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 #include "vp8/common/blockd.h"
12 #include "onyxd_int.h"
13 #include "vpx_mem/vpx_mem.h"
14 #include "vpx_ports/mem.h"
15 #include "detokenize.h"
16
vp8_reset_mb_tokens_context(MACROBLOCKD * x)17 void vp8_reset_mb_tokens_context(MACROBLOCKD *x) {
18 ENTROPY_CONTEXT *a_ctx = ((ENTROPY_CONTEXT *)x->above_context);
19 ENTROPY_CONTEXT *l_ctx = ((ENTROPY_CONTEXT *)x->left_context);
20
21 memset(a_ctx, 0, sizeof(ENTROPY_CONTEXT_PLANES) - 1);
22 memset(l_ctx, 0, sizeof(ENTROPY_CONTEXT_PLANES) - 1);
23
24 /* Clear entropy contexts for Y2 blocks */
25 if (!x->mode_info_context->mbmi.is_4x4) {
26 a_ctx[8] = l_ctx[8] = 0;
27 }
28 }
29
30 /*
31 ------------------------------------------------------------------------------
32 Residual decoding (Paragraph 13.2 / 13.3)
33 */
34 static const uint8_t kBands[16 + 1] = {
35 0, 1, 2, 3, 6, 4, 5, 6, 6,
36 6, 6, 6, 6, 6, 6, 7, 0 /* extra entry as sentinel */
37 };
38
39 static const uint8_t kCat3[] = { 173, 148, 140, 0 };
40 static const uint8_t kCat4[] = { 176, 155, 140, 135, 0 };
41 static const uint8_t kCat5[] = { 180, 157, 141, 134, 130, 0 };
42 static const uint8_t kCat6[] = { 254, 254, 243, 230, 196, 177,
43 153, 140, 133, 130, 129, 0 };
44 static const uint8_t *const kCat3456[] = { kCat3, kCat4, kCat5, kCat6 };
45 static const uint8_t kZigzag[16] = { 0, 1, 4, 8, 5, 2, 3, 6,
46 9, 12, 13, 10, 7, 11, 14, 15 };
47
48 #define VP8GetBit vp8dx_decode_bool
49 #define NUM_PROBAS 11
50 #define NUM_CTX 3
51
52 /* for const-casting */
53 typedef const uint8_t (*ProbaArray)[NUM_CTX][NUM_PROBAS];
54
GetSigned(BOOL_DECODER * br,int value_to_sign)55 static int GetSigned(BOOL_DECODER *br, int value_to_sign) {
56 int split = (br->range + 1) >> 1;
57 VP8_BD_VALUE bigsplit = (VP8_BD_VALUE)split << (VP8_BD_VALUE_SIZE - 8);
58 int v;
59
60 if (br->count < 0) vp8dx_bool_decoder_fill(br);
61
62 if (br->value < bigsplit) {
63 br->range = split;
64 v = value_to_sign;
65 } else {
66 br->range = br->range - split;
67 br->value = br->value - bigsplit;
68 v = -value_to_sign;
69 }
70 br->range += br->range;
71 br->value += br->value;
72 br->count--;
73
74 return v;
75 }
76 /*
77 Returns the position of the last non-zero coeff plus one
78 (and 0 if there's no coeff at all)
79 */
GetCoeffs(BOOL_DECODER * br,ProbaArray prob,int ctx,int n,int16_t * out)80 static int GetCoeffs(BOOL_DECODER *br, ProbaArray prob, int ctx, int n,
81 int16_t *out) {
82 const uint8_t *p = prob[n][ctx];
83 if (!VP8GetBit(br, p[0])) { /* first EOB is more a 'CBP' bit. */
84 return 0;
85 }
86 while (1) {
87 ++n;
88 if (!VP8GetBit(br, p[1])) {
89 p = prob[kBands[n]][0];
90 } else { /* non zero coeff */
91 int v, j;
92 if (!VP8GetBit(br, p[2])) {
93 p = prob[kBands[n]][1];
94 v = 1;
95 } else {
96 if (!VP8GetBit(br, p[3])) {
97 if (!VP8GetBit(br, p[4])) {
98 v = 2;
99 } else {
100 v = 3 + VP8GetBit(br, p[5]);
101 }
102 } else {
103 if (!VP8GetBit(br, p[6])) {
104 if (!VP8GetBit(br, p[7])) {
105 v = 5 + VP8GetBit(br, 159);
106 } else {
107 v = 7 + 2 * VP8GetBit(br, 165);
108 v += VP8GetBit(br, 145);
109 }
110 } else {
111 const uint8_t *tab;
112 const int bit1 = VP8GetBit(br, p[8]);
113 const int bit0 = VP8GetBit(br, p[9 + bit1]);
114 const int cat = 2 * bit1 + bit0;
115 v = 0;
116 for (tab = kCat3456[cat]; *tab; ++tab) {
117 v += v + VP8GetBit(br, *tab);
118 }
119 v += 3 + (8 << cat);
120 }
121 }
122 p = prob[kBands[n]][2];
123 }
124 j = kZigzag[n - 1];
125
126 out[j] = GetSigned(br, v);
127
128 if (n == 16 || !VP8GetBit(br, p[0])) { /* EOB */
129 return n;
130 }
131 }
132 if (n == 16) {
133 return 16;
134 }
135 }
136 }
137
vp8_decode_mb_tokens(VP8D_COMP * dx,MACROBLOCKD * x)138 int vp8_decode_mb_tokens(VP8D_COMP *dx, MACROBLOCKD *x) {
139 BOOL_DECODER *bc = x->current_bc;
140 const FRAME_CONTEXT *const fc = &dx->common.fc;
141 char *eobs = x->eobs;
142
143 int i;
144 int nonzeros;
145 int eobtotal = 0;
146
147 short *qcoeff_ptr;
148 ProbaArray coef_probs;
149 ENTROPY_CONTEXT *a_ctx = ((ENTROPY_CONTEXT *)x->above_context);
150 ENTROPY_CONTEXT *l_ctx = ((ENTROPY_CONTEXT *)x->left_context);
151 ENTROPY_CONTEXT *a;
152 ENTROPY_CONTEXT *l;
153 int skip_dc = 0;
154
155 qcoeff_ptr = &x->qcoeff[0];
156
157 if (!x->mode_info_context->mbmi.is_4x4) {
158 a = a_ctx + 8;
159 l = l_ctx + 8;
160
161 coef_probs = fc->coef_probs[1];
162
163 nonzeros = GetCoeffs(bc, coef_probs, (*a + *l), 0, qcoeff_ptr + 24 * 16);
164 *a = *l = (nonzeros > 0);
165
166 eobs[24] = nonzeros;
167 eobtotal += nonzeros - 16;
168
169 coef_probs = fc->coef_probs[0];
170 skip_dc = 1;
171 } else {
172 coef_probs = fc->coef_probs[3];
173 skip_dc = 0;
174 }
175
176 for (i = 0; i < 16; ++i) {
177 a = a_ctx + (i & 3);
178 l = l_ctx + ((i & 0xc) >> 2);
179
180 nonzeros = GetCoeffs(bc, coef_probs, (*a + *l), skip_dc, qcoeff_ptr);
181 *a = *l = (nonzeros > 0);
182
183 nonzeros += skip_dc;
184 eobs[i] = nonzeros;
185 eobtotal += nonzeros;
186 qcoeff_ptr += 16;
187 }
188
189 coef_probs = fc->coef_probs[2];
190
191 a_ctx += 4;
192 l_ctx += 4;
193 for (i = 16; i < 24; ++i) {
194 a = a_ctx + ((i > 19) << 1) + (i & 1);
195 l = l_ctx + ((i > 19) << 1) + ((i & 3) > 1);
196
197 nonzeros = GetCoeffs(bc, coef_probs, (*a + *l), 0, qcoeff_ptr);
198 *a = *l = (nonzeros > 0);
199
200 eobs[i] = nonzeros;
201 eobtotal += nonzeros;
202 qcoeff_ptr += 16;
203 }
204
205 return eobtotal;
206 }
207