sub: fix text subtitle aspect ratio with vo_xv and vo_lavc, refactor

This fixes that vo_xv didn't display text subtitles correctly when
using anamorphic video. It didn't pass the aspect information to the
subtitle renderer. Also, try to render OSD correctly with respect to
aspect ratio settings: on vo_xv, the OSD is rendered into the video,
and needs to be "stretched" too when playing anamorphic video. When
the -monitorpixelaspect option is used, even with VOs such as vo_opengl
the OSD has to be rendered with that aspect ratio.

As preparation for future commits, replace the weird vsfilter_scale
value with a somewhat more sensible video_par member.

Also, struct mp_eosd_res is a better place for the aspect ratio
parameters, as OSD needs this too.

Use osd_draw_on_image() directly in vo_lavc, which fixes aspect ratio
issues as well.

1 files changed, 13 insertions, 9 deletions

diff --git a/libmpcodecs/vf_ass.c b/libmpcodecs/vf_ass.c
index 77248b49c0..167ebd6e15 100644
--- a/libmpcodecs/vf_ass.c
+++ b/libmpcodecs/vf_ass.c
@@ -63,7 +63,7 @@ static const struct vf_priv_s {
     int auto_insert;
 
     struct osd_state *osd;
-    double aspect_correction;
+    struct mp_eosd_res dim;
 
     unsigned char *planes[3];
     struct line_limits {
@@ -92,7 +92,17 @@ static int config(struct vf_instance *vf,
     vf->priv->planes[2]   = malloc(vf->priv->outw * vf->priv->outh);
     vf->priv->line_limits = malloc((vf->priv->outh + 1) / 2 * sizeof(*vf->priv->line_limits));
 
-    vf->priv->aspect_correction = (double)width / height * d_height / d_width;
+    double dar = (double)d_width / d_height;
+    double sar = (double)width / height;
+
+    vf->priv->dim = (struct mp_eosd_res) {
+        .w = vf->priv->outw,
+        .h = vf->priv->outh,
+        .mt = opts->ass_top_margin,
+        .mb = opts->ass_bottom_margin,
+        .display_par = sar / dar,
+        .video_par = dar / sar,
+    };
 
     return vf_next_config(vf, vf->priv->outw, vf->priv->outh, d_width,
 			  d_height, flags, outfmt);
@@ -354,18 +364,12 @@ static int render_frame(struct vf_instance *vf, mp_image_t *mpi,
 static int put_image(struct vf_instance *vf, mp_image_t *mpi, double pts)
 {
     struct vf_priv_s *priv = vf->priv;
-    struct MPOpts *opts = vf->opts;
     struct osd_state *osd = priv->osd;
     struct sub_bitmaps imgs = (struct sub_bitmaps) {0};
     if (pts != MP_NOPTS_VALUE) {
         struct sub_render_params subparams = {
             .pts = pts,
-            .dim = { .w = vf->priv->outw,
-                     .h = vf->priv->outh,
-                     .mt = opts->ass_top_margin,
-                     .mb = opts->ass_bottom_margin },
-            .normal_scale = vf->priv->aspect_correction,
-            .vsfilter_scale = 1,
+            .dim = priv->dim,
         };
         bool formats[SUBBITMAP_COUNT] = {[SUBBITMAP_LIBASS] = true};
         osd_draw_sub(osd, &imgs, &subparams, formats);