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Rev | Author | Line No. | Line |
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6148 | serge | 1 | /* |
2 | * Wavesynth pseudo-codec |
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3 | * Copyright (c) 2011 Nicolas George |
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4 | * |
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5 | * This file is part of FFmpeg. |
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6 | * |
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7 | * FFmpeg is free software; you can redistribute it and/or |
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8 | * modify it under the terms of the GNU Lesser General Public |
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9 | * License as published by the Free Software Foundation; either |
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10 | * version 2.1 of the License, or (at your option) any later version. |
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11 | * |
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12 | * FFmpeg is distributed in the hope that it will be useful, |
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13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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15 | * Lesser General Public License for more details. |
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16 | * |
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17 | * You should have received a copy of the GNU Lesser General Public |
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18 | * License along with FFmpeg; if not, write to the Free Software |
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19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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20 | */ |
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21 | |||
22 | #include "libavutil/intreadwrite.h" |
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23 | #include "libavutil/log.h" |
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24 | #include "avcodec.h" |
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25 | #include "internal.h" |
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26 | |||
27 | |||
28 | #define SIN_BITS 14 |
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29 | #define WS_MAX_CHANNELS 32 |
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30 | #define INF_TS 0x7FFFFFFFFFFFFFFF |
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31 | |||
32 | #define PINK_UNIT 128 |
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33 | |||
34 | /* |
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35 | Format of the extradata and packets |
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36 | |||
37 | THIS INFORMATION IS NOT PART OF THE PUBLIC API OR ABI. |
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38 | IT CAN CHANGE WITHOUT NOTIFICATION. |
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39 | |||
40 | All numbers are in little endian. |
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41 | |||
42 | The codec extradata define a set of intervals with uniform content. |
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43 | Overlapping intervals are added together. |
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44 | |||
45 | extradata: |
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46 | uint32 number of intervals |
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47 | ... intervals |
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48 | |||
49 | interval: |
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50 | int64 start timestamp; time_base must be 1/sample_rate; |
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51 | start timestamps must be in ascending order |
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52 | int64 end timestamp |
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53 | uint32 type |
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54 | uint32 channels mask |
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55 | ... additional information, depends on type |
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56 | |||
57 | sine interval (type fourcc "SINE"): |
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58 | int32 start frequency, in 1/(1<<16) Hz |
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59 | int32 end frequency |
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60 | int32 start amplitude, 1<<16 is the full amplitude |
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61 | int32 end amplitude |
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62 | uint32 start phase, 0 is sin(0), 0x20000000 is sin(pi/2), etc.; |
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63 | n | (1<<31) means to match the phase of previous channel #n |
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64 | |||
65 | pink noise interval (type fourcc "NOIS"): |
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66 | int32 start amplitude |
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67 | int32 end amplitude |
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68 | |||
69 | The input packets encode the time and duration of the requested segment. |
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70 | |||
71 | packet: |
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72 | int64 start timestamp |
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73 | int32 duration |
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74 | |||
75 | */ |
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76 | |||
77 | enum ws_interval_type { |
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78 | WS_SINE = MKTAG('S','I','N','E'), |
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79 | WS_NOISE = MKTAG('N','O','I','S'), |
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80 | }; |
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81 | |||
82 | struct ws_interval { |
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83 | int64_t ts_start, ts_end; |
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84 | uint64_t phi0, dphi0, ddphi; |
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85 | uint64_t amp0, damp; |
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86 | uint64_t phi, dphi, amp; |
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87 | uint32_t channels; |
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88 | enum ws_interval_type type; |
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89 | int next; |
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90 | }; |
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91 | |||
92 | struct wavesynth_context { |
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93 | int64_t cur_ts; |
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94 | int64_t next_ts; |
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95 | int32_t *sin; |
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96 | AVFrame frame; |
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97 | struct ws_interval *inter; |
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98 | uint32_t dither_state; |
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99 | uint32_t pink_state; |
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100 | int32_t pink_pool[PINK_UNIT]; |
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101 | unsigned pink_need, pink_pos; |
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102 | int nb_inter; |
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103 | int cur_inter; |
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104 | int next_inter; |
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105 | }; |
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106 | |||
107 | #define LCG_A 1284865837 |
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108 | #define LCG_C 4150755663 |
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109 | #define LCG_AI 849225893 /* A*AI = 1 [mod 1<<32] */ |
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110 | |||
111 | static uint32_t lcg_next(uint32_t *s) |
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112 | { |
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113 | *s = *s * LCG_A + LCG_C; |
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114 | return *s; |
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115 | } |
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116 | |||
117 | static void lcg_seek(uint32_t *s, int64_t dt) |
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118 | { |
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119 | uint32_t a, c, t = *s; |
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120 | |||
121 | if (dt >= 0) { |
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122 | a = LCG_A; |
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123 | c = LCG_C; |
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124 | } else { /* coefficients for a step backward */ |
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125 | a = LCG_AI; |
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126 | c = (uint32_t)(LCG_AI * LCG_C); |
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127 | dt = -dt; |
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128 | } |
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129 | while (dt) { |
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130 | if (dt & 1) |
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131 | t = a * t + c; |
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132 | c *= a + 1; /* coefficients for a double step */ |
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133 | a *= a; |
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134 | dt >>= 1; |
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135 | } |
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136 | *s = t; |
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137 | } |
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138 | |||
139 | /* Emulate pink noise by summing white noise at the sampling frequency, |
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140 | * white noise at half the sampling frequency (each value taken twice), |
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141 | * etc., with a total of 8 octaves. |
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142 | * This is known as the Voss-McCartney algorithm. */ |
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143 | |||
144 | static void pink_fill(struct wavesynth_context *ws) |
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145 | { |
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146 | int32_t vt[7] = { 0 }, v = 0; |
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147 | int i, j; |
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148 | |||
149 | ws->pink_pos = 0; |
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150 | if (!ws->pink_need) |
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151 | return; |
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152 | for (i = 0; i < PINK_UNIT; i++) { |
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153 | for (j = 0; j < 7; j++) { |
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154 | if ((i >> j) & 1) |
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155 | break; |
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156 | v -= vt[j]; |
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157 | vt[j] = (int32_t)lcg_next(&ws->pink_state) >> 3; |
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158 | v += vt[j]; |
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159 | } |
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160 | ws->pink_pool[i] = v + ((int32_t)lcg_next(&ws->pink_state) >> 3); |
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161 | } |
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162 | lcg_next(&ws->pink_state); /* so we use exactly 256 steps */ |
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163 | } |
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164 | |||
165 | /** |
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166 | * @return (1<<64) * a / b, without overflow, if a < b |
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167 | */ |
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168 | static uint64_t frac64(uint64_t a, uint64_t b) |
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169 | { |
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170 | uint64_t r = 0; |
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171 | int i; |
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172 | |||
173 | if (b < (uint64_t)1 << 32) { /* b small, use two 32-bits steps */ |
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174 | a <<= 32; |
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175 | return ((a / b) << 32) | ((a % b) << 32) / b; |
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176 | } |
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177 | if (b < (uint64_t)1 << 48) { /* b medium, use four 16-bits steps */ |
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178 | for (i = 0; i < 4; i++) { |
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179 | a <<= 16; |
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180 | r = (r << 16) | (a / b); |
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181 | a %= b; |
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182 | } |
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183 | return r; |
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184 | } |
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185 | for (i = 63; i >= 0; i--) { |
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186 | if (a >= (uint64_t)1 << 63 || a << 1 >= b) { |
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187 | r |= (uint64_t)1 << i; |
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188 | a = (a << 1) - b; |
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189 | } else { |
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190 | a <<= 1; |
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191 | } |
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192 | } |
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193 | return r; |
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194 | } |
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195 | |||
196 | static uint64_t phi_at(struct ws_interval *in, int64_t ts) |
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197 | { |
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198 | uint64_t dt = ts - in->ts_start; |
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199 | uint64_t dt2 = dt & 1 ? /* dt * (dt - 1) / 2 without overflow */ |
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200 | dt * ((dt - 1) >> 1) : (dt >> 1) * (dt - 1); |
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201 | return in->phi0 + dt * in->dphi0 + dt2 * in->ddphi; |
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202 | } |
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203 | |||
204 | static void wavesynth_seek(struct wavesynth_context *ws, int64_t ts) |
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205 | { |
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206 | int *last, i; |
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207 | struct ws_interval *in; |
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208 | |||
209 | last = &ws->cur_inter; |
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210 | for (i = 0; i < ws->nb_inter; i++) { |
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211 | in = &ws->inter[i]; |
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212 | if (ts < in->ts_start) |
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213 | break; |
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214 | if (ts >= in->ts_end) |
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215 | continue; |
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216 | *last = i; |
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217 | last = &in->next; |
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218 | in->phi = phi_at(in, ts); |
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219 | in->dphi = in->dphi0 + (ts - in->ts_start) * in->ddphi; |
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220 | in->amp = in->amp0 + (ts - in->ts_start) * in->damp; |
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221 | } |
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222 | ws->next_inter = i; |
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223 | ws->next_ts = i < ws->nb_inter ? ws->inter[i].ts_start : INF_TS; |
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224 | *last = -1; |
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225 | lcg_seek(&ws->dither_state, ts - ws->cur_ts); |
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226 | if (ws->pink_need) { |
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227 | int64_t pink_ts_cur = (ws->cur_ts + PINK_UNIT - 1) & ~(PINK_UNIT - 1); |
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228 | int64_t pink_ts_next = ts & ~(PINK_UNIT - 1); |
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229 | int pos = ts & (PINK_UNIT - 1); |
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230 | lcg_seek(&ws->pink_state, (pink_ts_next - pink_ts_cur) << 1); |
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231 | if (pos) { |
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232 | pink_fill(ws); |
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233 | ws->pink_pos = pos; |
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234 | } else { |
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235 | ws->pink_pos = PINK_UNIT; |
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236 | } |
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237 | } |
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238 | ws->cur_ts = ts; |
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239 | } |
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240 | |||
241 | static int wavesynth_parse_extradata(AVCodecContext *avc) |
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242 | { |
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243 | struct wavesynth_context *ws = avc->priv_data; |
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244 | struct ws_interval *in; |
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245 | uint8_t *edata, *edata_end; |
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246 | int32_t f1, f2, a1, a2; |
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247 | uint32_t phi; |
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248 | int64_t dphi1, dphi2, dt, cur_ts = -0x8000000000000000; |
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249 | int i; |
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250 | |||
251 | if (avc->extradata_size < 4) |
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252 | return AVERROR(EINVAL); |
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253 | edata = avc->extradata; |
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254 | edata_end = edata + avc->extradata_size; |
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255 | ws->nb_inter = AV_RL32(edata); |
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256 | edata += 4; |
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257 | if (ws->nb_inter < 0) |
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258 | return AVERROR(EINVAL); |
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259 | ws->inter = av_calloc(ws->nb_inter, sizeof(*ws->inter)); |
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260 | if (!ws->inter) |
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261 | return AVERROR(ENOMEM); |
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262 | for (i = 0; i < ws->nb_inter; i++) { |
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263 | in = &ws->inter[i]; |
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264 | if (edata_end - edata < 24) |
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265 | return AVERROR(EINVAL); |
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266 | in->ts_start = AV_RL64(edata + 0); |
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267 | in->ts_end = AV_RL64(edata + 8); |
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268 | in->type = AV_RL32(edata + 16); |
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269 | in->channels = AV_RL32(edata + 20); |
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270 | edata += 24; |
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271 | if (in->ts_start < cur_ts || in->ts_end <= in->ts_start) |
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272 | return AVERROR(EINVAL); |
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273 | cur_ts = in->ts_start; |
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274 | dt = in->ts_end - in->ts_start; |
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275 | switch (in->type) { |
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276 | case WS_SINE: |
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277 | if (edata_end - edata < 20) |
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278 | return AVERROR(EINVAL); |
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279 | f1 = AV_RL32(edata + 0); |
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280 | f2 = AV_RL32(edata + 4); |
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281 | a1 = AV_RL32(edata + 8); |
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282 | a2 = AV_RL32(edata + 12); |
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283 | phi = AV_RL32(edata + 16); |
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284 | edata += 20; |
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285 | dphi1 = frac64(f1, (int64_t)avc->sample_rate << 16); |
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286 | dphi2 = frac64(f2, (int64_t)avc->sample_rate << 16); |
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287 | in->dphi0 = dphi1; |
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288 | in->ddphi = (dphi2 - dphi1) / dt; |
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289 | if (phi & 0x80000000) { |
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290 | phi &= ~0x80000000; |
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291 | if (phi >= i) |
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292 | return AVERROR(EINVAL); |
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293 | in->phi0 = phi_at(&ws->inter[phi], in->ts_start); |
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294 | } else { |
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295 | in->phi0 = (uint64_t)phi << 33; |
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296 | } |
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297 | break; |
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298 | case WS_NOISE: |
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299 | if (edata_end - edata < 8) |
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300 | return AVERROR(EINVAL); |
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301 | a1 = AV_RL32(edata + 0); |
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302 | a2 = AV_RL32(edata + 4); |
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303 | edata += 8; |
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304 | break; |
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305 | default: |
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306 | return AVERROR(EINVAL); |
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307 | } |
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308 | in->amp0 = (int64_t)a1 << 32; |
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309 | in->damp = (((int64_t)a2 << 32) - ((int64_t)a1 << 32)) / dt; |
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310 | } |
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311 | if (edata != edata_end) |
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312 | return AVERROR(EINVAL); |
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313 | return 0; |
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314 | } |
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315 | |||
316 | static av_cold int wavesynth_init(AVCodecContext *avc) |
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317 | { |
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318 | struct wavesynth_context *ws = avc->priv_data; |
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319 | int i, r; |
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320 | |||
321 | if (avc->channels > WS_MAX_CHANNELS) { |
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322 | av_log(avc, AV_LOG_ERROR, |
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323 | "This implementation is limited to %d channels.\n", |
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324 | WS_MAX_CHANNELS); |
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325 | return AVERROR(EINVAL); |
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326 | } |
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327 | r = wavesynth_parse_extradata(avc); |
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328 | if (r < 0) { |
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329 | av_log(avc, AV_LOG_ERROR, "Invalid intervals definitions.\n"); |
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330 | goto fail; |
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331 | } |
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332 | ws->sin = av_malloc(sizeof(*ws->sin) << SIN_BITS); |
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333 | if (!ws->sin) { |
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334 | r = AVERROR(ENOMEM); |
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335 | goto fail; |
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336 | } |
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337 | for (i = 0; i < 1 << SIN_BITS; i++) |
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338 | ws->sin[i] = floor(32767 * sin(2 * M_PI * i / (1 << SIN_BITS))); |
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339 | ws->dither_state = MKTAG('D','I','T','H'); |
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340 | for (i = 0; i < ws->nb_inter; i++) |
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341 | ws->pink_need += ws->inter[i].type == WS_NOISE; |
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342 | ws->pink_state = MKTAG('P','I','N','K'); |
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343 | ws->pink_pos = PINK_UNIT; |
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344 | avcodec_get_frame_defaults(&ws->frame); |
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345 | avc->coded_frame = &ws->frame; |
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346 | wavesynth_seek(ws, 0); |
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347 | avc->sample_fmt = AV_SAMPLE_FMT_S16; |
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348 | return 0; |
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349 | |||
350 | fail: |
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351 | av_free(ws->inter); |
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352 | av_free(ws->sin); |
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353 | return r; |
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354 | } |
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355 | |||
356 | static void wavesynth_synth_sample(struct wavesynth_context *ws, int64_t ts, |
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357 | int32_t *channels) |
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358 | { |
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359 | int32_t amp, val, *cv; |
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360 | struct ws_interval *in; |
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361 | int i, *last, pink; |
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362 | uint32_t c, all_ch = 0; |
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363 | |||
364 | i = ws->cur_inter; |
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365 | last = &ws->cur_inter; |
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366 | if (ws->pink_pos == PINK_UNIT) |
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367 | pink_fill(ws); |
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368 | pink = ws->pink_pool[ws->pink_pos++] >> 16; |
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369 | while (i >= 0) { |
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370 | in = &ws->inter[i]; |
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371 | i = in->next; |
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372 | if (ts >= in->ts_end) { |
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373 | *last = i; |
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374 | continue; |
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375 | } |
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376 | last = &in->next; |
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377 | amp = in->amp >> 32; |
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378 | in->amp += in->damp; |
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379 | switch (in->type) { |
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380 | case WS_SINE: |
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381 | val = amp * ws->sin[in->phi >> (64 - SIN_BITS)]; |
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382 | in->phi += in->dphi; |
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383 | in->dphi += in->ddphi; |
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384 | break; |
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385 | case WS_NOISE: |
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386 | val = amp * pink; |
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387 | break; |
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388 | default: |
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389 | val = 0; |
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390 | } |
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391 | all_ch |= in->channels; |
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392 | for (c = in->channels, cv = channels; c; c >>= 1, cv++) |
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393 | if (c & 1) |
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394 | *cv += val; |
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395 | } |
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396 | val = (int32_t)lcg_next(&ws->dither_state) >> 16; |
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397 | for (c = all_ch, cv = channels; c; c >>= 1, cv++) |
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398 | if (c & 1) |
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399 | *cv += val; |
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400 | } |
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401 | |||
402 | static void wavesynth_enter_intervals(struct wavesynth_context *ws, int64_t ts) |
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403 | { |
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404 | int *last, i; |
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405 | struct ws_interval *in; |
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406 | |||
407 | last = &ws->cur_inter; |
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408 | for (i = ws->cur_inter; i >= 0; i = ws->inter[i].next) |
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409 | last = &ws->inter[i].next; |
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410 | for (i = ws->next_inter; i < ws->nb_inter; i++) { |
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411 | in = &ws->inter[i]; |
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412 | if (ts < in->ts_start) |
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413 | break; |
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414 | if (ts >= in->ts_end) |
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415 | continue; |
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416 | *last = i; |
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417 | last = &in->next; |
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418 | in->phi = in->phi0; |
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419 | in->dphi = in->dphi0; |
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420 | in->amp = in->amp0; |
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421 | } |
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422 | ws->next_inter = i; |
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423 | ws->next_ts = i < ws->nb_inter ? ws->inter[i].ts_start : INF_TS; |
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424 | *last = -1; |
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425 | } |
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426 | |||
427 | static int wavesynth_decode(AVCodecContext *avc, void *rframe, int *rgot_frame, |
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428 | AVPacket *packet) |
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429 | { |
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430 | struct wavesynth_context *ws = avc->priv_data; |
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431 | int64_t ts; |
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432 | int duration; |
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433 | int s, c, r; |
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434 | int16_t *pcm; |
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435 | int32_t channels[WS_MAX_CHANNELS]; |
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436 | |||
437 | *rgot_frame = 0; |
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438 | if (packet->size != 12) |
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439 | return AVERROR_INVALIDDATA; |
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440 | ts = AV_RL64(packet->data); |
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441 | if (ts != ws->cur_ts) |
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442 | wavesynth_seek(ws, ts); |
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443 | duration = AV_RL32(packet->data + 8); |
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444 | if (duration <= 0) |
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445 | return AVERROR(EINVAL); |
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446 | ws->frame.nb_samples = duration; |
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447 | r = ff_get_buffer(avc, &ws->frame, 0); |
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448 | if (r < 0) |
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449 | return r; |
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450 | pcm = (int16_t *)ws->frame.data[0]; |
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451 | for (s = 0; s < duration; s++, ts++) { |
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452 | memset(channels, 0, avc->channels * sizeof(*channels)); |
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453 | if (ts >= ws->next_ts) |
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454 | wavesynth_enter_intervals(ws, ts); |
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455 | wavesynth_synth_sample(ws, ts, channels); |
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456 | for (c = 0; c < avc->channels; c++) |
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457 | *(pcm++) = channels[c] >> 16; |
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458 | } |
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459 | ws->cur_ts += duration; |
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460 | *rgot_frame = 1; |
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461 | *(AVFrame *)rframe = ws->frame; |
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462 | return packet->size; |
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463 | } |
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464 | |||
465 | static av_cold int wavesynth_close(AVCodecContext *avc) |
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466 | { |
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467 | struct wavesynth_context *ws = avc->priv_data; |
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468 | |||
469 | av_free(ws->sin); |
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470 | av_free(ws->inter); |
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471 | return 0; |
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472 | } |
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473 | |||
474 | AVCodec ff_ffwavesynth_decoder = { |
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475 | .name = "wavesynth", |
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476 | .long_name = NULL_IF_CONFIG_SMALL("Wave synthesis pseudo-codec"), |
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477 | .type = AVMEDIA_TYPE_AUDIO, |
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478 | .id = AV_CODEC_ID_FFWAVESYNTH, |
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479 | .priv_data_size = sizeof(struct wavesynth_context), |
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480 | .init = wavesynth_init, |
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481 | .close = wavesynth_close, |
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482 | .decode = wavesynth_decode, |
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483 | .capabilities = CODEC_CAP_DR1, |
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484 | };>>>=>>>>>><>><>>><>>><>><>><>>><>><>><>>=>>>>>>><>>>>=><=>><>><>><>><>><>=><=>>><>>><>><>=><=>><>>>64)><64)>>>32]><32]>31)><31)>16><16>16)><16)> |