f_autoconvert: provide a function to determine if conversion works

This adds the function as seen in the f_autoconvert.h part of the patch.
It's pretty simple, but goes along with an intrusive code move. I guess
the resulting code is slightly nicer anyway.

1 files changed, 13 insertions, 0 deletions

diff --git a/filters/f_autoconvert.h b/filters/f_autoconvert.h
index d8fac346e5..c26612f2f9 100644
--- a/filters/f_autoconvert.h
+++ b/filters/f_autoconvert.h
@@ -2,6 +2,8 @@
 
 #include "filter.h"
 
+struct mp_image;
+
 // A filter which automatically creates and uses a conversion filter based on
 // the filter settings, or passes through data unchanged if no conversion is
 // required.
@@ -34,6 +36,17 @@ void mp_autoconvert_add_imgfmt(struct mp_autoconvert *c, int imgfmt, int subfmt)
 // as the normal semantics will exclude other formats (including hw ones).
 void mp_autoconvert_add_all_sw_imgfmts(struct mp_autoconvert *c);
 
+// Approximate test for whether the input would be accepted for conversion
+// according to the current settings. If false is returned, conversion will
+// definitely fail; if true is returned, it might succeed, but with no hard
+// guarantee. This is mainly intended for better error reporting to the user.
+// The result is "approximate" because it could still fail at runtime.
+// The mp_image is not mutated.
+// This function is relatively slow.
+// Accepting mp_image instead of any mp_frame is the result of laziness.
+bool mp_autoconvert_probe_input_video(struct mp_autoconvert *c,
+                                      struct mp_image *img);
+
 // Add the formats supported by the hwdec interops (or essentially refine them),
 // and trigger conversion if hw_subfmts mismatch. This is mostly a hack for
 // D3D11/ANGLE (which supports NV12 only).