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 ********************************************************************
13
14 function: single-block PCM synthesis
15 last mod: $Id: synthesis.c,v 1.4 2003/03/29 03:07:21 xiphmont Exp $
16
17 ********************************************************************/
18
19 #include <stdio.h>
20 #include "ogg.h"
21 #include "ivorbiscodec.h"
22 #include "codec_internal.h"
23 #include "registry.h"
24 #include "misc.h"
25 #include "block.h"
26
_vorbis_synthesis1(vorbis_block * vb,ogg_packet * op,int decodep)27 static int _vorbis_synthesis1(vorbis_block *vb,ogg_packet *op,int decodep){
28 vorbis_dsp_state *vd=vb->vd;
29 private_state *b=(private_state *)vd->backend_state;
30 vorbis_info *vi=vd->vi;
31 codec_setup_info *ci=(codec_setup_info *)vi->codec_setup;
32 oggpack_buffer *opb=&vb->opb;
33 int type,mode,i;
34
35 /* first things first. Make sure decode is ready */
36 _vorbis_block_ripcord(vb);
37 oggpack_readinit(opb,op->packet);
38
39 /* Check the packet type */
40 if(oggpack_read(opb,1)!=0){
41 /* Oops. This is not an audio data packet */
42 return(OV_ENOTAUDIO);
43 }
44
45 /* read our mode and pre/post windowsize */
46 mode=oggpack_read(opb,b->modebits);
47 if(mode==-1)return(OV_EBADPACKET);
48
49 vb->mode=mode;
50 vb->W=ci->mode_param[mode]->blockflag;
51 if(vb->W){
52 vb->lW=oggpack_read(opb,1);
53 vb->nW=oggpack_read(opb,1);
54 if(vb->nW==-1) return(OV_EBADPACKET);
55 }else{
56 vb->lW=0;
57 vb->nW=0;
58 }
59
60 /* more setup */
61 vb->granulepos=op->granulepos;
62 vb->sequence=op->packetno-3; /* first block is third packet */
63 vb->eofflag=op->e_o_s;
64
65 if(decodep){
66 /* alloc pcm passback storage */
67 vb->pcmend=ci->blocksizes[vb->W];
68 vb->pcm=(ogg_int32_t **)_vorbis_block_alloc(vb,sizeof(*vb->pcm)*vi->channels);
69 for(i=0;i<vi->channels;i++)
70 vb->pcm[i]=(ogg_int32_t *)_vorbis_block_alloc(vb,vb->pcmend*sizeof(*vb->pcm[i]));
71
72 /* unpack_header enforces range checking */
73 type=ci->map_type[ci->mode_param[mode]->mapping];
74
75 return(_mapping_P[type]->inverse(vb,b->mode[mode]));
76 }else{
77 /* no pcm */
78 vb->pcmend=0;
79 vb->pcm=NULL;
80
81 return(0);
82 }
83 }
84
vorbis_synthesis(vorbis_block * vb,ogg_packet * op)85 int vorbis_synthesis(vorbis_block *vb,ogg_packet *op){
86 return _vorbis_synthesis1(vb,op,1);
87 }
88
vorbis_synthesis_trackonly(vorbis_block * vb,ogg_packet * op)89 int vorbis_synthesis_trackonly(vorbis_block *vb,ogg_packet *op){
90 return _vorbis_synthesis1(vb,op,0);
91 }
92
vorbis_packet_blocksize(vorbis_info * vi,ogg_packet * op)93 long vorbis_packet_blocksize(vorbis_info *vi,ogg_packet *op){
94 codec_setup_info *ci=(codec_setup_info *)vi->codec_setup;
95 oggpack_buffer opb;
96 int mode;
97
98 oggpack_readinit(&opb,op->packet);
99
100 /* Check the packet type */
101 if(oggpack_read(&opb,1)!=0){
102 /* Oops. This is not an audio data packet */
103 return(OV_ENOTAUDIO);
104 }
105
106 {
107 int modebits=0;
108 int v=ci->modes;
109 while(v>1){
110 modebits++;
111 v>>=1;
112 }
113
114 /* read our mode and pre/post windowsize */
115 mode=oggpack_read(&opb,modebits);
116 }
117 if(mode==-1)return(OV_EBADPACKET);
118 return(ci->blocksizes[ci->mode_param[mode]->blockflag]);
119 }
120
121
122