diff --git a/CHANGELOG.md b/CHANGELOG.md
index f9c24a4..665919c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -24,6 +24,12 @@
     Likewise `retina::codec::CodecItem`.
 *   minimum Rust version is now 1.56.
 
+## `v0.3.10` (2022-05-09)
+
+*   ignore unparseable `rtptime` values in the `PLAY` response's `RTP-Info` header.
+    This improves compatibility with the OMNY M5S2A 2812 camera, as described in
+    [scottlamb/moonfire-nvr#224](https://github.com/scottlamb/moonfire-nvr/issues/224).
+
 ## `v0.3.9` (2022-04-12)
 
 *   camera interop: eliminate `bad clockrate in rtpmap` errors with cameras that
diff --git a/src/client/parse.rs b/src/client/parse.rs
index 56af658..a541a34 100644
--- a/src/client/parse.rs
+++ b/src/client/parse.rs
@@ -2,7 +2,7 @@
 // SPDX-License-Identifier: MIT OR Apache-2.0
 
 use bytes::Bytes;
-use log::debug;
+use log::{debug, warn};
 use sdp_types::Media;
 use std::{net::IpAddr, num::NonZeroU16};
 use url::Url;
@@ -646,11 +646,10 @@ pub(crate) fn parse_play(
                         .map_err(|_| format!("bad seq {:?}", value))?;
                     state.initial_seq = Some(seq);
                 }
-                "rtptime" => {
-                    let rtptime = u32::from_str_radix(value, 10)
-                        .map_err(|_| format!("bad rtptime {:?}", value))?;
-                    state.initial_rtptime = Some(rtptime);
-                }
+                "rtptime" => match u32::from_str_radix(value, 10) {
+                    Ok(v) => state.initial_rtptime = Some(v),
+                    Err(_) => warn!("Unparseable rtptime in RTP-Info header {:?}", rtp_info),
+                },
                 "ssrc" => {
                     let ssrc = u32::from_str_radix(value, 16)
                         .map_err(|_| format!("Unparseable ssrc {}", value))?;
@@ -1068,6 +1067,32 @@ mod tests {
         };
     }
 
+    /// Simulates a negative `rtptime` value in the `PLAY` response, as returned by the OMNY M5S2A
+    /// 2812 in [scottlamb/moonfire-nvr#224](https://github.com/scottlamb/moonfire-nvr/issues/224).
+    ///
+    /// The rest of the data is copied from the `bunny` test above.
+    ///
+    /// This is currently treated as if the `rtptime` parameter were absent.
+    #[test]
+    fn bad_rtptime() {
+        let prefix = "rtsp://wowzaec2demo.streamlock.net/vod/mp4:BigBuckBunny_115k.mov";
+        let mut p = parse_describe(prefix, include_bytes!("testdata/bunny_describe.txt")).unwrap();
+        p.streams[0].state = dummy_stream_state_init(None);
+        super::parse_play(
+            &response(include_bytes!("testdata/bad_rtptime.txt")),
+            &mut p,
+        )
+        .unwrap();
+        match &p.streams[0].state {
+            StreamState::Init(state) => {
+                assert_eq!(state.initial_rtptime, None);
+                assert_eq!(state.initial_seq, Some(1));
+                assert_eq!(state.ssrc, None);
+            }
+            _ => panic!(),
+        };
+    }
+
     #[test]
     fn foscam() {
         // DESCRIBE.
diff --git a/src/client/testdata/bad_rtptime.txt b/src/client/testdata/bad_rtptime.txt
new file mode 100644
index 0000000..1aff116
--- /dev/null
+++ b/src/client/testdata/bad_rtptime.txt
@@ -0,0 +1,9 @@
+RTSP/1.0 200 OK
+Notes: copied from bunny_play.txt; modified to simulate a bad rtptime value as in https://github.com/scottlamb/moonfire-nvr/issues/224
+RTP-Info: url=trackID=1;seq=1;rtptime=-1,url=rtsp://wowzaec2demo.streamlock.net/vod/mp4:BigBuckBunny_115k.mov/trackID=2;seq=1;rtptime=-1
+CSeq: 3
+Server: Wowza Streaming Engine 4.8.10 build20210217143515
+Cache-Control: no-cache
+Range: npt=0.0-596.48
+Session: 551045787;timeout=60
+