From 199b2a84e2b29bd7da582ab1588ebcb6f158928c Mon Sep 17 00:00:00 2001
From: Nils Wallménius <nils@rockbox.org>
Date: Wed, 8 Dec 2010 16:34:25 +0000
Subject: libtremor: merge upstream revision 17534 and 17536, fixing a possible
 64 bit math overflow and correct types for some comparisons.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@28769 a1c6a512-1295-4272-9138-f99709370657
---
 apps/codecs/libtremor/vorbisfile.c | 43 ++++++++++++++++++++++++++++++++------
 1 file changed, 37 insertions(+), 6 deletions(-)

(limited to 'apps/codecs/libtremor')

diff --git a/apps/codecs/libtremor/vorbisfile.c b/apps/codecs/libtremor/vorbisfile.c
index 9365ba344b..f0a83364ec 100644
--- a/apps/codecs/libtremor/vorbisfile.c
+++ b/apps/codecs/libtremor/vorbisfile.c
@@ -193,7 +193,7 @@ static void _add_serialno(ogg_page *og,ogg_uint32_t **serialno_list, int *n){
 }
 
 /* returns nonzero if found */
-static int _lookup_serialno(long s, ogg_uint32_t *serialno_list, int n){
+static int _lookup_serialno(ogg_uint32_t s, ogg_uint32_t *serialno_list, int n){
   if(serialno_list){
     while(n--){
       if(*serialno_list == (ogg_uint32_t) s) return 1;
@@ -204,7 +204,7 @@ static int _lookup_serialno(long s, ogg_uint32_t *serialno_list, int n){
 }
 
 static int _lookup_page_serialno(ogg_page *og, ogg_uint32_t *serialno_list, int n){
-  long s = ogg_page_serialno(og);
+  ogg_uint32_t s = ogg_page_serialno(og);
   return _lookup_serialno(s,serialno_list,n);
 }
 
@@ -245,12 +245,12 @@ static ogg_int64_t _get_prev_page_serial(OggVorbis_File *vf,
         ret_gran=ogg_page_granulepos(&og);
         offset=ret;
 
-        if(ret_serialno == (ogg_uint32_t) *serialno){
+        if((ogg_uint32_t)ret_serialno == (ogg_uint32_t)*serialno){
           prefoffset=ret;
           *granpos=ret_gran;
         }
 
-        if(!_lookup_serialno(ret_serialno,serial_list,serial_n)){
+        if(!_lookup_serialno((ogg_uint32_t)ret_serialno,serial_list,serial_n)){
           /* we fell off the end of the link, which means we seeked
              back too far and shouldn't have been looking in that link
              to begin with.  If we found the preferred serial number,
@@ -1201,6 +1201,36 @@ int ov_raw_seek(OggVorbis_File *vf,ogg_int64_t pos){
   return OV_EBADLINK;
 }
 
+/* rescales the number x from the range of [0,from] to [0,to]
+   x is in the range [0,from]
+   from, to are in the range [1, 1<<62-1] */
+ogg_int64_t rescale64(ogg_int64_t x, ogg_int64_t from, ogg_int64_t to){
+  ogg_int64_t frac=0;
+  ogg_int64_t ret=0;
+  int i;
+  if(x >= from) return to;
+  if(x <= 0) return 0;
+
+  for(i=0;i<64;i++){
+    if(x>=from){
+      frac|=1;
+      x-=from;
+    }
+    x<<=1;
+    frac<<=1;
+  }
+
+  for(i=0;i<64;i++){
+    if(frac & 1){
+      ret+=to;
+    }
+    frac>>=1;
+    ret>>=1;
+  }
+
+  return ret;
+}
+
 /* Page granularity seek (faster than sample granularity because we
    don't do the last bit of decode to find a specific sample).
 
@@ -1246,8 +1276,9 @@ int ov_pcm_seek_page(OggVorbis_File *vf,ogg_int64_t pos){
         bisect=begin;
       }else{
         /* take a (pretty decent) guess. */
-        bisect=begin +
-          (target-begintime)*(end-begin)/(endtime-begintime) - CHUNKSIZE;
+        bisect=begin + rescale64(target-begintime,
+				 endtime-begintime,
+				 end-begin) - CHUNKSIZE;
         if(bisect<begin+CHUNKSIZE)
           bisect=begin;
       }
-- 
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