extend test coverage

main_test.go

@@ -214,7 +214,46 @@ func TestSampleRate(t *testing.T) {
 			[]byte{0xff, 0xfa, 0x9c, 0},
 			0,
 		},
-		// TODO finish
+		{
+			"MPEG2 22.05k",
+			[]byte{0xff, 0xf6, 0x90, 0},
+			22050,
+		},
+		{
+			"MPEG2 24k",
+			[]byte{0xff, 0xf6, 0x94, 0},
+			24000,
+		},
+		{
+			"MPEG2 16k",
+			[]byte{0xff, 0xf6, 0x98, 0},
+			16000,
+		},
+		{
+			"MPEG2 Reserved",
+			[]byte{0xff, 0xf6, 0x9c, 0},
+			0,
+		},
+		{
+			"MPEG25 11.025k",
+			[]byte{0xff, 0xe6, 0x90, 0},
+			11025,
+		},
+		{
+			"MPEG25 12k",
+			[]byte{0xff, 0xe6, 0x94, 0},
+			12000,
+		},
+		{
+			"MPEG25 8k",
+			[]byte{0xff, 0xe6, 0x98, 0},
+			8000,
+		},
+		{
+			"MPEG25 Reserved",
+			[]byte{0xff, 0xe6, 0x9c, 0},
+			0,
+		},
 	}
 
 	for _, tc := range testCases {