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Rev | Author | Line No. | Line |
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4349 | Serge | 1 | /* |
2 | * AAC encoder psychoacoustic model |
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3 | * Copyright (C) 2008 Konstantin Shishkov |
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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 | /** |
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23 | * @file |
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24 | * AAC encoder psychoacoustic model |
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25 | */ |
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26 | |||
27 | #include "libavutil/attributes.h" |
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28 | #include "libavutil/libm.h" |
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29 | |||
30 | #include "avcodec.h" |
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31 | #include "aactab.h" |
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32 | #include "psymodel.h" |
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33 | |||
34 | /*********************************** |
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35 | * TODOs: |
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36 | * try other bitrate controlling mechanism (maybe use ratecontrol.c?) |
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37 | * control quality for quality-based output |
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38 | **********************************/ |
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39 | |||
40 | /** |
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41 | * constants for 3GPP AAC psychoacoustic model |
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42 | * @{ |
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43 | */ |
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44 | #define PSY_3GPP_THR_SPREAD_HI 1.5f // spreading factor for low-to-hi threshold spreading (15 dB/Bark) |
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45 | #define PSY_3GPP_THR_SPREAD_LOW 3.0f // spreading factor for hi-to-low threshold spreading (30 dB/Bark) |
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46 | /* spreading factor for low-to-hi energy spreading, long block, > 22kbps/channel (20dB/Bark) */ |
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47 | #define PSY_3GPP_EN_SPREAD_HI_L1 2.0f |
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48 | /* spreading factor for low-to-hi energy spreading, long block, <= 22kbps/channel (15dB/Bark) */ |
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49 | #define PSY_3GPP_EN_SPREAD_HI_L2 1.5f |
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50 | /* spreading factor for low-to-hi energy spreading, short block (15 dB/Bark) */ |
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51 | #define PSY_3GPP_EN_SPREAD_HI_S 1.5f |
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52 | /* spreading factor for hi-to-low energy spreading, long block (30dB/Bark) */ |
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53 | #define PSY_3GPP_EN_SPREAD_LOW_L 3.0f |
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54 | /* spreading factor for hi-to-low energy spreading, short block (20dB/Bark) */ |
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55 | #define PSY_3GPP_EN_SPREAD_LOW_S 2.0f |
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56 | |||
57 | #define PSY_3GPP_RPEMIN 0.01f |
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58 | #define PSY_3GPP_RPELEV 2.0f |
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59 | |||
60 | #define PSY_3GPP_C1 3.0f /* log2(8) */ |
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61 | #define PSY_3GPP_C2 1.3219281f /* log2(2.5) */ |
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62 | #define PSY_3GPP_C3 0.55935729f /* 1 - C2 / C1 */ |
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63 | |||
64 | #define PSY_SNR_1DB 7.9432821e-1f /* -1dB */ |
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65 | #define PSY_SNR_25DB 3.1622776e-3f /* -25dB */ |
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66 | |||
67 | #define PSY_3GPP_SAVE_SLOPE_L -0.46666667f |
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68 | #define PSY_3GPP_SAVE_SLOPE_S -0.36363637f |
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69 | #define PSY_3GPP_SAVE_ADD_L -0.84285712f |
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70 | #define PSY_3GPP_SAVE_ADD_S -0.75f |
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71 | #define PSY_3GPP_SPEND_SLOPE_L 0.66666669f |
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72 | #define PSY_3GPP_SPEND_SLOPE_S 0.81818181f |
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73 | #define PSY_3GPP_SPEND_ADD_L -0.35f |
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74 | #define PSY_3GPP_SPEND_ADD_S -0.26111111f |
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75 | #define PSY_3GPP_CLIP_LO_L 0.2f |
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76 | #define PSY_3GPP_CLIP_LO_S 0.2f |
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77 | #define PSY_3GPP_CLIP_HI_L 0.95f |
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78 | #define PSY_3GPP_CLIP_HI_S 0.75f |
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79 | |||
80 | #define PSY_3GPP_AH_THR_LONG 0.5f |
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81 | #define PSY_3GPP_AH_THR_SHORT 0.63f |
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82 | |||
83 | enum { |
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84 | PSY_3GPP_AH_NONE, |
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85 | PSY_3GPP_AH_INACTIVE, |
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86 | PSY_3GPP_AH_ACTIVE |
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87 | }; |
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88 | |||
89 | #define PSY_3GPP_BITS_TO_PE(bits) ((bits) * 1.18f) |
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90 | |||
91 | /* LAME psy model constants */ |
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92 | #define PSY_LAME_FIR_LEN 21 ///< LAME psy model FIR order |
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93 | #define AAC_BLOCK_SIZE_LONG 1024 ///< long block size |
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94 | #define AAC_BLOCK_SIZE_SHORT 128 ///< short block size |
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95 | #define AAC_NUM_BLOCKS_SHORT 8 ///< number of blocks in a short sequence |
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96 | #define PSY_LAME_NUM_SUBBLOCKS 3 ///< Number of sub-blocks in each short block |
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97 | |||
98 | /** |
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99 | * @} |
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100 | */ |
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101 | |||
102 | /** |
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103 | * information for single band used by 3GPP TS26.403-inspired psychoacoustic model |
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104 | */ |
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105 | typedef struct AacPsyBand{ |
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106 | float energy; ///< band energy |
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107 | float thr; ///< energy threshold |
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108 | float thr_quiet; ///< threshold in quiet |
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109 | float nz_lines; ///< number of non-zero spectral lines |
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110 | float active_lines; ///< number of active spectral lines |
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111 | float pe; ///< perceptual entropy |
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112 | float pe_const; ///< constant part of the PE calculation |
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113 | float norm_fac; ///< normalization factor for linearization |
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114 | int avoid_holes; ///< hole avoidance flag |
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115 | }AacPsyBand; |
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116 | |||
117 | /** |
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118 | * single/pair channel context for psychoacoustic model |
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119 | */ |
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120 | typedef struct AacPsyChannel{ |
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121 | AacPsyBand band[128]; ///< bands information |
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122 | AacPsyBand prev_band[128]; ///< bands information from the previous frame |
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123 | |||
124 | float win_energy; ///< sliding average of channel energy |
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125 | float iir_state[2]; ///< hi-pass IIR filter state |
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126 | uint8_t next_grouping; ///< stored grouping scheme for the next frame (in case of 8 short window sequence) |
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127 | enum WindowSequence next_window_seq; ///< window sequence to be used in the next frame |
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128 | /* LAME psy model specific members */ |
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129 | float attack_threshold; ///< attack threshold for this channel |
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130 | float prev_energy_subshort[AAC_NUM_BLOCKS_SHORT * PSY_LAME_NUM_SUBBLOCKS]; |
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131 | int prev_attack; ///< attack value for the last short block in the previous sequence |
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132 | }AacPsyChannel; |
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133 | |||
134 | /** |
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135 | * psychoacoustic model frame type-dependent coefficients |
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136 | */ |
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137 | typedef struct AacPsyCoeffs{ |
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138 | float ath; ///< absolute threshold of hearing per bands |
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139 | float barks; ///< Bark value for each spectral band in long frame |
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140 | float spread_low[2]; ///< spreading factor for low-to-high threshold spreading in long frame |
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141 | float spread_hi [2]; ///< spreading factor for high-to-low threshold spreading in long frame |
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142 | float min_snr; ///< minimal SNR |
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143 | }AacPsyCoeffs; |
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144 | |||
145 | /** |
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146 | * 3GPP TS26.403-inspired psychoacoustic model specific data |
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147 | */ |
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148 | typedef struct AacPsyContext{ |
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149 | int chan_bitrate; ///< bitrate per channel |
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150 | int frame_bits; ///< average bits per frame |
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151 | int fill_level; ///< bit reservoir fill level |
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152 | struct { |
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153 | float min; ///< minimum allowed PE for bit factor calculation |
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154 | float max; ///< maximum allowed PE for bit factor calculation |
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155 | float previous; ///< allowed PE of the previous frame |
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156 | float correction; ///< PE correction factor |
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157 | } pe; |
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158 | AacPsyCoeffs psy_coef[2][64]; |
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159 | AacPsyChannel *ch; |
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160 | }AacPsyContext; |
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161 | |||
162 | /** |
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163 | * LAME psy model preset struct |
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164 | */ |
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165 | typedef struct { |
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166 | int quality; ///< Quality to map the rest of the vaules to. |
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167 | /* This is overloaded to be both kbps per channel in ABR mode, and |
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168 | * requested quality in constant quality mode. |
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169 | */ |
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170 | float st_lrm; ///< short threshold for L, R, and M channels |
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171 | } PsyLamePreset; |
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172 | |||
173 | /** |
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174 | * LAME psy model preset table for ABR |
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175 | */ |
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176 | static const PsyLamePreset psy_abr_map[] = { |
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177 | /* TODO: Tuning. These were taken from LAME. */ |
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178 | /* kbps/ch st_lrm */ |
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179 | { 8, 6.60}, |
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180 | { 16, 6.60}, |
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181 | { 24, 6.60}, |
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182 | { 32, 6.60}, |
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183 | { 40, 6.60}, |
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184 | { 48, 6.60}, |
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185 | { 56, 6.60}, |
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186 | { 64, 6.40}, |
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187 | { 80, 6.00}, |
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188 | { 96, 5.60}, |
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189 | {112, 5.20}, |
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190 | {128, 5.20}, |
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191 | {160, 5.20} |
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192 | }; |
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193 | |||
194 | /** |
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195 | * LAME psy model preset table for constant quality |
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196 | */ |
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197 | static const PsyLamePreset psy_vbr_map[] = { |
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198 | /* vbr_q st_lrm */ |
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199 | { 0, 4.20}, |
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200 | { 1, 4.20}, |
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201 | { 2, 4.20}, |
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202 | { 3, 4.20}, |
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203 | { 4, 4.20}, |
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204 | { 5, 4.20}, |
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205 | { 6, 4.20}, |
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206 | { 7, 4.20}, |
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207 | { 8, 4.20}, |
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208 | { 9, 4.20}, |
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209 | {10, 4.20} |
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210 | }; |
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211 | |||
212 | /** |
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213 | * LAME psy model FIR coefficient table |
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214 | */ |
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215 | static const float psy_fir_coeffs[] = { |
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216 | -8.65163e-18 * 2, -0.00851586 * 2, -6.74764e-18 * 2, 0.0209036 * 2, |
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217 | -3.36639e-17 * 2, -0.0438162 * 2, -1.54175e-17 * 2, 0.0931738 * 2, |
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218 | -5.52212e-17 * 2, -0.313819 * 2 |
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219 | }; |
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220 | |||
221 | #if ARCH_MIPS |
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222 | # include "mips/aacpsy_mips.h" |
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223 | #endif /* ARCH_MIPS */ |
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224 | |||
225 | /** |
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226 | * Calculate the ABR attack threshold from the above LAME psymodel table. |
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227 | */ |
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228 | static float lame_calc_attack_threshold(int bitrate) |
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229 | { |
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230 | /* Assume max bitrate to start with */ |
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231 | int lower_range = 12, upper_range = 12; |
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232 | int lower_range_kbps = psy_abr_map[12].quality; |
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233 | int upper_range_kbps = psy_abr_map[12].quality; |
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234 | int i; |
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235 | |||
236 | /* Determine which bitrates the value specified falls between. |
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237 | * If the loop ends without breaking our above assumption of 320kbps was correct. |
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238 | */ |
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239 | for (i = 1; i < 13; i++) { |
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240 | if (FFMAX(bitrate, psy_abr_map[i].quality) != bitrate) { |
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241 | upper_range = i; |
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242 | upper_range_kbps = psy_abr_map[i ].quality; |
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243 | lower_range = i - 1; |
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244 | lower_range_kbps = psy_abr_map[i - 1].quality; |
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245 | break; /* Upper range found */ |
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246 | } |
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247 | } |
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248 | |||
249 | /* Determine which range the value specified is closer to */ |
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250 | if ((upper_range_kbps - bitrate) > (bitrate - lower_range_kbps)) |
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251 | return psy_abr_map[lower_range].st_lrm; |
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252 | return psy_abr_map[upper_range].st_lrm; |
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253 | } |
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254 | |||
255 | /** |
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256 | * LAME psy model specific initialization |
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257 | */ |
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258 | static av_cold void lame_window_init(AacPsyContext *ctx, AVCodecContext *avctx) |
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259 | { |
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260 | int i, j; |
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261 | |||
262 | for (i = 0; i < avctx->channels; i++) { |
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263 | AacPsyChannel *pch = &ctx->ch[i]; |
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264 | |||
265 | if (avctx->flags & CODEC_FLAG_QSCALE) |
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266 | pch->attack_threshold = psy_vbr_map[avctx->global_quality / FF_QP2LAMBDA].st_lrm; |
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267 | else |
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268 | pch->attack_threshold = lame_calc_attack_threshold(avctx->bit_rate / avctx->channels / 1000); |
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269 | |||
270 | for (j = 0; j < AAC_NUM_BLOCKS_SHORT * PSY_LAME_NUM_SUBBLOCKS; j++) |
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271 | pch->prev_energy_subshort[j] = 10.0f; |
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272 | } |
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273 | } |
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274 | |||
275 | /** |
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276 | * Calculate Bark value for given line. |
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277 | */ |
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278 | static av_cold float calc_bark(float f) |
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279 | { |
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280 | return 13.3f * atanf(0.00076f * f) + 3.5f * atanf((f / 7500.0f) * (f / 7500.0f)); |
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281 | } |
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282 | |||
283 | #define ATH_ADD 4 |
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284 | /** |
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285 | * Calculate ATH value for given frequency. |
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286 | * Borrowed from Lame. |
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287 | */ |
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288 | static av_cold float ath(float f, float add) |
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289 | { |
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290 | f /= 1000.0f; |
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291 | return 3.64 * pow(f, -0.8) |
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292 | - 6.8 * exp(-0.6 * (f - 3.4) * (f - 3.4)) |
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293 | + 6.0 * exp(-0.15 * (f - 8.7) * (f - 8.7)) |
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294 | + (0.6 + 0.04 * add) * 0.001 * f * f * f * f; |
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295 | } |
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296 | |||
297 | static av_cold int psy_3gpp_init(FFPsyContext *ctx) { |
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298 | AacPsyContext *pctx; |
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299 | float bark; |
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300 | int i, j, g, start; |
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301 | float prev, minscale, minath, minsnr, pe_min; |
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302 | const int chan_bitrate = ctx->avctx->bit_rate / ctx->avctx->channels; |
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303 | const int bandwidth = ctx->avctx->cutoff ? ctx->avctx->cutoff : AAC_CUTOFF(ctx->avctx); |
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304 | const float num_bark = calc_bark((float)bandwidth); |
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305 | |||
306 | ctx->model_priv_data = av_mallocz(sizeof(AacPsyContext)); |
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307 | pctx = (AacPsyContext*) ctx->model_priv_data; |
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308 | |||
309 | pctx->chan_bitrate = chan_bitrate; |
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310 | pctx->frame_bits = chan_bitrate * AAC_BLOCK_SIZE_LONG / ctx->avctx->sample_rate; |
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311 | pctx->pe.min = 8.0f * AAC_BLOCK_SIZE_LONG * bandwidth / (ctx->avctx->sample_rate * 2.0f); |
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312 | pctx->pe.max = 12.0f * AAC_BLOCK_SIZE_LONG * bandwidth / (ctx->avctx->sample_rate * 2.0f); |
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313 | ctx->bitres.size = 6144 - pctx->frame_bits; |
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314 | ctx->bitres.size -= ctx->bitres.size % 8; |
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315 | pctx->fill_level = ctx->bitres.size; |
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316 | minath = ath(3410, ATH_ADD); |
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317 | for (j = 0; j < 2; j++) { |
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318 | AacPsyCoeffs *coeffs = pctx->psy_coef[j]; |
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319 | const uint8_t *band_sizes = ctx->bands[j]; |
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320 | float line_to_frequency = ctx->avctx->sample_rate / (j ? 256.f : 2048.0f); |
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321 | float avg_chan_bits = chan_bitrate * (j ? 128.0f : 1024.0f) / ctx->avctx->sample_rate; |
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322 | /* reference encoder uses 2.4% here instead of 60% like the spec says */ |
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323 | float bark_pe = 0.024f * PSY_3GPP_BITS_TO_PE(avg_chan_bits) / num_bark; |
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324 | float en_spread_low = j ? PSY_3GPP_EN_SPREAD_LOW_S : PSY_3GPP_EN_SPREAD_LOW_L; |
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325 | /* High energy spreading for long blocks <= 22kbps/channel and short blocks are the same. */ |
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326 | float en_spread_hi = (j || (chan_bitrate <= 22.0f)) ? PSY_3GPP_EN_SPREAD_HI_S : PSY_3GPP_EN_SPREAD_HI_L1; |
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327 | |||
328 | i = 0; |
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329 | prev = 0.0; |
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330 | for (g = 0; g < ctx->num_bands[j]; g++) { |
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331 | i += band_sizes[g]; |
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332 | bark = calc_bark((i-1) * line_to_frequency); |
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333 | coeffs[g].barks = (bark + prev) / 2.0; |
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334 | prev = bark; |
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335 | } |
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336 | for (g = 0; g < ctx->num_bands[j] - 1; g++) { |
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337 | AacPsyCoeffs *coeff = &coeffs[g]; |
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338 | float bark_width = coeffs[g+1].barks - coeffs->barks; |
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339 | coeff->spread_low[0] = pow(10.0, -bark_width * PSY_3GPP_THR_SPREAD_LOW); |
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340 | coeff->spread_hi [0] = pow(10.0, -bark_width * PSY_3GPP_THR_SPREAD_HI); |
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341 | coeff->spread_low[1] = pow(10.0, -bark_width * en_spread_low); |
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342 | coeff->spread_hi [1] = pow(10.0, -bark_width * en_spread_hi); |
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343 | pe_min = bark_pe * bark_width; |
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344 | minsnr = exp2(pe_min / band_sizes[g]) - 1.5f; |
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345 | coeff->min_snr = av_clipf(1.0f / minsnr, PSY_SNR_25DB, PSY_SNR_1DB); |
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346 | } |
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347 | start = 0; |
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348 | for (g = 0; g < ctx->num_bands[j]; g++) { |
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349 | minscale = ath(start * line_to_frequency, ATH_ADD); |
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350 | for (i = 1; i < band_sizes[g]; i++) |
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351 | minscale = FFMIN(minscale, ath((start + i) * line_to_frequency, ATH_ADD)); |
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352 | coeffs[g].ath = minscale - minath; |
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353 | start += band_sizes[g]; |
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354 | } |
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355 | } |
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356 | |||
357 | pctx->ch = av_mallocz(sizeof(AacPsyChannel) * ctx->avctx->channels); |
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358 | |||
359 | lame_window_init(pctx, ctx->avctx); |
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360 | |||
361 | return 0; |
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362 | } |
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363 | |||
364 | /** |
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365 | * IIR filter used in block switching decision |
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366 | */ |
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367 | static float iir_filter(int in, float state[2]) |
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368 | { |
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369 | float ret; |
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370 | |||
371 | ret = 0.7548f * (in - state[0]) + 0.5095f * state[1]; |
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372 | state[0] = in; |
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373 | state[1] = ret; |
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374 | return ret; |
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375 | } |
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376 | |||
377 | /** |
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378 | * window grouping information stored as bits (0 - new group, 1 - group continues) |
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379 | */ |
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380 | static const uint8_t window_grouping[9] = { |
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381 | 0xB6, 0x6C, 0xD8, 0xB2, 0x66, 0xC6, 0x96, 0x36, 0x36 |
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382 | }; |
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383 | |||
384 | /** |
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385 | * Tell encoder which window types to use. |
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386 | * @see 3GPP TS26.403 5.4.1 "Blockswitching" |
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387 | */ |
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388 | static av_unused FFPsyWindowInfo psy_3gpp_window(FFPsyContext *ctx, |
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389 | const int16_t *audio, |
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390 | const int16_t *la, |
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391 | int channel, int prev_type) |
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392 | { |
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393 | int i, j; |
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394 | int br = ctx->avctx->bit_rate / ctx->avctx->channels; |
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395 | int attack_ratio = br <= 16000 ? 18 : 10; |
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396 | AacPsyContext *pctx = (AacPsyContext*) ctx->model_priv_data; |
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397 | AacPsyChannel *pch = &pctx->ch[channel]; |
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398 | uint8_t grouping = 0; |
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399 | int next_type = pch->next_window_seq; |
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400 | FFPsyWindowInfo wi = { { 0 } }; |
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401 | |||
402 | if (la) { |
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403 | float s[8], v; |
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404 | int switch_to_eight = 0; |
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405 | float sum = 0.0, sum2 = 0.0; |
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406 | int attack_n = 0; |
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407 | int stay_short = 0; |
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408 | for (i = 0; i < 8; i++) { |
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409 | for (j = 0; j < 128; j++) { |
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410 | v = iir_filter(la[i*128+j], pch->iir_state); |
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411 | sum += v*v; |
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412 | } |
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413 | s[i] = sum; |
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414 | sum2 += sum; |
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415 | } |
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416 | for (i = 0; i < 8; i++) { |
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417 | if (s[i] > pch->win_energy * attack_ratio) { |
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418 | attack_n = i + 1; |
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419 | switch_to_eight = 1; |
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420 | break; |
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421 | } |
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422 | } |
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423 | pch->win_energy = pch->win_energy*7/8 + sum2/64; |
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424 | |||
425 | wi.window_type[1] = prev_type; |
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426 | switch (prev_type) { |
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427 | case ONLY_LONG_SEQUENCE: |
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428 | wi.window_type[0] = switch_to_eight ? LONG_START_SEQUENCE : ONLY_LONG_SEQUENCE; |
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429 | next_type = switch_to_eight ? EIGHT_SHORT_SEQUENCE : ONLY_LONG_SEQUENCE; |
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430 | break; |
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431 | case LONG_START_SEQUENCE: |
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432 | wi.window_type[0] = EIGHT_SHORT_SEQUENCE; |
||
433 | grouping = pch->next_grouping; |
||
434 | next_type = switch_to_eight ? EIGHT_SHORT_SEQUENCE : LONG_STOP_SEQUENCE; |
||
435 | break; |
||
436 | case LONG_STOP_SEQUENCE: |
||
437 | wi.window_type[0] = switch_to_eight ? LONG_START_SEQUENCE : ONLY_LONG_SEQUENCE; |
||
438 | next_type = switch_to_eight ? EIGHT_SHORT_SEQUENCE : ONLY_LONG_SEQUENCE; |
||
439 | break; |
||
440 | case EIGHT_SHORT_SEQUENCE: |
||
441 | stay_short = next_type == EIGHT_SHORT_SEQUENCE || switch_to_eight; |
||
442 | wi.window_type[0] = stay_short ? EIGHT_SHORT_SEQUENCE : LONG_STOP_SEQUENCE; |
||
443 | grouping = next_type == EIGHT_SHORT_SEQUENCE ? pch->next_grouping : 0; |
||
444 | next_type = switch_to_eight ? EIGHT_SHORT_SEQUENCE : LONG_STOP_SEQUENCE; |
||
445 | break; |
||
446 | } |
||
447 | |||
448 | pch->next_grouping = window_grouping[attack_n]; |
||
449 | pch->next_window_seq = next_type; |
||
450 | } else { |
||
451 | for (i = 0; i < 3; i++) |
||
452 | wi.window_type[i] = prev_type; |
||
453 | grouping = (prev_type == EIGHT_SHORT_SEQUENCE) ? window_grouping[0] : 0; |
||
454 | } |
||
455 | |||
456 | wi.window_shape = 1; |
||
457 | if (wi.window_type[0] != EIGHT_SHORT_SEQUENCE) { |
||
458 | wi.num_windows = 1; |
||
459 | wi.grouping[0] = 1; |
||
460 | } else { |
||
461 | int lastgrp = 0; |
||
462 | wi.num_windows = 8; |
||
463 | for (i = 0; i < 8; i++) { |
||
464 | if (!((grouping >> i) & 1)) |
||
465 | lastgrp = i; |
||
466 | wi.grouping[lastgrp]++; |
||
467 | } |
||
468 | } |
||
469 | |||
470 | return wi; |
||
471 | } |
||
472 | |||
473 | /* 5.6.1.2 "Calculation of Bit Demand" */ |
||
474 | static int calc_bit_demand(AacPsyContext *ctx, float pe, int bits, int size, |
||
475 | int short_window) |
||
476 | { |
||
477 | const float bitsave_slope = short_window ? PSY_3GPP_SAVE_SLOPE_S : PSY_3GPP_SAVE_SLOPE_L; |
||
478 | const float bitsave_add = short_window ? PSY_3GPP_SAVE_ADD_S : PSY_3GPP_SAVE_ADD_L; |
||
479 | const float bitspend_slope = short_window ? PSY_3GPP_SPEND_SLOPE_S : PSY_3GPP_SPEND_SLOPE_L; |
||
480 | const float bitspend_add = short_window ? PSY_3GPP_SPEND_ADD_S : PSY_3GPP_SPEND_ADD_L; |
||
481 | const float clip_low = short_window ? PSY_3GPP_CLIP_LO_S : PSY_3GPP_CLIP_LO_L; |
||
482 | const float clip_high = short_window ? PSY_3GPP_CLIP_HI_S : PSY_3GPP_CLIP_HI_L; |
||
483 | float clipped_pe, bit_save, bit_spend, bit_factor, fill_level; |
||
484 | |||
485 | ctx->fill_level += ctx->frame_bits - bits; |
||
486 | ctx->fill_level = av_clip(ctx->fill_level, 0, size); |
||
487 | fill_level = av_clipf((float)ctx->fill_level / size, clip_low, clip_high); |
||
488 | clipped_pe = av_clipf(pe, ctx->pe.min, ctx->pe.max); |
||
489 | bit_save = (fill_level + bitsave_add) * bitsave_slope; |
||
490 | assert(bit_save <= 0.3f && bit_save >= -0.05000001f); |
||
491 | bit_spend = (fill_level + bitspend_add) * bitspend_slope; |
||
492 | assert(bit_spend <= 0.5f && bit_spend >= -0.1f); |
||
493 | /* The bit factor graph in the spec is obviously incorrect. |
||
494 | * bit_spend + ((bit_spend - bit_spend))... |
||
495 | * The reference encoder subtracts everything from 1, but also seems incorrect. |
||
496 | * 1 - bit_save + ((bit_spend + bit_save))... |
||
497 | * Hopefully below is correct. |
||
498 | */ |
||
499 | bit_factor = 1.0f - bit_save + ((bit_spend - bit_save) / (ctx->pe.max - ctx->pe.min)) * (clipped_pe - ctx->pe.min); |
||
500 | /* NOTE: The reference encoder attempts to center pe max/min around the current pe. */ |
||
501 | ctx->pe.max = FFMAX(pe, ctx->pe.max); |
||
502 | ctx->pe.min = FFMIN(pe, ctx->pe.min); |
||
503 | |||
504 | return FFMIN(ctx->frame_bits * bit_factor, ctx->frame_bits + size - bits); |
||
505 | } |
||
506 | |||
507 | static float calc_pe_3gpp(AacPsyBand *band) |
||
508 | { |
||
509 | float pe, a; |
||
510 | |||
511 | band->pe = 0.0f; |
||
512 | band->pe_const = 0.0f; |
||
513 | band->active_lines = 0.0f; |
||
514 | if (band->energy > band->thr) { |
||
515 | a = log2f(band->energy); |
||
516 | pe = a - log2f(band->thr); |
||
517 | band->active_lines = band->nz_lines; |
||
518 | if (pe < PSY_3GPP_C1) { |
||
519 | pe = pe * PSY_3GPP_C3 + PSY_3GPP_C2; |
||
520 | a = a * PSY_3GPP_C3 + PSY_3GPP_C2; |
||
521 | band->active_lines *= PSY_3GPP_C3; |
||
522 | } |
||
523 | band->pe = pe * band->nz_lines; |
||
524 | band->pe_const = a * band->nz_lines; |
||
525 | } |
||
526 | |||
527 | return band->pe; |
||
528 | } |
||
529 | |||
530 | static float calc_reduction_3gpp(float a, float desired_pe, float pe, |
||
531 | float active_lines) |
||
532 | { |
||
533 | float thr_avg, reduction; |
||
534 | |||
535 | if(active_lines == 0.0) |
||
536 | return 0; |
||
537 | |||
538 | thr_avg = exp2f((a - pe) / (4.0f * active_lines)); |
||
539 | reduction = exp2f((a - desired_pe) / (4.0f * active_lines)) - thr_avg; |
||
540 | |||
541 | return FFMAX(reduction, 0.0f); |
||
542 | } |
||
543 | |||
544 | static float calc_reduced_thr_3gpp(AacPsyBand *band, float min_snr, |
||
545 | float reduction) |
||
546 | { |
||
547 | float thr = band->thr; |
||
548 | |||
549 | if (band->energy > thr) { |
||
550 | thr = sqrtf(thr); |
||
551 | thr = sqrtf(thr) + reduction; |
||
552 | thr *= thr; |
||
553 | thr *= thr; |
||
554 | |||
555 | /* This deviates from the 3GPP spec to match the reference encoder. |
||
556 | * It performs min(thr_reduced, max(thr, energy/min_snr)) only for bands |
||
557 | * that have hole avoidance on (active or inactive). It always reduces the |
||
558 | * threshold of bands with hole avoidance off. |
||
559 | */ |
||
560 | if (thr > band->energy * min_snr && band->avoid_holes != PSY_3GPP_AH_NONE) { |
||
561 | thr = FFMAX(band->thr, band->energy * min_snr); |
||
562 | band->avoid_holes = PSY_3GPP_AH_ACTIVE; |
||
563 | } |
||
564 | } |
||
565 | |||
566 | return thr; |
||
567 | } |
||
568 | |||
569 | #ifndef calc_thr_3gpp |
||
570 | static void calc_thr_3gpp(const FFPsyWindowInfo *wi, const int num_bands, AacPsyChannel *pch, |
||
571 | const uint8_t *band_sizes, const float *coefs) |
||
572 | { |
||
573 | int i, w, g; |
||
574 | int start = 0; |
||
575 | for (w = 0; w < wi->num_windows*16; w += 16) { |
||
576 | for (g = 0; g < num_bands; g++) { |
||
577 | AacPsyBand *band = &pch->band[w+g]; |
||
578 | |||
579 | float form_factor = 0.0f; |
||
580 | float Temp; |
||
581 | band->energy = 0.0f; |
||
582 | for (i = 0; i < band_sizes[g]; i++) { |
||
583 | band->energy += coefs[start+i] * coefs[start+i]; |
||
584 | form_factor += sqrtf(fabs(coefs[start+i])); |
||
585 | } |
||
586 | Temp = band->energy > 0 ? sqrtf((float)band_sizes[g] / band->energy) : 0; |
||
587 | band->thr = band->energy * 0.001258925f; |
||
588 | band->nz_lines = form_factor * sqrtf(Temp); |
||
589 | |||
590 | start += band_sizes[g]; |
||
591 | } |
||
592 | } |
||
593 | } |
||
594 | #endif /* calc_thr_3gpp */ |
||
595 | |||
596 | #ifndef psy_hp_filter |
||
597 | static void psy_hp_filter(const float *firbuf, float *hpfsmpl, const float *psy_fir_coeffs) |
||
598 | { |
||
599 | int i, j; |
||
600 | for (i = 0; i < AAC_BLOCK_SIZE_LONG; i++) { |
||
601 | float sum1, sum2; |
||
602 | sum1 = firbuf[i + (PSY_LAME_FIR_LEN - 1) / 2]; |
||
603 | sum2 = 0.0; |
||
604 | for (j = 0; j < ((PSY_LAME_FIR_LEN - 1) / 2) - 1; j += 2) { |
||
605 | sum1 += psy_fir_coeffs[j] * (firbuf[i + j] + firbuf[i + PSY_LAME_FIR_LEN - j]); |
||
606 | sum2 += psy_fir_coeffs[j + 1] * (firbuf[i + j + 1] + firbuf[i + PSY_LAME_FIR_LEN - j - 1]); |
||
607 | } |
||
608 | /* NOTE: The LAME psymodel expects it's input in the range -32768 to 32768. |
||
609 | * Tuning this for normalized floats would be difficult. */ |
||
610 | hpfsmpl[i] = (sum1 + sum2) * 32768.0f; |
||
611 | } |
||
612 | } |
||
613 | #endif /* psy_hp_filter */ |
||
614 | |||
615 | /** |
||
616 | * Calculate band thresholds as suggested in 3GPP TS26.403 |
||
617 | */ |
||
618 | static void psy_3gpp_analyze_channel(FFPsyContext *ctx, int channel, |
||
619 | const float *coefs, const FFPsyWindowInfo *wi) |
||
620 | { |
||
621 | AacPsyContext *pctx = (AacPsyContext*) ctx->model_priv_data; |
||
622 | AacPsyChannel *pch = &pctx->ch[channel]; |
||
623 | int i, w, g; |
||
624 | float desired_bits, desired_pe, delta_pe, reduction= NAN, spread_en[128] = {0}; |
||
625 | float a = 0.0f, active_lines = 0.0f, norm_fac = 0.0f; |
||
626 | float pe = pctx->chan_bitrate > 32000 ? 0.0f : FFMAX(50.0f, 100.0f - pctx->chan_bitrate * 100.0f / 32000.0f); |
||
627 | const int num_bands = ctx->num_bands[wi->num_windows == 8]; |
||
628 | const uint8_t *band_sizes = ctx->bands[wi->num_windows == 8]; |
||
629 | AacPsyCoeffs *coeffs = pctx->psy_coef[wi->num_windows == 8]; |
||
630 | const float avoid_hole_thr = wi->num_windows == 8 ? PSY_3GPP_AH_THR_SHORT : PSY_3GPP_AH_THR_LONG; |
||
631 | |||
632 | //calculate energies, initial thresholds and related values - 5.4.2 "Threshold Calculation" |
||
633 | calc_thr_3gpp(wi, num_bands, pch, band_sizes, coefs); |
||
634 | |||
635 | //modify thresholds and energies - spread, threshold in quiet, pre-echo control |
||
636 | for (w = 0; w < wi->num_windows*16; w += 16) { |
||
637 | AacPsyBand *bands = &pch->band[w]; |
||
638 | |||
639 | /* 5.4.2.3 "Spreading" & 5.4.3 "Spread Energy Calculation" */ |
||
640 | spread_en[0] = bands[0].energy; |
||
641 | for (g = 1; g < num_bands; g++) { |
||
642 | bands[g].thr = FFMAX(bands[g].thr, bands[g-1].thr * coeffs[g].spread_hi[0]); |
||
643 | spread_en[w+g] = FFMAX(bands[g].energy, spread_en[w+g-1] * coeffs[g].spread_hi[1]); |
||
644 | } |
||
645 | for (g = num_bands - 2; g >= 0; g--) { |
||
646 | bands[g].thr = FFMAX(bands[g].thr, bands[g+1].thr * coeffs[g].spread_low[0]); |
||
647 | spread_en[w+g] = FFMAX(spread_en[w+g], spread_en[w+g+1] * coeffs[g].spread_low[1]); |
||
648 | } |
||
649 | //5.4.2.4 "Threshold in quiet" |
||
650 | for (g = 0; g < num_bands; g++) { |
||
651 | AacPsyBand *band = &bands[g]; |
||
652 | |||
653 | band->thr_quiet = band->thr = FFMAX(band->thr, coeffs[g].ath); |
||
654 | //5.4.2.5 "Pre-echo control" |
||
655 | if (!(wi->window_type[0] == LONG_STOP_SEQUENCE || (wi->window_type[1] == LONG_START_SEQUENCE && !w))) |
||
656 | band->thr = FFMAX(PSY_3GPP_RPEMIN*band->thr, FFMIN(band->thr, |
||
657 | PSY_3GPP_RPELEV*pch->prev_band[w+g].thr_quiet)); |
||
658 | |||
659 | /* 5.6.1.3.1 "Preparatory steps of the perceptual entropy calculation" */ |
||
660 | pe += calc_pe_3gpp(band); |
||
661 | a += band->pe_const; |
||
662 | active_lines += band->active_lines; |
||
663 | |||
664 | /* 5.6.1.3.3 "Selection of the bands for avoidance of holes" */ |
||
665 | if (spread_en[w+g] * avoid_hole_thr > band->energy || coeffs[g].min_snr > 1.0f) |
||
666 | band->avoid_holes = PSY_3GPP_AH_NONE; |
||
667 | else |
||
668 | band->avoid_holes = PSY_3GPP_AH_INACTIVE; |
||
669 | } |
||
670 | } |
||
671 | |||
672 | /* 5.6.1.3.2 "Calculation of the desired perceptual entropy" */ |
||
673 | ctx->ch[channel].entropy = pe; |
||
674 | desired_bits = calc_bit_demand(pctx, pe, ctx->bitres.bits, ctx->bitres.size, wi->num_windows == 8); |
||
675 | desired_pe = PSY_3GPP_BITS_TO_PE(desired_bits); |
||
676 | /* NOTE: PE correction is kept simple. During initial testing it had very |
||
677 | * little effect on the final bitrate. Probably a good idea to come |
||
678 | * back and do more testing later. |
||
679 | */ |
||
680 | if (ctx->bitres.bits > 0) |
||
681 | desired_pe *= av_clipf(pctx->pe.previous / PSY_3GPP_BITS_TO_PE(ctx->bitres.bits), |
||
682 | 0.85f, 1.15f); |
||
683 | pctx->pe.previous = PSY_3GPP_BITS_TO_PE(desired_bits); |
||
684 | |||
685 | if (desired_pe < pe) { |
||
686 | /* 5.6.1.3.4 "First Estimation of the reduction value" */ |
||
687 | for (w = 0; w < wi->num_windows*16; w += 16) { |
||
688 | reduction = calc_reduction_3gpp(a, desired_pe, pe, active_lines); |
||
689 | pe = 0.0f; |
||
690 | a = 0.0f; |
||
691 | active_lines = 0.0f; |
||
692 | for (g = 0; g < num_bands; g++) { |
||
693 | AacPsyBand *band = &pch->band[w+g]; |
||
694 | |||
695 | band->thr = calc_reduced_thr_3gpp(band, coeffs[g].min_snr, reduction); |
||
696 | /* recalculate PE */ |
||
697 | pe += calc_pe_3gpp(band); |
||
698 | a += band->pe_const; |
||
699 | active_lines += band->active_lines; |
||
700 | } |
||
701 | } |
||
702 | |||
703 | /* 5.6.1.3.5 "Second Estimation of the reduction value" */ |
||
704 | for (i = 0; i < 2; i++) { |
||
705 | float pe_no_ah = 0.0f, desired_pe_no_ah; |
||
706 | active_lines = a = 0.0f; |
||
707 | for (w = 0; w < wi->num_windows*16; w += 16) { |
||
708 | for (g = 0; g < num_bands; g++) { |
||
709 | AacPsyBand *band = &pch->band[w+g]; |
||
710 | |||
711 | if (band->avoid_holes != PSY_3GPP_AH_ACTIVE) { |
||
712 | pe_no_ah += band->pe; |
||
713 | a += band->pe_const; |
||
714 | active_lines += band->active_lines; |
||
715 | } |
||
716 | } |
||
717 | } |
||
718 | desired_pe_no_ah = FFMAX(desired_pe - (pe - pe_no_ah), 0.0f); |
||
719 | if (active_lines > 0.0f) |
||
720 | reduction += calc_reduction_3gpp(a, desired_pe_no_ah, pe_no_ah, active_lines); |
||
721 | |||
722 | pe = 0.0f; |
||
723 | for (w = 0; w < wi->num_windows*16; w += 16) { |
||
724 | for (g = 0; g < num_bands; g++) { |
||
725 | AacPsyBand *band = &pch->band[w+g]; |
||
726 | |||
727 | if (active_lines > 0.0f) |
||
728 | band->thr = calc_reduced_thr_3gpp(band, coeffs[g].min_snr, reduction); |
||
729 | pe += calc_pe_3gpp(band); |
||
730 | band->norm_fac = band->active_lines / band->thr; |
||
731 | norm_fac += band->norm_fac; |
||
732 | } |
||
733 | } |
||
734 | delta_pe = desired_pe - pe; |
||
735 | if (fabs(delta_pe) > 0.05f * desired_pe) |
||
736 | break; |
||
737 | } |
||
738 | |||
739 | if (pe < 1.15f * desired_pe) { |
||
740 | /* 6.6.1.3.6 "Final threshold modification by linearization" */ |
||
741 | norm_fac = 1.0f / norm_fac; |
||
742 | for (w = 0; w < wi->num_windows*16; w += 16) { |
||
743 | for (g = 0; g < num_bands; g++) { |
||
744 | AacPsyBand *band = &pch->band[w+g]; |
||
745 | |||
746 | if (band->active_lines > 0.5f) { |
||
747 | float delta_sfb_pe = band->norm_fac * norm_fac * delta_pe; |
||
748 | float thr = band->thr; |
||
749 | |||
750 | thr *= exp2f(delta_sfb_pe / band->active_lines); |
||
751 | if (thr > coeffs[g].min_snr * band->energy && band->avoid_holes == PSY_3GPP_AH_INACTIVE) |
||
752 | thr = FFMAX(band->thr, coeffs[g].min_snr * band->energy); |
||
753 | band->thr = thr; |
||
754 | } |
||
755 | } |
||
756 | } |
||
757 | } else { |
||
758 | /* 5.6.1.3.7 "Further perceptual entropy reduction" */ |
||
759 | g = num_bands; |
||
760 | while (pe > desired_pe && g--) { |
||
761 | for (w = 0; w < wi->num_windows*16; w+= 16) { |
||
762 | AacPsyBand *band = &pch->band[w+g]; |
||
763 | if (band->avoid_holes != PSY_3GPP_AH_NONE && coeffs[g].min_snr < PSY_SNR_1DB) { |
||
764 | coeffs[g].min_snr = PSY_SNR_1DB; |
||
765 | band->thr = band->energy * PSY_SNR_1DB; |
||
766 | pe += band->active_lines * 1.5f - band->pe; |
||
767 | } |
||
768 | } |
||
769 | } |
||
770 | /* TODO: allow more holes (unused without mid/side) */ |
||
771 | } |
||
772 | } |
||
773 | |||
774 | for (w = 0; w < wi->num_windows*16; w += 16) { |
||
775 | for (g = 0; g < num_bands; g++) { |
||
776 | AacPsyBand *band = &pch->band[w+g]; |
||
777 | FFPsyBand *psy_band = &ctx->ch[channel].psy_bands[w+g]; |
||
778 | |||
779 | psy_band->threshold = band->thr; |
||
780 | psy_band->energy = band->energy; |
||
781 | } |
||
782 | } |
||
783 | |||
784 | memcpy(pch->prev_band, pch->band, sizeof(pch->band)); |
||
785 | } |
||
786 | |||
787 | static void psy_3gpp_analyze(FFPsyContext *ctx, int channel, |
||
788 | const float **coeffs, const FFPsyWindowInfo *wi) |
||
789 | { |
||
790 | int ch; |
||
791 | FFPsyChannelGroup *group = ff_psy_find_group(ctx, channel); |
||
792 | |||
793 | for (ch = 0; ch < group->num_ch; ch++) |
||
794 | psy_3gpp_analyze_channel(ctx, channel + ch, coeffs[ch], &wi[ch]); |
||
795 | } |
||
796 | |||
797 | static av_cold void psy_3gpp_end(FFPsyContext *apc) |
||
798 | { |
||
799 | AacPsyContext *pctx = (AacPsyContext*) apc->model_priv_data; |
||
800 | av_freep(&pctx->ch); |
||
801 | av_freep(&apc->model_priv_data); |
||
802 | } |
||
803 | |||
804 | static void lame_apply_block_type(AacPsyChannel *ctx, FFPsyWindowInfo *wi, int uselongblock) |
||
805 | { |
||
806 | int blocktype = ONLY_LONG_SEQUENCE; |
||
807 | if (uselongblock) { |
||
808 | if (ctx->next_window_seq == EIGHT_SHORT_SEQUENCE) |
||
809 | blocktype = LONG_STOP_SEQUENCE; |
||
810 | } else { |
||
811 | blocktype = EIGHT_SHORT_SEQUENCE; |
||
812 | if (ctx->next_window_seq == ONLY_LONG_SEQUENCE) |
||
813 | ctx->next_window_seq = LONG_START_SEQUENCE; |
||
814 | if (ctx->next_window_seq == LONG_STOP_SEQUENCE) |
||
815 | ctx->next_window_seq = EIGHT_SHORT_SEQUENCE; |
||
816 | } |
||
817 | |||
818 | wi->window_type[0] = ctx->next_window_seq; |
||
819 | ctx->next_window_seq = blocktype; |
||
820 | } |
||
821 | |||
822 | static FFPsyWindowInfo psy_lame_window(FFPsyContext *ctx, const float *audio, |
||
823 | const float *la, int channel, int prev_type) |
||
824 | { |
||
825 | AacPsyContext *pctx = (AacPsyContext*) ctx->model_priv_data; |
||
826 | AacPsyChannel *pch = &pctx->ch[channel]; |
||
827 | int grouping = 0; |
||
828 | int uselongblock = 1; |
||
829 | int attacks[AAC_NUM_BLOCKS_SHORT + 1] = { 0 }; |
||
830 | int i; |
||
831 | FFPsyWindowInfo wi = { { 0 } }; |
||
832 | |||
833 | if (la) { |
||
834 | float hpfsmpl[AAC_BLOCK_SIZE_LONG]; |
||
835 | float const *pf = hpfsmpl; |
||
836 | float attack_intensity[(AAC_NUM_BLOCKS_SHORT + 1) * PSY_LAME_NUM_SUBBLOCKS]; |
||
837 | float energy_subshort[(AAC_NUM_BLOCKS_SHORT + 1) * PSY_LAME_NUM_SUBBLOCKS]; |
||
838 | float energy_short[AAC_NUM_BLOCKS_SHORT + 1] = { 0 }; |
||
839 | const float *firbuf = la + (AAC_BLOCK_SIZE_SHORT/4 - PSY_LAME_FIR_LEN); |
||
840 | int att_sum = 0; |
||
841 | |||
842 | /* LAME comment: apply high pass filter of fs/4 */ |
||
843 | psy_hp_filter(firbuf, hpfsmpl, psy_fir_coeffs); |
||
844 | |||
845 | /* Calculate the energies of each sub-shortblock */ |
||
846 | for (i = 0; i < PSY_LAME_NUM_SUBBLOCKS; i++) { |
||
847 | energy_subshort[i] = pch->prev_energy_subshort[i + ((AAC_NUM_BLOCKS_SHORT - 1) * PSY_LAME_NUM_SUBBLOCKS)]; |
||
848 | assert(pch->prev_energy_subshort[i + ((AAC_NUM_BLOCKS_SHORT - 2) * PSY_LAME_NUM_SUBBLOCKS + 1)] > 0); |
||
849 | attack_intensity[i] = energy_subshort[i] / pch->prev_energy_subshort[i + ((AAC_NUM_BLOCKS_SHORT - 2) * PSY_LAME_NUM_SUBBLOCKS + 1)]; |
||
850 | energy_short[0] += energy_subshort[i]; |
||
851 | } |
||
852 | |||
853 | for (i = 0; i < AAC_NUM_BLOCKS_SHORT * PSY_LAME_NUM_SUBBLOCKS; i++) { |
||
854 | float const *const pfe = pf + AAC_BLOCK_SIZE_LONG / (AAC_NUM_BLOCKS_SHORT * PSY_LAME_NUM_SUBBLOCKS); |
||
855 | float p = 1.0f; |
||
856 | for (; pf < pfe; pf++) |
||
857 | p = FFMAX(p, fabsf(*pf)); |
||
858 | pch->prev_energy_subshort[i] = energy_subshort[i + PSY_LAME_NUM_SUBBLOCKS] = p; |
||
859 | energy_short[1 + i / PSY_LAME_NUM_SUBBLOCKS] += p; |
||
860 | /* NOTE: The indexes below are [i + 3 - 2] in the LAME source. |
||
861 | * Obviously the 3 and 2 have some significance, or this would be just [i + 1] |
||
862 | * (which is what we use here). What the 3 stands for is ambiguous, as it is both |
||
863 | * number of short blocks, and the number of sub-short blocks. |
||
864 | * It seems that LAME is comparing each sub-block to sub-block + 1 in the |
||
865 | * previous block. |
||
866 | */ |
||
867 | if (p > energy_subshort[i + 1]) |
||
868 | p = p / energy_subshort[i + 1]; |
||
869 | else if (energy_subshort[i + 1] > p * 10.0f) |
||
870 | p = energy_subshort[i + 1] / (p * 10.0f); |
||
871 | else |
||
872 | p = 0.0; |
||
873 | attack_intensity[i + PSY_LAME_NUM_SUBBLOCKS] = p; |
||
874 | } |
||
875 | |||
876 | /* compare energy between sub-short blocks */ |
||
877 | for (i = 0; i < (AAC_NUM_BLOCKS_SHORT + 1) * PSY_LAME_NUM_SUBBLOCKS; i++) |
||
878 | if (!attacks[i / PSY_LAME_NUM_SUBBLOCKS]) |
||
879 | if (attack_intensity[i] > pch->attack_threshold) |
||
880 | attacks[i / PSY_LAME_NUM_SUBBLOCKS] = (i % PSY_LAME_NUM_SUBBLOCKS) + 1; |
||
881 | |||
882 | /* should have energy change between short blocks, in order to avoid periodic signals */ |
||
883 | /* Good samples to show the effect are Trumpet test songs */ |
||
884 | /* GB: tuned (1) to avoid too many short blocks for test sample TRUMPET */ |
||
885 | /* RH: tuned (2) to let enough short blocks through for test sample FSOL and SNAPS */ |
||
886 | for (i = 1; i < AAC_NUM_BLOCKS_SHORT + 1; i++) { |
||
887 | float const u = energy_short[i - 1]; |
||
888 | float const v = energy_short[i]; |
||
889 | float const m = FFMAX(u, v); |
||
890 | if (m < 40000) { /* (2) */ |
||
891 | if (u < 1.7f * v && v < 1.7f * u) { /* (1) */ |
||
892 | if (i == 1 && attacks[0] < attacks[i]) |
||
893 | attacks[0] = 0; |
||
894 | attacks[i] = 0; |
||
895 | } |
||
896 | } |
||
897 | att_sum += attacks[i]; |
||
898 | } |
||
899 | |||
900 | if (attacks[0] <= pch->prev_attack) |
||
901 | attacks[0] = 0; |
||
902 | |||
903 | att_sum += attacks[0]; |
||
904 | /* 3 below indicates the previous attack happened in the last sub-block of the previous sequence */ |
||
905 | if (pch->prev_attack == 3 || att_sum) { |
||
906 | uselongblock = 0; |
||
907 | |||
908 | for (i = 1; i < AAC_NUM_BLOCKS_SHORT + 1; i++) |
||
909 | if (attacks[i] && attacks[i-1]) |
||
910 | attacks[i] = 0; |
||
911 | } |
||
912 | } else { |
||
913 | /* We have no lookahead info, so just use same type as the previous sequence. */ |
||
914 | uselongblock = !(prev_type == EIGHT_SHORT_SEQUENCE); |
||
915 | } |
||
916 | |||
917 | lame_apply_block_type(pch, &wi, uselongblock); |
||
918 | |||
919 | wi.window_type[1] = prev_type; |
||
920 | if (wi.window_type[0] != EIGHT_SHORT_SEQUENCE) { |
||
921 | wi.num_windows = 1; |
||
922 | wi.grouping[0] = 1; |
||
923 | if (wi.window_type[0] == LONG_START_SEQUENCE) |
||
924 | wi.window_shape = 0; |
||
925 | else |
||
926 | wi.window_shape = 1; |
||
927 | } else { |
||
928 | int lastgrp = 0; |
||
929 | |||
930 | wi.num_windows = 8; |
||
931 | wi.window_shape = 0; |
||
932 | for (i = 0; i < 8; i++) { |
||
933 | if (!((pch->next_grouping >> i) & 1)) |
||
934 | lastgrp = i; |
||
935 | wi.grouping[lastgrp]++; |
||
936 | } |
||
937 | } |
||
938 | |||
939 | /* Determine grouping, based on the location of the first attack, and save for |
||
940 | * the next frame. |
||
941 | * FIXME: Move this to analysis. |
||
942 | * TODO: Tune groupings depending on attack location |
||
943 | * TODO: Handle more than one attack in a group |
||
944 | */ |
||
945 | for (i = 0; i < 9; i++) { |
||
946 | if (attacks[i]) { |
||
947 | grouping = i; |
||
948 | break; |
||
949 | } |
||
950 | } |
||
951 | pch->next_grouping = window_grouping[grouping]; |
||
952 | |||
953 | pch->prev_attack = attacks[8]; |
||
954 | |||
955 | return wi; |
||
956 | } |
||
957 | |||
958 | const FFPsyModel ff_aac_psy_model = |
||
959 | { |
||
960 | .name = "3GPP TS 26.403-inspired model", |
||
961 | .init = psy_3gpp_init, |
||
962 | .window = psy_lame_window, |
||
963 | .analyze = psy_3gpp_analyze, |
||
964 | .end = psy_3gpp_end, |
||
965 | };>>>=>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>=>=>>>>>>=>>>>>=>=>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>=> |