vf_expand: add sanity checks

Make vf expand more picky:
refuse operating on compressed or hwaccel formats and
fix up offsets that would cause color corruption for YUV
formats with downsampled chroma.

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@34356 b3059339-0415-0410-9bf9-f77b7e298cf2
Author: reimar

1 files changed, 20 insertions, 1 deletions

diff --git a/libmpcodecs/vf_expand.c b/libmpcodecs/vf_expand.c
index 6cc7a810b6..a5ce57fa98 100644
--- a/libmpcodecs/vf_expand.c
+++ b/libmpcodecs/vf_expand.c
@@ -132,11 +132,13 @@ static int config(struct vf_instance *vf,
 	unsigned int flags, unsigned int outfmt)
 {
     struct MPOpts *opts = vf->opts;
+    mp_image_t test_mpi;
     if(outfmt == IMGFMT_MPEGPES) {
       vf->priv->passthrough = 1;
       return vf_next_config(vf,width,height,d_width,d_height,flags,outfmt);
     }
-    if (outfmt == IMGFMT_IF09) return 0;
+    mp_image_setfmt(&test_mpi, outfmt);
+    if (outfmt == IMGFMT_IF09 || !test_mpi.bpp) return 0;
     vf->priv->exp_x = vf->priv->cfg_exp_x;
     vf->priv->exp_y = vf->priv->cfg_exp_y;
     vf->priv->exp_w = vf->priv->cfg_exp_w;
@@ -169,6 +171,23 @@ static int config(struct vf_instance *vf,
 
     if(vf->priv->exp_x<0 || vf->priv->exp_x+width>vf->priv->exp_w) vf->priv->exp_x=(vf->priv->exp_w-width)/2;
     if(vf->priv->exp_y<0 || vf->priv->exp_y+height>vf->priv->exp_h) vf->priv->exp_y=(vf->priv->exp_h-height)/2;
+    if(test_mpi.flags & MP_IMGFLAG_YUV) {
+        int x_align_mask = (1 << test_mpi.chroma_x_shift) - 1;
+        int y_align_mask = (1 << test_mpi.chroma_y_shift) - 1;
+        // For 1-plane format non-aligned offsets will completely
+        // destroy the colours, for planar it will break the chroma
+        // sampling position.
+        if (vf->priv->exp_x & x_align_mask) {
+            vf->priv->exp_x &= ~x_align_mask;
+            mp_msg(MSGT_VFILTER, MSGL_ERR, "Specified x offset not supported "
+                   "for YUV, reduced to %i.\n", vf->priv->exp_x);
+        }
+        if (vf->priv->exp_y & y_align_mask) {
+            vf->priv->exp_y &= ~y_align_mask;
+            mp_msg(MSGT_VFILTER, MSGL_ERR, "Specified y offset not supported "
+                   "for YUV, reduced to %i.\n", vf->priv->exp_y);
+        }
+    }
 
     if(!opts->screen_size_x && !opts->screen_size_y){
 	d_width=d_width*vf->priv->exp_w/width;