Fix read-fault misclassification, DTS AMODE channel table, and untestable guards

- resolve_fmts_key_map: distinguish a genuinely-not-FMTS disc from a
  transient live-drive read fault. read_filesystem now returns the new
  Error::UdfNotFilesystem for a deterministic tag/format mismatch (no AVDP,
  no partition descriptor, no FSD); resolve maps only UdfNotFilesystem (fs)
  and UdfNotFound (.tbl absent) to Ok(None), and PROPAGATES DiscRead / other
  I/O faults so a marginal AACS 2.1 disc fails loud instead of silently
  dropping forensic content under a base-Unit-Key-only map.

- DTS_AMODE_CH (mp4/audio.rs): extend 10→16 entries
  {1,2,2,2,2,3,3,4,4,5,6,6,6,7,8,8} (the spec per-AMODE channel table / ETSI TS 102 114) so
  the spec-legal high AMODEs that now pass the decodability gate declare
  their true channelcount (AMODE 13→7, 14/15→8) instead of a truncated 6.

- session.rs resolve_keys "called before scan" guard is now testable:
  from_parts_for_test takes Option<Disc>; added a test that a disc-less
  session returns a clean DeviceNotReady Err rather than panicking.

- mp4/read.rs: a track with samples but a missing/malformed stts (mandatory
  per ISO/IEC 14496-12) is dropped rather than emitting all-zero timestamps,
  matching the existing stco/stsc guards; all-tracks-dropped → Mp4Invalid.

- Remove the inert MuxInput::Iso.key_map field (the Iso path re-derives its
  map inside build_iso_pipeline); the live path keeps Live.key_map.

All four fixes are mutation-verified.

src/mux/driver.rs

@@ -111,10 +111,6 @@ pub enum MuxInput<'a> {
         format: crate::disc::ContentFormat,
         /// Decryption keys for the title (`DecryptKeys::None` for raw/clear).
         keys: DecryptKeys,
-        /// Optional pre-resolved AACS key map. Carried for forward-compat and
-        /// the live path; the file highway re-derives its own map from
-        /// `keys`/`key_fetch` inside [`build_iso_pipeline`].
-        key_map: Option<Arc<AacsKeyMap>>,
         /// Optional read-time key fetch closure (banked by `resolve_keys`).
         key_fetch: Option<KeyFetch>,
     },
@@ -280,7 +276,6 @@ pub fn mux_stream(
             title,
             format,
             keys,
-            key_map: _,
             key_fetch,
         } => {
             let reader = FileSectorSource::open(path)?;
@@ -1307,7 +1302,6 @@ mod tests {
                 title,
                 format: crate::disc::ContentFormat::BdTs,
                 keys: DecryptKeys::None,
-                key_map: None,
                 key_fetch: None,
             },
             "null://",
@@ -1620,7 +1614,7 @@ mod tests {
         let disc = aacs_session_disc(title, unit_key);
         // No caller key_fetch: a single-CPS disc resolves its base map with the
         // banked unit key alone (the FMTS/multi-CPS fetch path is not exercised).
-        let mut session = DiscSession::from_parts_for_test(disc, Some(reader), None);
+        let mut session = DiscSession::from_parts_for_test(Some(disc), Some(reader), None);
 
         let opts = MuxOptions {
             skip_errors: false, // a DecryptFailed must PROPAGATE, not zero-fill
@@ -1670,7 +1664,7 @@ mod tests {
         }];
         let disc = aacs_session_disc(title, unit_key);
         // reader: None — never staged.
-        let mut session = DiscSession::from_parts_for_test(disc, None, None);
+        let mut session = DiscSession::from_parts_for_test(Some(disc), None, None);
 
         let opts = MuxOptions {
             skip_errors: false,

src/mux/mp4/audio.rs

@@ -239,8 +239,12 @@ const DTS_SFREQ: [u32; 16] = [
     48_000, 8_000, 16_000, 32_000, 48_000, 48_000, 11_025, 22_050, 44_100, 48_000, 48_000, 12_000,
     24_000, 48_000, 96_000, 192_000,
 ];
-/// DTS core base channel count per `AMODE` (0..=9); higher AMODEs are rare on disc.
-const DTS_AMODE_CH: [u8; 10] = [1, 2, 2, 2, 2, 3, 3, 4, 4, 5];
+/// DTS core base channel count per `AMODE` (all 16 defined values). Matches the
+/// reference `ff_dca_channels[16]` table (ETSI TS 102 114) that the decodability
+/// gate in `dts.rs` (`DTS_AMODE_COUNT`) also uses, so a spec-legal DTS-ES / 6.1 /
+/// 7.1 core (AMODE 13→7, 14/15→8) is DECLARED with its true channel count in the
+/// mp4 AudioSampleEntry / `ddts` box rather than a truncated 6.
+const DTS_AMODE_CH: [u8; 16] = [1, 2, 2, 2, 2, 3, 3, 4, 4, 5, 6, 6, 6, 7, 8, 8];
 
 /// Decoded DTS core parameters needed for the `ddts` box.
 struct DtsConfig {
@@ -557,6 +561,37 @@ mod tests {
         assert_eq!(&e[4..8], b"dtsh");
     }
 
+    #[test]
+    fn dts_high_amode_channel_counts_are_declared() {
+        // The 16-entry DTS_AMODE_CH must declare the true core channel count for the
+        // spec-legal high AMODEs that now pass the decodability gate: AMODE 13→7,
+        // 14→8, 15→8 (ETSI TS 102 114 / ff_dca_channels). The old 10-entry table
+        // fell through `unwrap_or(6)` → every one of these was declared as 6.
+        //
+        // Frame layout (mirrors dts_core_5_1_and_ddts): SFREQ=13 (48k), LFF=0 (no
+        // LFE) so `channels` is the bare base count. AMODE is split across
+        // f[7] low nibble (amode>>2) and f[8] top 2 bits (amode&3).
+        //   f[8] = (amode&3)<<6 | 13<<2 = ...  (keeps SFREQ=13)
+        let frame = |f7: u8, f8: u8| {
+            vec![
+                0x7F, 0xFE, 0x80, 0x01, 0x00, 0x05, 0xF2, f7, f8, 0x00, 0x00, 0x00,
+            ]
+        };
+        // AMODE 13 → base 7 channels.
+        let c = parse_dts(&frame(0xF3, 0x74)).expect("amode 13 parses");
+        assert_eq!(c.amode, 13);
+        assert!(!c.lfe);
+        assert_eq!(c.channels, 7, "AMODE 13 core is 7 channels, not 6");
+        // AMODE 14 → base 8 channels.
+        let c = parse_dts(&frame(0xF3, 0xB4)).expect("amode 14 parses");
+        assert_eq!(c.amode, 14);
+        assert_eq!(c.channels, 8, "AMODE 14 core is 8 channels, not 6");
+        // AMODE 15 → base 8 channels.
+        let c = parse_dts(&frame(0xF3, 0xF4)).expect("amode 15 parses");
+        assert_eq!(c.amode, 15);
+        assert_eq!(c.channels, 8, "AMODE 15 core is 8 channels, not 6");
+    }
+
     #[test]
     fn sample_entry_samplerate_does_not_overflow_at_96k() {
         // 96 kHz > 65535: the 16.16 integer part must saturate, not wrap to garbage.

src/mux/mp4/read.rs

@@ -201,6 +201,15 @@ impl<R: Read + Seek> Mp4Reader<R> {
             let durations = find_box(stbl, b"stts")
                 .map(|b| parse_stts(b, n))
                 .unwrap_or_default();
+            if durations.is_empty() {
+                // Samples exist but there is no decoding-time table: `stts` is
+                // mandatory in a valid stbl (ISO/IEC 14496-12 §8.6.1). Without it
+                // every sample would take dur=0 → all-zero, identical timestamps,
+                // collapsing the whole track onto one instant. Drop the track
+                // rather than emit degenerate timing (mirrors the stco/stsc
+                // guards above); an all-tracks-dropped file fails Mp4Invalid below.
+                continue;
+            }
             let ctts = find_box(stbl, b"ctts")
                 .map(|b| parse_ctts(b, n))
                 .unwrap_or_default();
@@ -1216,11 +1225,21 @@ mod tests {
             p.extend_from_slice(&0u32.to_be_bytes()); // sample_desc_idx
             mp4_box(b"stsc", &p)
         };
+        let stts = {
+            // Mandatory time-to-sample box: 1 entry → 1 sample × 1000 ticks.
+            let mut p = Vec::new();
+            p.extend_from_slice(&[0, 0, 0, 0]); // version+flags
+            p.extend_from_slice(&1u32.to_be_bytes()); // entry_count
+            p.extend_from_slice(&1u32.to_be_bytes()); // sample_count
+            p.extend_from_slice(&1000u32.to_be_bytes()); // sample_delta
+            mp4_box(b"stts", &p)
+        };
         let mut stbl = Vec::new();
         stbl.extend_from_slice(&stsd);
         stbl.extend_from_slice(&stsz);
         stbl.extend_from_slice(&stco);
         stbl.extend_from_slice(&stsc);
+        stbl.extend_from_slice(&stts);
         let minf = mp4_box(b"minf", &mp4_box(b"stbl", &stbl));
         let mut mdia = Vec::new();
         mdia.extend_from_slice(&mdhd);
@@ -1319,11 +1338,20 @@ mod tests {
             p.extend_from_slice(&0u32.to_be_bytes()); // sample_desc_idx
             mp4_box(b"stsc", &p)
         };
+        let stts = {
+            let mut p = Vec::new();
+            p.extend_from_slice(&[0, 0, 0, 0]); // version+flags
+            p.extend_from_slice(&1u32.to_be_bytes()); // entry_count
+            p.extend_from_slice(&1u32.to_be_bytes()); // sample_count
+            p.extend_from_slice(&1000u32.to_be_bytes()); // sample_delta
+            mp4_box(b"stts", &p)
+        };
         let mut stbl = Vec::new();
         stbl.extend_from_slice(&stsd);
         stbl.extend_from_slice(&stsz);
         stbl.extend_from_slice(&stco);
         stbl.extend_from_slice(&stsc);
+        stbl.extend_from_slice(&stts);
         let minf = mp4_box(b"minf", &mp4_box(b"stbl", &stbl));
         let mut mdia = Vec::new();
         mdia.extend_from_slice(&mdhd);
@@ -1397,6 +1425,15 @@ mod tests {
             p.extend_from_slice(&0u32.to_be_bytes()); // sample_desc_idx
             mp4_box(b"stsc", &p)
         };
+        let stts = {
+            // Mandatory time-to-sample box: 3 entries' worth via one run (3×1000).
+            let mut p = Vec::new();
+            p.extend_from_slice(&[0, 0, 0, 0]); // version+flags
+            p.extend_from_slice(&1u32.to_be_bytes()); // entry_count
+            p.extend_from_slice(&3u32.to_be_bytes()); // sample_count
+            p.extend_from_slice(&1000u32.to_be_bytes()); // sample_delta
+            mp4_box(b"stts", &p)
+        };
         let mut stbl = Vec::new();
         stbl.extend_from_slice(&stsd);
         stbl.extend_from_slice(&stsz);
@@ -1406,6 +1443,9 @@ mod tests {
         if omit != b"stsc" {
             stbl.extend_from_slice(&stsc);
         }
+        if omit != b"stts" {
+            stbl.extend_from_slice(&stts);
+        }
         let minf = mp4_box(b"minf", &mp4_box(b"stbl", &stbl));
         let mut mdia = Vec::new();
         mdia.extend_from_slice(&mdhd);
@@ -1446,6 +1486,23 @@ mod tests {
         );
     }
 
+    /// A track with samples (`stsz`) but no time-to-sample table (`stts`, mandatory
+    /// per ISO/IEC 14496-12 §8.6.1) must be DROPPED — without it every sample takes
+    /// dur=0, collapsing the whole track onto one instant (all-zero timestamps).
+    /// With it the only track, the file fails `Mp4Invalid`.
+    /// Mutation check: delete the `if durations.is_empty() { continue; }` guard and
+    /// `from_reader` returns `Ok` (all-zero-timestamp samples), flipping this to FAIL.
+    #[test]
+    fn missing_stts_drops_track_all_dropped_is_invalid() {
+        use std::io::Cursor;
+        let moov = mp4_box(b"moov", &audio_trak_missing(b"stts"));
+        let rd = Mp4Reader::from_reader(Cursor::new(moov), "no-stts".into());
+        assert!(
+            rd.is_err(),
+            "a track with stsz but no stts must be dropped; all-dropped → Mp4Invalid"
+        );
+    }
+
     /// Sanity companion: the SAME builder WITH both tables present yields a valid,
     /// indexed single-track file — proving the two Err results above come from the
     /// missing table, not from some unrelated defect in the fixture builder.

src/mux/resolve.rs

@@ -789,12 +789,26 @@ fn resolve_fmts_key_map(
         Ok(())
     };
 
-    // Load the segment map; absent → not an FMTS disc.
-    let Ok(udf) = crate::udf::read_filesystem(reader) else {
-        return Ok(None);
+    // Load the segment map. Distinguish a genuine "not an FMTS disc" negative
+    // from a transient live-drive I/O fault: swallowing the latter into Ok(None)
+    // would fall through to a base-Unit-Key-only map, garble the forensic units,
+    // let the demux drop them, and complete the mux with NO error — silently
+    // losing forensic content, contradicting this function's fail-loud contract.
+    //   - `UdfNotFilesystem`: bytes read fine but are not a UDF disc (deterministic
+    //     tag/format mismatch) → genuinely not FMTS → Ok(None).
+    //   - `UdfNotFound`: the disc is UDF but has no `IndividualSegment.tbl`
+    //     → genuinely not FMTS → Ok(None).
+    //   - any other error (notably `DiscRead`): a read fault → propagate so the
+    //     rip fails loud / can be retried rather than dropping forensic content.
+    let udf = match crate::udf::read_filesystem(reader) {
+        Ok(u) => u,
+        Err(crate::error::Error::UdfNotFilesystem) => return Ok(None),
+        Err(e) => return Err(e.into()),
     };
-    let Ok(tbl) = udf.read_file(reader, "/AACS/IndividualSegment.tbl") else {
-        return Ok(None);
+    let tbl = match udf.read_file(reader, "/AACS/IndividualSegment.tbl") {
+        Ok(t) => t,
+        Err(crate::error::Error::UdfNotFound { .. }) => return Ok(None),
+        Err(e) => return Err(e.into()),
     };
     let Some(segments) = parse_individual_segments(&tbl) else {
         return Ok(None);
@@ -2834,4 +2848,95 @@ mod tests {
             "the fetched key is appended at pool index 2 and keys the extent"
         );
     }
+
+    // ── Fix 1: read-fault vs genuinely-not-FMTS in resolve_fmts_key_map ──────
+
+    /// A SectorSource whose every read is a transient I/O fault (`DiscRead`),
+    /// modelling a marginal live drive stalling while `resolve_fmts_key_map`
+    /// probes the UDF metadata / segment table.
+    struct FaultSource;
+    impl SectorSource for FaultSource {
+        fn capacity_sectors(&self) -> u32 {
+            1_000_000
+        }
+        fn read_sectors(
+            &mut self,
+            lba: u32,
+            _count: u16,
+            _buf: &mut [u8],
+            _recovery: bool,
+        ) -> crate::error::Result<usize> {
+            Err(crate::error::Error::DiscRead {
+                sector: lba as u64,
+                status: None,
+                sense: None,
+            })
+        }
+    }
+
+    /// A transient `DiscRead` fault while reading the UDF metadata for the segment
+    /// table must PROPAGATE (fail loud / retryable), NOT be swallowed into the
+    /// not-FMTS `Ok(None)` fall-through — otherwise a marginal AACS 2.1 disc would
+    /// silently drop its forensic content under a base-Unit-Key-only map and the
+    /// mux would report success.
+    ///
+    /// Mutation: revert the read_filesystem arm to `let Ok(udf) = ... else { return
+    /// Ok(None) }` → this returns `Ok(None)` and the assert fails.
+    #[test]
+    fn resolve_fmts_key_map_read_fault_propagates() {
+        let mut reader = FaultSource;
+        let title = multi_cps_title(1000, 30);
+        let mut keys = DecryptKeys::Aacs {
+            unit_keys: vec![(0, [0x01u8; 16])],
+            read_data_key: None,
+            format: ContentFormat::BdTs,
+        };
+        let got = super::resolve_fmts_key_map(
+            &mut reader,
+            &title,
+            &mut keys,
+            None,
+            ContentFormat::BdTs,
+            None,
+        );
+        let err = got.expect_err("a transient DiscRead must fail loud, never Ok(None)");
+        let expected = std::io::Error::from(crate::error::Error::DiscRead {
+            sector: 256,
+            status: None,
+            sense: None,
+        })
+        .to_string();
+        assert_eq!(
+            err.to_string(),
+            expected,
+            "the DiscRead fault must propagate"
+        );
+    }
+
+    /// A reader whose bytes are structurally NOT a UDF disc (all zeros → no AVDP at
+    /// sector 256 → `UdfNotFilesystem`) is genuinely not FMTS: it must map to the
+    /// clean `Ok(None)` negative, NOT fail loud. Guards against Fix 1 over-reaching
+    /// and rejecting benign non-FMTS discs.
+    #[test]
+    fn resolve_fmts_key_map_not_udf_is_clean_none() {
+        // CipherSource with no registered units reads as all zeros everywhere, so
+        // read_filesystem sees tag_id 0 at sector 256 → UdfNotFilesystem.
+        let mut reader = CipherSource { units: Vec::new() };
+        let title = multi_cps_title(1000, 30);
+        let mut keys = DecryptKeys::Aacs {
+            unit_keys: vec![(0, [0x01u8; 16])],
+            read_data_key: None,
+            format: ContentFormat::BdTs,
+        };
+        let got = super::resolve_fmts_key_map(
+            &mut reader,
+            &title,
+            &mut keys,
+            None,
+            ContentFormat::BdTs,
+            None,
+        )
+        .expect("a structurally non-UDF disc is a clean not-FMTS negative");
+        assert!(got.is_none(), "not a UDF/FMTS disc → Ok(None)");
+    }
 }