Two reasoned decisions were sitting in comments with nothing under them.
`AndroidDeviceCodecs.mimeFor`'s `COPY, NONE -> null` arm explains itself by
naming a consequence at another seam: returning null is what makes `canEncode`
answer true, because a copied or absent track places no demand on the hardware.
#90 pinned the null; nothing pinned the answer. Put a MIME in that arm and a
device with no matching encoder starts refusing stream copies — jobs that encode
nothing — and the router hands FFmpeg a re-mux Media3 could have done. Asserted
now against `forTesting(encoders = emptySet())`, with an H.264 refusal alongside
so a `canEncode` that simply said yes could not satisfy it.
The second is a whole table. `Media3Engine.videoMimeTypeFor` is `VideoCodec ->
MIME` on the same axis as `mimeFor`, and until #85 and #87 widened both to
`internal` no test could see them together. Each had per-arm coverage pinning its
own answers, which is exactly the shape that cannot notice the two tables
describing different codecs: change one arm and its own expectation together and
both suites stay green while the device is asked about H.265 and Transformer is
told to produce H.264.
They do not agree everywhere, and forcing them to would be a regression, so the
test sorts every codec into the three buckets that exist and asserts the fourth
is empty. H.264 and H.265 must match. VP8, VP9 and AV1 are named by the device
table and not by Transformer's, deliberately: `setVideoMimeType` rejects them so
the router never asks Media3, while the device may genuinely own a VP9 encoder
and `canEncode` has to answer about it truthfully. COPY and NONE are named by
neither. Sorting rather than filtering means a convergence fails too, so moving
the line requires saying so in the file.
Audio has no partner — `AndroidDeviceCodecs` enumerates video MIME types only,
so `audioMimeTypeFor` has nothing to cross-check against and a missing audio
encoder is still discovered by failing rather than up front. Named in the KDoc
as unfinished rather than left as an unexplained asymmetry.
Closes#86
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
