Fixes for two bugs relating to short files in vorbisfile:

 1) _get_prev_page could get stuck in an infinite loop trying to seek to < 0
 2) _process_packet could return OV_EOF when there were valid packets awaiting
    decode.

Remaining problem: on my test file (739 samples long), seeking_example fails
the pcm exact seeking test.

svn path=/trunk/vorbis/; revision=2350

diff --git a/lib/vorbisfile.c b/lib/vorbisfile.c
index 1246d5e..e3f2857 100644 (file)
--- a/lib/vorbisfile.c
+++ b/lib/vorbisfile.c
@@ -11,7 +11,7 @@
  ********************************************************************
 
  function: stdio-based convenience library for opening/seeking/decoding
- last mod: $Id: vorbisfile.c,v 1.50 2001/10/02 00:14:32 segher Exp $
+ last mod: $Id: vorbisfile.c,v 1.51 2001/11/12 13:41:10 msmith Exp $
 
  ********************************************************************/
 
@@ -142,6 +142,8 @@ static long _get_prev_page(OggVorbis_File *vf,ogg_page *og){
 
   while(offset==-1){
     begin-=CHUNKSIZE;
+    if(begin<0)
+      begin=0;
     _seek_helper(vf,begin);
     while(vf->offset<begin+CHUNKSIZE){
       ret=_get_next_page(vf,og,begin+CHUNKSIZE-vf->offset);
@@ -425,57 +427,61 @@ static int _process_packet(OggVorbis_File *vf,int readp){
     /* process a packet if we can.  If the machine isn't loaded,
        neither is a page */
     if(vf->ready_state==INITSET){
-      ogg_packet op;
-      int result=ogg_stream_packetout(&vf->os,&op);
-      ogg_int64_t granulepos;
-
-      if(result==-1)return(OV_HOLE); /* hole in the data. */
-      if(result>0){
-       /* got a packet.  process it */
-       granulepos=op.granulepos;
-       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 */
-
-         /* suck in the synthesis data and track bitrate */
-         {
-           int oldsamples=vorbis_synthesis_pcmout(&vf->vd,NULL);
-           vorbis_synthesis_blockin(&vf->vd,&vf->vb);
-           vf->samptrack+=vorbis_synthesis_pcmout(&vf->vd,NULL)-oldsamples;
-           vf->bittrack+=op.bytes*8;
-         }
+      while(1) {
+       ogg_packet op;
+       int result=ogg_stream_packetout(&vf->os,&op);
+       ogg_int64_t granulepos;
+
+       if(result==-1)return(OV_HOLE); /* hole in the data. */
+       if(result>0){
+         /* got a packet.  process it */
+         granulepos=op.granulepos;
+         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 */
+
+           /* suck in the synthesis data and track bitrate */
+           {
+             int oldsamples=vorbis_synthesis_pcmout(&vf->vd,NULL);
+             vorbis_synthesis_blockin(&vf->vd,&vf->vb);
+             vf->samptrack+=vorbis_synthesis_pcmout(&vf->vd,NULL)-oldsamples;
+             vf->bittrack+=op.bytes*8;
+           }
          
-         /* update the pcm offset. */
-         if(granulepos!=-1 && !op.e_o_s){
-           int link=(vf->seekable?vf->current_link:0);
-           int i,samples;
+           /* update the pcm offset. */
+           if(granulepos!=-1 && !op.e_o_s){
+             int link=(vf->seekable?vf->current_link:0);
+             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*
-
-              As an aside, this trick is inaccurate if we begin
-              reading anew right at the last page; the end-of-stream
-              granulepos declares the last frame in the stream, and the
-              last packet of the last page may be a partial frame.
-              So, we need a previous granulepos from an in-sequence page
-              to have a reference point.  Thus the !op.e_o_s clause
-              above */
+             /* 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*
+
+                As an aside, this trick is inaccurate if we begin
+                reading anew right at the last page; the end-of-stream
+                granulepos declares the last frame in the stream, and the
+                last packet of the last page may be a partial frame.
+                So, we need a previous granulepos from an in-sequence page
+                to have a reference point.  Thus the !op.e_o_s clause
+                above */
            
-           samples=vorbis_synthesis_pcmout(&vf->vd,NULL);
+             samples=vorbis_synthesis_pcmout(&vf->vd,NULL);
            
-           granulepos-=samples;
-           for(i=0;i<link;i++)
-             granulepos+=vf->pcmlengths[i];
-           vf->pcm_offset=granulepos;
+             granulepos-=samples;
+             for(i=0;i<link;i++)
+               granulepos+=vf->pcmlengths[i];
+             vf->pcm_offset=granulepos;
+           }
+           return(1);
          }
-         return(1);
        }
+       else 
+         break;
       }
     }