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6148 | serge | 1 | /** |
2 | * @file |
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3 | * Common code for Vorbis I encoder and decoder |
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4 | * @author Denes Balatoni ( dbalatoni programozo hu ) |
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5 | * |
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6 | * This file is part of FFmpeg. |
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7 | * |
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8 | * FFmpeg is free software; you can redistribute it and/or |
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9 | * modify it under the terms of the GNU Lesser General Public |
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10 | * License as published by the Free Software Foundation; either |
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11 | * version 2.1 of the License, or (at your option) any later version. |
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12 | * |
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13 | * FFmpeg is distributed in the hope that it will be useful, |
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14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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16 | * Lesser General Public License for more details. |
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17 | * |
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18 | * You should have received a copy of the GNU Lesser General Public |
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19 | * License along with FFmpeg; if not, write to the Free Software |
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20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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21 | */ |
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22 | |||
23 | /** |
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24 | * @file |
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25 | * Common code for Vorbis I encoder and decoder |
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26 | * @author Denes Balatoni ( dbalatoni programozo hu ) |
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27 | */ |
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28 | |||
29 | #define BITSTREAM_READER_LE |
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30 | #include "avcodec.h" |
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31 | #include "get_bits.h" |
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32 | |||
33 | #include "vorbis.h" |
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34 | |||
35 | |||
36 | /* Helper functions */ |
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37 | |||
38 | // x^(1/n) |
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39 | unsigned int ff_vorbis_nth_root(unsigned int x, unsigned int n) |
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40 | { |
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41 | unsigned int ret = 0, i, j; |
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42 | |||
43 | do { |
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44 | ++ret; |
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45 | for (i = 0, j = ret; i < n - 1; i++) |
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46 | j *= ret; |
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47 | } while (j <= x); |
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48 | |||
49 | return ret - 1; |
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50 | } |
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51 | |||
52 | // Generate vlc codes from vorbis huffman code lengths |
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53 | |||
54 | // the two bits[p] > 32 checks should be redundant, all calling code should |
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55 | // already ensure that, but since it allows overwriting the stack it seems |
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56 | // reasonable to check redundantly. |
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57 | int ff_vorbis_len2vlc(uint8_t *bits, uint32_t *codes, unsigned num) |
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58 | { |
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59 | uint32_t exit_at_level[33] = { 404 }; |
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60 | |||
61 | unsigned i, j, p, code; |
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62 | |||
63 | #ifdef DEBUG |
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64 | GetBitContext gb; |
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65 | #endif |
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66 | |||
67 | for (p = 0; (bits[p] == 0) && (p < num); ++p) |
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68 | ; |
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69 | if (p == num) |
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70 | return 0; |
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71 | |||
72 | codes[p] = 0; |
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73 | if (bits[p] > 32) |
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74 | return 1; |
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75 | for (i = 0; i < bits[p]; ++i) |
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76 | exit_at_level[i+1] = 1 << i; |
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77 | |||
78 | #ifdef DEBUG |
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79 | av_log(NULL, AV_LOG_INFO, " %u. of %u code len %d code %d - ", p, num, bits[p], codes[p]); |
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80 | init_get_bits(&gb, (uint8_t *)&codes[p], bits[p]); |
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81 | for (i = 0; i < bits[p]; ++i) |
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82 | av_log(NULL, AV_LOG_INFO, "%s", get_bits1(&gb) ? "1" : "0"); |
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83 | av_log(NULL, AV_LOG_INFO, "\n"); |
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84 | #endif |
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85 | |||
86 | ++p; |
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87 | |||
88 | for (; p < num; ++p) { |
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89 | if (bits[p] > 32) |
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90 | return 1; |
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91 | if (bits[p] == 0) |
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92 | continue; |
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93 | // find corresponding exit(node which the tree can grow further from) |
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94 | for (i = bits[p]; i > 0; --i) |
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95 | if (exit_at_level[i]) |
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96 | break; |
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97 | if (!i) // overspecified tree |
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98 | return 1; |
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99 | code = exit_at_level[i]; |
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100 | exit_at_level[i] = 0; |
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101 | // construct code (append 0s to end) and introduce new exits |
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102 | for (j = i + 1 ;j <= bits[p]; ++j) |
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103 | exit_at_level[j] = code + (1 << (j - 1)); |
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104 | codes[p] = code; |
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105 | |||
106 | #ifdef DEBUG |
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107 | av_log(NULL, AV_LOG_INFO, " %d. code len %d code %d - ", p, bits[p], codes[p]); |
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108 | init_get_bits(&gb, (uint8_t *)&codes[p], bits[p]); |
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109 | for (i = 0; i < bits[p]; ++i) |
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110 | av_log(NULL, AV_LOG_INFO, "%s", get_bits1(&gb) ? "1" : "0"); |
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111 | av_log(NULL, AV_LOG_INFO, "\n"); |
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112 | #endif |
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113 | |||
114 | } |
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115 | |||
116 | //no exits should be left (underspecified tree - ie. unused valid vlcs - not allowed by SPEC) |
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117 | for (p = 1; p < 33; p++) |
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118 | if (exit_at_level[p]) |
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119 | return 1; |
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120 | |||
121 | return 0; |
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122 | } |
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123 | |||
124 | int ff_vorbis_ready_floor1_list(AVCodecContext *avctx, |
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125 | vorbis_floor1_entry *list, int values) |
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126 | { |
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127 | int i; |
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128 | list[0].sort = 0; |
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129 | list[1].sort = 1; |
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130 | for (i = 2; i < values; i++) { |
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131 | int j; |
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132 | list[i].low = 0; |
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133 | list[i].high = 1; |
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134 | list[i].sort = i; |
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135 | for (j = 2; j < i; j++) { |
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136 | int tmp = list[j].x; |
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137 | if (tmp < list[i].x) { |
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138 | if (tmp > list[list[i].low].x) |
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139 | list[i].low = j; |
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140 | } else { |
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141 | if (tmp < list[list[i].high].x) |
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142 | list[i].high = j; |
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143 | } |
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144 | } |
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145 | } |
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146 | for (i = 0; i < values - 1; i++) { |
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147 | int j; |
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148 | for (j = i + 1; j < values; j++) { |
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149 | if (list[i].x == list[j].x) { |
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150 | av_log(avctx, AV_LOG_ERROR, |
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151 | "Duplicate value found in floor 1 X coordinates\n"); |
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152 | return AVERROR_INVALIDDATA; |
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153 | } |
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154 | if (list[list[i].sort].x > list[list[j].sort].x) { |
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155 | int tmp = list[i].sort; |
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156 | list[i].sort = list[j].sort; |
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157 | list[j].sort = tmp; |
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158 | } |
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159 | } |
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160 | } |
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161 | return 0; |
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162 | } |
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163 | |||
164 | static inline void render_line_unrolled(intptr_t x, int y, int x1, |
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165 | intptr_t sy, int ady, int adx, |
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166 | float *buf) |
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167 | { |
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168 | int err = -adx; |
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169 | x -= x1 - 1; |
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170 | buf += x1 - 1; |
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171 | while (++x < 0) { |
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172 | err += ady; |
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173 | if (err >= 0) { |
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174 | err += ady - adx; |
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175 | y += sy; |
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176 | buf[x++] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)]; |
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177 | } |
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178 | buf[x] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)]; |
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179 | } |
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180 | if (x <= 0) { |
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181 | if (err + ady >= 0) |
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182 | y += sy; |
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183 | buf[x] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)]; |
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184 | } |
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185 | } |
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186 | |||
187 | static void render_line(int x0, int y0, int x1, int y1, float *buf) |
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188 | { |
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189 | int dy = y1 - y0; |
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190 | int adx = x1 - x0; |
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191 | int ady = FFABS(dy); |
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192 | int sy = dy < 0 ? -1 : 1; |
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193 | buf[x0] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y0)]; |
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194 | if (ady*2 <= adx) { // optimized common case |
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195 | render_line_unrolled(x0, y0, x1, sy, ady, adx, buf); |
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196 | } else { |
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197 | int base = dy / adx; |
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198 | int x = x0; |
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199 | int y = y0; |
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200 | int err = -adx; |
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201 | ady -= FFABS(base) * adx; |
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202 | while (++x < x1) { |
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203 | y += base; |
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204 | err += ady; |
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205 | if (err >= 0) { |
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206 | err -= adx; |
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207 | y += sy; |
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208 | } |
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209 | buf[x] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)]; |
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210 | } |
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211 | } |
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212 | } |
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213 | |||
214 | void ff_vorbis_floor1_render_list(vorbis_floor1_entry * list, int values, |
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215 | uint16_t *y_list, int *flag, |
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216 | int multiplier, float *out, int samples) |
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217 | { |
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218 | int lx, ly, i; |
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219 | lx = 0; |
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220 | ly = y_list[0] * multiplier; |
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221 | for (i = 1; i < values; i++) { |
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222 | int pos = list[i].sort; |
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223 | if (flag[pos]) { |
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224 | int x1 = list[pos].x; |
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225 | int y1 = y_list[pos] * multiplier; |
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226 | if (lx < samples) |
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227 | render_line(lx, ly, FFMIN(x1,samples), y1, out); |
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228 | lx = x1; |
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229 | ly = y1; |
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230 | } |
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231 | if (lx >= samples) |
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232 | break; |
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233 | } |
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234 | if (lx < samples) |
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235 | render_line(lx, ly, samples, ly, out); |
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236 | }>>>>=>>=>>>>>>>>>>><>=>>>><>>>=>> |