added tests for more coverage on av1

crates/av1/src/config.rs

@@ -144,6 +144,33 @@ mod tests {
         "#);
     }
 
+    #[test]
+    fn test_config_demux_with_initial_presentation_delay() {
+        let data = b"\x81\r\x0c\x3f\n\x0f\0\0\0j\xef\xbf\xe1\xbc\x02\x19\x90\x10\x10\x10@".to_vec();
+
+        let config = AV1CodecConfigurationRecord::demux(&mut io::Cursor::new(data.into())).unwrap();
+
+        insta::assert_debug_snapshot!(config, @r#"
+        AV1CodecConfigurationRecord {
+            marker: true,
+            version: 1,
+            seq_profile: 0,
+            seq_level_idx_0: 13,
+            seq_tier_0: false,
+            high_bitdepth: false,
+            twelve_bit: false,
+            monochrome: false,
+            chroma_subsampling_x: true,
+            chroma_subsampling_y: true,
+            chroma_sample_position: 0,
+            initial_presentation_delay_minus_one: Some(
+                15,
+            ),
+            config_obu: b"\n\x0f\0\0\0j\xef\xbf\xe1\xbc\x02\x19\x90\x10\x10\x10@",
+        }
+        "#);
+    }
+
     #[test]
     fn test_config_mux() {
         let config = AV1CodecConfigurationRecord {