dvd: route private_stream_1 audio sub-ids by positional stream number

The private_stream_1 sub-stream id low nibble is the DVD audio-stream
NUMBER (0-7), shared across codecs, not a per-codec ordinal. A DTS (or
LPCM) track that isn't the disc's first audio stream got a sub-id one
too low, so the demux routing key (0xBD00 | sub_id) never matched and
every packet was dropped -> present-but-silent track. AC-3 at position
0 coincidentally worked (ordinal==position). Route by positional index.

Fixes silent DTS 5.0 track on The Punisher (AC-3 5.1 @ pos0 plays,
DTS 5.0 @ pos1 was 0xBD88, real wire id 0xBD89).

src/disc/dvd.rs

@@ -922,18 +922,19 @@ mod tests {
             2,
             "DTS 2.0 nibble must decode to 2 channels"
         );
-        // PIDs route via the per-codec sub-id table: AC-3 #0 → 0x80 → 0xBD80,
+        // PIDs route via the positional sub-id table: AC-3 @ pos 0 → 0x80 →
-        // DTS #0 → 0x88 → 0xBD88. Distinct (no 0xBD00 collision) AND the exact
+        // 0xBD80, DTS @ pos 1 → 0x89 → 0xBD89 (the shared audio-stream number
-        // canonical PIDs.
+        // in the low nibble, NOT a per-codec ordinal). Distinct AND the exact
-        assert_eq!(audios[0].pid, 0xBD80, "AC-3 #0 → 0xBD80");
+        // canonical wire PIDs the demux routes on.
-        assert_eq!(audios[1].pid, 0xBD88, "DTS #0 → 0xBD88");
+        assert_eq!(audios[0].pid, 0xBD80, "AC-3 @ pos 0 → 0xBD80");
+        assert_eq!(audios[1].pid, 0xBD89, "DTS @ pos 1 → 0xBD89");
         assert_ne!(audios[0].pid, audios[1].pid);
     }
 
     /// LPCM SCAN ROUTING (audit §2 / §5 #6): the 0xA0..=0xA7 PID range was never
-    /// exercised in the dvd.rs scan. An LPCM stream (coding_mode 4) must get
+    /// exercised in the dvd.rs scan. An LPCM stream (coding_mode 4) at audio
-    /// sub_stream_id 0xA0 → PID 0xBDA0 via `dvd_audio_pid`, distinct from the
+    /// position 1 must get sub_stream_id 0xA1 → PID 0xBDA1 via `dvd_audio_pid`,
-    /// AC-3 0xBD80 space, with its real channel count preserved.
+    /// distinct from the AC-3 0xBD80 space, with its real channel count preserved.
     #[test]
     fn scan_dvd_titles_lpcm_routes_to_a0_pid_range() {
         let mut disc = MemDisc::new();
@@ -978,10 +979,10 @@ mod tests {
         assert_eq!(audios.len(), 2);
         assert_eq!(audios[0].codec, Codec::Ac3);
         assert_eq!(audios[1].codec, Codec::Lpcm, "coding_mode 4 → LPCM");
-        assert_eq!(audios[0].pid, 0xBD80, "AC-3 #0 → 0xBD80");
+        assert_eq!(audios[0].pid, 0xBD80, "AC-3 @ pos 0 → 0xBD80");
         assert_eq!(
-            audios[1].pid, 0xBDA0,
+            audios[1].pid, 0xBDA1,
-            "LPCM #0 → 0xBDA0 (the 0xA0 sub-id range), NOT the AC-3 space"
+            "LPCM @ pos 1 → 0xBDA1 (the 0xA0 sub-id range | position), NOT the AC-3 space"
         );
         assert_eq!(
             audios[1].channels.count(),

src/ifo.rs

@@ -621,37 +621,34 @@ fn parse_audio_attr(data: &[u8], offset: usize) -> Result<DvdAudioAttr> {
 }
 
 /// Assign the on-wire `private_stream_1` sub-stream id to each audio
-/// stream by per-codec ordinal, matching DVD authoring convention and the
+/// stream. On DVD-Video the sub-id's **low nibble is the audio-stream
-/// muxer's `dvd_pid()` routing:
+/// *number* (0-7), shared across all codecs** — the single stream index the
-///   - AC-3  → `0x80 + n` (n = 0-based index among AC-3 streams)
+/// PGC `audio_control` table / navigation registers select — and the high
-///   - DTS   → `0x88 + n`
+/// nibble is the codec base. So the sub-id is `codec_base | position`, where
-///   - LPCM  → `0xA0 + n`
+/// `position` is the stream's index in the IFO audio-attribute table (NOT a
+/// per-codec running count):
+///   - AC-3  → `0x80 | i`
+///   - DTS   → `0x88 | i`
+///   - LPCM  → `0xA0 | i`
 ///   - MP1/MP2 and anything else → `None` (regular MPEG-audio PES, not a
 ///     private-stream-1 sub-id).
 ///
-/// Indices saturate at the codec range ceiling (8 AC-3/DTS, 8 LPCM) so a
+/// A per-codec ordinal was wrong: it only coincides with the wire id when a
-/// malformed over-count never produces an out-of-range sub-id.
+/// codec's first stream is also the disc's audio stream #0. Any codec that is
+/// not the first audio stream (e.g. a DTS track after an AC-3 track) then got
+/// a sub-id one-too-low, so the demux routing key (`0xBD00 | sub_id`) never
+/// matched and the track muxed silent. The positional index is the real wire
+/// number, so distinct positions still give distinct sub-ids (no collision).
+///
+/// Position saturates at 7 so a malformed over-count never produces an
+/// out-of-range sub-id.
 fn assign_audio_sub_stream_ids(streams: &mut [DvdAudioAttr]) {
-    let mut n_ac3 = 0u8;
+    for (i, s) in streams.iter_mut().enumerate() {
-    let mut n_dts = 0u8;
+        let n = (i as u8).min(7);
-    let mut n_lpcm = 0u8;
-    for s in streams.iter_mut() {
         s.sub_stream_id = match s.codec {
-            Codec::Ac3 => {
+            Codec::Ac3 => Some(0x80 | n),
-                let id = 0x80 + n_ac3.min(7);
+            Codec::Dts => Some(0x88 | n),
-                n_ac3 = n_ac3.saturating_add(1);
+            Codec::Lpcm => Some(0xA0 | n),
-                Some(id)
-            }
-            Codec::Dts => {
-                let id = 0x88 + n_dts.min(7);
-                n_dts = n_dts.saturating_add(1);
-                Some(id)
-            }
-            Codec::Lpcm => {
-                let id = 0xA0 + n_lpcm.min(7);
-                n_lpcm = n_lpcm.saturating_add(1);
-                Some(id)
-            }
             _ => None,
         };
     }
@@ -1138,9 +1135,10 @@ mod tests {
 
     #[test]
     fn mixed_codec_sub_stream_ids_are_distinct() {
-        // A title mixing AC-3, DTS and LPCM must get per-codec ordinal
+        // A title mixing AC-3, DTS and LPCM: the sub-id low nibble is the
-        // sub-ids (0x80, 0x88, 0xA0...), all distinct — this is the
+        // POSITIONAL audio-stream number (shared across codecs), OR'd with the
-        // routing key that keeps mixed-codec audio from colliding.
+        // codec base. So idx 1 (DTS) → 0x89, idx 3 (AC-3) → 0x83 — the real
+        // wire ids the demux routes on. All distinct (positions are unique).
         let mut streams = vec![
             DvdAudioAttr {
                 codec: Codec::Ac3,
@@ -1172,10 +1170,10 @@ mod tests {
             },
         ];
         assign_audio_sub_stream_ids(&mut streams);
-        assert_eq!(streams[0].sub_stream_id, Some(0x80)); // AC-3 #0
+        assert_eq!(streams[0].sub_stream_id, Some(0x80)); // AC-3 @ pos 0
-        assert_eq!(streams[1].sub_stream_id, Some(0x88)); // DTS  #0
+        assert_eq!(streams[1].sub_stream_id, Some(0x89)); // DTS  @ pos 1
-        assert_eq!(streams[2].sub_stream_id, Some(0xA0)); // LPCM #0
+        assert_eq!(streams[2].sub_stream_id, Some(0xA2)); // LPCM @ pos 2
-        assert_eq!(streams[3].sub_stream_id, Some(0x81)); // AC-3 #1
+        assert_eq!(streams[3].sub_stream_id, Some(0x83)); // AC-3 @ pos 3
         // All sub-ids unique.
         let ids: Vec<u8> = streams.iter().filter_map(|s| s.sub_stream_id).collect();
         let mut sorted = ids.clone();
@@ -1184,6 +1182,42 @@ mod tests {
         assert_eq!(ids.len(), sorted.len(), "sub-stream ids must be unique");
     }
 
+    /// Regression (The Punisher 2004): audio[0]=AC-3 5.1, audio[1]=DTS 5.0.
+    /// The DTS track sits at audio position 1, so its wire sub-id is 0x89
+    /// (0x88 | 1), NOT the per-codec 0x88. With the old per-codec ordinal it
+    /// got 0x88 → demux routing key 0xBD88 had no match → every DTS packet
+    /// (which carries 0x89) was dropped → the track muxed present-but-silent
+    /// while the AC-3 (at position 0, where ordinal and position coincide)
+    /// played fine. Positional numbering fixes it end-to-end.
+    #[test]
+    fn dts_after_ac3_uses_positional_substream_id() {
+        let mut streams = vec![
+            DvdAudioAttr {
+                codec: Codec::Ac3,
+                channels: 6,
+                sample_rate: 48000,
+                language: "en".into(),
+                sub_stream_id: None,
+            },
+            DvdAudioAttr {
+                codec: Codec::Dts,
+                channels: 5,
+                sample_rate: 48000,
+                language: "en".into(),
+                sub_stream_id: None,
+            },
+        ];
+        assign_audio_sub_stream_ids(&mut streams);
+        assert_eq!(streams[0].sub_stream_id, Some(0x80));
+        assert_eq!(
+            streams[1].sub_stream_id,
+            Some(0x89),
+            "DTS at audio position 1 routes to 0x89 on the wire, not 0x88"
+        );
+        // The routing key the muxer actually uses must resolve for 0x89.
+        assert_eq!(crate::mux::ps::dvd_audio_pid(0x89), Some(0xBD89));
+    }
+
     #[test]
     fn audio_attr_dts() {
         let mut data = vec![0u8; 16];
@@ -1371,10 +1405,10 @@ mod tests {
         ];
         assign_audio_sub_stream_ids(&mut streams);
         assert_eq!(streams[0].sub_stream_id, None); // MP2 → no sub-id
-        assert_eq!(streams[1].sub_stream_id, Some(0x80)); // AC3 #0
+        assert_eq!(streams[1].sub_stream_id, Some(0x81)); // AC3 @ pos 1
     }
 
-    /// assign_audio_sub_stream_ids saturates the per-codec ordinal at the
+    /// assign_audio_sub_stream_ids saturates the positional index at the
     /// range ceiling (min(7)) so a malformed over-count never produces an
     /// out-of-range sub-id. 9 AC-3 streams: the 9th still ≤ 0x87.
     #[test]