Handle non-audio packets (eg, header packets) properly in _process_packet.

Monty

svn path=/trunk/vorbis/; revision=171

diff --git a/lib/vorbisfile.c b/lib/vorbisfile.c
index 3d5fff8..26fbb85 100644 (file)
--- a/lib/vorbisfile.c
+++ b/lib/vorbisfile.c
@@ -14,7 +14,7 @@
  function: stdio-based convenience library for opening/seeking/decoding
  author: Monty <xiphmont@mit.edu>
  modifications by: Monty
- last modification date: Nov 04 1999
+ last modification date: Nov 16 1999
 
  ********************************************************************/
 
@@ -351,6 +351,7 @@ static int _open_seekable(OggVorbis_File *vf){
   }
 
   _prefetch_all_headers(vf,&initial,dataoffset);
+  ov_raw_seek(vf,0);
 
   return(0);
 }
@@ -404,28 +405,35 @@ static int _process_packet(OggVorbis_File *vf,int readp){
       if(result>0){
        /* got a packet.  process it */
        frameno=op.frameno;
-       vorbis_synthesis(&vf->vb,&op);
-       vorbis_synthesis_blockin(&vf->vd,&vf->vb);
-       
-       /* update the pcm offset. */
-       if(frameno!=-1){
-         int link=(vf->seekable?vf->current_link:0);
-         double **dummy;
-         int i,samples;
-         
-         /* this packet has a pcm_offset on it (the last packet
-            completed on a page carries the offset) After processing
-            (above), we know the pcm position of the *last* sample
-            ready to be returned. Find the offset of the *first* */
+       if(!vorbis_synthesis(&vf->vb,&op)){ /* lazy check for lazy
+                                               header handling.  The
+                                               header packets aren't
+                                               audio, so if/when we
+                                               submit them,
+                                               vorbis_synthesis will
+                                               reject them */
+         vorbis_synthesis_blockin(&vf->vd,&vf->vb);
          
-         samples=vorbis_synthesis_pcmout(&vf->vd,&dummy);
-         
-         frameno-=samples;
-         for(i=0;i<link;i++)
-           frameno+=vf->pcmlengths[i];
-         vf->pcm_offset=frameno;
+         /* update the pcm offset. */
+         if(frameno!=-1){
+           int link=(vf->seekable?vf->current_link:0);
+           double **dummy;
+           int i,samples;
+           
+           /* this packet has a pcm_offset on it (the last packet
+              completed on a page carries the offset) After processing
+              (above), we know the pcm position of the *last* sample
+              ready to be returned. Find the offset of the *first* */
+           
+           samples=vorbis_synthesis_pcmout(&vf->vd,&dummy);
+           
+           frameno-=samples;
+           for(i=0;i<link;i++)
+             frameno+=vf->pcmlengths[i];
+           vf->pcm_offset=frameno;
+         }
+         return(1);
        }
-       return(1);
       }
     }
 
@@ -998,7 +1006,7 @@ long ov_read(OggVorbis_File *vf,char *buffer,int length,
        
        vorbis_synthesis_read(&vf->vd,samples);
        vf->pcm_offset+=samples;
-       *bitstream=vf->current_link;
+       if(bitstream)*bitstream=vf->current_link;
        return(samples*bytespersample);
       }
     }