Add a calc_src_dst_rects that calculates from window size, panscan etc.

which part of the video source must be scaled onto which part of the window.
Direct3D and (future) VDPAU need this, for XvMC it makes it easier to add
cropping support and Xv is changed to keep the diff to XvMC small.


git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@28546 b3059339-0415-0410-9bf9-f77b7e298cf2

1 files changed, 60 insertions, 0 deletions

diff --git a/libvo/video_out.c b/libvo/video_out.c
index c99f312e16..27853d5ed4 100644
--- a/libvo/video_out.c
+++ b/libvo/video_out.c
@@ -355,6 +355,66 @@ int lookup_keymap_table(const struct keymap *map, int key) {
   return map->to;
 }
 
+/**
+ * \brief helper function for the kind of panscan-scaling that needs a source
+ *        and destination rectangle like Direct3D and VDPAU
+ */
+static void src_dst_split_scaling(int src_size, int dst_size, int scaled_src_size,
+                                  int *src_start, int *src_end, int *dst_start, int *dst_end) {
+  if (scaled_src_size > dst_size) {
+    int border = src_size * (scaled_src_size - dst_size) / scaled_src_size;
+    // round to a multiple of 2, this is at least needed for vo_direct3d and ATI cards
+    border = (border / 2 + 1) & ~1;
+    *src_start = border;
+    *src_end   = src_size - border;
+    *dst_start = 0;
+    *dst_end   = dst_size;
+  } else {
+    *src_start = 0;
+    *src_end   = src_size;
+    *dst_start = (dst_size - scaled_src_size) / 2;
+    *dst_end   = *dst_start + scaled_src_size;
+  }
+}
+
+/**
+ * Calculate the appropriate source and destination rectangle to
+ * get a correctly scaled picture, including pan-scan.
+ * Can be extended to take future cropping support into account.
+ *
+ * \param crop specifies the cropping border size in the left, right, top and bottom members, may be NULL
+ */
+void calc_src_dst_rects(int src_width, int src_height, struct vo_rect *src, struct vo_rect *dst, struct vo_rect *crop) {
+  static const struct vo_rect no_crop = {0, 0, 0, 0, 0, 0};
+  int scaled_width  = 0;
+  int scaled_height = 0;
+  if (!crop) crop = &no_crop;
+  src_width  -= crop->left + crop->right;
+  src_height -= crop->top  + crop->bottom;
+  if (src_width  < 2) src_width  = 2;
+  if (src_height < 2) src_height = 2;
+  dst->left = 0; dst->right  = vo_dwidth;
+  dst->top  = 0; dst->bottom = vo_dheight;
+  src->left = 0; src->right  = src_width;
+  src->top  = 0; src->bottom = src_height;
+  if (vo_fs) {
+    aspect(&scaled_width, &scaled_height, A_ZOOM);
+    panscan_calc();
+    scaled_width  += vo_panscan_x;
+    scaled_height += vo_panscan_y;
+    src_dst_split_scaling(src_width, vo_dwidth, scaled_width,
+                          &src->left, &src->right, &dst->left, &dst->right);
+    src_dst_split_scaling(src_height, vo_dheight, scaled_height,
+                          &src->top, &src->bottom, &dst->top, &dst->bottom);
+  }
+  src->left += crop->left; src->right  += crop->left;
+  src->top  += crop->top;  src->bottom += crop->top;
+  src->width  = src->right  - src->left;
+  src->height = src->bottom - src->top;
+  dst->width  = dst->right  - dst->left;
+  dst->height = dst->bottom - dst->top;
+}
+
 #if defined(CONFIG_FBDEV) || defined(CONFIG_VESA)
 /* Borrowed from vo_fbdev.c
 Monitor ranges related functions*/