ref: ccfb9118a3bf19a0a943b3a7bbfddd82cf4ddc5b
dir: /sys/src/cmd/audio/libvorbis/bitrate.c/
/********************************************************************
* *
* 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 1994-2002 *
* by the XIPHOPHORUS Company http://www.xiph.org/ *
* *
********************************************************************
function: bitrate tracking and management
last mod: $Id: bitrate.c,v 1.20 2002/07/18 02:12:20 xiphmont Exp $
********************************************************************/
#include <stdio.h>
#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"
static long BINBYTES(bitrate_manager_state *bm,long pos,long bin){
int bins=bm->queue_bins;
return(bm->queue_binned[pos*bins+bin]);
}
#define LIMITBYTES(pos,bin) (bm->minmax_binstack[(pos)*bins*2+((bin)+bins)])
static long LACING_ADJUST(long bytes){
int addto=bytes/255+1;
return(bytes+addto);
}
static int floater_interpolate(bitrate_manager_state *bm,vorbis_info *vi,
double desired_rate){
int bin=rint(bm->avgfloat);
double lobitrate,hibitrate;
lobitrate=(double)(bm->avg_binacc[bin]*8)/bm->avg_sampleacc*vi->rate;
while(lobitrate>desired_rate && bin>0){
bin--;
lobitrate=(double)(bm->avg_binacc[bin]*8)/bm->avg_sampleacc*vi->rate;
}
if(bin+1<bm->queue_bins){
hibitrate=(double)(bm->avg_binacc[bin+1]*8)/bm->avg_sampleacc*vi->rate;
if(fabs(hibitrate-desired_rate) < fabs(lobitrate-desired_rate))bin++;
}
return(bin);
}
/* try out a new limit */
static long limit_sum(bitrate_manager_state *bm,int limit){
int i=bm->minmax_stackptr;
long acc=bm->minmax_acctotal;
long bins=bm->queue_bins;
acc-=LIMITBYTES(i,0);
acc+=LIMITBYTES(i,limit);
while(i-->0){
if(bm->minmax_limitstack[i]<=limit)break;
acc-=LIMITBYTES(i,bm->minmax_limitstack[i]);
acc+=LIMITBYTES(i,limit);
}
return(acc);
}
/* compute bitrate tracking setup, allocate circular packet size queue */
void vorbis_bitrate_init(vorbis_info *vi,bitrate_manager_state *bm){
int i;
codec_setup_info *ci=vi->codec_setup;
bitrate_manager_info *bi=&ci->bi;
long maxlatency;
memset(bm,0,sizeof(*bm));
if(bi){
bm->avg_sampledesired=bi->queue_avg_time*vi->rate;
bm->avg_centerdesired=bi->queue_avg_time*vi->rate*bi->queue_avg_center;
bm->minmax_sampledesired=bi->queue_minmax_time*vi->rate;
/* first find the max possible needed queue size */
maxlatency=max(bm->avg_sampledesired-bm->avg_centerdesired,
bm->minmax_sampledesired)+bm->avg_centerdesired;
if(maxlatency>0 &&
(bi->queue_avgmin>0 || bi->queue_avgmax>0 || bi->queue_hardmax>0 ||
bi->queue_hardmin>0)){
long maxpackets=maxlatency/(ci->blocksizes[0]>>1)+3;
long bins=PACKETBLOBS;
bm->queue_size=maxpackets;
bm->queue_bins=bins;
bm->queue_binned=_ogg_calloc(maxpackets,bins*sizeof(*bm->queue_binned));
bm->queue_actual=_ogg_calloc(maxpackets,sizeof(*bm->queue_actual));
if((bi->queue_avgmin>0 || bi->queue_avgmax>0) &&
bi->queue_avg_time>0){
bm->avg_binacc=_ogg_calloc(bins,sizeof(*bm->avg_binacc));
bm->avgfloat=PACKETBLOBS/2;
}else{
bm->avg_tail= -1;
}
if((bi->queue_hardmin>0 || bi->queue_hardmax>0) &&
bi->queue_minmax_time>0){
bm->minmax_binstack=_ogg_calloc((bins*2+1)*bins*2,
sizeof(*bm->minmax_binstack));
bm->minmax_posstack=_ogg_calloc((bins*2+1),
sizeof(*bm->minmax_posstack));
bm->minmax_limitstack=_ogg_calloc((bins*2+1),
sizeof(*bm->minmax_limitstack));
}else{
bm->minmax_tail= -1;
}
/* space for the packet queueing */
bm->packetbuffers=_ogg_calloc(maxpackets,sizeof(*bm->packetbuffers));
bm->packets=_ogg_calloc(maxpackets,sizeof(*bm->packets));
for(i=0;i<maxpackets;i++)
oggpack_writeinit(bm->packetbuffers+i);
}else{
bm->packetbuffers=_ogg_calloc(1,sizeof(*bm->packetbuffers));
bm->packets=_ogg_calloc(1,sizeof(*bm->packets));
oggpack_writeinit(bm->packetbuffers);
}
}
}
void vorbis_bitrate_clear(bitrate_manager_state *bm){
int i;
if(bm){
if(bm->queue_binned)_ogg_free(bm->queue_binned);
if(bm->queue_actual)_ogg_free(bm->queue_actual);
if(bm->avg_binacc)_ogg_free(bm->avg_binacc);
if(bm->minmax_binstack)_ogg_free(bm->minmax_binstack);
if(bm->minmax_posstack)_ogg_free(bm->minmax_posstack);
if(bm->minmax_limitstack)_ogg_free(bm->minmax_limitstack);
if(bm->packetbuffers){
if(bm->queue_size==0){
oggpack_writeclear(bm->packetbuffers);
}else{
for(i=0;i<bm->queue_size;i++)
oggpack_writeclear(bm->packetbuffers+i);
}
_ogg_free(bm->packetbuffers);
}
if(bm->packets)_ogg_free(bm->packets);
memset(bm,0,sizeof(*bm));
}
}
int vorbis_bitrate_managed(vorbis_block *vb){
vorbis_dsp_state *vd=vb->vd;
backend_lookup_state *b=vd->backend_state;
bitrate_manager_state *bm=&b->bms;
if(bm->queue_binned)return(1);
return(0);
}
/* finish taking in the block we just processed */
int vorbis_bitrate_addblock(vorbis_block *vb){
int i;
vorbis_block_internal *vbi=vb->internal;
vorbis_dsp_state *vd=vb->vd;
backend_lookup_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 eofflag=vb->eofflag;
int head=bm->queue_head;
int next_head=head+1;
int bins=bm->queue_bins;
int minmax_head,new_minmax_head;
ogg_uint32_t *head_ptr;
oggpack_buffer temp;
if(!bm->queue_binned){
oggpack_buffer temp;
/* not a bitrate managed stream, but for API simplicity, we'll
buffer one packet to keep the code path clean */
if(bm->queue_head)return(-1); /* one has been submitted without
being claimed */
bm->queue_head++;
bm->packets[0].packet=oggpack_get_buffer(&vb->opb);
bm->packets[0].bytes=oggpack_bytes(&vb->opb);
bm->packets[0].b_o_s=0;
bm->packets[0].e_o_s=vb->eofflag;
bm->packets[0].granulepos=vb->granulepos;
bm->packets[0].packetno=vb->sequence; /* for sake of completeness */
memcpy(&temp,bm->packetbuffers,sizeof(vb->opb));
memcpy(bm->packetbuffers,&vb->opb,sizeof(vb->opb));
memcpy(&vb->opb,&temp,sizeof(vb->opb));
return(0);
}
/* add encoded packet to head */
if(next_head>=bm->queue_size)next_head=0;
head_ptr=bm->queue_binned+bins*head;
/* is there room to add a block? In proper use of the API, this will
never come up... but guard it anyway */
if(next_head==bm->avg_tail || next_head==bm->minmax_tail)return(-1);
/* add the block to the toplevel queue */
bm->queue_head=next_head;
bm->queue_actual[head]=(vb->W?0x80000000UL:0);
/* buffer packet fields */
bm->packets[head].packet=oggpack_get_buffer(&vb->opb);
bm->packets[head].bytes=oggpack_bytes(&vb->opb);
bm->packets[head].b_o_s=0;
bm->packets[head].e_o_s=vb->eofflag;
bm->packets[head].granulepos=vb->granulepos;
bm->packets[head].packetno=vb->sequence; /* for sake of completeness */
/* swap packet buffers */
memcpy(&temp,bm->packetbuffers+head,sizeof(vb->opb));
memcpy(bm->packetbuffers+head,&vb->opb,sizeof(vb->opb));
memcpy(&vb->opb,&temp,sizeof(vb->opb));
/* save markers */
head_ptr[0]=vbi->packetblob_markers[0];
for(i=1;i<PACKETBLOBS;i++){
head_ptr[i]=vbi->packetblob_markers[i]-vbi->packetblob_markers[i-1];
}
if(bm->avg_binacc)
new_minmax_head=minmax_head=bm->avg_center;
else
new_minmax_head=minmax_head=head;
/* the average tracking queue is updated first; its results (if it's
in use) are taken into account by the min/max limiter (if min/max
is in use) */
if(bm->avg_binacc){
unsigned long desired_center=bm->avg_centerdesired;
if(eofflag)desired_center=0;
/* update the avg head */
for(i=0;i<bins;i++)
bm->avg_binacc[i]+=LACING_ADJUST(head_ptr[i]);
bm->avg_sampleacc+=ci->blocksizes[vb->W]>>1;
bm->avg_centeracc+=ci->blocksizes[vb->W]>>1;
if(bm->avg_sampleacc>bm->avg_sampledesired || eofflag){
/* update the avg center */
if(bm->avg_centeracc>desired_center){
/* choose the new average floater */
int samples=ci->blocksizes[vb->W]>>1;
double upper=floater_interpolate(bm,vi,bi->queue_avgmax);
double lower=floater_interpolate(bm,vi,bi->queue_avgmin);
double new=PACKETBLOBS/2.,slew;
int bin;
if(upper<new)new=upper;
if(lower>new)new=lower;
slew=(new-bm->avgfloat)/samples*vi->rate;
if(slew<bi->avgfloat_downslew_max)
new=bm->avgfloat+bi->avgfloat_downslew_max/vi->rate*samples;
if(slew>bi->avgfloat_upslew_max)
new=bm->avgfloat+bi->avgfloat_upslew_max/vi->rate*samples;
bm->avgfloat=new;
/* apply the average floater to new blocks */
bin=rint(bm->avgfloat);
/*fprintf(stderr,"%d ",bin);*/
while(bm->avg_centeracc>desired_center){
samples=ci->blocksizes[bm->queue_actual[bm->avg_center]&
0x80000000UL?1:0]>>1;
bm->queue_actual[bm->avg_center]|=bin;
bm->avg_centeracc-=samples;
bm->avg_center++;
if(bm->avg_center>=bm->queue_size)bm->avg_center=0;
}
new_minmax_head=bm->avg_center;
}
/* update the avg tail if needed */
while(bm->avg_sampleacc>bm->avg_sampledesired){
int samples=
ci->blocksizes[bm->queue_actual[bm->avg_tail]&0x80000000UL?1:0]>>1;
for(i=0;i<bm->queue_bins;i++)
bm->avg_binacc[i]-=LACING_ADJUST(bm->queue_binned[bins*bm->avg_tail+i]);
bm->avg_sampleacc-=samples;
bm->avg_tail++;
if(bm->avg_tail>=bm->queue_size)bm->avg_tail=0;
}
}
}else{
/* if we're not using an average tracker, the 'float' is nailed to
the avgfloat_initial value. It needs to be set for the min/max
to deal properly */
long bin=PACKETBLOBS/2;
bm->queue_actual[head]|=bin;
new_minmax_head=next_head;
}
/* update the min/max queues and enforce limits */
if(bm->minmax_binstack){
unsigned long sampledesired=eofflag?0:bm->minmax_sampledesired;
/* add to stack recent */
while(minmax_head!=new_minmax_head){
unsigned int i;
int samples=ci->blocksizes[bm->queue_actual[minmax_head]&
0x80000000UL?1:0]>>1;
int actual=bm->queue_actual[minmax_head]&0x7fffffffUL;
for(i=0;i<(unsigned int)bins;i++){
bm->minmax_binstack[bm->minmax_stackptr*bins*2+bins+i]+=
LACING_ADJUST(BINBYTES(bm,minmax_head,
actual>i?actual:i));
bm->minmax_binstack[bm->minmax_stackptr*bins*2+i]+=
LACING_ADJUST(BINBYTES(bm,minmax_head,
actual<i?actual:i));
}
bm->minmax_posstack[bm->minmax_stackptr]=minmax_head; /* not one
past
like
typical */
bm->minmax_limitstack[bm->minmax_stackptr]=0;
bm->minmax_sampleacc+=samples;
bm->minmax_acctotal+=
LACING_ADJUST(BINBYTES(bm,minmax_head,actual));
minmax_head++;
if(minmax_head>=bm->queue_size)minmax_head=0;
}
/* check limits, enforce changes */
if(bm->minmax_sampleacc>sampledesired){
double bitrate=(double)(bm->minmax_acctotal*8)/
bm->minmax_sampleacc*vi->rate;
int limit=0;
if((bi->queue_hardmax>0 && bitrate>bi->queue_hardmax) ||
(bi->queue_hardmin>0 && bitrate<bi->queue_hardmin)){
int newstack;
int stackctr;
long bitsum=bm->minmax_acctotal*8;
bitrate=(double)bitsum/bm->minmax_sampleacc*vi->rate;
/* we're off rate. Iteratively try out new hard floater
limits until we find one that brings us inside. Here's
where we see the whole point of the limit stacks. */
if(bi->queue_hardmax>0 && bitrate>bi->queue_hardmax){
for(limit=-1;limit>-bins+1;limit--){
long bitsum=limit_sum(bm,limit)*8;
bitrate=(double)bitsum/bm->minmax_sampleacc*vi->rate;
if(bitrate<=bi->queue_hardmax)break;
}
}else if(bitrate<bi->queue_hardmin){
for(limit=1;limit<bins-1;limit++){
long bitsum=limit_sum(bm,limit)*8;
bitrate=(double)bitsum/bm->minmax_sampleacc*vi->rate;
if(bitrate>=bi->queue_hardmin)break;
}
if(bitrate>bi->queue_hardmax)limit--;
}
/* trace the limit backward, stop when we see a lower limit */
newstack=bm->minmax_stackptr-1;
while(newstack>=0){
if(bm->minmax_limitstack[newstack]<limit)break;
newstack--;
}
/* update bit counter with new limit and replace any stack
limits that have been replaced by our new lower limit */
stackctr=bm->minmax_stackptr;
while(stackctr>newstack){
bm->minmax_acctotal-=
LIMITBYTES(stackctr,bm->minmax_limitstack[stackctr]);
bm->minmax_acctotal+=LIMITBYTES(stackctr,limit);
if(stackctr<bm->minmax_stackptr)
for(i=0;i<bins*2;i++)
bm->minmax_binstack[stackctr*bins*2+i]+=
bm->minmax_binstack[(stackctr+1)*bins*2+i];
stackctr--;
}
stackctr++;
bm->minmax_posstack[stackctr]=bm->minmax_posstack[bm->minmax_stackptr];
bm->minmax_limitstack[stackctr]=limit;
/* set up new blank stack entry */
stackctr++;
bm->minmax_stackptr=stackctr;
memset(&bm->minmax_binstack[stackctr*bins*2],
0,
sizeof(*bm->minmax_binstack)*bins*2);
bm->minmax_limitstack[stackctr]=0;
bm->minmax_posstack[stackctr]=-1;
}
}
/* remove from tail */
while(bm->minmax_sampleacc>sampledesired){
int samples=
ci->blocksizes[bm->queue_actual[bm->minmax_tail]&0x80000000UL?1:0]>>1;
int actual=bm->queue_actual[bm->minmax_tail]&0x7fffffffUL;
for(i=0;i<bins;i++){
bm->minmax_binstack[bins+i]-= /* always comes off the stack bottom */
LACING_ADJUST(BINBYTES(bm,bm->minmax_tail,
actual>i?
actual:i));
bm->minmax_binstack[i]-=
LACING_ADJUST(BINBYTES(bm,bm->minmax_tail,
actual<i?
actual:i));
}
if(bm->minmax_limitstack[0]>actual)
actual=bm->minmax_limitstack[0];
if(bins+bm->minmax_limitstack[0]<actual)
actual=bins+bm->minmax_limitstack[0];
bm->minmax_acctotal-=LACING_ADJUST(BINBYTES(bm,bm->minmax_tail,actual));
bm->minmax_sampleacc-=samples;
/* revise queue_actual to reflect the limit */
bm->queue_actual[bm->minmax_tail]&=0x80000000UL;
bm->queue_actual[bm->minmax_tail]|=actual;
if(bm->minmax_tail==bm->minmax_posstack[0]){
/* the stack becomes a FIFO; the first data has fallen off */
memmove(bm->minmax_binstack,bm->minmax_binstack+bins*2,
sizeof(*bm->minmax_binstack)*bins*2*bm->minmax_stackptr);
memmove(bm->minmax_posstack,bm->minmax_posstack+1,
sizeof(*bm->minmax_posstack)*bm->minmax_stackptr);
memmove(bm->minmax_limitstack,bm->minmax_limitstack+1,
sizeof(*bm->minmax_limitstack)*bm->minmax_stackptr);
bm->minmax_stackptr--;
}
bm->minmax_tail++;
if(bm->minmax_tail>=bm->queue_size)bm->minmax_tail=0;
}
bm->last_to_flush=bm->minmax_tail;
}else{
bm->last_to_flush=bm->avg_center;
}
if(eofflag)
bm->last_to_flush=bm->queue_head;
return(0);
}
int vorbis_bitrate_flushpacket(vorbis_dsp_state *vd,ogg_packet *op){
backend_lookup_state *b=vd->backend_state;
bitrate_manager_state *bm=&b->bms;
if(bm->queue_size==0){
if(bm->queue_head==0)return(0);
memcpy(op,bm->packets,sizeof(*op));
bm->queue_head=0;
}else{
if(bm->next_to_flush==bm->last_to_flush)return(0);
{
long bin=bm->queue_actual[bm->next_to_flush]&0x7fffffff,i;
long bins=bm->queue_bins;
ogg_uint32_t *markers=bm->queue_binned+bins*bm->next_to_flush;
long bytes=markers[bin];
memcpy(op,bm->packets+bm->next_to_flush,sizeof(*op));
/* we have [PACKETBLOBS] possible packets all squished together in
the buffer, in sequence. count in to number [bin] */
for(i=0;i<bin;i++)
op->packet+=markers[i];
op->bytes=bytes;
}
bm->next_to_flush++;
if(bm->next_to_flush>=bm->queue_size)bm->next_to_flush=0;
}
return(1);
}