From f8eb63aed0df0e9c99b5d652728ccb01a2d4eb68 Mon Sep 17 00:00:00 2001
From: van <vanj.hb@gmail.com>
Date: Fri, 8 Aug 2008 06:19:54 +0000
Subject:  - change aspect from a scaled int to a double so we can handle the
 wider    range of aspect ratios we get from ffmpeg files.

 - add container_aspect to title struct (always zero except for DVDs
   when it's the aspect from the VTSI). To handle broken French DVDs,
   make HB complain & use the container aspect if it's different from
   the aspect computed from the video PAR.

 - fix ScanFunc's job template init so that it doesn't think the only
   legal aspect ratios are 16:9 & 4:3.

 - hb_reduce wouldn't reduce any fraction where both terms were equal and
   prime (e.g., 2/2, 3/3, 5/5, etc. would not become 1/1). Recoded it using
   Euclid's Algorithm so it always works and is faster.


git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@1616 b64f7644-9d1e-0410-96f1-a4d463321fa5
---
 libhb/common.c | 46 +++++++++++++++++++++++++---------------------
 1 file changed, 25 insertions(+), 21 deletions(-)

(limited to 'libhb/common.c')

diff --git a/libhb/common.c b/libhb/common.c
index c625bec9b..c8cc8dddc 100644
--- a/libhb/common.c
+++ b/libhb/common.c
@@ -82,18 +82,26 @@ const char * hb_mixdown_get_short_name_from_mixdown( int amixdown )
  *********************************************************************/
 void hb_reduce( int *x, int *y, int num, int den )
 {
-    int lower = MIN( num, den );
-    int i;
-    *x = num;
-    *y = den;
-    for( i = lower - 1; i > 1; --i )
+    // find the greatest common divisor of num & den by Euclid's algorithm
+    int n = num, d = den;
+    while ( d )
     {
-        if( ( num % i == 0 ) && ( den % i == 0 ) )
-        {
-            *x = num / i;
-            *y = den / i;
-            break;
-        }
+        int t = d;
+        d = n % d;
+        n = t;
+    }
+
+    // at this point n is the gcd. if it's non-zero remove it from num
+    // and den. Otherwise just return the original values.
+    if ( n )
+    {
+        *x = num / n;
+        *y = den / n;
+    }
+    else
+    {
+        *x = num;
+        *y = den;
     }
 }
 
@@ -143,22 +151,18 @@ void hb_fix_aspect( hb_job_t * job, int keep )
         }
     }
 
+    double par = (double)title->width / ( (double)title->height * title->aspect );
+    double cropped_sar = (double)( title->height - job->crop[0] - job->crop[1] ) /
+                         (double)(title->width - job->crop[2] - job->crop[3] );
+    double ar = par * cropped_sar;
     if( keep == HB_KEEP_WIDTH )
     {
-        job->height = MULTIPLE_16(
-            (uint64_t) job->width * title->width * HB_ASPECT_BASE *
-              ( title->height - job->crop[0] - job->crop[1] ) /
-            ( (uint64_t) title->height * title->aspect *
-              ( title->width - job->crop[2] - job->crop[3] ) ) );
+        job->height = MULTIPLE_16( (uint64_t)( (double)job->width * ar ) );
         job->height = MAX( 16, job->height );
     }
     else
     {
-        job->width = MULTIPLE_16(
-            (uint64_t) job->height * title->height * title->aspect *
-              ( title->width - job->crop[2] - job->crop[3] ) /
-            ( (uint64_t) title->width * HB_ASPECT_BASE *
-              ( title->height - job->crop[0] - job->crop[1] ) ) );
+        job->width = MULTIPLE_16( (uint64_t)( (double)job->height / ar ) );
         job->width = MAX( 16, job->width );
     }
 }
-- 
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