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/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 ? 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;
34
35 if (!vd || !b || !vi || !ci || !opb) {
36 return OV_EBADPACKET;
37 }
38
39 /* first things first. Make sure decode is ready */
40 _vorbis_block_ripcord(vb);
41 oggpack_readinit(opb,op->packet,op->bytes);
42
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 }
48
49 /* read our mode and pre/post windowsize */
50 mode=oggpack_read(opb,b->modebits);
51 if(mode==-1)return(OV_EBADPACKET);
52
53 vb->mode=mode;
54 if(!ci->mode_param[mode]){
55 return(OV_EBADPACKET);
56 }
57
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 }
67
68 /* more setup */
69 vb->granulepos=op->granulepos;
70 vb->sequence=op->packetno; /* first block is third packet */
71 vb->eofflag=op->e_o_s;
72
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]));
79
80 /* unpack_header enforces range checking */
81 type=ci->map_type[ci->mode_param[mode]->mapping];
82
83 return(_mapping_P[type]->inverse(vb,b->mode[mode]));
84 }else{
85 /* no pcm */
86 vb->pcmend=0;
87 vb->pcm=NULL;
88
89 return(0);
90 }
91 }
92
vorbis_synthesis(vorbis_block * vb,ogg_packet * op)93 int vorbis_synthesis(vorbis_block *vb,ogg_packet *op){
94 return _vorbis_synthesis1(vb,op,1);
95 }
96
97 /* used to track pcm position without actually performing decode.
98 Useful for sequential 'fast forward' */
vorbis_synthesis_trackonly(vorbis_block * vb,ogg_packet * op)99 int vorbis_synthesis_trackonly(vorbis_block *vb,ogg_packet *op){
100 return _vorbis_synthesis1(vb,op,0);
101 }
102
vorbis_packet_blocksize(vorbis_info * vi,ogg_packet * op)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;
107
108 oggpack_readinit(&opb,op->packet,op->bytes);
109
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 }
115
116 {
117 int modebits=0;
118 int v=ci->modes;
119 while(v>1){
120 modebits++;
121 v>>=1;
122 }
123
124 /* read our mode and pre/post windowsize */
125 mode=oggpack_read(&opb,modebits);
126 }
127 if(mode==-1 || !ci->mode_param[mode])return(OV_EBADPACKET);
128 return(ci->blocksizes[ci->mode_param[mode]->blockflag]);
129 }
130
131
132