[MPlayer-dev-eng] Scaling with maximum limit

[Jan Engelhardt]

The following patch implements a noup=3 mode, which is doing about the 
same as xine's -G option, whereby the window will be up- or down-scaled 
but never to go over the specified maximum size in any dimension.

Example:
  mplayer foo.avi -vf scale=400:300::::::3

VIDEO:  [XVID]  704x396  12bpp  23.976 fps  885.7 kbps (108.1 kbyte/s)
[swscaler @ 0x8997300]704x396 -> 400x226
VO: [xv] 400x226 => 401x226 Planar YV12 

(Oh see, there's a slight rounding issue yet.)


  mplayer foo.avi -vf scale=1024:768::::::3

[swscaler @ 0x8997300]704x396 -> 1024x576
VO: [xv] 1024x576 => 1024x576 Planar YV12 


The drawback here is that it uses swscaler, and I would have liked to 
make use of hardware scaling when available, but mplayer's 
current options are limited.


---
 libmpcodecs/vf_scale.c |   16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

Index: MPlayer-1.0rc2_r29116/libmpcodecs/vf_scale.c
===================================================================
--- MPlayer-1.0rc2_r29116.orig/libmpcodecs/vf_scale.c
+++ MPlayer-1.0rc2_r29116/libmpcodecs/vf_scale.c
@@ -152,7 +152,16 @@ static int config(struct vf_instance_s*
 	}
     }
 
-    if(vf->priv->noup){
+    if (vf->priv->noup == 3) {
+        double f;
+        if ((double)vf->priv->w / vf->priv->h >=
+            (double)width / height)
+		f = (double)vf->priv->h / height;
+	else
+		f = (double)vf->priv->w / width;
+	vf->priv->w = width * f;
+	vf->priv->h = height * f;
+    } else if (vf->priv->noup > 0) {
         if((vf->priv->w > width) + (vf->priv->h > height) >= vf->priv->noup){
             vf->priv->w= width;
             vf->priv->h= height;
@@ -659,7 +671,7 @@ static m_option_t vf_opts_fields[] = {
   // Note that here the 2 field is NULL (ie 0)
   // As we want this option to act on the option struct itself
   {"presize", 0, CONF_TYPE_OBJ_PRESETS, 0, 0, 0, &size_preset},
-  {"noup", ST_OFF(noup), CONF_TYPE_INT, M_OPT_RANGE, 0, 2, NULL},
+  {"noup", ST_OFF(noup), CONF_TYPE_INT, M_OPT_RANGE, 0, 3, NULL},
   {"arnd", ST_OFF(accurate_rnd), CONF_TYPE_FLAG, 0, 0, 1, NULL},
   { NULL, NULL, 0, 0, 0, 0,  NULL }
 };