Remove multiple subtly different inline and static implementaitonos of ilog()

Add a few additional sanity checks, mostly functioning to ensure we're always
calling ilog() with >=0 input.


svn path=/trunk/vorbis/; revision=19441

1 files changed, 7 insertions, 11 deletions

diff --git a/lib/synthesis.c b/lib/synthesis.c
index f55091ff..3fa5ab93 100644
--- a/lib/synthesis.c
+++ b/lib/synthesis.c
@@ -145,6 +145,11 @@ long vorbis_packet_blocksize(vorbis_info *vi,ogg_packet *op){
   oggpack_buffer       opb;
   int                  mode;
 
+  if(ci==NULL || ci->modes<=0){
+    /* codec setup not properly intialized */
+    return(OV_EFAULT);
+  }
+
   oggpack_readinit(&opb,op->packet,op->bytes);
 
   /* Check the packet type */
@@ -153,17 +158,8 @@ long vorbis_packet_blocksize(vorbis_info *vi,ogg_packet *op){
     return(OV_ENOTAUDIO);
   }
 
-  {
-    int modebits=0;
-    int v=ci->modes;
-    while(v>1){
-      modebits++;
-      v>>=1;
-    }
-
-    /* read our mode and pre/post windowsize */
-    mode=oggpack_read(&opb,modebits);
-  }
+  /* read our mode and pre/post windowsize */
+  mode=oggpack_read(&opb,ov_ilog(ci->modes-1));
   if(mode==-1 || !ci->mode_param[mode])return(OV_EBADPACKET);
   return(ci->blocksizes[ci->mode_param[mode]->blockflag]);
 }