1/********************************************************************
2 * *
3 * THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE. *
4 * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS *
5 * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
6 * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. *
7 * *
8 * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2015 *
9 * by the Xiph.Org Foundation https://xiph.org/ *
10 * *
11 ********************************************************************
12
13 function: single-block PCM synthesis
14
15 ********************************************************************/
16
17#include <stdio.h>
18#include <ogg/ogg.h>
19#include "vorbis/codec.h"
20#include "codec_internal.h"
21#include "registry.h"
22#include "misc.h"
23#include "os.h"
24
25int vorbis_synthesis(vorbis_block *vb,ogg_packet *op){
26 vorbis_dsp_state *vd= vb ? vb->vd : 0;
27 private_state *b= vd ? vd->backend_state : 0;
28 vorbis_info *vi= vd ? vd->vi : 0;
29 codec_setup_info *ci= vi ? vi->codec_setup : 0;
30 oggpack_buffer *opb=vb ? &vb->opb : 0;
31 int type,mode,i;
32
33 if (!vd || !b || !vi || !ci || !opb) {
34 return OV_EBADPACKET;
35 }
36
37 /* first things first. Make sure decode is ready */
38 _vorbis_block_ripcord(vb);
39 oggpack_readinit(opb,op->packet,op->bytes);
40
41 /* Check the packet type */
42 if(oggpack_read(opb,1)!=0){
43 /* Oops. This is not an audio data packet */
44 return(OV_ENOTAUDIO);
45 }
46
47 /* read our mode and pre/post windowsize */
48 mode=oggpack_read(opb,b->modebits);
49 if(mode==-1){
50 return(OV_EBADPACKET);
51 }
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
61 /* this doesn;t get mapped through mode selection as it's used
62 only for window selection */
63 vb->lW=oggpack_read(opb,1);
64 vb->nW=oggpack_read(opb,1);
65 if(vb->nW==-1){
66 return(OV_EBADPACKET);
67 }
68 }else{
69 vb->lW=0;
70 vb->nW=0;
71 }
72
73 /* more setup */
74 vb->granulepos=op->granulepos;
75 vb->sequence=op->packetno;
76 vb->eofflag=op->e_o_s;
77
78 /* alloc pcm passback storage */
79 vb->pcmend=ci->blocksizes[vb->W];
80 vb->pcm=_vorbis_block_alloc(vb,sizeof(*vb->pcm)*vi->channels);
81 for(i=0;i<vi->channels;i++)
82 vb->pcm[i]=_vorbis_block_alloc(vb,vb->pcmend*sizeof(*vb->pcm[i]));
83
84 /* unpack_header enforces range checking */
85 type=ci->map_type[ci->mode_param[mode]->mapping];
86
87 return(_mapping_P[type]->inverse(vb,ci->map_param[ci->mode_param[mode]->
88 mapping]));
89}
90
91/* used to track pcm position without actually performing decode.
92 Useful for sequential 'fast forward' */
93int vorbis_synthesis_trackonly(vorbis_block *vb,ogg_packet *op){
94 vorbis_dsp_state *vd=vb->vd;
95 private_state *b=vd->backend_state;
96 vorbis_info *vi=vd->vi;
97 codec_setup_info *ci=vi->codec_setup;
98 oggpack_buffer *opb=&vb->opb;
99 int mode;
100
101 /* first things first. Make sure decode is ready */
102 _vorbis_block_ripcord(vb);
103 oggpack_readinit(opb,op->packet,op->bytes);
104
105 /* Check the packet type */
106 if(oggpack_read(opb,1)!=0){
107 /* Oops. This is not an audio data packet */
108 return(OV_ENOTAUDIO);
109 }
110
111 /* read our mode and pre/post windowsize */
112 mode=oggpack_read(opb,b->modebits);
113 if(mode==-1)return(OV_EBADPACKET);
114
115 vb->mode=mode;
116 if(!ci->mode_param[mode]){
117 return(OV_EBADPACKET);
118 }
119
120 vb->W=ci->mode_param[mode]->blockflag;
121 if(vb->W){
122 vb->lW=oggpack_read(opb,1);
123 vb->nW=oggpack_read(opb,1);
124 if(vb->nW==-1) return(OV_EBADPACKET);
125 }else{
126 vb->lW=0;
127 vb->nW=0;
128 }
129
130 /* more setup */
131 vb->granulepos=op->granulepos;
132 vb->sequence=op->packetno;
133 vb->eofflag=op->e_o_s;
134
135 /* no pcm */
136 vb->pcmend=0;
137 vb->pcm=NULL;
138
139 return(0);
140}
141
142long vorbis_packet_blocksize(vorbis_info *vi,ogg_packet *op){
143 codec_setup_info *ci=vi->codec_setup;
144 oggpack_buffer opb;
145 int mode;
146
147 if(ci==NULL || ci->modes<=0){
148 /* codec setup not properly intialized */
149 return(OV_EFAULT);
150 }
151
152 oggpack_readinit(&opb,op->packet,op->bytes);
153
154 /* Check the packet type */
155 if(oggpack_read(&opb,1)!=0){
156 /* Oops. This is not an audio data packet */
157 return(OV_ENOTAUDIO);
158 }
159
160 /* read our mode and pre/post windowsize */
161 mode=oggpack_read(&opb,ov_ilog(ci->modes-1));
162 if(mode==-1 || !ci->mode_param[mode])return(OV_EBADPACKET);
163 return(ci->blocksizes[ci->mode_param[mode]->blockflag]);
164}
165
166int vorbis_synthesis_halfrate(vorbis_info *vi,int flag){
167 /* set / clear half-sample-rate mode */
168 codec_setup_info *ci=vi->codec_setup;
169
170 /* right now, our MDCT can't handle < 64 sample windows. */
171 if(ci->blocksizes[0]<=64 && flag)return -1;
172 ci->halfrate_flag=(flag?1:0);
173 return 0;
174}
175
176int vorbis_synthesis_halfrate_p(vorbis_info *vi){
177 codec_setup_info *ci=vi->codec_setup;
178 return ci->halfrate_flag;
179}
180