From fcfd04409008cf1eed62b778f0b388023f00c005 Mon Sep 17 00:00:00 2001
From: wm4 <wm4@nowhere>
Date: Wed, 11 Dec 2013 23:15:29 +0100
Subject: [PATCH] sd_lavc: factor out bitmap positioning code

---
 sub/osd.c     | 31 +++++++++++++++++++++++++++++++
 sub/osd.h     |  3 +++
 sub/sd_lavc.c | 44 ++++++++++++++------------------------------
 3 files changed, 48 insertions(+), 30 deletions(-)

diff --git a/sub/osd.c b/sub/osd.c
index bd06dbf8d4..66b79f7bb8 100644
--- a/sub/osd.c
+++ b/sub/osd.c
@@ -322,3 +322,34 @@ void osd_object_get_scale_factor(struct osd_state *osd, struct osd_object *obj,
     *sw = nw / (double)obj->vo_res.w;
     *sh = nh / (double)obj->vo_res.h;
 }
+
+// Position the subbitmaps in imgs on the screen. Basically, this fits the
+// subtitle canvas (of size frame_w x frame_h) onto the screen, such that it
+// fills the whole video area (especially if the video is magnified, e.g. on
+// fullscreen). If compensate_par is given, adjust the way the subtitles are
+// "stretched" on the screen, and letter-box the result.
+void osd_rescale_bitmaps(struct sub_bitmaps *imgs, int frame_w, int frame_h,
+                         struct mp_osd_res res, double compensate_par)
+{
+    int vidw = res.w - res.ml - res.mr;
+    int vidh = res.h - res.mt - res.mb;
+    double xscale = (double)vidw / frame_w;
+    double yscale = (double)vidh / frame_h;
+    if (compensate_par > 0) {
+        if (compensate_par > 1.0) {
+            xscale /= compensate_par;
+        } else {
+            yscale *= compensate_par;
+        }
+    }
+    int cx = vidw / 2 - (int)(frame_w * xscale) / 2;
+    int cy = vidh / 2 - (int)(frame_h * yscale) / 2;
+    for (int i = 0; i < imgs->num_parts; i++) {
+        struct sub_bitmap *bi = &imgs->parts[i];
+        bi->x = bi->x * xscale + cx + res.ml;
+        bi->y = bi->y * yscale + cy + res.mt;
+        bi->dw = bi->w * xscale;
+        bi->dh = bi->h * yscale;
+    }
+    imgs->scaled = xscale != 1 || yscale != 1;
+}
diff --git a/sub/osd.h b/sub/osd.h
index cdd681b339..fc2b76df00 100644
--- a/sub/osd.h
+++ b/sub/osd.h
@@ -231,6 +231,9 @@ void osd_draw_on_image_p(struct osd_state *osd, struct mp_osd_res res,
 void osd_object_get_scale_factor(struct osd_state *osd, struct osd_object *obj,
                                  double *sw, double *sh);
 
+void osd_rescale_bitmaps(struct sub_bitmaps *imgs, int frame_w, int frame_h,
+                         struct mp_osd_res res, double compensate_par);
+
 // defined in osd_libass.c and osd_dummy.c
 
 void osd_object_get_bitmaps(struct osd_state *osd, struct osd_object *obj,
diff --git a/sub/sd_lavc.c b/sub/sd_lavc.c
index 9741b0de70..724a4fe77c 100644
--- a/sub/sd_lavc.c
+++ b/sub/sd_lavc.c
@@ -212,45 +212,29 @@ static void get_bitmaps(struct sd *sd, struct mp_osd_res d, double pts,
     if (priv->endpts != MP_NOPTS_VALUE && (pts >= priv->endpts ||
                                            pts < priv->endpts - 300))
         clear(priv);
-    if (priv->bitmaps_changed && priv->count > 0)
-        priv->outbitmaps = talloc_memdup(priv, priv->inbitmaps,
-                                         talloc_get_size(priv->inbitmaps));
+    size_t size = talloc_get_size(priv->inbitmaps);
+    if (!priv->outbitmaps)
+        priv->outbitmaps = talloc_size(priv, size);
+    memcpy(priv->outbitmaps, priv->inbitmaps, size);
     int inw = priv->avctx->width;
     int inh = priv->avctx->height;
     guess_resolution(priv->avctx->codec_id, &inw, &inh);
-    int vidw = d.w - d.ml - d.mr;
-    int vidh = d.h - d.mt - d.mb;
-    double xscale = (double)vidw / inw;
-    double yscale = (double)vidh / inh;
-    if (priv->avctx->codec_id == AV_CODEC_ID_DVD_SUBTITLE &&
-            opts->stretch_dvd_subs) {
-        // For DVD subs, try to keep the subtitle PAR at display PAR.
-        double video_par =
-              (priv->video_params.d_w / (double)priv->video_params.d_h)
-            / (priv->video_params.w   / (double)priv->video_params.h);
-        if (video_par > 1.0) {
-            xscale /= video_par;
-        } else {
-            yscale *= video_par;
-        }
-    }
-    int cx = vidw / 2 - (int)(inw * xscale) / 2;
-    int cy = vidh / 2 - (int)(inh * yscale) / 2;
-    for (int i = 0; i < priv->count; i++) {
-        struct sub_bitmap *bi = &priv->inbitmaps[i];
-        struct sub_bitmap *bo = &priv->outbitmaps[i];
-        bo->x = bi->x * xscale + cx + d.ml;
-        bo->y = bi->y * yscale + cy + d.mt;
-        bo->dw = bi->w * xscale;
-        bo->dh = bi->h * yscale;
-    }
     res->parts = priv->outbitmaps;
     res->num_parts = priv->count;
     if (priv->bitmaps_changed)
         res->bitmap_id = ++res->bitmap_pos_id;
     priv->bitmaps_changed = false;
     res->format = SUBBITMAP_INDEXED;
-    res->scaled = xscale != 1 || yscale != 1;
+
+    double video_par = -1;
+    if (priv->avctx->codec_id == AV_CODEC_ID_DVD_SUBTITLE &&
+            opts->stretch_dvd_subs) {
+        // For DVD subs, try to keep the subtitle PAR at display PAR.
+        video_par =
+              (priv->video_params.d_w / (double)priv->video_params.d_h)
+            / (priv->video_params.w   / (double)priv->video_params.h);
+    }
+    osd_rescale_bitmaps(res, inw, inh, d, video_par);
 }
 
 static void reset(struct sd *sd)