The Tor Browser: media/libvorbis/lib/vorbis_floor0.c@97036ab72558 (annotated)

media/libvorbis/lib/vorbis_floor0.c@97036ab72558 (annotated)

media/libvorbis/lib/vorbis_floor0.c

Tue, 06 Jan 2015 21:39:09 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Tue, 06 Jan 2015 21:39:09 +0100
branch: TOR_BUG_9701
changeset 8: 97036ab72558
permissions: -rw-r--r--

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 /********************************************************************
  *                                                                  *
  * 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: floor backend 0 implementation
  last mod: $Id: floor0.c 19031 2013-12-03 19:20:50Z tterribe $
  ********************************************************************/
 #include <stdlib.h>
 #include <string.h>
 #include <math.h>
 #include <ogg/ogg.h>
 #include "vorbis/codec.h"
 #include "codec_internal.h"
 #include "registry.h"
 #include "lpc.h"
 #include "lsp.h"
 #include "codebook.h"
 #include "scales.h"
 #include "misc.h"
 #include "os.h"
 #include "misc.h"
 #include <stdio.h>
 typedef struct {
   int ln;
   int  m;
   int **linearmap;
   int  n[2];
   vorbis_info_floor0 *vi;
   long bits;
   long frames;
 } vorbis_look_floor0;
 /***********************************************/
 static void floor0_free_info(vorbis_info_floor *i){
   vorbis_info_floor0 *info=(vorbis_info_floor0 *)i;
   if(info){
     memset(info,0,sizeof(*info));
     _ogg_free(info);
   }
 }
 static void floor0_free_look(vorbis_look_floor *i){
   vorbis_look_floor0 *look=(vorbis_look_floor0 *)i;
   if(look){
     if(look->linearmap){
       if(look->linearmap[0])_ogg_free(look->linearmap[0]);
       if(look->linearmap[1])_ogg_free(look->linearmap[1]);
       _ogg_free(look->linearmap);
     }
     memset(look,0,sizeof(*look));
     _ogg_free(look);
   }
 }
 static vorbis_info_floor *floor0_unpack (vorbis_info *vi,oggpack_buffer *opb){
   codec_setup_info     *ci=vi->codec_setup;
   int j;
   vorbis_info_floor0 *info=_ogg_malloc(sizeof(*info));
   info->order=oggpack_read(opb,8);
   info->rate=oggpack_read(opb,16);
   info->barkmap=oggpack_read(opb,16);
   info->ampbits=oggpack_read(opb,6);
   info->ampdB=oggpack_read(opb,8);
   info->numbooks=oggpack_read(opb,4)+1;
   if(info->order<1)goto err_out;
   if(info->rate<1)goto err_out;
   if(info->barkmap<1)goto err_out;
   if(info->numbooks<1)goto err_out;
   for(j=0;j<info->numbooks;j++){
     info->books[j]=oggpack_read(opb,8);
     if(info->books[j]<0 || info->books[j]>=ci->books)goto err_out;
     if(ci->book_param[info->books[j]]->maptype==0)goto err_out;
     if(ci->book_param[info->books[j]]->dim<1)goto err_out;
   }
   return(info);
  err_out:
   floor0_free_info(info);
   return(NULL);
 }
 /* initialize Bark scale and normalization lookups.  We could do this
    with static tables, but Vorbis allows a number of possible
    combinations, so it's best to do it computationally.
    The below is authoritative in terms of defining scale mapping.
    Note that the scale depends on the sampling rate as well as the
    linear block and mapping sizes */
 static void floor0_map_lazy_init(vorbis_block      *vb,
                                  vorbis_info_floor *infoX,
                                  vorbis_look_floor0 *look){
   if(!look->linearmap[vb->W]){
     vorbis_dsp_state   *vd=vb->vd;
     vorbis_info        *vi=vd->vi;
     codec_setup_info   *ci=vi->codec_setup;
     vorbis_info_floor0 *info=(vorbis_info_floor0 *)infoX;
     int W=vb->W;
     int n=ci->blocksizes[W]/2,j;
     /* we choose a scaling constant so that:
        floor(bark(rate/2-1)*C)=mapped-1
      floor(bark(rate/2)*C)=mapped */
     float scale=look->ln/toBARK(info->rate/2.f);
     /* the mapping from a linear scale to a smaller bark scale is
        straightforward.  We do *not* make sure that the linear mapping
        does not skip bark-scale bins; the decoder simply skips them and
        the encoder may do what it wishes in filling them.  They're
        necessary in some mapping combinations to keep the scale spacing
        accurate */
     look->linearmap[W]=_ogg_malloc((n+1)*sizeof(**look->linearmap));
     for(j=0;j<n;j++){
       int val=floor( toBARK((info->rate/2.f)/n*j)
                      *scale); /* bark numbers represent band edges */
       if(val>=look->ln)val=look->ln-1; /* guard against the approximation */
       look->linearmap[W][j]=val;
     }
     look->linearmap[W][j]=-1;
     look->n[W]=n;
   }
 }
 static vorbis_look_floor *floor0_look(vorbis_dsp_state *vd,
                                       vorbis_info_floor *i){
   vorbis_info_floor0 *info=(vorbis_info_floor0 *)i;
   vorbis_look_floor0 *look=_ogg_calloc(1,sizeof(*look));
   (void)vd;
   look->m=info->order;
   look->ln=info->barkmap;
   look->vi=info;
   look->linearmap=_ogg_calloc(2,sizeof(*look->linearmap));
   return look;
 }
 static void *floor0_inverse1(vorbis_block *vb,vorbis_look_floor *i){
   vorbis_look_floor0 *look=(vorbis_look_floor0 *)i;
   vorbis_info_floor0 *info=look->vi;
   int j,k;
   int ampraw=oggpack_read(&vb->opb,info->ampbits);
   if(ampraw>0){ /* also handles the -1 out of data case */
     long maxval=(1<<info->ampbits)-1;
     float amp=(float)ampraw/maxval*info->ampdB;
     int booknum=oggpack_read(&vb->opb,_ilog(info->numbooks));
     if(booknum!=-1 && booknum<info->numbooks){ /* be paranoid */
       codec_setup_info  *ci=vb->vd->vi->codec_setup;
       codebook *b=ci->fullbooks+info->books[booknum];
       float last=0.f;
       /* the additional b->dim is a guard against any possible stack
          smash; b->dim is provably more than we can overflow the
          vector */
       float *lsp=_vorbis_block_alloc(vb,sizeof(*lsp)*(look->m+b->dim+1));
       if(vorbis_book_decodev_set(b,lsp,&vb->opb,look->m)==-1)goto eop;
       for(j=0;j<look->m;){
         for(k=0;j<look->m && k<b->dim;k++,j++)lsp[j]+=last;
         last=lsp[j-1];
       }
       lsp[look->m]=amp;
       return(lsp);
     }
   }
  eop:
   return(NULL);
 }
 static int floor0_inverse2(vorbis_block *vb,vorbis_look_floor *i,
                            void *memo,float *out){
   vorbis_look_floor0 *look=(vorbis_look_floor0 *)i;
   vorbis_info_floor0 *info=look->vi;
   floor0_map_lazy_init(vb,info,look);
   if(memo){
     float *lsp=(float *)memo;
     float amp=lsp[look->m];
     /* take the coefficients back to a spectral envelope curve */
     vorbis_lsp_to_curve(out,
                         look->linearmap[vb->W],
                         look->n[vb->W],
                         look->ln,
                         lsp,look->m,amp,(float)info->ampdB);
     return(1);
   }
   memset(out,0,sizeof(*out)*look->n[vb->W]);
   return(0);
 }
 /* export hooks */
 const vorbis_func_floor floor0_exportbundle={
   NULL,&floor0_unpack,&floor0_look,&floor0_free_info,
   &floor0_free_look,&floor0_inverse1,&floor0_inverse2
 };

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media/libvorbis/lib/vorbis_floor0.c@97036ab72558 (annotated)

media/libvorbis/lib/vorbis_floor0.c