Add a few encoding tests

tests/tests.rs

@@ -0,0 +1,66 @@
+extern crate opus;
+
+#[test]
+fn version_ascii() {
+	println!("Opus version: {}", opus::version());
+}
+
+// 48000Hz * 1 channel * 20 ms / 1000
+const MONO_20MS: usize = 48000 * 1 * 20 / 1000;
+
+#[test]
+fn encode_mono() {
+	let mut encoder = opus::Encoder::new(48000, opus::Channels::Mono, opus::CodingMode::Audio).unwrap();
+	
+	let mut output = [0; 256];
+	let len = encoder.encode(&[0_i16; MONO_20MS], &mut output).unwrap();
+	assert_eq!(&output[..len], &[244, 255, 254]);
+
+	let len = encoder.encode(&[0_i16; MONO_20MS], &mut output).unwrap();
+	assert_eq!(&output[..len], &[244, 255, 254]);
+
+	let len = encoder.encode(&[1_i16; MONO_20MS], &mut output).unwrap();
+	assert!(len > 190 && len < 220);
+
+	let len = encoder.encode(&[0_i16; MONO_20MS], &mut output).unwrap();
+	assert!(len > 170 && len < 190);
+}
+
+#[test]
+fn encode_stereo() {
+	let mut encoder = opus::Encoder::new(48000, opus::Channels::Stereo, opus::CodingMode::Audio).unwrap();
+
+	let mut output = [0; 512];
+	let len = encoder.encode(&[0_i16; 2 * MONO_20MS], &mut output).unwrap();
+	assert_eq!(&output[..len], &[249, 255, 254, 255, 254]);
+
+	let len = encoder.encode(&[0_i16; 2 * MONO_20MS], &mut output).unwrap();
+	assert_eq!(&output[..len], &[249, 255, 254, 255, 254]);
+
+	let len = encoder.encode(&[17_i16; 2 * MONO_20MS], &mut output).unwrap();
+	assert!(len > 240);
+
+	let len = encoder.encode(&[0_i16; 2 * MONO_20MS], &mut output).unwrap();
+	assert!(len > 240);
+
+	// Very small buffer should still succeed
+	let len = encoder.encode(&[95_i16; 2 * MONO_20MS], &mut [0; 20]).unwrap();
+	assert!(len < 20);
+}
+
+#[test]
+fn encode_bad_rate() {
+	match opus::Encoder::new(48001, opus::Channels::Mono, opus::CodingMode::Audio) {
+		Ok(_) => panic!("Encoder::new did not return BadArg"),
+		Err(err) => assert_eq!(err.code(), opus::ErrorCode::BadArg),
+	}
+}
+
+#[test]
+fn encode_bad_buffer() {
+	let mut encoder = opus::Encoder::new(48000, opus::Channels::Stereo, opus::CodingMode::Audio).unwrap();
+	match encoder.encode(&[1_i16; 2 * MONO_20MS], &mut [0; 0]) {
+		Ok(_) => panic!("encode with 0-length buffer did not return BadArg"),
+		Err(err) => assert_eq!(err.code(), opus::ErrorCode::BadArg),
+	}
+}