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| 1 : | edgomez | 221 | /***************************************************************************** |
| 2 : | * | ||
| 3 : | * XVID MPEG-4 VIDEO CODEC | ||
| 4 : | * - Rate Controler module - | ||
| 5 : | * | ||
| 6 : | edgomez | 423 | * Copyright(C) 2002 Michael Militzer |
| 7 : | * | ||
| 8 : | * This program is an implementation of a part of one or more MPEG-4 | ||
| 9 : | * Video tools as specified in ISO/IEC 14496-2 standard. Those intending | ||
| 10 : | * to use this software module in hardware or software products are | ||
| 11 : | * advised that its use may infringe existing patents or copyrights, and | ||
| 12 : | * any such use would be at such party's own risk. The original | ||
| 13 : | * developer of this software module and his/her company, and subsequent | ||
| 14 : | * editors and their companies, will have no liability for use of this | ||
| 15 : | * software or modifications or derivatives thereof. | ||
| 16 : | * | ||
| 17 : | * This program is free software; you can redistribute it and/or modify | ||
| 18 : | edgomez | 221 | * it under the terms of the GNU General Public License as published by |
| 19 : | edgomez | 423 | * the Free Software Foundation; either version 2 of the License, or |
| 20 : | edgomez | 221 | * (at your option) any later version. |
| 21 : | * | ||
| 22 : | * This program is distributed in the hope that it will be useful, | ||
| 23 : | edgomez | 423 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 24 : | edgomez | 221 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 25 : | * GNU General Public License for more details. | ||
| 26 : | * | ||
| 27 : | * You should have received a copy of the GNU General Public License | ||
| 28 : | edgomez | 423 | * along with this program; if not, write to the Free Software |
| 29 : | edgomez | 221 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 30 : | * | ||
| 31 : | edgomez | 423 | * $Id: ratecontrol.c,v 1.14 2002-09-05 21:23:03 edgomez Exp $ |
| 32 : | edgomez | 221 | * |
| 33 : | ****************************************************************************/ | ||
| 34 : | |||
| 35 : | #include <math.h> | ||
| 36 : | #include "ratecontrol.h" | ||
| 37 : | |||
| 38 : | /***************************************************************************** | ||
| 39 : | * Local prototype - defined at the end of the file | ||
| 40 : | ****************************************************************************/ | ||
| 41 : | |||
| 42 : | static int get_initial_quant(int bpp); | ||
| 43 : | |||
| 44 : | /***************************************************************************** | ||
| 45 : | * RateControlInit | ||
| 46 : | * | ||
| 47 : | * This function initialize the structure members of 'rate_control' argument | ||
| 48 : | * according to the other arguments. | ||
| 49 : | * | ||
| 50 : | * Returned value : None | ||
| 51 : | * | ||
| 52 : | ****************************************************************************/ | ||
| 53 : | |||
| 54 : | void | ||
| 55 : | RateControlInit(RateControl * rate_control, | ||
| 56 : | uint32_t target_rate, | ||
| 57 : | uint32_t reaction_delay_factor, | ||
| 58 : | uint32_t averaging_period, | ||
| 59 : | uint32_t buffer, | ||
| 60 : | int framerate, | ||
| 61 : | int max_quant, | ||
| 62 : | int min_quant) | ||
| 63 : | { | ||
| 64 : | int i; | ||
| 65 : | |||
| 66 : | rate_control->frames = 0; | ||
| 67 : | rate_control->total_size = 0; | ||
| 68 : | |||
| 69 : | rate_control->framerate = framerate / 1000.0; | ||
| 70 : | rate_control->target_rate = target_rate; | ||
| 71 : | |||
| 72 : | rate_control->rtn_quant = get_initial_quant(0); | ||
| 73 : | rate_control->max_quant = max_quant; | ||
| 74 : | rate_control->min_quant = min_quant; | ||
| 75 : | |||
| 76 : | for (i = 0; i < 32; ++i) { | ||
| 77 : | rate_control->quant_error[i] = 0.0; | ||
| 78 : | } | ||
| 79 : | |||
| 80 : | rate_control->target_framesize = | ||
| 81 : | (double) target_rate / 8.0 / rate_control->framerate; | ||
| 82 : | rate_control->sequence_quality = 2.0 / (double) rate_control->rtn_quant; | ||
| 83 : | rate_control->avg_framesize = rate_control->target_framesize; | ||
| 84 : | |||
| 85 : | rate_control->reaction_delay_factor = reaction_delay_factor; | ||
| 86 : | rate_control->averaging_period = averaging_period; | ||
| 87 : | rate_control->buffer = buffer; | ||
| 88 : | } | ||
| 89 : | |||
| 90 : | /***************************************************************************** | ||
| 91 : | * RateControlGetQ | ||
| 92 : | * | ||
| 93 : | * Returned value : - the current 'rate_control' quantizer value | ||
| 94 : | * | ||
| 95 : | ****************************************************************************/ | ||
| 96 : | |||
| 97 : | int | ||
| 98 : | RateControlGetQ(RateControl * rate_control, | ||
| 99 : | int keyframe) | ||
| 100 : | { | ||
| 101 : | return rate_control->rtn_quant; | ||
| 102 : | } | ||
| 103 : | |||
| 104 : | /***************************************************************************** | ||
| 105 : | * RateControlUpdate | ||
| 106 : | * | ||
| 107 : | * This function is called once a coded frame to update all internal | ||
| 108 : | * parameters of 'rate_control'. | ||
| 109 : | * | ||
| 110 : | * Returned value : None | ||
| 111 : | * | ||
| 112 : | ****************************************************************************/ | ||
| 113 : | |||
| 114 : | void | ||
| 115 : | RateControlUpdate(RateControl * rate_control, | ||
| 116 : | int16_t quant, | ||
| 117 : | int frame_size, | ||
| 118 : | int keyframe) | ||
| 119 : | { | ||
| 120 : | int64_t deviation; | ||
| 121 : | double overflow, averaging_period, reaction_delay_factor; | ||
| 122 : | double quality_scale, base_quality, target_quality; | ||
| 123 : | int32_t rtn_quant; | ||
| 124 : | |||
| 125 : | rate_control->frames++; | ||
| 126 : | rate_control->total_size += frame_size; | ||
| 127 : | |||
| 128 : | deviation = | ||
| 129 : | (int64_t) ((double) rate_control->total_size - | ||
| 130 : | ((double) | ||
| 131 : | ((double) rate_control->target_rate / 8.0 / | ||
| 132 : | (double) rate_control->framerate) * | ||
| 133 : | (double) rate_control->frames)); | ||
| 134 : | |||
| 135 : | DEBUGCBR((int32_t) (rate_control->frames - 1), rate_control->rtn_quant, | ||
| 136 : | (int32_t) deviation); | ||
| 137 : | |||
| 138 : | if (rate_control->rtn_quant >= 2) { | ||
| 139 : | averaging_period = (double) rate_control->averaging_period; | ||
| 140 : | rate_control->sequence_quality -= | ||
| 141 : | rate_control->sequence_quality / averaging_period; | ||
| 142 : | rate_control->sequence_quality += | ||
| 143 : | 2.0 / (double) rate_control->rtn_quant / averaging_period; | ||
| 144 : | if (rate_control->sequence_quality < 0.1) | ||
| 145 : | rate_control->sequence_quality = 0.1; | ||
| 146 : | |||
| 147 : | if (!keyframe) { | ||
| 148 : | reaction_delay_factor = | ||
| 149 : | (double) rate_control->reaction_delay_factor; | ||
| 150 : | rate_control->avg_framesize -= | ||
| 151 : | rate_control->avg_framesize / reaction_delay_factor; | ||
| 152 : | rate_control->avg_framesize += frame_size / reaction_delay_factor; | ||
| 153 : | } | ||
| 154 : | } | ||
| 155 : | |||
| 156 : | quality_scale = | ||
| 157 : | rate_control->target_framesize / rate_control->avg_framesize * | ||
| 158 : | rate_control->target_framesize / rate_control->avg_framesize; | ||
| 159 : | |||
| 160 : | base_quality = rate_control->sequence_quality; | ||
| 161 : | if (quality_scale >= 1.0) { | ||
| 162 : | base_quality = 1.0 - (1.0 - base_quality) / quality_scale; | ||
| 163 : | } else { | ||
| 164 : | base_quality = 0.06452 + (base_quality - 0.06452) * quality_scale; | ||
| 165 : | } | ||
| 166 : | |||
| 167 : | overflow = -((double) deviation / (double) rate_control->buffer); | ||
| 168 : | |||
| 169 : | target_quality = | ||
| 170 : | base_quality + (base_quality - | ||
| 171 : | 0.06452) * overflow / rate_control->target_framesize; | ||
| 172 : | |||
| 173 : | if (target_quality > 2.0) | ||
| 174 : | target_quality = 2.0; | ||
| 175 : | else if (target_quality < 0.06452) | ||
| 176 : | target_quality = 0.06452; | ||
| 177 : | |||
| 178 : | rtn_quant = (int32_t) (2.0 / target_quality); | ||
| 179 : | |||
| 180 : | if (rtn_quant < 31) { | ||
| 181 : | rate_control->quant_error[rtn_quant] += | ||
| 182 : | 2.0 / target_quality - rtn_quant; | ||
| 183 : | if (rate_control->quant_error[rtn_quant] >= 1.0) { | ||
| 184 : | rate_control->quant_error[rtn_quant] -= 1.0; | ||
| 185 : | rtn_quant++; | ||
| 186 : | } | ||
| 187 : | } | ||
| 188 : | |||
| 189 : | if (rtn_quant > rate_control->rtn_quant + 1) | ||
| 190 : | rtn_quant = rate_control->rtn_quant + 1; | ||
| 191 : | else if (rtn_quant < rate_control->rtn_quant - 1) | ||
| 192 : | rtn_quant = rate_control->rtn_quant - 1; | ||
| 193 : | |||
| 194 : | if (rtn_quant > rate_control->max_quant) | ||
| 195 : | rtn_quant = rate_control->max_quant; | ||
| 196 : | else if (rtn_quant < rate_control->min_quant) | ||
| 197 : | rtn_quant = rate_control->min_quant; | ||
| 198 : | |||
| 199 : | rate_control->rtn_quant = rtn_quant; | ||
| 200 : | } | ||
| 201 : | |||
| 202 : | /***************************************************************************** | ||
| 203 : | * Local functions | ||
| 204 : | ****************************************************************************/ | ||
| 205 : | |||
| 206 : | static int | ||
| 207 : | get_initial_quant(int bpp) | ||
| 208 : | { | ||
| 209 : | return 5; | ||
| 210 : | } |
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