video: add metadata handling for spherical video

This adds handling of spherical video metadata: retrieving it from
demux_lavf and demux_mkv, passing it through filters, and adjusting it
with vf_format. This does not include support for rendering this type of
video.

We don't expect we need/want to support the other projection types like
cube maps, so we don't include that for now. They can be added later as
needed.

Also raise the maximum sizes of stringified image params, since they
can get really long.

1 files changed, 27 insertions, 1 deletions

diff --git a/video/mp_image.c b/video/mp_image.c
index 765289f8ff..45e5330947 100644
--- a/video/mp_image.c
+++ b/video/mp_image.c
@@ -41,6 +41,14 @@
 #define HAVE_OPAQUE_REF (LIBAVUTIL_VERSION_MICRO >= 100 && \
                          LIBAVUTIL_VERSION_INT >= AV_VERSION_INT(55, 47, 100))
 
+const struct m_opt_choice_alternatives mp_spherical_names[] = {
+    {"auto",        MP_SPHERICAL_AUTO},
+    {"none",        MP_SPHERICAL_NONE},
+    {"unknown",     MP_SPHERICAL_UNKNOWN},
+    {"equirect",    MP_SPHERICAL_EQUIRECTANGULAR},
+    {0}
+};
+
 // Determine strides, plane sizes, and total required size for an image
 // allocation. Returns total size on success, <0 on error. Unused planes
 // have out_stride/out_plane_size to 0, and out_plane_offset set to -1 up
@@ -525,6 +533,7 @@ void mp_image_copy_attributes(struct mp_image *dst, struct mp_image *src)
         dst->params.color.levels = src->params.color.levels;
         dst->params.chroma_location = src->params.chroma_location;
     }
+    dst->params.spherical = src->params.spherical;
     mp_image_params_guess_csp(&dst->params); // ensure colorspace consistency
     if ((dst->fmt.flags & MP_IMGFLAG_PAL) && (src->fmt.flags & MP_IMGFLAG_PAL)) {
         if (dst->planes[1] && src->planes[1]) {
@@ -657,6 +666,12 @@ char *mp_image_params_to_str_buf(char *b, size_t bs,
                             MP_STEREO3D_NAME_DEF(p->stereo_in, "?"),
                             MP_STEREO3D_NAME_DEF(p->stereo_out, "?"));
         }
+        if (p->spherical.type != MP_SPHERICAL_NONE) {
+            const float *a = p->spherical.ref_angles;
+            mp_snprintf_cat(b, bs, " (%s %f/%f/%f)",
+                            m_opt_choice_str(mp_spherical_names, p->spherical.type),
+                            a[0], a[1], a[2]);
+        }
     } else {
         snprintf(b, bs, "???");
     }
@@ -691,6 +706,16 @@ bool mp_image_params_valid(const struct mp_image_params *p)
     return true;
 }
 
+static bool mp_spherical_equal(const struct mp_spherical_params *p1,
+                               const struct mp_spherical_params *p2)
+{
+    for (int n = 0; n < 3; n++) {
+        if (p1->ref_angles[n] != p2->ref_angles[n])
+            return false;
+    }
+    return p1->type == p2->type;
+}
+
 bool mp_image_params_equal(const struct mp_image_params *p1,
                            const struct mp_image_params *p2)
 {
@@ -702,7 +727,8 @@ bool mp_image_params_equal(const struct mp_image_params *p1,
            p1->chroma_location == p2->chroma_location &&
            p1->rotate == p2->rotate &&
            p1->stereo_in == p2->stereo_in &&
-           p1->stereo_out == p2->stereo_out;
+           p1->stereo_out == p2->stereo_out &&
+           mp_spherical_equal(&p1->spherical, &p2->spherical);
 }
 
 // Set most image parameters, but not image format or size.