--- /dev/null
+/********************************************************************
+ * *
+ * THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE. *
+ * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS *
+ * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
+ * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. *
+ * *
+ * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2009 *
+ * by the Xiph.Org Foundation http://www.xiph.org/ *
+ * *
+ ********************************************************************
+
+ function: bitrate tracking and management
+ last mod: $Id: bitrate.c 16227 2009-07-08 06:58:46Z xiphmont $
+
+ ********************************************************************/
+
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#include <ogg/ogg.h>
+#include "vorbis/codec.h"
+#include "codec_internal.h"
+#include "os.h"
+#include "misc.h"
+#include "bitrate.h"
+
+/* compute bitrate tracking setup */
+void vorbis_bitrate_init(vorbis_info *vi,bitrate_manager_state *bm){
+ codec_setup_info *ci=vi->codec_setup;
+ bitrate_manager_info *bi=&ci->bi;
+
+ memset(bm,0,sizeof(*bm));
+
+ if(bi && (bi->reservoir_bits>0)){
+ long ratesamples=vi->rate;
+ int halfsamples=ci->blocksizes[0]>>1;
+
+ bm->short_per_long=ci->blocksizes[1]/ci->blocksizes[0];
+ bm->managed=1;
+
+ bm->avg_bitsper= rint(1.*bi->avg_rate*halfsamples/ratesamples);
+ bm->min_bitsper= rint(1.*bi->min_rate*halfsamples/ratesamples);
+ bm->max_bitsper= rint(1.*bi->max_rate*halfsamples/ratesamples);
+
+ bm->avgfloat=PACKETBLOBS/2;
+
+ /* not a necessary fix, but one that leads to a more balanced
+ typical initialization */
+ {
+ long desired_fill=bi->reservoir_bits*bi->reservoir_bias;
+ bm->minmax_reservoir=desired_fill;
+ bm->avg_reservoir=desired_fill;
+ }
+
+ }
+}
+
+void vorbis_bitrate_clear(bitrate_manager_state *bm){
+ memset(bm,0,sizeof(*bm));
+ return;
+}
+
+int vorbis_bitrate_managed(vorbis_block *vb){
+ vorbis_dsp_state *vd=vb->vd;
+ private_state *b=vd->backend_state;
+ bitrate_manager_state *bm=&b->bms;
+
+ if(bm && bm->managed)return(1);
+ return(0);
+}
+
+/* finish taking in the block we just processed */
+int vorbis_bitrate_addblock(vorbis_block *vb){
+ vorbis_block_internal *vbi=vb->internal;
+ vorbis_dsp_state *vd=vb->vd;
+ private_state *b=vd->backend_state;
+ bitrate_manager_state *bm=&b->bms;
+ vorbis_info *vi=vd->vi;
+ codec_setup_info *ci=vi->codec_setup;
+ bitrate_manager_info *bi=&ci->bi;
+
+ int choice=rint(bm->avgfloat);
+ long this_bits=oggpack_bytes(vbi->packetblob[choice])*8;
+ long min_target_bits=(vb->W?bm->min_bitsper*bm->short_per_long:bm->min_bitsper);
+ long max_target_bits=(vb->W?bm->max_bitsper*bm->short_per_long:bm->max_bitsper);
+ int samples=ci->blocksizes[vb->W]>>1;
+ long desired_fill=bi->reservoir_bits*bi->reservoir_bias;
+ if(!bm->managed){
+ /* not a bitrate managed stream, but for API simplicity, we'll
+ buffer the packet to keep the code path clean */
+
+ if(bm->vb)return(-1); /* one has been submitted without
+ being claimed */
+ bm->vb=vb;
+ return(0);
+ }
+
+ bm->vb=vb;
+
+ /* look ahead for avg floater */
+ if(bm->avg_bitsper>0){
+ double slew=0.;
+ long avg_target_bits=(vb->W?bm->avg_bitsper*bm->short_per_long:bm->avg_bitsper);
+ double slewlimit= 15./bi->slew_damp;
+
+ /* choosing a new floater:
+ if we're over target, we slew down
+ if we're under target, we slew up
+
+ choose slew as follows: look through packetblobs of this frame
+ and set slew as the first in the appropriate direction that
+ gives us the slew we want. This may mean no slew if delta is
+ already favorable.
+
+ Then limit slew to slew max */
+
+ if(bm->avg_reservoir+(this_bits-avg_target_bits)>desired_fill){
+ while(choice>0 && this_bits>avg_target_bits &&
+ bm->avg_reservoir+(this_bits-avg_target_bits)>desired_fill){
+ choice--;
+ this_bits=oggpack_bytes(vbi->packetblob[choice])*8;
+ }
+ }else if(bm->avg_reservoir+(this_bits-avg_target_bits)<desired_fill){
+ while(choice+1<PACKETBLOBS && this_bits<avg_target_bits &&
+ bm->avg_reservoir+(this_bits-avg_target_bits)<desired_fill){
+ choice++;
+ this_bits=oggpack_bytes(vbi->packetblob[choice])*8;
+ }
+ }
+
+ slew=rint(choice-bm->avgfloat)/samples*vi->rate;
+ if(slew<-slewlimit)slew=-slewlimit;
+ if(slew>slewlimit)slew=slewlimit;
+ choice=rint(bm->avgfloat+= slew/vi->rate*samples);
+ this_bits=oggpack_bytes(vbi->packetblob[choice])*8;
+ }
+
+
+
+ /* enforce min(if used) on the current floater (if used) */
+ if(bm->min_bitsper>0){
+ /* do we need to force the bitrate up? */
+ if(this_bits<min_target_bits){
+ while(bm->minmax_reservoir-(min_target_bits-this_bits)<0){
+ choice++;
+ if(choice>=PACKETBLOBS)break;
+ this_bits=oggpack_bytes(vbi->packetblob[choice])*8;
+ }
+ }
+ }
+
+ /* enforce max (if used) on the current floater (if used) */
+ if(bm->max_bitsper>0){
+ /* do we need to force the bitrate down? */
+ if(this_bits>max_target_bits){
+ while(bm->minmax_reservoir+(this_bits-max_target_bits)>bi->reservoir_bits){
+ choice--;
+ if(choice<0)break;
+ this_bits=oggpack_bytes(vbi->packetblob[choice])*8;
+ }
+ }
+ }
+
+ /* Choice of packetblobs now made based on floater, and min/max
+ requirements. Now boundary check extreme choices */
+
+ if(choice<0){
+ /* choosing a smaller packetblob is insufficient to trim bitrate.
+ frame will need to be truncated */
+ long maxsize=(max_target_bits+(bi->reservoir_bits-bm->minmax_reservoir))/8;
+ bm->choice=choice=0;
+
+ if(oggpack_bytes(vbi->packetblob[choice])>maxsize){
+
+ oggpack_writetrunc(vbi->packetblob[choice],maxsize*8);
+ this_bits=oggpack_bytes(vbi->packetblob[choice])*8;
+ }
+ }else{
+ long minsize=(min_target_bits-bm->minmax_reservoir+7)/8;
+ if(choice>=PACKETBLOBS)
+ choice=PACKETBLOBS-1;
+
+ bm->choice=choice;
+
+ /* prop up bitrate according to demand. pad this frame out with zeroes */
+ minsize-=oggpack_bytes(vbi->packetblob[choice]);
+ while(minsize-->0)oggpack_write(vbi->packetblob[choice],0,8);
+ this_bits=oggpack_bytes(vbi->packetblob[choice])*8;
+
+ }
+
+ /* now we have the final packet and the final packet size. Update statistics */
+ /* min and max reservoir */
+ if(bm->min_bitsper>0 || bm->max_bitsper>0){
+
+ if(max_target_bits>0 && this_bits>max_target_bits){
+ bm->minmax_reservoir+=(this_bits-max_target_bits);
+ }else if(min_target_bits>0 && this_bits<min_target_bits){
+ bm->minmax_reservoir+=(this_bits-min_target_bits);
+ }else{
+ /* inbetween; we want to take reservoir toward but not past desired_fill */
+ if(bm->minmax_reservoir>desired_fill){
+ if(max_target_bits>0){ /* logical bulletproofing against initialization state */
+ bm->minmax_reservoir+=(this_bits-max_target_bits);
+ if(bm->minmax_reservoir<desired_fill)bm->minmax_reservoir=desired_fill;
+ }else{
+ bm->minmax_reservoir=desired_fill;
+ }
+ }else{
+ if(min_target_bits>0){ /* logical bulletproofing against initialization state */
+ bm->minmax_reservoir+=(this_bits-min_target_bits);
+ if(bm->minmax_reservoir>desired_fill)bm->minmax_reservoir=desired_fill;
+ }else{
+ bm->minmax_reservoir=desired_fill;
+ }
+ }
+ }
+ }
+
+ /* avg reservoir */
+ if(bm->avg_bitsper>0){
+ long avg_target_bits=(vb->W?bm->avg_bitsper*bm->short_per_long:bm->avg_bitsper);
+ bm->avg_reservoir+=this_bits-avg_target_bits;
+ }
+
+ return(0);
+}
+
+int vorbis_bitrate_flushpacket(vorbis_dsp_state *vd,ogg_packet *op){
+ private_state *b=vd->backend_state;
+ bitrate_manager_state *bm=&b->bms;
+ vorbis_block *vb=bm->vb;
+ int choice=PACKETBLOBS/2;
+ if(!vb)return 0;
+
+ if(op){
+ vorbis_block_internal *vbi=vb->internal;
+
+ if(vorbis_bitrate_managed(vb))
+ choice=bm->choice;
+
+ op->packet=oggpack_get_buffer(vbi->packetblob[choice]);
+ op->bytes=oggpack_bytes(vbi->packetblob[choice]);
+ op->b_o_s=0;
+ op->e_o_s=vb->eofflag;
+ op->granulepos=vb->granulepos;
+ op->packetno=vb->sequence; /* for sake of completeness */
+ }
+
+ bm->vb=0;
+ return(1);
+}
projects / laserbrain_demo / blobdiff