"Loose" anamorphic:

- Scales the storage frame size to arbitrary widths, like 640 for the iPod.
- Uses dimensions that divide cleanly by an arbitrary number (default: 16) and adjusts the SAR to match
- Uses ITU PAR values when the video is meant to be overscanned ( 7+ pixels cropped on left+right)

git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@1029 b64f7644-9d1e-0410-96f1-a4d463321fa5

4 files changed, 166 insertions, 3 deletions

diff --git a/libhb/common.h b/libhb/common.h
index e71959142..1cf6cdb59 100644
--- a/libhb/common.h
+++ b/libhb/common.h
@@ -27,6 +27,7 @@
 
 #define EVEN( a )        ( (a) + ( (a) & 1 ) )
 #define MULTIPLE_16( a ) ( 16 * ( ( (a) + 8 ) / 16 ) )
+#define MULTIPLE_MOD( a, b ) ( b * ( ( (a) + (b / 2) ) / b ) )
 
 #define HB_DVD_READ_BUFFER_SIZE 2048
 
@@ -139,6 +140,7 @@ struct hb_job_s
     int             pixel_ratio;
     int             pixel_aspect_width;
     int             pixel_aspect_height;
+    int             modulus;
 	int				maxWidth;
 	int				maxHeight;
 
diff --git a/libhb/hb.c b/libhb/hb.c
index a53bd1f4a..6b108bdf0 100644
--- a/libhb/hb.c
+++ b/libhb/hb.c
@@ -427,6 +427,156 @@ void hb_get_preview( hb_handle_t * h, hb_title_t * title, int picture,
 }
 
 /**
+ * Calculates job width and height for anamorphic content.
+ * @param job Handle to hb_job_t.
+ */
+void hb_set_anamorphic_size( hb_job_t * job)
+{
+    hb_title_t * title = job->title;
+
+    /* "Loose" anamorphic.
+        - Uses mod16-compliant dimensions,
+        - Allows users to set the width
+        - Handles ITU pixel aspects
+    */
+    
+    /* Set up some variables to make the math easier to follow. */
+    int cropped_width = title->width - job->crop[2] - job->crop[3] ;
+    int cropped_height = title->height - job->crop[0] - job->crop[1] ;
+    int storage_aspect = cropped_width * 10000 / cropped_height;        
+
+    /* Gotta handle bounding dimensions differently
+       than for non-anamorphic encodes:
+       If the width is too big, just reset it with no rescaling.
+       Instead of using the aspect-scaled job height,
+       we need to see if the job width divided by the storage aspect
+       is bigger than the max. If so, set it to the max (this is sloppy).
+       If not, set job height to job width divided by storage aspect.
+    */
+    if ( job->maxWidth && (job->maxWidth < job->width) )
+        job->width = job->maxWidth;
+        
+    if ( job->maxHeight && (job->maxHeight < (job->width / storage_aspect * 10000)) )
+    {
+        job->height = job->maxHeight;
+    }
+    else
+    {
+        job->height = job->width * 10000 / storage_aspect;
+    }
+        
+    /* Time to get picture dimensions that divide cleanly.
+       These variables will store temporary dimensions as we iterate. */
+    int i, w, h, mod;
+
+    /* In case the user specified a modulus, use it */
+    if (job->modulus)
+        mod = job->modulus;
+    else
+        mod = 16;
+        
+    /* Iterate through multiples of mod to find one close to job->width. */
+    for( i = 1;; i++ )
+    {
+        w = mod * i;
+        
+        if (w < job->width)
+        {
+            if ( ( job->width - w ) <= ( mod / 2 ) )
+                /* We'll take a width that's
+                   smaller, but close enough. */
+                break;
+        }
+        if (w == job->width)
+            /* Mod 16 dimensions, how nice! */
+            break;
+        if( w > job->width )
+        {
+            if ( ( w - job->width ) < (mod/2) )
+                /* We'll take a width that's bigger, if we have to. */
+                break;
+        }
+    }
+    job->width  = mod * (i);
+    
+    /* Now do the same for a mod-friendly value near job->height. */
+    for( i = 1;; i++)
+    {
+        h = i * mod;
+        
+        if (h < job->height)
+            {
+                if ( ( job->height - h ) <= ( mod / 2 ))
+                    /* Go with a smaller height,
+                       if it's close enough.    */
+                    break;
+            }
+        if (h == job->height)
+            /* Mod 16 dimensions, how nice! */
+            break;
+            
+        if ( h > job->height)
+        {
+            if ( ( h - job->height ) < ( mod / 2 ))
+                /* Use a taller height if necessary */
+                break;
+        }
+    }
+    job->height = mod  * (i);
+    
+    if (cropped_width <= 706)
+    {
+        /* Handle ITU PARs */
+        if (title->height == 480)
+        {
+            /* It's NTSC */
+            if (title->aspect == 16)
+            {
+                /* It's widescreen */
+                job->pixel_aspect_width = 40;
+                job->pixel_aspect_height = 33;
+            }
+            else
+            {
+                /* It's 4:3 */
+                job->pixel_aspect_width = 10;
+                job->pixel_aspect_height = 11;
+            }
+        }
+        else if (title->height == 576)
+        {
+            /* It's PAL */
+            if(title->aspect == 16)
+            {
+                /* It's widescreen */
+                job->pixel_aspect_width = 16;
+                job->pixel_aspect_height = 11;
+            }
+            else
+            {
+                /* It's 4:3 */
+                job->pixel_aspect_width = 12;
+                job->pixel_aspect_height = 11;
+            }
+        }
+    }
+
+    /* Figure out what dimensions the source would display at. */
+    int source_display_width = cropped_width * ((float)job->pixel_aspect_width / (float)job->pixel_aspect_height) ;
+   
+    /* The film AR is the source's display width / cropped source height.
+       The output display width is the output height * film AR.
+       The output PAR is the output display width / output storage width. */
+    job->pixel_aspect_width = job->height * source_display_width / cropped_height;
+    job->pixel_aspect_height = job->width;
+    
+    /* While x264 is smart enough to reduce fractions on its own, libavcodec
+       needs some help with the math, so lose superfluous factors.            */
+    hb_reduce( &job->pixel_aspect_width, &job->pixel_aspect_height,
+               job->pixel_aspect_width, job->pixel_aspect_height );
+}
+
+/**
  * Calculates job width, height, and cropping parameters.
  * @param job Handle to hb_job_t.
  * @param aspect Desired aspect ratio. Value of -1 uses title aspect.
diff --git a/libhb/hb.h b/libhb/hb.h
index 6f8af2aee..be629505f 100644
--- a/libhb/hb.h
+++ b/libhb/hb.h
@@ -78,6 +78,7 @@ hb_list_t   * hb_get_titles( hb_handle_t * );
 void          hb_get_preview( hb_handle_t *, hb_title_t *, int,
                               uint8_t * );
 void          hb_set_size( hb_job_t *, int ratio, int pixels );
+void          hb_set_anamorphic_size( hb_job_t * );
 
 /* Handling jobs */
 int           hb_count( hb_handle_t * );
diff --git a/libhb/work.c b/libhb/work.c
index 72d12d75a..22e081532 100644
--- a/libhb/work.c
+++ b/libhb/work.c
@@ -128,16 +128,26 @@ static void do_job( hb_job_t * job, int cpu_count )
     	job->height=title->height-job->crop[0]-job->crop[1];
     	job->width=title->width-job->crop[2]-job->crop[3];
     }
+    else if ( job->pixel_ratio == 2 )
+    {
+
+        /* While keeping the DVD storage aspect, resize the job width and height
+           so they fit into the user's specified dimensions. */
+        hb_set_anamorphic_size(job);
+    }
 
-	/* Keep width and height within these boundaries */
-	if (job->maxHeight && (job->height > job->maxHeight) )
+	/* Keep width and height within these boundaries,
+	   but ignore for "loose" anamorphic encodes, for
+	   which this stuff is covered in the pixel_ratio
+	   section right above.*/
+	if (job->maxHeight && (job->height > job->maxHeight) && (job->pixel_ratio != 2))
 	{
 		job->height = job->maxHeight;
 		hb_fix_aspect( job, HB_KEEP_HEIGHT );
 		hb_log("Height out of bounds, scaling down to %i", job->maxHeight);
 		hb_log("New dimensions %i * %i", job->width, job->height);
 	}
-	if (job->maxWidth && (job->width > job->maxWidth) )
+	if (job->maxWidth && (job->width > job->maxWidth) && (job->pixel_ratio != 2))
 	{
 		job->width = job->maxWidth;
 		hb_fix_aspect( job, HB_KEEP_WIDTH );