EBML: Finish parsing segment.Info

Signed-off-by: Serial <69764315+Serial-ATA@users.noreply.github.com>

Author: Serial-ATA

src/ebml/element_reader.rs

@@ -373,8 +373,13 @@ where
 		String::from_utf8(content).map_err(Into::into)
 	}
 
-	pub(crate) fn read_utf8(&mut self) -> Result<String> {
-		todo!()
+	pub(crate) fn read_utf8(&mut self, element_length: u64) -> Result<String> {
+		// https://www.rfc-editor.org/rfc/rfc8794.html#section-7.5
+		// A UTF-8 Element MUST declare a length in octets from zero to VINTMAX
+
+		// Since the UTF-8 and String elements are both just turned into `String`s,
+		// we can just reuse the `read_string` method.
+		self.read_string(element_length)
 	}
 
 	pub(crate) fn read_date(&mut self) -> Result<String> {

src/ebml/read/segment_info.rs

@@ -41,8 +41,12 @@ where
 							}
 						}
 					},
-					ElementIdent::MuxingApp => todo!("Support segment.Info.MuxingApp"),
-					ElementIdent::WritingApp => todo!("Support segment.Info.WritingApp"),
+					ElementIdent::MuxingApp => {
+						properties.segment_info.muxing_app = element_reader.read_utf8(size)?
+					},
+					ElementIdent::WritingApp => {
+						properties.segment_info.writing_app = element_reader.read_utf8(size)?
+					},
 					_ => {
 						// We do not end up using information from all of the segment
 						// elements, so we can just skip any useless ones.