1 * a + 7) * 9) >> 7
498  p[-3*step] = VP8kclip1[p2 + a3];
499  p[-2*step] = VP8kclip1[p1 + a2];
500  p[-  step] = VP8kclip1[p0 + a1];
501  p[      0] = VP8kclip1[q0 - a1];
502  p[   step] = VP8kclip1[q1 - a2];
503  p[ 2*step] = VP8kclip1[q2 - a3];
504}
505
506static WEBP_INLINE int hev(const uint8_t* p, int step, int thresh) {
507  const int p1 = p[-2*step], p0 = p[-step], q0 = p[0], q1 = p[step];
508  return (VP8kabs0[p1 - p0] > thresh) || (VP8kabs0[q1 - q0] > thresh);
509}
510
511static WEBP_INLINE int needs_filter(const uint8_t* p, int step, int t) {
512  const int p1 = p[-2 * step], p0 = p[-step], q0 = p[0], q1 = p[step];
513  return ((4 * VP8kabs0[p0 - q0] + VP8kabs0[p1 - q1]) <= t);
514}
515
516static WEBP_INLINE int needs_filter2(const uint8_t* p,
517                                     int step, int t, int it) {
518  const int p3 = p[-4 * step], p2 = p[-3 * step], p1 = p[-2 * step];
519  const int p0 = p[-step], q0 = p[0];
520  const int q1 = p[step], q2 = p[2 * step], q3 = p[3 * step];
521  if ((4 * VP8kabs0[p0 - q0] + VP8kabs0[p1 - q1]) > t) return 0;
522  return VP8kabs0[p3 - p2] <= it && VP8kabs0[p2 - p1] <= it &&
523         VP8kabs0[p1 - p0] <= it && VP8kabs0[q3 - q2] <= it &&
524         VP8kabs0[q2 - q1] <= it && VP8kabs0[q1 - q0] <= it;
525}
526
527//------------------------------------------------------------------------------
528// Simple In-loop filtering (Paragraph 15.2)
529
530static void SimpleVFilter16(uint8_t* p, int stride, int thresh) {
531  int i;
532  const int thresh2 = 2 * thresh + 1;
533  for (i = 0; i < 16; ++i) {
534    if (needs_filter(p + i, stride, thresh2)) {
535      do_filter2(p + i, stride);
536    }
537  }
538}
539
540static void SimpleHFilter16(uint8_t* p, int stride, int thresh) {
541  int i;
542  const int thresh2 = 2 * thresh + 1;
543  for (i = 0; i < 16; ++i) {
544    if (needs_filter(p + i * stride, 1, thresh2)) {
545      do_filter2(p + i * stride, 1);
546    }
547  }
548}
549
550static void SimpleVFilter16i(uint8_t* p, int stride, int thresh) {
551  int k;
552  for (k = 3; k > 0; --k) {
553    p += 4 * stride;
554    SimpleVFilter16(p, stride, thresh);
555  }
556}
557
558static void SimpleHFilter16i(uint8_t* p, int stride, int thresh) {
559  int k;
560  for (k = 3; k > 0; --k) {
561    p += 4;
562    SimpleHFilter16(p, stride, thresh);
563  }
564}
565
566//------------------------------------------------------------------------------
567// Complex In-loop filtering (Paragraph 15.3)
568
569static WEBP_INLINE void FilterLoop26(uint8_t* p,
570                                     int hstride, int vstride, int size,
571                                     int thresh, int ithresh, int hev_thresh) {
572  const int thresh2 = 2 * thresh + 1;
573  while (size-- > 0) {
574    if (needs_filter2(p, hstride, thresh2, ithresh)) {
575      if (hev(p, hstride, hev_thresh)) {
576        do_filter2(p, hstride);
577      } else {
578        do_filter6(p, hstride);
579      }
580    }
581    p += vstride;
582  }
583}
584
585static WEBP_INLINE void FilterLoop24(uint8_t* p,
586                                     int hstride, int vstride, int size,
587                                     int thresh, int ithresh, int hev_thresh) {
588  const int thresh2 = 2 * thresh + 1;
589  while (size-- > 0) {
590    if (needs_filter2(p, hstride, thresh2, ithresh)) {
591      if (hev(p, hstride, hev_thresh)) {
592        do_filter2(p, hstride);
593      } else {
594        do_filter4(p, hstride);
595      }
596    }
597    p += vstride;
598  }
599}
600
601// on macroblock edges
602static void VFilter16(uint8_t* p, int stride,
603                      int thresh, int ithresh, int hev_thresh) {
604  FilterLoop26(p, stride, 1, 16, thresh, ithresh, hev_thresh);
605}
606
607static void HFilter16(uint8_t* p, int stride,
608                      int thresh, int ithresh, int hev_thresh) {
609  FilterLoop26(p, 1, stride, 16, thresh, ithresh, hev_thresh);
610}
611
612// on three inner edges
613static void VFilter16i(uint8_t* p, int stride,
614                       int thresh, int ithresh, int hev_thresh) {
615  int k;
616  for (k = 3; k > 0; --k) {
617    p += 4 * stride;
618    FilterLoop24(p, stride, 1, 16, thresh, ithresh, hev_thresh);
619  }
620}
621
622static void HFilter16i(uint8_t* p, int stride,
623                       int thresh, int ithresh, int hev_thresh) {
624  int k;
625  for (k = 3; k > 0; --k) {
626    p += 4;
627    FilterLoop24(p, 1, stride, 16, thresh, ithresh, hev_thresh);
628  }
629}
630
631// 8-pixels wide variant, for chroma filtering
632static void VFilter8(uint8_t* u, uint8_t* v, int stride,
633                     int thresh, int ithresh, int hev_thresh) {
634  FilterLoop26(u, stride, 1, 8, thresh, ithresh, hev_thresh);
635  FilterLoop26(v, stride, 1, 8, thresh, ithresh, hev_thresh);
636}
637
638static void HFilter8(uint8_t* u, uint8_t* v, int stride,
639                     int thresh, int ithresh, int hev_thresh) {
640  FilterLoop26(u, 1, stride, 8, thresh, ithresh, hev_thresh);
641  FilterLoop26(v, 1, stride, 8, thresh, ithresh, hev_thresh);
642}
643
644static void VFilter8i(uint8_t* u, uint8_t* v, int stride,
645                      int thresh, int ithresh, int hev_thresh) {
646  FilterLoop24(u + 4 * stride, stride, 1, 8, thresh, ithresh, hev_thresh);
647  FilterLoop24(v + 4 * stride, stride, 1, 8, thresh, ithresh, hev_thresh);
648}
649
650static void HFilter8i(uint8_t* u, uint8_t* v, int stride,
651                      int thresh, int ithresh, int hev_thresh) {
652  FilterLoop24(u + 4, 1, stride, 8, thresh, ithresh, hev_thresh);
653  FilterLoop24(v + 4, 1, stride, 8, thresh, ithresh, hev_thresh);
654}
655
656//------------------------------------------------------------------------------
657
658static void DitherCombine8x8(const uint8_t* dither, uint8_t* dst,
659                             int dst_stride) {
660  int i, j;
661  for (j = 0; j < 8; ++j) {
662    for (i = 0; i < 8; ++i) {
663      const int delta0 = dither[i] - VP8_DITHER_AMP_CENTER;
664      const int delta1 =
665          (delta0 + VP8_DITHER_DESCALE_ROUNDER) >> VP8_DITHER_DESCALE;
666      dst[i] = clip_8b((int)dst[i] + delta1);
667    }
668    dst += dst_stride;
669    dither += 8;
670  }
671}
672
673//------------------------------------------------------------------------------
674
675VP8DecIdct2 VP8Transform;
676VP8DecIdct VP8TransformAC3;
677VP8DecIdct VP8TransformUV;
678VP8DecIdct VP8TransformDC;
679VP8DecIdct VP8TransformDCUV;
680
681VP8LumaFilterFunc VP8VFilter16;
682VP8LumaFilterFunc VP8HFilter16;
683VP8ChromaFilterFunc VP8VFilter8;
684VP8ChromaFilterFunc VP8HFilter8;
685VP8LumaFilterFunc VP8VFilter16i;
686VP8LumaFilterFunc VP8HFilter16i;
687VP8ChromaFilterFunc VP8VFilter8i;
688VP8ChromaFilterFunc VP8HFilter8i;
689VP8SimpleFilterFunc VP8SimpleVFilter16;
690VP8SimpleFilterFunc VP8SimpleHFilter16;
691VP8SimpleFilterFunc VP8SimpleVFilter16i;
692VP8SimpleFilterFunc VP8SimpleHFilter16i;
693
694void (*VP8DitherCombine8x8)(const uint8_t* dither, uint8_t* dst,
695                            int dst_stride);
696
697extern void VP8DspInitSSE2(void);
698extern void VP8DspInitSSE41(void);
699extern void VP8DspInitNEON(void);
700extern void VP8DspInitMIPS32(void);
701extern void VP8DspInitMIPSdspR2(void);
702extern void VP8DspInitMSA(void);
703
704static volatile VP8CPUInfo dec_last_cpuinfo_used =
705    (VP8CPUInfo)&dec_last_cpuinfo_used;
706
707WEBP_TSAN_IGNORE_FUNCTION void VP8DspInit(void) {
708  if (dec_last_cpuinfo_used == VP8GetCPUInfo) return;
709
710  VP8InitClipTables();
711
712  VP8TransformWHT = TransformWHT;
713  VP8Transform = TransformTwo;
714  VP8TransformUV = TransformUV;
715  VP8TransformDC = TransformDC;
716  VP8TransformDCUV = TransformDCUV;
717  VP8TransformAC3 = TransformAC3;
718
719  VP8VFilter16 = VFilter16;
720  VP8HFilter16 = HFilter16;
721  VP8VFilter8 = VFilter8;
722  VP8HFilter8 = HFilter8;
723  VP8VFilter16i = VFilter16i;
724  VP8HFilter16i = HFilter16i;
725  VP8VFilter8i = VFilter8i;
726  VP8HFilter8i = HFilter8i;
727  VP8SimpleVFilter16 = SimpleVFilter16;
728  VP8SimpleHFilter16 = SimpleHFilter16;
729  VP8SimpleVFilter16i = SimpleVFilter16i;
730  VP8SimpleHFilter16i = SimpleHFilter16i;
731
732  VP8PredLuma4[0] = DC4;
733  VP8PredLuma4[1] = TM4;
734  VP8PredLuma4[2] = VE4;
735  VP8PredLuma4[3] = HE4;
736  VP8PredLuma4[4] = RD4;
737  VP8PredLuma4[5] = VR4;
738  VP8PredLuma4[6] = LD4;
739  VP8PredLuma4[7] = VL4;
740  VP8PredLuma4[8] = HD4;
741  VP8PredLuma4[9] = HU4;
742
743  VP8PredLuma16[0] = DC16;
744  VP8PredLuma16[1] = TM16;
745  VP8PredLuma16[2] = VE16;
746  VP8PredLuma16[3] = HE16;
747  VP8PredLuma16[4] = DC16NoTop;
748  VP8PredLuma16[5] = DC16NoLeft;
749  VP8PredLuma16[6] = DC16NoTopLeft;
750
751  VP8PredChroma8[0] = DC8uv;
752  VP8PredChroma8[1] = TM8uv;
753  VP8PredChroma8[2] = VE8uv;
754  VP8PredChroma8[3] = HE8uv;
755  VP8PredChroma8[4] = DC8uvNoTop;
756  VP8PredChroma8[5] = DC8uvNoLeft;
757  VP8PredChroma8[6] = DC8uvNoTopLeft;
758
759  VP8DitherCombine8x8 = DitherCombine8x8;
760
761  // If defined, use CPUInfo() to overwrite some pointers with faster versions.
762  if (VP8GetCPUInfo != NULL) {
763#if defined(WEBP_USE_SSE2)
764    if (VP8GetCPUInfo(kSSE2)) {
765      VP8DspInitSSE2();
766#if defined(WEBP_USE_SSE41)
767      if (VP8GetCPUInfo(kSSE4_1)) {
768        VP8DspInitSSE41();
769      }
770#endif
771    }
772#endif
773#if defined(WEBP_USE_NEON)
774    if (VP8GetCPUInfo(kNEON)) {
775      VP8DspInitNEON();
776    }
777#endif
778#if defined(WEBP_USE_MIPS32)
779    if (VP8GetCPUInfo(kMIPS32)) {
780      VP8DspInitMIPS32();
781    }
782#endif
783#if defined(WEBP_USE_MIPS_DSP_R2)
784    if (VP8GetCPUInfo(kMIPSdspR2)) {
785      VP8DspInitMIPSdspR2();
786    }
787#endif
788#if defined(WEBP_USE_MSA)
789    if (VP8GetCPUInfo(kMSA)) {
790      VP8DspInitMSA();
791    }
792#endif
793  }
794  dec_last_cpuinfo_used = VP8GetCPUInfo;
795}
796