LCOV - code coverage report
Current view: directory - media/libvorbis/lib - vorbis_bitrate.c (source / functions) Found Hit Coverage
Test: app.info Lines: 124 0 0.0 %
Date: 2012-06-02 Functions: 5 0 0.0 %

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

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