Attachment 303976 Details for Bug 444443 – Patch from Monty (xiphmont)

[patch] Patch from Monty (xiphmont)

vorbis-check_words-pre1.0.diff (text/plain), 1.50 KB, created by Tomas Hoger on 2008-04-28 13:53:16 UTC

(hide)

Description:

Filename:

MIME Type:

Creator: Tomas Hoger

Created: 2008-04-28 13:53:16 UTC

Size: 1.50 KB

patch

obsolete

>Index: lib/codebook.c
>===================================================================
>--- lib/codebook.c	(revision 14799)
>+++ lib/codebook.c	(working copy)
>@@ -144,6 +144,49 @@
>   return(0);
> }
> 
>+/* Like _make_words, but it only a dry-run to sanity check the
>+   codebook at a point where we can still report errors within the rc2
>+   ABI. */
>+int _check_words(long *l,long n){
>+  long i,j;
>+  long marker[33];
>+  memset(marker,0,sizeof(marker));
>+
>+  for(i=0;i<n;i++){
>+    long length=l[i];
>+
>+    if(length>0){
>+      long entry=marker[length];
>+      
>+      if(length<32 && (entry>>length)) return -1;
>+
>+      for(j=length;j>0;j--){	
>+	if(marker[j]&1){
>+	  if(j==1)
>+	    marker[1]++;
>+	  else
>+	    marker[j]=marker[j-1]<<1;
>+	    break;
>+	}
>+	marker[j]++;
>+      }
>+      
>+      for(j=length+1;j<33;j++)
>+	if((marker[j]>>1) == entry){
>+	  entry=marker[j];
>+	  marker[j]=marker[j-1]<<1;
>+	}else
>+	  break;
>+    }
>+  }
>+
>+  /* sanity check the huffman tree; an underpopulated tree must be rejected. */
>+  for(i=1;i<33;i++)
>+    if(marker[i] & (0xffffffffUL>>(32-i))) return -1;
>+
>+  return(0);
>+}
>+
> /* unpacks a codebook from the packet buffer into the codebook struct,
>    readies the codebook auxiliary structures for decode *************/
> int vorbis_staticbook_unpack(oggpack_buffer *opb,static_codebook *s){
>@@ -244,7 +287,11 @@
>     goto _errout;
>   }
> 
>+  /* lastly, sanity check the declared book huffman structure */
>+  if(_check_words(s->lengthlist,s->entries))
>+    goto _errout;
>+
>   /* all set */
>   return(0);
>

Actions: View | Diff

Attachments on bug 444443: 303976