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products/Sources/formale Sprachen/C/LibreOffice/icon-themes/breeze_svg/cmd/32/   (Office von Apache Version 25.8.3.2©)  Datei vom 5.10.2025 mit Größe 1 kB image not shown  

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detokenize.c


products/Sources/formale Sprachen/C/Firefox/media/libvpx/libvpx/vp8/decoder/detokenize.c

/* * Copyright (c) 2010 The WebM project authors. All Rights Reserved. * * Use of this source code is governed by a BSD-style license * that can be found in the LICENSE file in the root of the source * tree. An additional intellectual property rights grant can be found * in the file PATENTS. All contributing project authors may * be found in the AUTHORS file in the root of the source tree. */ #include "vp8/common/blockd.h" #include "onyxd_int.h" #include "vpx_mem/vpx_mem.h" #include "vpx_ports/compiler_attributes.h" #include "vpx_ports/mem.h" #include "detokenize.h" void vp8_reset_mb_tokens_context(MACROBLOCKD *x) { ENTROPY_CONTEXT *a_ctx = ((ENTROPY_CONTEXT *)x->above_context); ENTROPY_CONTEXT *l_ctx = ((ENTROPY_CONTEXT *)x->left_context); memset(a_ctx, 0, sizeof(ENTROPY_CONTEXT_PLANES) - 1); memset(l_ctx, 0, sizeof(ENTROPY_CONTEXT_PLANES) - 1); /* Clear entropy contexts for Y2 blocks */ if (!x->mode_info_context->mbmi.is_4x4) { a_ctx[8] = l_ctx[8] = 0; } } /* ------------------------------------------------------------------------------ Residual decoding (Paragraph 13.2 / 13.3) */ static const uint8_t kBands[16 + 1] = { 0, 1, 2, 3, 6, 4, 5, 6, 6, 6, 6, 6, 6, 6, 6, 7, 0 /* extra entry as sentinel */ }; static const uint8_t kCat3[] = { 173, 148, 140, 0 }; static const uint8_t kCat4[] = { 176, 155, 140, 135, 0 }; static const uint8_t kCat5[] = { 180, 157, 141, 134, 130, 0 }; static const uint8_t kCat6[] = { 254, 254, 243, 230, 196, 177, 153, 140, 133, 130, 129, 0 }; static const uint8_t *const kCat3456[] = { kCat3, kCat4, kCat5, kCat6 }; static const uint8_t kZigzag[16] = { 0, 1, 4, 8, 5, 2, 3, 6, 9, 12, 13, 10, 7, 11, 14, 15 }; #define VP8GetBit vp8dx_decode_bool #define NUM_PROBAS 11 #define NUM_CTX 3 /* for const-casting */ typedef const uint8_t (*ProbaArray)[NUM_CTX][NUM_PROBAS]; // With corrupt / fuzzed streams the calculation of br->value may overflow. See // b/148271109. static VPX_NO_UNSIGNED_OVERFLOW_CHECK int GetSigned(BOOL_DECODER *br, int value_to_sign) { int split = (br->range + 1) >> 1; VP8_BD_VALUE bigsplit = (VP8_BD_VALUE)split << (VP8_BD_VALUE_SIZE - 8); int v; if (br->count < 0) vp8dx_bool_decoder_fill(br); if (br->value < bigsplit) { br->range = split; v = value_to_sign; } else { br->range = br->range - split; br->value = br->value - bigsplit; v = -value_to_sign; } br->range += br->range; br->value += br->value; br->count--; return v; } /* Returns the position of the last non-zero coeff plus one (and 0 if there's no coeff at all) */ static int GetCoeffs(BOOL_DECODER *br, ProbaArray prob, int ctx, int n, int16_t *out) { const uint8_t *p = prob[n][ctx]; if (!VP8GetBit(br, p[0])) { /* first EOB is more a 'CBP' bit. */ return 0; } while (1) { ++n; if (!VP8GetBit(br, p[1])) { p = prob[kBands[n]][0]; } else { /* non zero coeff */ int v, j; if (!VP8GetBit(br, p[2])) { p = prob[kBands[n]][1]; v = 1; } else { if (!VP8GetBit(br, p[3])) { if (!VP8GetBit(br, p[4])) { v = 2; } else { v = 3 + VP8GetBit(br, p[5]); } } else { if (!VP8GetBit(br, p[6])) { if (!VP8GetBit(br, p[7])) { v = 5 + VP8GetBit(br, 159); } else { v = 7 + 2 * VP8GetBit(br, 165); v += VP8GetBit(br, 145); } } else { const uint8_t *tab; const int bit1 = VP8GetBit(br, p[8]); const int bit0 = VP8GetBit(br, p[9 + bit1]); const int cat = 2 * bit1 + bit0; v = 0; for (tab = kCat3456[cat]; *tab; ++tab) { v += v + VP8GetBit(br, *tab); } v += 3 + (8 << cat); } } p = prob[kBands[n]][2]; } j = kZigzag[n - 1]; out[j] = GetSigned(br, v); if (n == 16 || !VP8GetBit(br, p[0])) { /* EOB */ return n; } } if (n == 16) { return 16; } } } int vp8_decode_mb_tokens(VP8D_COMP *dx, MACROBLOCKD *x) { BOOL_DECODER *bc = x->current_bc; const FRAME_CONTEXT *const fc = &dx->common.fc; char *eobs = x->eobs; int i; int nonzeros; int eobtotal = 0; short *qcoeff_ptr; ProbaArray coef_probs; ENTROPY_CONTEXT *a_ctx = ((ENTROPY_CONTEXT *)x->above_context); ENTROPY_CONTEXT *l_ctx = ((ENTROPY_CONTEXT *)x->left_context); ENTROPY_CONTEXT *a; ENTROPY_CONTEXT *l; int skip_dc = 0; qcoeff_ptr = &x->qcoeff[0]; if (!x->mode_info_context->mbmi.is_4x4) { a = a_ctx + 8; l = l_ctx + 8; coef_probs = fc->coef_probs[1]; nonzeros = GetCoeffs(bc, coef_probs, (*a + *l), 0, qcoeff_ptr + 24 * 16); *a = *l = (nonzeros > 0); eobs[24] = nonzeros; eobtotal += nonzeros - 16; coef_probs = fc->coef_probs[0]; skip_dc = 1; } else { coef_probs = fc->coef_probs[3]; skip_dc = 0; } for (i = 0; i < 16; ++i) { a = a_ctx + (i & 3); l = l_ctx + ((i & 0xc) >> 2); nonzeros = GetCoeffs(bc, coef_probs, (*a + *l), skip_dc, qcoeff_ptr); *a = *l = (nonzeros > 0); nonzeros += skip_dc; eobs[i] = nonzeros; eobtotal += nonzeros; qcoeff_ptr += 16; } coef_probs = fc->coef_probs[2]; a_ctx += 4; l_ctx += 4; for (i = 16; i < 24; ++i) { a = a_ctx + ((i > 19) << 1) + (i & 1); l = l_ctx + ((i > 19) << 1) + ((i & 3) > 1); nonzeros = GetCoeffs(bc, coef_probs, (*a + *l), 0, qcoeff_ptr); *a = *l = (nonzeros > 0); eobs[i] = nonzeros; eobtotal += nonzeros; qcoeff_ptr += 16; } return eobtotal; }

                                                                                                                                                                                                                                                                                                                                                                                                     

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