video: switch from using display aspect to sample aspect

MPlayer traditionally always used the display aspect ratio, e.g. 16:9,
while FFmpeg uses the sample (aka pixel) aspect ratio.

Both have a bunch of advantages and disadvantages. Actually, it seems
using sample aspect ratio is generally nicer. The main reason for the
change is making mpv closer to how FFmpeg works in order to make life
easier. It's also nice that everything uses integer fractions instead
of floats now (except --video-aspect option/property).

Note that there is at least 1 user-visible change: vf_dsize now does
not set the display size, only the display aspect ratio. This is
because the image_params d_w/d_h fields did not just set the display
aspect, but also the size (except in encoding mode).

4 files changed, 19 insertions, 21 deletions

diff --git a/player/command.c b/player/command.c
index cc30d2b21a..ecae0df1a9 100644
--- a/player/command.c
+++ b/player/command.c
@@ -2449,8 +2449,8 @@ static int property_imgparams(struct mp_image_params p, int action, void *arg)
     if (!p.imgfmt)
         return M_PROPERTY_UNAVAILABLE;
 
-    double dar = p.d_w / (double)p.d_h;
-    double sar = p.w / (double)p.h;
+    int d_w, d_h;
+    mp_image_params_get_dsize(&p, &d_w, &d_h);
 
     struct mp_imgfmt_desc desc = mp_imgfmt_get_desc(p.imgfmt);
     int bpp = 0;
@@ -2465,10 +2465,10 @@ static int property_imgparams(struct mp_image_params p, int action, void *arg)
                             .unavailable = !(desc.flags & MP_IMGFLAG_PLANAR)},
         {"w",               SUB_PROP_INT(p.w)},
         {"h",               SUB_PROP_INT(p.h)},
-        {"dw",              SUB_PROP_INT(p.d_w)},
-        {"dh",              SUB_PROP_INT(p.d_h)},
-        {"aspect",          SUB_PROP_FLOAT(dar)},
-        {"par",             SUB_PROP_FLOAT(dar / sar)},
+        {"dw",              SUB_PROP_INT(d_w)},
+        {"dh",              SUB_PROP_INT(d_h)},
+        {"aspect",          SUB_PROP_FLOAT(d_w / (double)d_h)},
+        {"par",             SUB_PROP_FLOAT(p.p_w / (double)p.p_h)},
         {"colormatrix",
             SUB_PROP_STR(m_opt_choice_str(mp_csp_names, p.colorspace))},
         {"colorlevels",
@@ -2561,8 +2561,8 @@ static int mp_property_window_scale(void *ctx, struct m_property *prop,
         return M_PROPERTY_UNAVAILABLE;
 
     struct mp_image_params params = get_video_out_params(mpctx);
-    int vid_w = params.d_w;
-    int vid_h = params.d_h;
+    int vid_w, vid_h;
+    mp_image_params_get_dsize(&params, &vid_w, &vid_h);
     if (vid_w < 1 || vid_h < 1)
         return M_PROPERTY_UNAVAILABLE;
 
@@ -2781,8 +2781,10 @@ static int mp_property_aspect(void *ctx, struct m_property *prop,
             struct dec_video *d_video = mpctx->d_video;
             struct sh_video *sh_video = d_video->header->video;
             struct mp_image_params *params = &d_video->vfilter->override_params;
-            if (params && params->d_w && params->d_h) {
-                aspect = (float)params->d_w / params->d_h;
+            if (params && params->p_w > 0 && params->p_h > 0) {
+                int d_w, d_h;
+                mp_image_params_get_dsize(params, &d_w, &d_h);
+                aspect = (float)d_w / d_h;
             } else if (sh_video->disp_w && sh_video->disp_h) {
                 aspect = (float)sh_video->disp_w / sh_video->disp_h;
             }
diff --git a/player/playloop.c b/player/playloop.c
index 5efb048cb2..892baf1a09 100644
--- a/player/playloop.c
+++ b/player/playloop.c
@@ -889,7 +889,7 @@ int handle_force_window(struct MPContext *mpctx, bool force)
         struct mp_image_params p = {
             .imgfmt = config_format,
             .w = w,   .h = h,
-            .d_w = w, .d_h = h,
+            .p_w = 1, .p_h = 1,
         };
         if (vo_reconfig(vo, &p) < 0)
             goto err;
diff --git a/player/screenshot.c b/player/screenshot.c
index 9c4f5cc84e..76c7874498 100644
--- a/player/screenshot.c
+++ b/player/screenshot.c
@@ -308,14 +308,7 @@ static char *gen_fname(screenshot_ctx *ctx, const char *file_ext)
 
 static void add_subs(struct MPContext *mpctx, struct mp_image *image)
 {
-    double sar = (double)image->w / image->h;
-    double dar = (double)image->params.d_w / image->params.d_h;
-    struct mp_osd_res res = {
-        .w = image->w,
-        .h = image->h,
-        .display_par = sar / dar,
-    };
-
+    struct mp_osd_res res = osd_res_from_image_params(&image->params);
     osd_draw_on_image(mpctx->osd, res, mpctx->video_pts,
                       OSD_DRAW_SUB_ONLY, image);
 }
diff --git a/player/video.c b/player/video.c
index 9be4f6a9a0..1178557e24 100644
--- a/player/video.c
+++ b/player/video.c
@@ -1186,8 +1186,11 @@ void write_video(struct MPContext *mpctx, double endpts)
 
         const struct vo_driver *info = mpctx->video_out->driver;
         char extra[20] = {0};
-        if (p.w != p.d_w || p.h != p.d_h)
-            snprintf(extra, sizeof(extra), " => %dx%d", p.d_w, p.d_h);
+        if (p.p_w != p.p_h) {
+            int d_w, d_h;
+            mp_image_params_get_dsize(&p, &d_w, &d_h);
+            snprintf(extra, sizeof(extra), " => %dx%d", d_w, d_h);
+        }
         MP_INFO(mpctx, "VO: [%s] %dx%d%s %s\n",
                 info->name, p.w, p.h, extra, vo_format_name(p.imgfmt));
         MP_VERBOSE(mpctx, "VO: Description: %s\n", info->description);