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 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 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 */ 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 } 137 138 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
