dbf-halloween2015

annotate libs/vorbis/bitrate.c @ 3:c37fe5d8a4ed

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windows port
author John Tsiombikas <nuclear@member.fsf.org>
date Sun, 01 Nov 2015 06:04:28 +0200
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rev   line source
nuclear@1 1 /********************************************************************
nuclear@1 2 * *
nuclear@1 3 * THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE. *
nuclear@1 4 * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS *
nuclear@1 5 * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
nuclear@1 6 * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. *
nuclear@1 7 * *
nuclear@1 8 * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2009 *
nuclear@1 9 * by the Xiph.Org Foundation http://www.xiph.org/ *
nuclear@1 10 * *
nuclear@1 11 ********************************************************************
nuclear@1 12
nuclear@1 13 function: bitrate tracking and management
nuclear@1 14 last mod: $Id: bitrate.c 16227 2009-07-08 06:58:46Z xiphmont $
nuclear@1 15
nuclear@1 16 ********************************************************************/
nuclear@1 17
nuclear@1 18 #include <stdlib.h>
nuclear@1 19 #include <string.h>
nuclear@1 20 #include <math.h>
nuclear@1 21 #include <ogg/ogg.h>
nuclear@1 22 #include "vorbis/codec.h"
nuclear@1 23 #include "codec_internal.h"
nuclear@1 24 #include "os.h"
nuclear@1 25 #include "misc.h"
nuclear@1 26 #include "bitrate.h"
nuclear@1 27
nuclear@1 28 /* compute bitrate tracking setup */
nuclear@1 29 void vorbis_bitrate_init(vorbis_info *vi,bitrate_manager_state *bm){
nuclear@1 30 codec_setup_info *ci=vi->codec_setup;
nuclear@1 31 bitrate_manager_info *bi=&ci->bi;
nuclear@1 32
nuclear@1 33 memset(bm,0,sizeof(*bm));
nuclear@1 34
nuclear@1 35 if(bi && (bi->reservoir_bits>0)){
nuclear@1 36 long ratesamples=vi->rate;
nuclear@1 37 int halfsamples=ci->blocksizes[0]>>1;
nuclear@1 38
nuclear@1 39 bm->short_per_long=ci->blocksizes[1]/ci->blocksizes[0];
nuclear@1 40 bm->managed=1;
nuclear@1 41
nuclear@1 42 bm->avg_bitsper= rint(1.*bi->avg_rate*halfsamples/ratesamples);
nuclear@1 43 bm->min_bitsper= rint(1.*bi->min_rate*halfsamples/ratesamples);
nuclear@1 44 bm->max_bitsper= rint(1.*bi->max_rate*halfsamples/ratesamples);
nuclear@1 45
nuclear@1 46 bm->avgfloat=PACKETBLOBS/2;
nuclear@1 47
nuclear@1 48 /* not a necessary fix, but one that leads to a more balanced
nuclear@1 49 typical initialization */
nuclear@1 50 {
nuclear@1 51 long desired_fill=bi->reservoir_bits*bi->reservoir_bias;
nuclear@1 52 bm->minmax_reservoir=desired_fill;
nuclear@1 53 bm->avg_reservoir=desired_fill;
nuclear@1 54 }
nuclear@1 55
nuclear@1 56 }
nuclear@1 57 }
nuclear@1 58
nuclear@1 59 void vorbis_bitrate_clear(bitrate_manager_state *bm){
nuclear@1 60 memset(bm,0,sizeof(*bm));
nuclear@1 61 return;
nuclear@1 62 }
nuclear@1 63
nuclear@1 64 int vorbis_bitrate_managed(vorbis_block *vb){
nuclear@1 65 vorbis_dsp_state *vd=vb->vd;
nuclear@1 66 private_state *b=vd->backend_state;
nuclear@1 67 bitrate_manager_state *bm=&b->bms;
nuclear@1 68
nuclear@1 69 if(bm && bm->managed)return(1);
nuclear@1 70 return(0);
nuclear@1 71 }
nuclear@1 72
nuclear@1 73 /* finish taking in the block we just processed */
nuclear@1 74 int vorbis_bitrate_addblock(vorbis_block *vb){
nuclear@1 75 vorbis_block_internal *vbi=vb->internal;
nuclear@1 76 vorbis_dsp_state *vd=vb->vd;
nuclear@1 77 private_state *b=vd->backend_state;
nuclear@1 78 bitrate_manager_state *bm=&b->bms;
nuclear@1 79 vorbis_info *vi=vd->vi;
nuclear@1 80 codec_setup_info *ci=vi->codec_setup;
nuclear@1 81 bitrate_manager_info *bi=&ci->bi;
nuclear@1 82
nuclear@1 83 int choice=rint(bm->avgfloat);
nuclear@1 84 long this_bits=oggpack_bytes(vbi->packetblob[choice])*8;
nuclear@1 85 long min_target_bits=(vb->W?bm->min_bitsper*bm->short_per_long:bm->min_bitsper);
nuclear@1 86 long max_target_bits=(vb->W?bm->max_bitsper*bm->short_per_long:bm->max_bitsper);
nuclear@1 87 int samples=ci->blocksizes[vb->W]>>1;
nuclear@1 88 long desired_fill=bi->reservoir_bits*bi->reservoir_bias;
nuclear@1 89 if(!bm->managed){
nuclear@1 90 /* not a bitrate managed stream, but for API simplicity, we'll
nuclear@1 91 buffer the packet to keep the code path clean */
nuclear@1 92
nuclear@1 93 if(bm->vb)return(-1); /* one has been submitted without
nuclear@1 94 being claimed */
nuclear@1 95 bm->vb=vb;
nuclear@1 96 return(0);
nuclear@1 97 }
nuclear@1 98
nuclear@1 99 bm->vb=vb;
nuclear@1 100
nuclear@1 101 /* look ahead for avg floater */
nuclear@1 102 if(bm->avg_bitsper>0){
nuclear@1 103 double slew=0.;
nuclear@1 104 long avg_target_bits=(vb->W?bm->avg_bitsper*bm->short_per_long:bm->avg_bitsper);
nuclear@1 105 double slewlimit= 15./bi->slew_damp;
nuclear@1 106
nuclear@1 107 /* choosing a new floater:
nuclear@1 108 if we're over target, we slew down
nuclear@1 109 if we're under target, we slew up
nuclear@1 110
nuclear@1 111 choose slew as follows: look through packetblobs of this frame
nuclear@1 112 and set slew as the first in the appropriate direction that
nuclear@1 113 gives us the slew we want. This may mean no slew if delta is
nuclear@1 114 already favorable.
nuclear@1 115
nuclear@1 116 Then limit slew to slew max */
nuclear@1 117
nuclear@1 118 if(bm->avg_reservoir+(this_bits-avg_target_bits)>desired_fill){
nuclear@1 119 while(choice>0 && this_bits>avg_target_bits &&
nuclear@1 120 bm->avg_reservoir+(this_bits-avg_target_bits)>desired_fill){
nuclear@1 121 choice--;
nuclear@1 122 this_bits=oggpack_bytes(vbi->packetblob[choice])*8;
nuclear@1 123 }
nuclear@1 124 }else if(bm->avg_reservoir+(this_bits-avg_target_bits)<desired_fill){
nuclear@1 125 while(choice+1<PACKETBLOBS && this_bits<avg_target_bits &&
nuclear@1 126 bm->avg_reservoir+(this_bits-avg_target_bits)<desired_fill){
nuclear@1 127 choice++;
nuclear@1 128 this_bits=oggpack_bytes(vbi->packetblob[choice])*8;
nuclear@1 129 }
nuclear@1 130 }
nuclear@1 131
nuclear@1 132 slew=rint(choice-bm->avgfloat)/samples*vi->rate;
nuclear@1 133 if(slew<-slewlimit)slew=-slewlimit;
nuclear@1 134 if(slew>slewlimit)slew=slewlimit;
nuclear@1 135 choice=rint(bm->avgfloat+= slew/vi->rate*samples);
nuclear@1 136 this_bits=oggpack_bytes(vbi->packetblob[choice])*8;
nuclear@1 137 }
nuclear@1 138
nuclear@1 139
nuclear@1 140
nuclear@1 141 /* enforce min(if used) on the current floater (if used) */
nuclear@1 142 if(bm->min_bitsper>0){
nuclear@1 143 /* do we need to force the bitrate up? */
nuclear@1 144 if(this_bits<min_target_bits){
nuclear@1 145 while(bm->minmax_reservoir-(min_target_bits-this_bits)<0){
nuclear@1 146 choice++;
nuclear@1 147 if(choice>=PACKETBLOBS)break;
nuclear@1 148 this_bits=oggpack_bytes(vbi->packetblob[choice])*8;
nuclear@1 149 }
nuclear@1 150 }
nuclear@1 151 }
nuclear@1 152
nuclear@1 153 /* enforce max (if used) on the current floater (if used) */
nuclear@1 154 if(bm->max_bitsper>0){
nuclear@1 155 /* do we need to force the bitrate down? */
nuclear@1 156 if(this_bits>max_target_bits){
nuclear@1 157 while(bm->minmax_reservoir+(this_bits-max_target_bits)>bi->reservoir_bits){
nuclear@1 158 choice--;
nuclear@1 159 if(choice<0)break;
nuclear@1 160 this_bits=oggpack_bytes(vbi->packetblob[choice])*8;
nuclear@1 161 }
nuclear@1 162 }
nuclear@1 163 }
nuclear@1 164
nuclear@1 165 /* Choice of packetblobs now made based on floater, and min/max
nuclear@1 166 requirements. Now boundary check extreme choices */
nuclear@1 167
nuclear@1 168 if(choice<0){
nuclear@1 169 /* choosing a smaller packetblob is insufficient to trim bitrate.
nuclear@1 170 frame will need to be truncated */
nuclear@1 171 long maxsize=(max_target_bits+(bi->reservoir_bits-bm->minmax_reservoir))/8;
nuclear@1 172 bm->choice=choice=0;
nuclear@1 173
nuclear@1 174 if(oggpack_bytes(vbi->packetblob[choice])>maxsize){
nuclear@1 175
nuclear@1 176 oggpack_writetrunc(vbi->packetblob[choice],maxsize*8);
nuclear@1 177 this_bits=oggpack_bytes(vbi->packetblob[choice])*8;
nuclear@1 178 }
nuclear@1 179 }else{
nuclear@1 180 long minsize=(min_target_bits-bm->minmax_reservoir+7)/8;
nuclear@1 181 if(choice>=PACKETBLOBS)
nuclear@1 182 choice=PACKETBLOBS-1;
nuclear@1 183
nuclear@1 184 bm->choice=choice;
nuclear@1 185
nuclear@1 186 /* prop up bitrate according to demand. pad this frame out with zeroes */
nuclear@1 187 minsize-=oggpack_bytes(vbi->packetblob[choice]);
nuclear@1 188 while(minsize-->0)oggpack_write(vbi->packetblob[choice],0,8);
nuclear@1 189 this_bits=oggpack_bytes(vbi->packetblob[choice])*8;
nuclear@1 190
nuclear@1 191 }
nuclear@1 192
nuclear@1 193 /* now we have the final packet and the final packet size. Update statistics */
nuclear@1 194 /* min and max reservoir */
nuclear@1 195 if(bm->min_bitsper>0 || bm->max_bitsper>0){
nuclear@1 196
nuclear@1 197 if(max_target_bits>0 && this_bits>max_target_bits){
nuclear@1 198 bm->minmax_reservoir+=(this_bits-max_target_bits);
nuclear@1 199 }else if(min_target_bits>0 && this_bits<min_target_bits){
nuclear@1 200 bm->minmax_reservoir+=(this_bits-min_target_bits);
nuclear@1 201 }else{
nuclear@1 202 /* inbetween; we want to take reservoir toward but not past desired_fill */
nuclear@1 203 if(bm->minmax_reservoir>desired_fill){
nuclear@1 204 if(max_target_bits>0){ /* logical bulletproofing against initialization state */
nuclear@1 205 bm->minmax_reservoir+=(this_bits-max_target_bits);
nuclear@1 206 if(bm->minmax_reservoir<desired_fill)bm->minmax_reservoir=desired_fill;
nuclear@1 207 }else{
nuclear@1 208 bm->minmax_reservoir=desired_fill;
nuclear@1 209 }
nuclear@1 210 }else{
nuclear@1 211 if(min_target_bits>0){ /* logical bulletproofing against initialization state */
nuclear@1 212 bm->minmax_reservoir+=(this_bits-min_target_bits);
nuclear@1 213 if(bm->minmax_reservoir>desired_fill)bm->minmax_reservoir=desired_fill;
nuclear@1 214 }else{
nuclear@1 215 bm->minmax_reservoir=desired_fill;
nuclear@1 216 }
nuclear@1 217 }
nuclear@1 218 }
nuclear@1 219 }
nuclear@1 220
nuclear@1 221 /* avg reservoir */
nuclear@1 222 if(bm->avg_bitsper>0){
nuclear@1 223 long avg_target_bits=(vb->W?bm->avg_bitsper*bm->short_per_long:bm->avg_bitsper);
nuclear@1 224 bm->avg_reservoir+=this_bits-avg_target_bits;
nuclear@1 225 }
nuclear@1 226
nuclear@1 227 return(0);
nuclear@1 228 }
nuclear@1 229
nuclear@1 230 int vorbis_bitrate_flushpacket(vorbis_dsp_state *vd,ogg_packet *op){
nuclear@1 231 private_state *b=vd->backend_state;
nuclear@1 232 bitrate_manager_state *bm=&b->bms;
nuclear@1 233 vorbis_block *vb=bm->vb;
nuclear@1 234 int choice=PACKETBLOBS/2;
nuclear@1 235 if(!vb)return 0;
nuclear@1 236
nuclear@1 237 if(op){
nuclear@1 238 vorbis_block_internal *vbi=vb->internal;
nuclear@1 239
nuclear@1 240 if(vorbis_bitrate_managed(vb))
nuclear@1 241 choice=bm->choice;
nuclear@1 242
nuclear@1 243 op->packet=oggpack_get_buffer(vbi->packetblob[choice]);
nuclear@1 244 op->bytes=oggpack_bytes(vbi->packetblob[choice]);
nuclear@1 245 op->b_o_s=0;
nuclear@1 246 op->e_o_s=vb->eofflag;
nuclear@1 247 op->granulepos=vb->granulepos;
nuclear@1 248 op->packetno=vb->sequence; /* for sake of completeness */
nuclear@1 249 }
nuclear@1 250
nuclear@1 251 bm->vb=0;
nuclear@1 252 return(1);
nuclear@1 253 }