diff --git a/crates/codecs/src/avi.rs b/crates/codecs/src/avi.rs
index 8855c3a65..5fc7e1aff 100644
--- a/crates/codecs/src/avi.rs
+++ b/crates/codecs/src/avi.rs
@@ -194,10 +194,11 @@ fn split_frames(
         let Some(here) = win.get(pos - base..) else { break };
         match filmcraft_mpegts::frame_bytes(ts, here) {
             Some(n) if pos + n <= total => {
+                let fi = filmcraft_mpegts::frame_info(ts, here);
                 if info.is_none() {
-                    info = filmcraft_mpegts::frame_info(ts, here);
+                    info = fi;
                 }
-                let k = filmcraft_mpegts::frame_info(ts, here).map_or(0, |f| f.samples);
+                let k = fi.map_or(0, |f| f.samples);
                 first.push(pieces.len());
                 let mut p = pos;
                 while p < pos + n {
diff --git a/crates/mpegts/src/ts.rs b/crates/mpegts/src/ts.rs
index b73666e90..f1a7b69a0 100644
--- a/crates/mpegts/src/ts.rs
+++ b/crates/mpegts/src/ts.rs
@@ -114,11 +114,10 @@ impl PesAsm {
         }
         let before = self.hdr.len();
         self.hdr.extend_from_slice(payload);
-        if let Some(h) = pes::parse(&self.hdr)
-            && self.hdr.len() >= h.header_len
-        {
+        // `pes::parse` only succeeds once the whole header (`header_len` bytes) is buffered
+        if let Some(h) = pes::parse(&self.hdr) {
             self.waiting = false;
-            let skip = (h.header_len - before).min(payload.len());
+            let skip = h.header_len.saturating_sub(before).min(payload.len());
             return (Some(h), &payload[skip..]);
         }
         if self.hdr.len() > 1024 || (self.hdr.len() >= 6 && !(self.hdr[0] == 0 && self.hdr[1] == 0 && self.hdr[2] == 1)) {