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 1994-2007 * |
---|
9 | * by the Xiph.Org Foundation http://www.xiph.org/ * |
---|
10 | * * |
---|
11 | ******************************************************************** |
---|
12 | |
---|
13 | function: simple example decoder |
---|
14 | last mod: $Id: decoder_example.c 13293 2007-07-24 00:09:47Z xiphmont $ |
---|
15 | |
---|
16 | ********************************************************************/ |
---|
17 | |
---|
18 | /* Takes a vorbis bitstream from stdin and writes raw stereo PCM to |
---|
19 | stdout. Decodes simple and chained OggVorbis files from beginning |
---|
20 | to end. Vorbisfile.a is somewhat more complex than the code below. */ |
---|
21 | |
---|
22 | /* Note that this is POSIX, not ANSI code */ |
---|
23 | |
---|
24 | #include <stdio.h> |
---|
25 | #include <stdlib.h> |
---|
26 | #include <math.h> |
---|
27 | #include <vorbis/codec.h> |
---|
28 | |
---|
29 | #ifdef _WIN32 /* We need the following two to set stdin/stdout to binary */ |
---|
30 | #include <io.h> |
---|
31 | #include <fcntl.h> |
---|
32 | #endif |
---|
33 | |
---|
34 | #if defined(__MACOS__) && defined(__MWERKS__) |
---|
35 | #include <console.h> /* CodeWarrior's Mac "command-line" support */ |
---|
36 | #endif |
---|
37 | |
---|
38 | ogg_int16_t convbuffer[4096]; /* take 8k out of the data segment, not the stack */ |
---|
39 | int convsize=4096; |
---|
40 | |
---|
41 | extern void _VDBG_dump(void); |
---|
42 | |
---|
43 | int main(){ |
---|
44 | ogg_sync_state oy; /* sync and verify incoming physical bitstream */ |
---|
45 | ogg_stream_state os; /* take physical pages, weld into a logical |
---|
46 | stream of packets */ |
---|
47 | ogg_page og; /* one Ogg bitstream page. Vorbis packets are inside */ |
---|
48 | ogg_packet op; /* one raw packet of data for decode */ |
---|
49 | |
---|
50 | vorbis_info vi; /* struct that stores all the static vorbis bitstream |
---|
51 | settings */ |
---|
52 | vorbis_comment vc; /* struct that stores all the bitstream user comments */ |
---|
53 | vorbis_dsp_state vd; /* central working state for the packet->PCM decoder */ |
---|
54 | vorbis_block vb; /* local working space for packet->PCM decode */ |
---|
55 | |
---|
56 | char *buffer; |
---|
57 | int bytes; |
---|
58 | |
---|
59 | #ifdef _WIN32 /* We need to set stdin/stdout to binary mode. Damn windows. */ |
---|
60 | /* Beware the evil ifdef. We avoid these where we can, but this one we |
---|
61 | cannot. Don't add any more, you'll probably go to hell if you do. */ |
---|
62 | _setmode( _fileno( stdin ), _O_BINARY ); |
---|
63 | _setmode( _fileno( stdout ), _O_BINARY ); |
---|
64 | #endif |
---|
65 | |
---|
66 | #if defined(macintosh) && defined(__MWERKS__) |
---|
67 | { |
---|
68 | int argc; |
---|
69 | char **argv; |
---|
70 | argc=ccommand(&argv); /* get a "command line" from the Mac user */ |
---|
71 | /* this also lets the user set stdin and stdout */ |
---|
72 | } |
---|
73 | #endif |
---|
74 | |
---|
75 | /********** Decode setup ************/ |
---|
76 | |
---|
77 | ogg_sync_init(&oy); /* Now we can read pages */ |
---|
78 | |
---|
79 | while(1){ /* we repeat if the bitstream is chained */ |
---|
80 | int eos=0; |
---|
81 | int i; |
---|
82 | |
---|
83 | /* grab some data at the head of the stream. We want the first page |
---|
84 | (which is guaranteed to be small and only contain the Vorbis |
---|
85 | stream initial header) We need the first page to get the stream |
---|
86 | serialno. */ |
---|
87 | |
---|
88 | /* submit a 4k block to libvorbis' Ogg layer */ |
---|
89 | buffer=ogg_sync_buffer(&oy,4096); |
---|
90 | bytes=fread(buffer,1,4096,stdin); |
---|
91 | ogg_sync_wrote(&oy,bytes); |
---|
92 | |
---|
93 | /* Get the first page. */ |
---|
94 | if(ogg_sync_pageout(&oy,&og)!=1){ |
---|
95 | /* have we simply run out of data? If so, we're done. */ |
---|
96 | if(bytes<4096)break; |
---|
97 | |
---|
98 | /* error case. Must not be Vorbis data */ |
---|
99 | fprintf(stderr,"Input does not appear to be an Ogg bitstream.\n"); |
---|
100 | exit(1); |
---|
101 | } |
---|
102 | |
---|
103 | /* Get the serial number and set up the rest of decode. */ |
---|
104 | /* serialno first; use it to set up a logical stream */ |
---|
105 | ogg_stream_init(&os,ogg_page_serialno(&og)); |
---|
106 | |
---|
107 | /* extract the initial header from the first page and verify that the |
---|
108 | Ogg bitstream is in fact Vorbis data */ |
---|
109 | |
---|
110 | /* I handle the initial header first instead of just having the code |
---|
111 | read all three Vorbis headers at once because reading the initial |
---|
112 | header is an easy way to identify a Vorbis bitstream and it's |
---|
113 | useful to see that functionality seperated out. */ |
---|
114 | |
---|
115 | vorbis_info_init(&vi); |
---|
116 | vorbis_comment_init(&vc); |
---|
117 | if(ogg_stream_pagein(&os,&og)<0){ |
---|
118 | /* error; stream version mismatch perhaps */ |
---|
119 | fprintf(stderr,"Error reading first page of Ogg bitstream data.\n"); |
---|
120 | exit(1); |
---|
121 | } |
---|
122 | |
---|
123 | if(ogg_stream_packetout(&os,&op)!=1){ |
---|
124 | /* no page? must not be vorbis */ |
---|
125 | fprintf(stderr,"Error reading initial header packet.\n"); |
---|
126 | exit(1); |
---|
127 | } |
---|
128 | |
---|
129 | if(vorbis_synthesis_headerin(&vi,&vc,&op)<0){ |
---|
130 | /* error case; not a vorbis header */ |
---|
131 | fprintf(stderr,"This Ogg bitstream does not contain Vorbis " |
---|
132 | "audio data.\n"); |
---|
133 | exit(1); |
---|
134 | } |
---|
135 | |
---|
136 | /* At this point, we're sure we're Vorbis. We've set up the logical |
---|
137 | (Ogg) bitstream decoder. Get the comment and codebook headers and |
---|
138 | set up the Vorbis decoder */ |
---|
139 | |
---|
140 | /* The next two packets in order are the comment and codebook headers. |
---|
141 | They're likely large and may span multiple pages. Thus we reead |
---|
142 | and submit data until we get our two pacakets, watching that no |
---|
143 | pages are missing. If a page is missing, error out; losing a |
---|
144 | header page is the only place where missing data is fatal. */ |
---|
145 | |
---|
146 | i=0; |
---|
147 | while(i<2){ |
---|
148 | while(i<2){ |
---|
149 | int result=ogg_sync_pageout(&oy,&og); |
---|
150 | if(result==0)break; /* Need more data */ |
---|
151 | /* Don't complain about missing or corrupt data yet. We'll |
---|
152 | catch it at the packet output phase */ |
---|
153 | if(result==1){ |
---|
154 | ogg_stream_pagein(&os,&og); /* we can ignore any errors here |
---|
155 | as they'll also become apparent |
---|
156 | at packetout */ |
---|
157 | while(i<2){ |
---|
158 | result=ogg_stream_packetout(&os,&op); |
---|
159 | if(result==0)break; |
---|
160 | if(result<0){ |
---|
161 | /* Uh oh; data at some point was corrupted or missing! |
---|
162 | We can't tolerate that in a header. Die. */ |
---|
163 | fprintf(stderr,"Corrupt secondary header. Exiting.\n"); |
---|
164 | exit(1); |
---|
165 | } |
---|
166 | vorbis_synthesis_headerin(&vi,&vc,&op); |
---|
167 | i++; |
---|
168 | } |
---|
169 | } |
---|
170 | } |
---|
171 | /* no harm in not checking before adding more */ |
---|
172 | buffer=ogg_sync_buffer(&oy,4096); |
---|
173 | bytes=fread(buffer,1,4096,stdin); |
---|
174 | if(bytes==0 && i<2){ |
---|
175 | fprintf(stderr,"End of file before finding all Vorbis headers!\n"); |
---|
176 | exit(1); |
---|
177 | } |
---|
178 | ogg_sync_wrote(&oy,bytes); |
---|
179 | } |
---|
180 | |
---|
181 | /* Throw the comments plus a few lines about the bitstream we're |
---|
182 | decoding */ |
---|
183 | { |
---|
184 | char **ptr=vc.user_comments; |
---|
185 | while(*ptr){ |
---|
186 | fprintf(stderr,"%s\n",*ptr); |
---|
187 | ++ptr; |
---|
188 | } |
---|
189 | fprintf(stderr,"\nBitstream is %d channel, %ldHz\n",vi.channels,vi.rate); |
---|
190 | fprintf(stderr,"Encoded by: %s\n\n",vc.vendor); |
---|
191 | } |
---|
192 | |
---|
193 | convsize=4096/vi.channels; |
---|
194 | |
---|
195 | /* OK, got and parsed all three headers. Initialize the Vorbis |
---|
196 | packet->PCM decoder. */ |
---|
197 | vorbis_synthesis_init(&vd,&vi); /* central decode state */ |
---|
198 | vorbis_block_init(&vd,&vb); /* local state for most of the decode |
---|
199 | so multiple block decodes can |
---|
200 | proceed in parallel. We could init |
---|
201 | multiple vorbis_block structures |
---|
202 | for vd here */ |
---|
203 | |
---|
204 | /* The rest is just a straight decode loop until end of stream */ |
---|
205 | while(!eos){ |
---|
206 | while(!eos){ |
---|
207 | int result=ogg_sync_pageout(&oy,&og); |
---|
208 | if(result==0)break; /* need more data */ |
---|
209 | if(result<0){ /* missing or corrupt data at this page position */ |
---|
210 | fprintf(stderr,"Corrupt or missing data in bitstream; " |
---|
211 | "continuing...\n"); |
---|
212 | }else{ |
---|
213 | ogg_stream_pagein(&os,&og); /* can safely ignore errors at |
---|
214 | this point */ |
---|
215 | while(1){ |
---|
216 | result=ogg_stream_packetout(&os,&op); |
---|
217 | |
---|
218 | if(result==0)break; /* need more data */ |
---|
219 | if(result<0){ /* missing or corrupt data at this page position */ |
---|
220 | /* no reason to complain; already complained above */ |
---|
221 | }else{ |
---|
222 | /* we have a packet. Decode it */ |
---|
223 | float **pcm; |
---|
224 | int samples; |
---|
225 | |
---|
226 | if(vorbis_synthesis(&vb,&op)==0) /* test for success! */ |
---|
227 | vorbis_synthesis_blockin(&vd,&vb); |
---|
228 | /* |
---|
229 | |
---|
230 | **pcm is a multichannel float vector. In stereo, for |
---|
231 | example, pcm[0] is left, and pcm[1] is right. samples is |
---|
232 | the size of each channel. Convert the float values |
---|
233 | (-1.<=range<=1.) to whatever PCM format and write it out */ |
---|
234 | |
---|
235 | while((samples=vorbis_synthesis_pcmout(&vd,&pcm))>0){ |
---|
236 | int j; |
---|
237 | int clipflag=0; |
---|
238 | int bout=(samples<convsize?samples:convsize); |
---|
239 | |
---|
240 | /* convert floats to 16 bit signed ints (host order) and |
---|
241 | interleave */ |
---|
242 | for(i=0;i<vi.channels;i++){ |
---|
243 | ogg_int16_t *ptr=convbuffer+i; |
---|
244 | float *mono=pcm[i]; |
---|
245 | for(j=0;j<bout;j++){ |
---|
246 | #if 1 |
---|
247 | int val=mono[j]*32767.f; |
---|
248 | #else /* optional dither */ |
---|
249 | int val=mono[j]*32767.f+drand48()-0.5f; |
---|
250 | #endif |
---|
251 | /* might as well guard against clipping */ |
---|
252 | if(val>32767){ |
---|
253 | val=32767; |
---|
254 | clipflag=1; |
---|
255 | } |
---|
256 | if(val<-32768){ |
---|
257 | val=-32768; |
---|
258 | clipflag=1; |
---|
259 | } |
---|
260 | *ptr=val; |
---|
261 | ptr+=vi.channels; |
---|
262 | } |
---|
263 | } |
---|
264 | |
---|
265 | if(clipflag) |
---|
266 | fprintf(stderr,"Clipping in frame %ld\n",(long)(vd.sequence)); |
---|
267 | |
---|
268 | |
---|
269 | fwrite(convbuffer,2*vi.channels,bout,stdout); |
---|
270 | |
---|
271 | vorbis_synthesis_read(&vd,bout); /* tell libvorbis how |
---|
272 | many samples we |
---|
273 | actually consumed */ |
---|
274 | } |
---|
275 | } |
---|
276 | } |
---|
277 | if(ogg_page_eos(&og))eos=1; |
---|
278 | } |
---|
279 | } |
---|
280 | if(!eos){ |
---|
281 | buffer=ogg_sync_buffer(&oy,4096); |
---|
282 | bytes=fread(buffer,1,4096,stdin); |
---|
283 | ogg_sync_wrote(&oy,bytes); |
---|
284 | if(bytes==0)eos=1; |
---|
285 | } |
---|
286 | } |
---|
287 | |
---|
288 | /* clean up this logical bitstream; before exit we see if we're |
---|
289 | followed by another [chained] */ |
---|
290 | |
---|
291 | ogg_stream_clear(&os); |
---|
292 | |
---|
293 | /* ogg_page and ogg_packet structs always point to storage in |
---|
294 | libvorbis. They're never freed or manipulated directly */ |
---|
295 | |
---|
296 | vorbis_block_clear(&vb); |
---|
297 | vorbis_dsp_clear(&vd); |
---|
298 | vorbis_comment_clear(&vc); |
---|
299 | vorbis_info_clear(&vi); /* must be called last */ |
---|
300 | } |
---|
301 | |
---|
302 | /* OK, clean up the framer */ |
---|
303 | ogg_sync_clear(&oy); |
---|
304 | |
---|
305 | fprintf(stderr,"Done.\n"); |
---|
306 | return(0); |
---|
307 | } |
---|