examples/metadata: cleanup and find best streams

examples/metadata.rs

@@ -7,6 +7,19 @@ fn print_metadata(context: &ffmpeg::format::Context) {
 	for (k, v) in context.metadata().iter() {
 		println!("{}: {}", k, v);
 	}
+
+	if let Some(stream) = context.streams().best(ffmpeg::media::Type::Video) {
+		println!("Best video stream index: {}", stream.index());
+	}
+
+	if let Some(stream) = context.streams().best(ffmpeg::media::Type::Audio) {
+		println!("Best audio stream index: {}", stream.index());
+	}
+
+	if let Some(stream) = context.streams().best(ffmpeg::media::Type::Subtitle) {
+		println!("Best subtitle stream index: {}", stream.index());
+	}
+
 	for stream in context.streams() {
 		println!("stream index {}:", stream.index());
 		println!("\ttime_base: {}", stream.time_base());
@@ -39,6 +52,7 @@ fn print_metadata(context: &ffmpeg::format::Context) {
 				println!("\tvideo.intra_dc_precision: {}", video.intra_dc_precision());
 			}
 		}
+
 		if let Ok(decoder) = codec.decoder() {
 			if let Ok(audio) = decoder.audio() {
 				println!("\taudio.rate: {}", audio.rate());
@@ -55,13 +69,17 @@ fn print_metadata(context: &ffmpeg::format::Context) {
 }
 
 fn main() {
-	if let Ok(()) = ffmpeg::init() {
+	ffmpeg::init().unwrap();
+
 	if let Some(file) = env::args().nth(1) {
 		let path = Path::new(&file);
+
 		match ffmpeg::format::open(&path) {
-				Err(error) => println!("Error: {}", error),
 			Ok(context) => print_metadata(&context),
+			Err(error)  => println!("error: {}", error),
 		}
-		} else { println!("Usage: metadata path/to/file") }
+	}
+	else {
+		println!("Usage: metadata <path>")
 	}
 }