dvbsuboverlay: scale subtitles according to the display size

Display size is either transmitted in the display definition segment or
implicitly defined to 720x576. The subtitle window information also present in
the display definition segment is not yet used.

1 files changed, 15 insertions, 22 deletions

diff --git a/gst/dvbsuboverlay/gstdvbsuboverlay.c b/gst/dvbsuboverlay/gstdvbsuboverlay.c
index f18dd0178..9980e677f 100644
--- a/gst/dvbsuboverlay/gstdvbsuboverlay.c
+++ b/gst/dvbsuboverlay/gstdvbsuboverlay.c
@@ -480,7 +480,7 @@ blit_i420 (GstDVBSubOverlay * overlay, DVBSubtitles * subs, GstBuffer * buffer)
   guint32 color;
   const guint8 *src;
   guint8 *dst_y, *dst_y2, *dst_u, *dst_v;
-  gint x, y, w, h;
+  gint x, y;
   gint w2, h2;
   gint width = overlay->width;
   gint height = overlay->height;
@@ -518,7 +518,7 @@ blit_i420 (GstDVBSubOverlay * overlay, DVBSubtitles * subs, GstBuffer * buffer)
   v_stride = gst_video_format_get_row_stride (GST_VIDEO_FORMAT_I420, 2, width);
 
   for (counter = 0; counter < subs->num_rects; counter++) {
-    gint dw, dh;
+    gint dw, dh, dx, dy;
     gint32 sx = 0, sy;          /* 16.16 fixed point */
     gint32 xstep, ystep;        /* 16.16 fixed point */
 
@@ -527,18 +527,16 @@ blit_i420 (GstDVBSubOverlay * overlay, DVBSubtitles * subs, GstBuffer * buffer)
       continue;
 
     /* blend subtitles onto the video frame */
-    w = MIN (sub_region->w, width - sub_region->x);
-    h = MIN (sub_region->h, height - sub_region->y);
+    dx = sub_region->x * width / subs->display_def.display_width;
+    dy = sub_region->y * height / subs->display_def.display_height;
 
-    /* TODO
-       dw = MIN (sub_region->dw, width - sub_region->x);
-       dh = MIN (sub_region->dh, height - sub_region->y);
-     */
-    dw = w;
-    dh = h;
+    dw = MIN (sub_region->w * width / subs->display_def.display_width,
+        width - dx);
+    dh = MIN (sub_region->h * height / subs->display_def.display_height,
+        height - dy);
 
-    xstep = (w << 16) / dw;
-    ystep = (h << 16) / dh;
+    xstep = (sub_region->w << 16) / dw;
+    ystep = (sub_region->h << 16) / dh;
 
     w2 = (dw + 1) / 2;
     h2 = (dh + 1) / 2;
@@ -546,21 +544,16 @@ blit_i420 (GstDVBSubOverlay * overlay, DVBSubtitles * subs, GstBuffer * buffer)
     src_stride = sub_region->pict.rowstride;
 
     src = sub_region->pict.data;
-    dst_y = buffer->data + y_offset + sub_region->y * y_stride + sub_region->x;
-    dst_y2 =
-        buffer->data + y_offset + (sub_region->y + 1) * y_stride +
-        sub_region->x;
-    dst_u =
-        buffer->data + u_offset + ((sub_region->y + 1) / 2) * u_stride +
-        (sub_region->x + 1) / 2;
-    dst_v =
-        buffer->data + v_offset + ((sub_region->y + 1) / 2) * v_stride +
-        (sub_region->x + 1) / 2;
+    dst_y = buffer->data + y_offset + dy * y_stride + dx;
+    dst_y2 = buffer->data + y_offset + (dy + 1) * y_stride + dx;
+    dst_u = buffer->data + u_offset + ((dy + 1) / 2) * u_stride + (dx + 1) / 2;
+    dst_v = buffer->data + v_offset + ((dy + 1) / 2) * v_stride + (dx + 1) / 2;
 
     sy = 0;
     for (y = 0; y < dh - 1; y += 2) {
       sx = 0;
       for (x = 0; x < dw - 1; x += 2) {
+
         color =
             sub_region->pict.palette[src[(sy >> 16) * src_stride + (sx >> 16)]];
         a1 = (color >> 24) & 0xff;