Use 4 channel in file decode

components/rgbd-sources/src/file_source.cpp

@@ -98,7 +98,7 @@ bool FileSource::compute(int n, int b) {
 		auto &c = *i;
 
 		if (c.spkt.channel == Channel::Colour) {
-			rgb_.create(cv::Size(ftl::codecs::getWidth(c.pkt.definition),ftl::codecs::getHeight(c.pkt.definition)), CV_8UC3);
+			rgb_.create(cv::Size(ftl::codecs::getWidth(c.pkt.definition),ftl::codecs::getHeight(c.pkt.definition)), CV_8UC4);
 		} else {
 			depth_.create(cv::Size(ftl::codecs::getWidth(c.pkt.definition),ftl::codecs::getHeight(c.pkt.definition)), CV_32F);
 		}