examples/metadata: add a metadata fetching example

examples/metadata.rs

@@ -0,0 +1,67 @@
+extern crate ffmpeg;
+
+use std::env;
+use std::path::Path;
+
+fn print_metadata(context: &ffmpeg::format::Context) {
+	for (k, v) in context.metadata().iter() {
+		println!("{}: {}", k, v);
+	}
+	for stream in context.streams() {
+		println!("stream index {}:", stream.index());
+		println!("\ttime_base: {}", stream.time_base());
+		println!("\tstart_time: {}", stream.start_time());
+		println!("\tduration: {}", stream.duration());
+		println!("\tframes: {}", stream.frames());
+		println!("\tdisposition: {:?}", stream.disposition());
+		println!("\tdiscard: {:?}", stream.discard());
+		println!("\tframe_rate: {}", stream.frame_rate());
+
+		let codec = stream.codec();
+		println!("\tmedium: {:?}", codec.medium());
+		println!("\tid: {:?}", codec.id());
+		println!("\tbit_rate: {}", codec.bit_rate());
+		println!("\tdelay: {}", codec.delay());
+		
+        if let Ok(decoder) = codec.decoder() {
+            if let Ok(video) = decoder.video() {
+				println!("\tvideo.width: {}", video.width());
+				println!("\tvideo.height: {}", video.height());
+				println!("\tvideo.format: {:?}", video.format());
+				println!("\tvideo.has_b_frames: {}", video.has_b_frames());
+				println!("\tvideo.aspect_ratio: {}", video.aspect_ratio());
+				println!("\tvideo.color_space: {:?}", video.color_space());
+				println!("\tvideo.color_range: {:?}", video.color_range());
+				println!("\tvideo.color_primaries: {:?}", video.color_primaries());
+				println!("\tvideo.color_transfer_characteristic: {:?}", video.color_transfer_characteristic());
+				println!("\tvideo.chroma_location: {:?}", video.chroma_location());
+				println!("\tvideo.references: {}", video.references());
+				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());
+				println!("\taudio.channels: {}", audio.channels());
+				println!("\taudio.format: {:?}", audio.format());
+				println!("\taudio.frames: {}", audio.frames());
+				println!("\taudio.align: {}", audio.align());
+				println!("\taudio.channel_layout: {:?}", audio.channel_layout());
+				println!("\taudio.max_rate: {}", audio.max_rate());
+				println!("\taudio.frame_start: {:?}", audio.frame_start());
+			}
+        }
+    }
+}
+
+fn main() {
+	if let Ok(()) = ffmpeg::init() {
+		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),
+			}
+		} else { println!("Usage: metadata path/to/file") }
+	}
+}