Files
amethyst/commons
Claude 4714e3c723 fix(nests): T13 reset Opus decoder on publisher boundary in NestPlayer
The reissuing-subscribe wrapper splices fresh-publisher frames into the
same `SharedFlow` that NestPlayer consumes, so across a JWT-refresh
hot-swap (speaker side) or a cliff-detector recycle (listener side)
the decoder receives a discontinuous frame stream while keeping its
Opus predictor state. Result: an audible warble at every publisher
cycle. Single-stream tests don't catch it because they never present
two distinct publishers.

Detect the boundary via `MoqObject.trackAlias` — the underlying
`MoqLiteSession.subscribe` assigns a fresh subscribeId per SUBSCRIBE,
which the listener wrapper surfaces verbatim as `trackAlias` on every
emitted object. A change between consecutive objects = new publisher.

Add an optional `decoderFactory: (() -> OpusDecoder)?` to NestPlayer.
When non-null, NestPlayer tracks `lastTrackAlias` and on a change
releases the current decoder and rebuilds via the factory. The
default `null` preserves the legacy single-decoder behaviour so
existing tests / callers that don't care about boundaries stand
unchanged.

NestViewModel.openSubscription wires the factory: a closure capturing
the catalog-derived `channelCount` so a rebuild reuses the SAME
channel layout — without that capture, a rebuild after a stereo-
publisher cycle would default to mono and silently downmix.

Two new NestPlayerTest cases pin the behaviour:
  - `publisher_boundary_rebuilds_decoder_when_factory_provided`:
    factory invoked twice (initial + boundary), first decoder
    released on boundary, second released on stop.
  - `publisher_boundary_no_op_when_factory_is_null`: legacy path
    holds onto the same decoder across trackAlias changes (unchanged
    semantics).

NestPlayer's first constructor parameter is now `initialDecoder`
(was `decoder`); positional-arg call sites are unchanged but the
named-arg call sites in the test suite are updated accordingly.

https://claude.ai/code/session_014JfZJHSTvyYYWJbC9VbB47
2026-05-06 18:00:52 +00:00
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