1 /******************************************************************** |
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2 * * |
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3 * THIS FILE IS PART OF THE OggVorbis 'TREMOR' CODEC SOURCE CODE. * |
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4 * * |
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5 * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS * |
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6 * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE * |
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7 * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. * |
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8 * * |
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9 * THE OggVorbis 'TREMOR' SOURCE CODE IS (C) COPYRIGHT 1994-2003 * |
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10 * BY THE Xiph.Org FOUNDATION http://www.xiph.org/ * |
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11 * * |
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12 ******************************************************************** |
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13 |
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14 function: single-block PCM synthesis |
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15 last mod: $Id: synthesis.c,v 1.4 2003/03/29 03:07:21 xiphmont Exp $ |
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16 |
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17 ********************************************************************/ |
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18 |
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19 #include <stdio.h> |
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20 #include "ogg.h" |
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21 #include "ivorbiscodec.h" |
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22 #include "codec_internal.h" |
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23 #include "registry.h" |
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24 #include "misc.h" |
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25 #include "block.h" |
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26 |
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27 int vorbis_synthesis(vorbis_block *vb,ogg_packet *op,int decodep){ |
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28 vorbis_dsp_state *vd=vb->vd; |
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29 private_state *b=(private_state *)vd->backend_state; |
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30 vorbis_info *vi=vd->vi; |
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31 codec_setup_info *ci=(codec_setup_info *)vi->codec_setup; |
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32 oggpack_buffer *opb=&vb->opb; |
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33 int type,mode,i; |
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34 |
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35 /* first things first. Make sure decode is ready */ |
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36 _vorbis_block_ripcord(vb); |
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37 oggpack_readinit(opb,op->packet); |
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38 |
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39 /* Check the packet type */ |
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40 if(oggpack_read(opb,1)!=0){ |
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41 /* Oops. This is not an audio data packet */ |
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42 return(OV_ENOTAUDIO); |
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43 } |
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44 |
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45 /* read our mode and pre/post windowsize */ |
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46 mode=oggpack_read(opb,b->modebits); |
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47 if(mode==-1)return(OV_EBADPACKET); |
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48 |
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49 vb->mode=mode; |
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50 vb->W=ci->mode_param[mode]->blockflag; |
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51 if(vb->W){ |
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52 vb->lW=oggpack_read(opb,1); |
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53 vb->nW=oggpack_read(opb,1); |
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54 if(vb->nW==-1) return(OV_EBADPACKET); |
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55 }else{ |
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56 vb->lW=0; |
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57 vb->nW=0; |
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58 } |
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59 |
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60 /* more setup */ |
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61 vb->granulepos=op->granulepos; |
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62 vb->sequence=op->packetno-3; /* first block is third packet */ |
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63 vb->eofflag=op->e_o_s; |
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64 |
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65 if(decodep){ |
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66 /* alloc pcm passback storage */ |
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67 vb->pcmend=ci->blocksizes[vb->W]; |
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68 vb->pcm=(ogg_int32_t **)_vorbis_block_alloc(vb,sizeof(*vb->pcm)*vi->channels); |
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69 for(i=0;i<vi->channels;i++) |
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70 vb->pcm[i]=(ogg_int32_t *)_vorbis_block_alloc(vb,vb->pcmend*sizeof(*vb->pcm[i])); |
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71 |
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72 /* unpack_header enforces range checking */ |
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73 type=ci->map_type[ci->mode_param[mode]->mapping]; |
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74 |
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75 return(_mapping_P[type]->inverse(vb,b->mode[mode])); |
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76 }else{ |
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77 /* no pcm */ |
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78 vb->pcmend=0; |
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79 vb->pcm=NULL; |
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80 |
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81 return(0); |
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82 } |
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83 } |
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84 |
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85 long vorbis_packet_blocksize(vorbis_info *vi,ogg_packet *op){ |
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86 codec_setup_info *ci=(codec_setup_info *)vi->codec_setup; |
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87 oggpack_buffer opb; |
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88 int mode; |
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89 |
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90 oggpack_readinit(&opb,op->packet); |
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91 |
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92 /* Check the packet type */ |
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93 if(oggpack_read(&opb,1)!=0){ |
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94 /* Oops. This is not an audio data packet */ |
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95 return(OV_ENOTAUDIO); |
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96 } |
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97 |
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98 { |
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99 int modebits=0; |
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100 int v=ci->modes; |
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101 while(v>1){ |
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102 modebits++; |
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103 v>>=1; |
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104 } |
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105 |
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106 /* read our mode and pre/post windowsize */ |
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107 mode=oggpack_read(&opb,modebits); |
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108 } |
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109 if(mode==-1)return(OV_EBADPACKET); |
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110 return(ci->blocksizes[ci->mode_param[mode]->blockflag]); |
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111 } |
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112 |
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113 |
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