video-io: Add function to just get video format

libobs/media-io/video-io.c

@@ -398,6 +398,11 @@ void video_output_stop(video_t video)
 	}
 }
 
+enum video_format video_output_get_format(video_t video)
+{
+	return video ? video->info.format : VIDEO_FORMAT_NONE;
+}
+
 uint32_t video_output_get_width(video_t video)
 {
 	return video ? video->info.width : 0;

libobs/media-io/video-io.h

@@ -139,6 +139,7 @@ EXPORT uint64_t video_output_get_frame_time(video_t video);
 EXPORT uint64_t video_output_get_time(video_t video);
 EXPORT void video_output_stop(video_t video);
 
+EXPORT enum video_format video_output_get_format(video_t video);
 EXPORT uint32_t video_output_get_width(video_t video);
 EXPORT uint32_t video_output_get_height(video_t video);
 EXPORT double video_output_get_frame_rate(video_t video);