|
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 |
|
27 int vorbis_synthesis(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 |
|
85 long vorbis_packet_blocksize(vorbis_info *vi,ogg_packet *op){ |
|
86 codec_setup_info *ci=(codec_setup_info *)vi->codec_setup; |
|
87 oggpack_buffer opb; |
|
88 int mode; |
|
89 |
|
90 oggpack_readinit(&opb,op->packet); |
|
91 |
|
92 /* Check the packet type */ |
|
93 if(oggpack_read(&opb,1)!=0){ |
|
94 /* Oops. This is not an audio data packet */ |
|
95 return(OV_ENOTAUDIO); |
|
96 } |
|
97 |
|
98 { |
|
99 int modebits=0; |
|
100 int v=ci->modes; |
|
101 while(v>1){ |
|
102 modebits++; |
|
103 v>>=1; |
|
104 } |
|
105 |
|
106 /* read our mode and pre/post windowsize */ |
|
107 mode=oggpack_read(&opb,modebits); |
|
108 } |
|
109 if(mode==-1)return(OV_EBADPACKET); |
|
110 return(ci->blocksizes[ci->mode_param[mode]->blockflag]); |
|
111 } |
|
112 |
|
113 |