diff --git a/src/aacs/content.rs b/src/aacs/content.rs
index e395152..ca447f7 100644
--- a/src/aacs/content.rs
+++ b/src/aacs/content.rs
@@ -664,23 +664,11 @@ mod tests {
         let original = vec![0x42u8; 128]; // 8 blocks
         let mut data = original.clone();
 
-        // Encrypt with CBC manually (forward direction)
-        fn aes_cbc_encrypt(key: &[u8; 16], data: &mut [u8]) {
-            let cipher = Aes128::new(GenericArray::from_slice(key));
-            let mut prev = super::AACS_IV;
-            let num_blocks = data.len() / 16;
-            for i in 0..num_blocks {
-                let offset = i * 16;
-                for j in 0..16 {
-                    data[offset + j] ^= prev[j];
-                }
-                let mut block = GenericArray::clone_from_slice(&data[offset..offset + 16]);
-                cipher.encrypt_block(&mut block);
-                data[offset..offset + 16].copy_from_slice(&block);
-                prev.copy_from_slice(&data[offset..offset + 16]);
-            }
-        }
-
+        // Encrypt with the REAL production primitive. This test previously
+        // defined a local `fn aes_cbc_encrypt` that SHADOWED it, so it round-
+        // tripped a copy of the algorithm against itself and never exercised
+        // `crypto::aes_cbc_encrypt` at all — a mutation to the shipped function
+        // could not fail it.
         aes_cbc_encrypt(&key, &mut data);
         assert_ne!(data, original); // should be different after encrypt
 
diff --git a/src/mux/codec/dts.rs b/src/mux/codec/dts.rs
index accfe65..1acb4bc 100644
--- a/src/mux/codec/dts.rs
+++ b/src/mux/codec/dts.rs
@@ -691,9 +691,9 @@ const DTS_PCMBLOCK_SAMPLES: u32 = 32;
 const DTS_SUBBAND_SAMPLES: u32 = 8;
 /// Number of LEGAL `AMODE` (channel-arrangement) codes. The 6-bit AMODE field
 /// (ETSI TS 102 114 §5.3.1) has 16 defined channel arrangements, codes 0-15;
-/// only 16-63 are reserved/user-defined and undecodable. ffmpeg's
-/// `ff_dca_channels[16] = {1,2,2,2,2,3,3,4,4,5,6,6,6,7,8,8}` confirms all 16 are
-/// decodable — codes 10-15 are the 6/7/8-channel layouts. A frame is dropped
+/// only 16-63 are reserved/user-defined and undecodable. The per-AMODE channel
+/// counts in ETSI TS 102 114 §5.3.1 cover all 16, confirming they are decodable —
+/// codes 10-15 are the 6/7/8-channel layouts. A frame is dropped
 /// only when `audio_mode >= DTS_AMODE_COUNT` (i.e. a truly reserved 16-63 code);
 /// dropping a legal 10-15 multichannel core would silence recoverable audio.
 const DTS_AMODE_COUNT: u32 = 16;
diff --git a/src/mux/tsmux.rs b/src/mux/tsmux.rs
index bbed3ce..1b32dc4 100644
--- a/src/mux/tsmux.rs
+++ b/src/mux/tsmux.rs
@@ -195,8 +195,22 @@ impl<W: Write> TsMuxer<W> {
                         Codec::H264 => avcc_to_annex_b(cp),
                         _ => hvcc_to_annex_b(cp),
                     };
-                    if let Some(params) = params {
-                        annex_b.extend_from_slice(&params);
+                    match params {
+                        Some(params) => annex_b.extend_from_slice(&params),
+                        // A codec_private that EXISTS but will not parse means no
+                        // VPS/SPS/PPS reaches the stream and it is undecodable.
+                        // Arming the flag below is still right — retrying the same
+                        // bytes on the next keyframe cannot succeed — but it must
+                        // not be silent, which is what it was: the mux reported
+                        // success while emitting parameter-set-free video.
+                        None => tracing::warn!(
+                            track,
+                            codec = ?self.video_codec[track],
+                            codec_private_len = cp.len(),
+                            "bd-ts: codec_private did not parse as an avcC/hvcC \
+                             record; no parameter sets emitted and the video will \
+                             not decode"
+                        ),
                     }
                 }
                 self.params_written[track] = true;