1// Copyright 2011 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 encoding functions.
11//
12// Author: Skal (pascal.massimino@gmail.com)
13
14#include <assert.h>
15#include <stdlib.h>  // for abs()
16
17#include "./dsp.h"
18#include "../enc/vp8enci.h"
19
20static WEBP_INLINE uint8_t clip_8b(int v) {
21  return (!(v & ~0xff)) ? v : (v < 0) ? 0 : 255;
22}
23
24static WEBP_INLINE int clip_max(int v, int max) {
25  return (v > max) ? max : v;
26}
27
28//------------------------------------------------------------------------------
29// Compute susceptibility based on DCT-coeff histograms:
30// the higher, the "easier" the macroblock is to compress.
31
32const int VP8DspScan[16 + 4 + 4] = {
33  // Luma
34  0 +  0 * BPS,  4 +  0 * BPS, 8 +  0 * BPS, 12 +  0 * BPS,
35  0 +  4 * BPS,  4 +  4 * BPS, 8 +  4 * BPS, 12 +  4 * BPS,
36  0 +  8 * BPS,  4 +  8 * BPS, 8 +  8 * BPS, 12 +  8 * BPS,
37  0 + 12 * BPS,  4 + 12 * BPS, 8 + 12 * BPS, 12 + 12 * BPS,
38
39  0 + 0 * BPS,   4 + 0 * BPS, 0 + 4 * BPS,  4 + 4 * BPS,    // U
40  8 + 0 * BPS,  12 + 0 * BPS, 8 + 4 * BPS, 12 + 4 * BPS     // V
41};
42
43static void CollectHistogram(const uint8_t* ref, const uint8_t* pred,
44                             int start_block, int end_block,
45                             VP8Histogram* const histo) {
46  int j;
47  for (j = start_block; j < end_block; ++j) {
48    int k;
49    int16_t out[16];
50
51    VP8FTransform(ref + VP8DspScan[j], pred + VP8DspScan[j], out);
52
53    // Convert coefficients to bin.
54    for (k = 0; k < 16; ++k) {
55      const int v = abs(out[k]) >> 3;  // TODO(skal): add rounding?
56      const int clipped_value = clip_max(v, MAX_COEFF_THRESH);
57      histo->distribution[clipped_value]++;
58    }
59  }
60}
61
62//------------------------------------------------------------------------------
63// run-time tables (~4k)
64
65static uint8_t clip1[255 + 510 + 1];    // clips [-255,510] to [0,255]
66
67// We declare this variable 'volatile' to prevent instruction reordering
68// and make sure it's set to true _last_ (so as to be thread-safe)
69static volatile int tables_ok = 0;
70
71static void InitTables(void) {
72  if (!tables_ok) {
73    int i;
74    for (i = -255; i <= 255 + 255; ++i) {
75      clip1[255 + i] = clip_8b(i);
76    }
77    tables_ok = 1;
78  }
79}
80
81
82//------------------------------------------------------------------------------
83// Transforms (Paragraph 14.4)
84
85#define STORE(x, y, v) \
86  dst[(x) + (y) * BPS] = clip_8b(ref[(x) + (y) * BPS] + ((v) >> 3))
87
88static const int kC1 = 20091 + (1 << 16);
89static const int kC2 = 35468;
90#define MUL(a, b) (((a) * (b)) >> 16)
91
92static WEBP_INLINE void ITransformOne(const uint8_t* ref, const int16_t* in,
93                                      uint8_t* dst) {
94  int C[4 * 4], *tmp;
95  int i;
96  tmp = C;
97  for (i = 0; i < 4; ++i) {    // vertical pass
98    const int a = in[0] + in[8];
99    const int b = in[0] - in[8];
100    const int c = MUL(in[4], kC2) - MUL(in[12], kC1);
101    const int d = MUL(in[4], kC1) + MUL(in[12], kC2);
102    tmp[0] = a + d;
103    tmp[1] = b + c;
104    tmp[2] = b - c;
105    tmp[3] = a - d;
106    tmp += 4;
107    in++;
108  }
109
110  tmp = C;
111  for (i = 0; i < 4; ++i) {    // horizontal pass
112    const int dc = tmp[0] + 4;
113    const int a =  dc +  tmp[8];
114    const int b =  dc -  tmp[8];
115    const int c = MUL(tmp[4], kC2) - MUL(tmp[12], kC1);
116    const int d = MUL(tmp[4], kC1) + MUL(tmp[12], kC2);
117    STORE(0, i, a + d);
118    STORE(1, i, b + c);
119    STORE(2, i, b - c);
120    STORE(3, i, a - d);
121    tmp++;
122  }
123}
124
125static void ITransform(const uint8_t* ref, const int16_t* in, uint8_t* dst,
126                       int do_two) {
127  ITransformOne(ref, in, dst);
128  if (do_two) {
129    ITransformOne(ref + 4, in + 16, dst + 4);
130  }
131}
132
133static void FTransform(const uint8_t* src, const uint8_t* ref, int16_t* out) {
134  int i;
135  int tmp[16];
136  for (i = 0; i < 4; ++i, src += BPS, ref += BPS) {
137    const int d0 = src[0] - ref[0];   // 9bit dynamic range ([-255,255])
138    const int d1 = src[1] - ref[1];
139    const int d2 = src[2] - ref[2];
140    const int d3 = src[3] - ref[3];
141    const int a0 = (d0 + d3);         // 10b                      [-510,510]
142    const int a1 = (d1 + d2);
143    const int a2 = (d1 - d2);
144    const int a3 = (d0 - d3);
145    tmp[0 + i * 4] = (a0 + a1) * 8;   // 14b                      [-8160,8160]
146    tmp[1 + i * 4] = (a2 * 2217 + a3 * 5352 + 1812) >> 9;      // [-7536,7542]
147    tmp[2 + i * 4] = (a0 - a1) * 8;
148    tmp[3 + i * 4] = (a3 * 2217 - a2 * 5352 +  937) >> 9;
149  }
150  for (i = 0; i < 4; ++i) {
151    const int a0 = (tmp[0 + i] + tmp[12 + i]);  // 15b
152    const int a1 = (tmp[4 + i] + tmp[ 8 + i]);
153    const int a2 = (tmp[4 + i] - tmp[ 8 + i]);
154    const int a3 = (tmp[0 + i] - tmp[12 + i]);
155    out[0 + i] = (a0 + a1 + 7) >> 4;            // 12b
156    out[4 + i] = ((a2 * 2217 + a3 * 5352 + 12000) >> 16) + (a3 != 0);
157    out[8 + i] = (a0 - a1 + 7) >> 4;
158    out[12+ i] = ((a3 * 2217 - a2 * 5352 + 51000) >> 16);
159  }
160}
161
162static void FTransformWHT(const int16_t* in, int16_t* out) {
163  // input is 12b signed
164  int32_t tmp[16];
165  int i;
166  for (i = 0; i < 4; ++i, in += 64) {
167    const int a0 = (in[0 * 16] + in[2 * 16]);  // 13b
168    const int a1 = (in[1 * 16] + in[3 * 16]);
169    const int a2 = (in[1 * 16] - in[3 * 16]);
170    const int a3 = (in[0 * 16] - in[2 * 16]);
171    tmp[0 + i * 4] = a0 + a1;   // 14b
172    tmp[1 + i * 4] = a3 + a2;
173    tmp[2 + i * 4] = a3 - a2;
174    tmp[3 + i * 4] = a0 - a1;
175  }
176  for (i = 0; i < 4; ++i) {
177    const int a0 = (tmp[0 + i] + tmp[8 + i]);  // 15b
178    const int a1 = (tmp[4 + i] + tmp[12+ i]);
179    const int a2 = (tmp[4 + i] - tmp[12+ i]);
180    const int a3 = (tmp[0 + i] - tmp[8 + i]);
181    const int b0 = a0 + a1;    // 16b
182    const int b1 = a3 + a2;
183    const int b2 = a3 - a2;
184    const int b3 = a0 - a1;
185    out[ 0 + i] = b0 >> 1;     // 15b
186    out[ 4 + i] = b1 >> 1;
187    out[ 8 + i] = b2 >> 1;
188    out[12 + i] = b3 >> 1;
189  }
190}
191
192#undef MUL
193#undef STORE
194
195//------------------------------------------------------------------------------
196// Intra predictions
197
198#define DST(x, y) dst[(x) + (y) * BPS]
199
200static WEBP_INLINE void Fill(uint8_t* dst, int value, int size) {
201  int j;
202  for (j = 0; j < size; ++j) {
203    memset(dst + j * BPS, value, size);
204  }
205}
206
207static WEBP_INLINE void VerticalPred(uint8_t* dst,
208                                     const uint8_t* top, int size) {
209  int j;
210  if (top) {
211    for (j = 0; j < size; ++j) memcpy(dst + j * BPS, top, size);
212  } else {
213    Fill(dst, 127, size);
214  }
215}
216
217static WEBP_INLINE void HorizontalPred(uint8_t* dst,
218                                       const uint8_t* left, int size) {
219  if (left) {
220    int j;
221    for (j = 0; j < size; ++j) {
222      memset(dst + j * BPS, left[j], size);
223    }
224  } else {
225    Fill(dst, 129, size);
226  }
227}
228
229static WEBP_INLINE void TrueMotion(uint8_t* dst, const uint8_t* left,
230                                   const uint8_t* top, int size) {
231  int y;
232  if (left) {
233    if (top) {
234      const uint8_t* const clip = clip1 + 255 - left[-1];
235      for (y = 0; y < size; ++y) {
236        const uint8_t* const clip_table = clip + left[y];
237        int x;
238        for (x = 0; x < size; ++x) {
239          dst[x] = clip_table[top[x]];
240        }
241        dst += BPS;
242      }
243    } else {
244      HorizontalPred(dst, left, size);
245    }
246  } else {
247    // true motion without left samples (hence: with default 129 value)
248    // is equivalent to VE prediction where you just copy the top samples.
249    // Note that if top samples are not available, the default value is
250    // then 129, and not 127 as in the VerticalPred case.
251    if (top) {
252      VerticalPred(dst, top, size);
253    } else {
254      Fill(dst, 129, size);
255    }
256  }
257}
258
259static WEBP_INLINE void DCMode(uint8_t* dst, const uint8_t* left,
260                               const uint8_t* top,
261                               int size, int round, int shift) {
262  int DC = 0;
263  int j;
264  if (top) {
265    for (j = 0; j < size; ++j) DC += top[j];
266    if (left) {   // top and left present
267      for (j = 0; j < size; ++j) DC += left[j];
268    } else {      // top, but no left
269      DC += DC;
270    }
271    DC = (DC + round) >> shift;
272  } else if (left) {   // left but no top
273    for (j = 0; j < size; ++j) DC += left[j];
274    DC += DC;
275    DC = (DC + round) >> shift;
276  } else {   // no top, no left, nothing.
277    DC = 0x80;
278  }
279  Fill(dst, DC, size);
280}
281
282//------------------------------------------------------------------------------
283// Chroma 8x8 prediction (paragraph 12.2)
284
285static void IntraChromaPreds(uint8_t* dst, const uint8_t* left,
286                             const uint8_t* top) {
287  // U block
288  DCMode(C8DC8 + dst, left, top, 8, 8, 4);
289  VerticalPred(C8VE8 + dst, top, 8);
290  HorizontalPred(C8HE8 + dst, left, 8);
291  TrueMotion(C8TM8 + dst, left, top, 8);
292  // V block
293  dst += 8;
294  if (top) top += 8;
295  if (left) left += 16;
296  DCMode(C8DC8 + dst, left, top, 8, 8, 4);
297  VerticalPred(C8VE8 + dst, top, 8);
298  HorizontalPred(C8HE8 + dst, left, 8);
299  TrueMotion(C8TM8 + dst, left, top, 8);
300}
301
302//------------------------------------------------------------------------------
303// luma 16x16 prediction (paragraph 12.3)
304
305static void Intra16Preds(uint8_t* dst,
306                         const uint8_t* left, const uint8_t* top) {
307  DCMode(I16DC16 + dst, left, top, 16, 16, 5);
308  VerticalPred(I16VE16 + dst, top, 16);
309  HorizontalPred(I16HE16 + dst, left, 16);
310  TrueMotion(I16TM16 + dst, left, top, 16);
311}
312
313//------------------------------------------------------------------------------
314// luma 4x4 prediction
315
316#define AVG3(a, b, c) (((a) + 2 * (b) + (c) + 2) >> 2)
317#define AVG2(a, b) (((a) + (b) + 1) >> 1)
318
319static void VE4(uint8_t* dst, const uint8_t* top) {    // vertical
320  const uint8_t vals[4] = {
321    AVG3(top[-1], top[0], top[1]),
322    AVG3(top[ 0], top[1], top[2]),
323    AVG3(top[ 1], top[2], top[3]),
324    AVG3(top[ 2], top[3], top[4])
325  };
326  int i;
327  for (i = 0; i < 4; ++i) {
328    memcpy(dst + i * BPS, vals, 4);
329  }
330}
331
332static void HE4(uint8_t* dst, const uint8_t* top) {    // horizontal
333  const int X = top[-1];
334  const int I = top[-2];
335  const int J = top[-3];
336  const int K = top[-4];
337  const int L = top[-5];
338  *(uint32_t*)(dst + 0 * BPS) = 0x01010101U * AVG3(X, I, J);
339  *(uint32_t*)(dst + 1 * BPS) = 0x01010101U * AVG3(I, J, K);
340  *(uint32_t*)(dst + 2 * BPS) = 0x01010101U * AVG3(J, K, L);
341  *(uint32_t*)(dst + 3 * BPS) = 0x01010101U * AVG3(K, L, L);
342}
343
344static void DC4(uint8_t* dst, const uint8_t* top) {
345  uint32_t dc = 4;
346  int i;
347  for (i = 0; i < 4; ++i) dc += top[i] + top[-5 + i];
348  Fill(dst, dc >> 3, 4);
349}
350
351static void RD4(uint8_t* dst, const uint8_t* top) {
352  const int X = top[-1];
353  const int I = top[-2];
354  const int J = top[-3];
355  const int K = top[-4];
356  const int L = top[-5];
357  const int A = top[0];
358  const int B = top[1];
359  const int C = top[2];
360  const int D = top[3];
361  DST(0, 3)                                     = AVG3(J, K, L);
362  DST(0, 2) = DST(1, 3)                         = AVG3(I, J, K);
363  DST(0, 1) = DST(1, 2) = DST(2, 3)             = AVG3(X, I, J);
364  DST(0, 0) = DST(1, 1) = DST(2, 2) = DST(3, 3) = AVG3(A, X, I);
365  DST(1, 0) = DST(2, 1) = DST(3, 2)             = AVG3(B, A, X);
366  DST(2, 0) = DST(3, 1)                         = AVG3(C, B, A);
367  DST(3, 0)                                     = AVG3(D, C, B);
368}
369
370static void LD4(uint8_t* dst, const uint8_t* top) {
371  const int A = top[0];
372  const int B = top[1];
373  const int C = top[2];
374  const int D = top[3];
375  const int E = top[4];
376  const int F = top[5];
377  const int G = top[6];
378  const int H = top[7];
379  DST(0, 0)                                     = AVG3(A, B, C);
380  DST(1, 0) = DST(0, 1)                         = AVG3(B, C, D);
381  DST(2, 0) = DST(1, 1) = DST(0, 2)             = AVG3(C, D, E);
382  DST(3, 0) = DST(2, 1) = DST(1, 2) = DST(0, 3) = AVG3(D, E, F);
383  DST(3, 1) = DST(2, 2) = DST(1, 3)             = AVG3(E, F, G);
384  DST(3, 2) = DST(2, 3)                         = AVG3(F, G, H);
385  DST(3, 3)                                     = AVG3(G, H, H);
386}
387
388static void VR4(uint8_t* dst, const uint8_t* top) {
389  const int X = top[-1];
390  const int I = top[-2];
391  const int J = top[-3];
392  const int K = top[-4];
393  const int A = top[0];
394  const int B = top[1];
395  const int C = top[2];
396  const int D = top[3];
397  DST(0, 0) = DST(1, 2) = AVG2(X, A);
398  DST(1, 0) = DST(2, 2) = AVG2(A, B);
399  DST(2, 0) = DST(3, 2) = AVG2(B, C);
400  DST(3, 0)             = AVG2(C, D);
401
402  DST(0, 3) =             AVG3(K, J, I);
403  DST(0, 2) =             AVG3(J, I, X);
404  DST(0, 1) = DST(1, 3) = AVG3(I, X, A);
405  DST(1, 1) = DST(2, 3) = AVG3(X, A, B);
406  DST(2, 1) = DST(3, 3) = AVG3(A, B, C);
407  DST(3, 1) =             AVG3(B, C, D);
408}
409
410static void VL4(uint8_t* dst, const uint8_t* top) {
411  const int A = top[0];
412  const int B = top[1];
413  const int C = top[2];
414  const int D = top[3];
415  const int E = top[4];
416  const int F = top[5];
417  const int G = top[6];
418  const int H = top[7];
419  DST(0, 0) =             AVG2(A, B);
420  DST(1, 0) = DST(0, 2) = AVG2(B, C);
421  DST(2, 0) = DST(1, 2) = AVG2(C, D);
422  DST(3, 0) = DST(2, 2) = AVG2(D, E);
423
424  DST(0, 1) =             AVG3(A, B, C);
425  DST(1, 1) = DST(0, 3) = AVG3(B, C, D);
426  DST(2, 1) = DST(1, 3) = AVG3(C, D, E);
427  DST(3, 1) = DST(2, 3) = AVG3(D, E, F);
428              DST(3, 2) = AVG3(E, F, G);
429              DST(3, 3) = AVG3(F, G, H);
430}
431
432static void HU4(uint8_t* dst, const uint8_t* top) {
433  const int I = top[-2];
434  const int J = top[-3];
435  const int K = top[-4];
436  const int L = top[-5];
437  DST(0, 0) =             AVG2(I, J);
438  DST(2, 0) = DST(0, 1) = AVG2(J, K);
439  DST(2, 1) = DST(0, 2) = AVG2(K, L);
440  DST(1, 0) =             AVG3(I, J, K);
441  DST(3, 0) = DST(1, 1) = AVG3(J, K, L);
442  DST(3, 1) = DST(1, 2) = AVG3(K, L, L);
443  DST(3, 2) = DST(2, 2) =
444  DST(0, 3) = DST(1, 3) = DST(2, 3) = DST(3, 3) = L;
445}
446
447static void HD4(uint8_t* dst, const uint8_t* top) {
448  const int X = top[-1];
449  const int I = top[-2];
450  const int J = top[-3];
451  const int K = top[-4];
452  const int L = top[-5];
453  const int A = top[0];
454  const int B = top[1];
455  const int C = top[2];
456
457  DST(0, 0) = DST(2, 1) = AVG2(I, X);
458  DST(0, 1) = DST(2, 2) = AVG2(J, I);
459  DST(0, 2) = DST(2, 3) = AVG2(K, J);
460  DST(0, 3)             = AVG2(L, K);
461
462  DST(3, 0)             = AVG3(A, B, C);
463  DST(2, 0)             = AVG3(X, A, B);
464  DST(1, 0) = DST(3, 1) = AVG3(I, X, A);
465  DST(1, 1) = DST(3, 2) = AVG3(J, I, X);
466  DST(1, 2) = DST(3, 3) = AVG3(K, J, I);
467  DST(1, 3)             = AVG3(L, K, J);
468}
469
470static void TM4(uint8_t* dst, const uint8_t* top) {
471  int x, y;
472  const uint8_t* const clip = clip1 + 255 - top[-1];
473  for (y = 0; y < 4; ++y) {
474    const uint8_t* const clip_table = clip + top[-2 - y];
475    for (x = 0; x < 4; ++x) {
476      dst[x] = clip_table[top[x]];
477    }
478    dst += BPS;
479  }
480}
481
482#undef DST
483#undef AVG3
484#undef AVG2
485
486// Left samples are top[-5 .. -2], top_left is top[-1], top are
487// located at top[0..3], and top right is top[4..7]
488static void Intra4Preds(uint8_t* dst, const uint8_t* top) {
489  DC4(I4DC4 + dst, top);
490  TM4(I4TM4 + dst, top);
491  VE4(I4VE4 + dst, top);
492  HE4(I4HE4 + dst, top);
493  RD4(I4RD4 + dst, top);
494  VR4(I4VR4 + dst, top);
495  LD4(I4LD4 + dst, top);
496  VL4(I4VL4 + dst, top);
497  HD4(I4HD4 + dst, top);
498  HU4(I4HU4 + dst, top);
499}
500
501//------------------------------------------------------------------------------
502// Metric
503
504static WEBP_INLINE int GetSSE(const uint8_t* a, const uint8_t* b,
505                              int w, int h) {
506  int count = 0;
507  int y, x;
508  for (y = 0; y < h; ++y) {
509    for (x = 0; x < w; ++x) {
510      const int diff = (int)a[x] - b[x];
511      count += diff * diff;
512    }
513    a += BPS;
514    b += BPS;
515  }
516  return count;
517}
518
519static int SSE16x16(const uint8_t* a, const uint8_t* b) {
520  return GetSSE(a, b, 16, 16);
521}
522static int SSE16x8(const uint8_t* a, const uint8_t* b) {
523  return GetSSE(a, b, 16, 8);
524}
525static int SSE8x8(const uint8_t* a, const uint8_t* b) {
526  return GetSSE(a, b, 8, 8);
527}
528static int SSE4x4(const uint8_t* a, const uint8_t* b) {
529  return GetSSE(a, b, 4, 4);
530}
531
532//------------------------------------------------------------------------------
533// Texture distortion
534//
535// We try to match the spectral content (weighted) between source and
536// reconstructed samples.
537
538// Hadamard transform
539// Returns the weighted sum of the absolute value of transformed coefficients.
540static int TTransform(const uint8_t* in, const uint16_t* w) {
541  int sum = 0;
542  int tmp[16];
543  int i;
544  // horizontal pass
545  for (i = 0; i < 4; ++i, in += BPS) {
546    const int a0 = in[0] + in[2];
547    const int a1 = in[1] + in[3];
548    const int a2 = in[1] - in[3];
549    const int a3 = in[0] - in[2];
550    tmp[0 + i * 4] = a0 + a1;
551    tmp[1 + i * 4] = a3 + a2;
552    tmp[2 + i * 4] = a3 - a2;
553    tmp[3 + i * 4] = a0 - a1;
554  }
555  // vertical pass
556  for (i = 0; i < 4; ++i, ++w) {
557    const int a0 = tmp[0 + i] + tmp[8 + i];
558    const int a1 = tmp[4 + i] + tmp[12+ i];
559    const int a2 = tmp[4 + i] - tmp[12+ i];
560    const int a3 = tmp[0 + i] - tmp[8 + i];
561    const int b0 = a0 + a1;
562    const int b1 = a3 + a2;
563    const int b2 = a3 - a2;
564    const int b3 = a0 - a1;
565
566    sum += w[ 0] * abs(b0);
567    sum += w[ 4] * abs(b1);
568    sum += w[ 8] * abs(b2);
569    sum += w[12] * abs(b3);
570  }
571  return sum;
572}
573
574static int Disto4x4(const uint8_t* const a, const uint8_t* const b,
575                    const uint16_t* const w) {
576  const int sum1 = TTransform(a, w);
577  const int sum2 = TTransform(b, w);
578  return abs(sum2 - sum1) >> 5;
579}
580
581static int Disto16x16(const uint8_t* const a, const uint8_t* const b,
582                      const uint16_t* const w) {
583  int D = 0;
584  int x, y;
585  for (y = 0; y < 16 * BPS; y += 4 * BPS) {
586    for (x = 0; x < 16; x += 4) {
587      D += Disto4x4(a + x + y, b + x + y, w);
588    }
589  }
590  return D;
591}
592
593//------------------------------------------------------------------------------
594// Quantization
595//
596
597static const uint8_t kZigzag[16] = {
598  0, 1, 4, 8, 5, 2, 3, 6, 9, 12, 13, 10, 7, 11, 14, 15
599};
600
601// Simple quantization
602static int QuantizeBlock(int16_t in[16], int16_t out[16],
603                         const VP8Matrix* const mtx) {
604  int last = -1;
605  int n;
606  for (n = 0; n < 16; ++n) {
607    const int j = kZigzag[n];
608    const int sign = (in[j] < 0);
609    const uint32_t coeff = (sign ? -in[j] : in[j]) + mtx->sharpen_[j];
610    if (coeff > mtx->zthresh_[j]) {
611      const uint32_t Q = mtx->q_[j];
612      const uint32_t iQ = mtx->iq_[j];
613      const uint32_t B = mtx->bias_[j];
614      int level = QUANTDIV(coeff, iQ, B);
615      if (level > MAX_LEVEL) level = MAX_LEVEL;
616      if (sign) level = -level;
617      in[j] = level * Q;
618      out[n] = level;
619      if (level) last = n;
620    } else {
621      out[n] = 0;
622      in[j] = 0;
623    }
624  }
625  return (last >= 0);
626}
627
628static int QuantizeBlockWHT(int16_t in[16], int16_t out[16],
629                            const VP8Matrix* const mtx) {
630  int n, last = -1;
631  for (n = 0; n < 16; ++n) {
632    const int j = kZigzag[n];
633    const int sign = (in[j] < 0);
634    const uint32_t coeff = sign ? -in[j] : in[j];
635    assert(mtx->sharpen_[j] == 0);
636    if (coeff > mtx->zthresh_[j]) {
637      const uint32_t Q = mtx->q_[j];
638      const uint32_t iQ = mtx->iq_[j];
639      const uint32_t B = mtx->bias_[j];
640      int level = QUANTDIV(coeff, iQ, B);
641      if (level > MAX_LEVEL) level = MAX_LEVEL;
642      if (sign) level = -level;
643      in[j] = level * Q;
644      out[n] = level;
645      if (level) last = n;
646    } else {
647      out[n] = 0;
648      in[j] = 0;
649    }
650  }
651  return (last >= 0);
652}
653
654//------------------------------------------------------------------------------
655// Block copy
656
657static WEBP_INLINE void Copy(const uint8_t* src, uint8_t* dst, int size) {
658  int y;
659  for (y = 0; y < size; ++y) {
660    memcpy(dst, src, size);
661    src += BPS;
662    dst += BPS;
663  }
664}
665
666static void Copy4x4(const uint8_t* src, uint8_t* dst) { Copy(src, dst, 4); }
667
668//------------------------------------------------------------------------------
669// Initialization
670
671// Speed-critical function pointers. We have to initialize them to the default
672// implementations within VP8EncDspInit().
673VP8CHisto VP8CollectHistogram;
674VP8Idct VP8ITransform;
675VP8Fdct VP8FTransform;
676VP8WHT VP8FTransformWHT;
677VP8Intra4Preds VP8EncPredLuma4;
678VP8IntraPreds VP8EncPredLuma16;
679VP8IntraPreds VP8EncPredChroma8;
680VP8Metric VP8SSE16x16;
681VP8Metric VP8SSE8x8;
682VP8Metric VP8SSE16x8;
683VP8Metric VP8SSE4x4;
684VP8WMetric VP8TDisto4x4;
685VP8WMetric VP8TDisto16x16;
686VP8QuantizeBlock VP8EncQuantizeBlock;
687VP8QuantizeBlockWHT VP8EncQuantizeBlockWHT;
688VP8BlockCopy VP8Copy4x4;
689
690extern void VP8EncDspInitSSE2(void);
691extern void VP8EncDspInitAVX2(void);
692extern void VP8EncDspInitNEON(void);
693extern void VP8EncDspInitMIPS32(void);
694
695static volatile VP8CPUInfo enc_last_cpuinfo_used =
696    (VP8CPUInfo)&enc_last_cpuinfo_used;
697
698void VP8EncDspInit(void) {
699  if (enc_last_cpuinfo_used == VP8GetCPUInfo) return;
700
701  VP8DspInit();  // common inverse transforms
702  InitTables();
703
704  // default C implementations
705  VP8CollectHistogram = CollectHistogram;
706  VP8ITransform = ITransform;
707  VP8FTransform = FTransform;
708  VP8FTransformWHT = FTransformWHT;
709  VP8EncPredLuma4 = Intra4Preds;
710  VP8EncPredLuma16 = Intra16Preds;
711  VP8EncPredChroma8 = IntraChromaPreds;
712  VP8SSE16x16 = SSE16x16;
713  VP8SSE8x8 = SSE8x8;
714  VP8SSE16x8 = SSE16x8;
715  VP8SSE4x4 = SSE4x4;
716  VP8TDisto4x4 = Disto4x4;
717  VP8TDisto16x16 = Disto16x16;
718  VP8EncQuantizeBlock = QuantizeBlock;
719  VP8EncQuantizeBlockWHT = QuantizeBlockWHT;
720  VP8Copy4x4 = Copy4x4;
721
722  // If defined, use CPUInfo() to overwrite some pointers with faster versions.
723  if (VP8GetCPUInfo != NULL) {
724#if defined(WEBP_USE_SSE2)
725    if (VP8GetCPUInfo(kSSE2)) {
726      VP8EncDspInitSSE2();
727    }
728#endif
729#if defined(WEBP_USE_AVX2)
730    if (VP8GetCPUInfo(kAVX2)) {
731      VP8EncDspInitAVX2();
732    }
733#endif
734#if defined(WEBP_USE_NEON)
735    if (VP8GetCPUInfo(kNEON)) {
736      VP8EncDspInitNEON();
737    }
738#endif
739#if defined(WEBP_USE_MIPS32)
740    if (VP8GetCPUInfo(kMIPS32)) {
741      VP8EncDspInitMIPS32();
742    }
743#endif
744  }
745  enc_last_cpuinfo_used = VP8GetCPUInfo;
746}
747
748