Matthew Jackson 48fb9b2cf6 mpls: locate STN table past the multi-angle angle block (issue #45) ...

The PlayItem STN (stream-number) table offset was hard-coded to 32, which
is only correct for a single-angle PlayItem. A multi-angle PlayItem inserts
number_of_angles(1) + flags(1) + (number_of_angles-1) angle references (10
bytes each) right after still_time, so its STN begins at 32 + 2 +
(number_of_angles-1)*10. The fixed offset lands inside that angle block and
misreads the stream counts as garbage (e.g. n_video=51 on Spider-Man 3 UHD
00245/00246.mpls, number_of_angles=2 => real offset 44), dropping every
stream including the primary video. That makes DiscTitle::has_video() return
false, which drops a multi-angle/seamless-branch feature from the disc's nav
candidate set and loses it in main-title selection.

Compute the STN offset from is_multi_angle (bit 4 of item[10]) + number_of
_angles. Add a regression test building a 2-angle PlayItem and asserting the
video stream is found past the angle block.

Validated on a 92-disc real UHD/BD corpus (offline scan): 0 main-feature
pick changes vs baseline, 3 multi-angle titles (Spider-Man 3 244/245/246)
recover has_video. Adds examples/corpus_titledump.rs as the regression tool.

2026-09-18 16:38:45 -07:00

..

corpus_titledump.rs

mpls: locate STN table past the multi-angle angle block (issue #45)

2026-09-18 16:38:45 -07:00