The Tor Browser: media/libtremor/lib/tremor

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

     1 /********************************************************************

     2  *                                                                  *

     3  * THIS FILE IS PART OF THE OggVorbis 'TREMOR' CODEC SOURCE CODE.   *

     4  *                                                                  *

     5  * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *

     6  * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *

     7  * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *

     8  *                                                                  *

     9  * THE OggVorbis 'TREMOR' SOURCE CODE IS (C) COPYRIGHT 1994-2003    *

    10  * BY THE Xiph.Org FOUNDATION http://www.xiph.org/                  *

    11  *                                                                  *

    12  ********************************************************************

    14  function: single-block PCM synthesis

    15  last mod: $Id: synthesis.c,v 1.4 2003/03/29 03:07:21 xiphmont Exp $

    17  ********************************************************************/

    19 #include <stdio.h>

    20 #include <ogg/ogg.h>

    21 #include "ivorbiscodec.h"

    22 #include "codec_internal.h"

    23 #include "registry.h"

    24 #include "misc.h"

    25 #include "block.h"

    27 static int _vorbis_synthesis1(vorbis_block *vb,ogg_packet *op,int decodep){

    28   vorbis_dsp_state     *vd= vb ? vb->vd : 0;

    29   private_state        *b= vd ? (private_state *)vd->backend_state: 0;

    30   vorbis_info          *vi= vd ? vd->vi : 0;

    31   codec_setup_info     *ci= vi ? (codec_setup_info *)vi->codec_setup : 0;

    32   oggpack_buffer       *opb=vb ? &vb->opb : 0;

    33   int                   type,mode,i;

    35   if (!vd || !b || !vi || !ci || !opb) {

    36     return OV_EBADPACKET;

    37   }

    39   /* first things first.  Make sure decode is ready */

    40   _vorbis_block_ripcord(vb);

    41   oggpack_readinit(opb,op->packet,op->bytes);

    43   /* Check the packet type */

    44   if(oggpack_read(opb,1)!=0){

    45     /* Oops.  This is not an audio data packet */

    46     return(OV_ENOTAUDIO);

    47   }

    49   /* read our mode and pre/post windowsize */

    50   mode=oggpack_read(opb,b->modebits);

    51   if(mode==-1)return(OV_EBADPACKET);

    53   vb->mode=mode;

    54   if(!ci->mode_param[mode]){

    55     return(OV_EBADPACKET);

    56   }

    58   vb->W=ci->mode_param[mode]->blockflag;

    59   if(vb->W){

    60     vb->lW=oggpack_read(opb,1);

    61     vb->nW=oggpack_read(opb,1);

    62     if(vb->nW==-1)   return(OV_EBADPACKET);

    63   }else{

    64     vb->lW=0;

    65     vb->nW=0;

    66   }

    68   /* more setup */

    69   vb->granulepos=op->granulepos;

    70   vb->sequence=op->packetno-3; /* first block is third packet */

    71   vb->eofflag=op->e_o_s;

    73   if(decodep){

    74     /* alloc pcm passback storage */

    75     vb->pcmend=ci->blocksizes[vb->W];

    76     vb->pcm=(ogg_int32_t **)_vorbis_block_alloc(vb,sizeof(*vb->pcm)*vi->channels);

    77     for(i=0;i<vi->channels;i++)

    78       vb->pcm[i]=(ogg_int32_t *)_vorbis_block_alloc(vb,vb->pcmend*sizeof(*vb->pcm[i]));

    80     /* unpack_header enforces range checking */

    81     type=ci->map_type[ci->mode_param[mode]->mapping];

    83     return(_mapping_P[type]->inverse(vb,b->mode[mode]));

    84   }else{

    85     /* no pcm */

    86     vb->pcmend=0;

    87     vb->pcm=NULL;

    89     return(0);

    90   }

    91 }

    93 int vorbis_synthesis(vorbis_block *vb,ogg_packet *op){

    94   return _vorbis_synthesis1(vb,op,1);

    95 }

    97 /* used to track pcm position without actually performing decode.

    98    Useful for sequential 'fast forward' */

    99 int vorbis_synthesis_trackonly(vorbis_block *vb,ogg_packet *op){

   100   return _vorbis_synthesis1(vb,op,0);

   101 }

   103 long vorbis_packet_blocksize(vorbis_info *vi,ogg_packet *op){

   104   codec_setup_info     *ci=(codec_setup_info *)vi->codec_setup;

   105   oggpack_buffer       opb;

   106   int                  mode;

   108   oggpack_readinit(&opb,op->packet,op->bytes);

   110   /* Check the packet type */

   111   if(oggpack_read(&opb,1)!=0){

   112     /* Oops.  This is not an audio data packet */

   113     return(OV_ENOTAUDIO);

   114   }

   116   {

   117     int modebits=0;

   118     int v=ci->modes;

   119     while(v>1){

   120       modebits++;

   121       v>>=1;

   122     }

   124     /* read our mode and pre/post windowsize */

   125     mode=oggpack_read(&opb,modebits);

   126   }

   127   if(mode==-1)return(OV_EBADPACKET);

   128   return(ci->blocksizes[ci->mode_param[mode]->blockflag]);

   129 }

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