5 files changed, 47 insertions, 2 deletions

diff --git a/source/blender/blenkernel/BKE_image.h b/source/blender/blenkernel/BKE_image.h
index d12b048bc96..dd7e06259bd 100644
--- a/source/blender/blenkernel/BKE_image.h
+++ b/source/blender/blenkernel/BKE_image.h
@@ -152,6 +152,9 @@ void BKE_image_pool_free(struct ImagePool *pool);
 struct ImBuf *BKE_image_pool_acquire_ibuf(struct Image *ima, struct ImageUser *iuser, struct ImagePool *pool);
 void BKE_image_pool_release_ibuf(struct Image *ima, struct ImBuf *ibuf, struct ImagePool *pool);
 
+/* set an alpha mode based on file extension */
+void BKE_image_alpha_mode_from_extension(struct Image *image);
+
 /* returns a new image or NULL if it can't load */
 struct Image *BKE_image_load(struct Main *bmain, const char *filepath);
 /* returns existing Image when filename/type is same (frame optional) */
diff --git a/source/blender/blenkernel/BKE_sequencer.h b/source/blender/blenkernel/BKE_sequencer.h
index e3d9c513c5c..eef134a6872 100644
--- a/source/blender/blenkernel/BKE_sequencer.h
+++ b/source/blender/blenkernel/BKE_sequencer.h
@@ -356,6 +356,8 @@ typedef struct SeqLoadInfo {
 typedef struct Sequence *(*SeqLoadFunc)(struct bContext *, ListBase *, struct SeqLoadInfo *);
 
 struct Sequence *BKE_sequence_alloc(ListBase *lb, int cfra, int machine);
+
+void BKE_sequence_alpha_mode_from_extension(struct Sequence *seq);
 void BKE_sequence_init_colorspace(struct Sequence *seq);
 
 struct Sequence *BKE_sequencer_add_image_strip(struct bContext *C, ListBase *seqbasep, struct SeqLoadInfo *seq_load);
diff --git a/source/blender/blenkernel/intern/image.c b/source/blender/blenkernel/intern/image.c
index de85cb54cfd..3655afdf088 100644
--- a/source/blender/blenkernel/intern/image.c
+++ b/source/blender/blenkernel/intern/image.c
@@ -571,6 +571,20 @@ static void image_init_color_management(Image *ima)
 	}
 }
 
+void BKE_image_alpha_mode_from_extension(Image *image)
+{
+	if (BLI_testextensie(image->name, ".exr") ||
+	    BLI_testextensie(image->name, ".cin") ||
+	    BLI_testextensie(image->name, ".dpx") ||
+	    BLI_testextensie(image->name, ".hdr"))
+	{
+		image->alpha_mode = IMA_ALPHA_PREMUL;
+	}
+	else {
+		image->alpha_mode = IMA_ALPHA_STRAIGHT;
+	}
+}
+
 Image *BKE_image_load(Main *bmain, const char *filepath)
 {
 	Image *ima;
diff --git a/source/blender/blenkernel/intern/sequencer.c b/source/blender/blenkernel/intern/sequencer.c
index 45393726add..68618287546 100644
--- a/source/blender/blenkernel/intern/sequencer.c
+++ b/source/blender/blenkernel/intern/sequencer.c
@@ -3955,6 +3955,24 @@ Sequence *BKE_sequence_alloc(ListBase *lb, int cfra, int machine)
 	return seq;
 }
 
+void BKE_sequence_alpha_mode_from_extension(Sequence *seq)
+{
+	if (seq->strip && seq->strip->stripdata) {
+		char *name = seq->strip->stripdata->name;
+
+		if (BLI_testextensie(name, ".exr") ||
+		    BLI_testextensie(name, ".cin") ||
+		    BLI_testextensie(name, ".dpx") ||
+		    BLI_testextensie(name, ".hdr"))
+			{
+				seq->alpha_mode = IMA_ALPHA_PREMUL;
+			}
+		else {
+			seq->alpha_mode = IMA_ALPHA_STRAIGHT;
+		}
+	}
+}
+
 void BKE_sequence_init_colorspace(Sequence *seq)
 {
 	if (seq->strip && seq->strip->stripdata) {
diff --git a/source/blender/blenloader/intern/readfile.c b/source/blender/blenloader/intern/readfile.c
index 94dfb0cf399..4471e45be1d 100644
--- a/source/blender/blenloader/intern/readfile.c
+++ b/source/blender/blenloader/intern/readfile.c
@@ -8653,8 +8653,12 @@ static void do_versions(FileData *fd, Library *lib, Main *main)
 
 			SEQ_BEGIN (scene->ed, seq)
 			{
-				if (seq->flag & SEQ_MAKE_PREMUL)
+				if (seq->flag & SEQ_MAKE_PREMUL) {
 					seq->alpha_mode = SEQ_ALPHA_STRAIGHT;
+				}
+				else {
+					BKE_sequence_alpha_mode_from_extension(seq);
+				}
 			}
 			SEQ_END
 
@@ -8680,8 +8684,12 @@ static void do_versions(FileData *fd, Library *lib, Main *main)
 		}
 
 		for (image = main->image.first; image; image = image->id.next) {
-			if (image->flag & IMA_DO_PREMUL)
+			if (image->flag & IMA_DO_PREMUL) {
 				image->alpha_mode = IMA_ALPHA_STRAIGHT;
+			}
+			else {
+				BKE_image_alpha_mode_from_extension(image);
+			}
 
 			image->flag &= ~IMA_DONE_TAG;
 		}