lavfi: use mp_image to store the filter pad format

Preparation for enabling hw filters. mp_image_params can't have an
AVHWFramesContext reference (because it can't hold any allocations, and
isn't meant to hold "active" data in the first place.

So just use a mp_image. It has all real data removed, because that would
essentially leak 1 frame once the decoder or renderer don't need it
anymore.

1 files changed, 11 insertions, 0 deletions

diff --git a/video/mp_image.c b/video/mp_image.c
index e4e6ffa266..7e0dd173b7 100644
--- a/video/mp_image.c
+++ b/video/mp_image.c
@@ -177,6 +177,17 @@ void mp_image_steal_data(struct mp_image *dst, struct mp_image *src)
     talloc_free(src);
 }
 
+// Unref most data buffer (and clear the data array), but leave other fields
+// allocated. In particular, mp_image.hwctx is preserved.
+void mp_image_unref_data(struct mp_image *img)
+{
+    for (int n = 0; n < MP_MAX_PLANES; n++) {
+        img->planes[n] = NULL;
+        img->stride[n] = 0;
+        av_buffer_unref(&img->bufs[n]);
+    }
+}
+
 // Return a new reference to img. The returned reference is owned by the caller,
 // while img is left untouched.
 struct mp_image *mp_image_new_ref(struct mp_image *img)