Add Image::has_alpha().

2 files changed, 11 insertions, 0 deletions

diff --git a/src/lib/image.cc b/src/lib/image.cc
index 80ef92d06..1d06ef418 100644
--- a/src/lib/image.cc
+++ b/src/lib/image.cc
@@ -1728,3 +1728,12 @@ Image::crop(Crop crop) const
 	return out;
 }
 
+
+bool
+Image::has_alpha() const
+{
+	auto const d = av_pix_fmt_desc_get(_pixel_format);
+	DCPOMATIC_ASSERT(d);
+	return d->flags & AV_PIX_FMT_FLAG_ALPHA;
+}
+
diff --git a/src/lib/image.h b/src/lib/image.h
index 548ebf717..9eedaece7 100644
--- a/src/lib/image.h
+++ b/src/lib/image.h
@@ -99,6 +99,8 @@ public:
 		return _pixel_format;
 	}
 
+	bool has_alpha() const;
+
 	size_t memory_used () const;
 
 	static std::shared_ptr<const Image> ensure_alignment (std::shared_ptr<const Image> image, Alignment alignment);