probe() was 20 never-executed lines, the biggest single block on the report. It has been
looked at twice and left out twice, and both closes were right about what they closed:
#86 ruled it device-bound, and #133 re-checked that with ShadowMediaCodecList in hand and
still declined, because MediaCodecInfoBuilder has no setIsAlias and no setCanonicalName --
"so the alias skip and the canonical-name dedup, the two things the class's KDoc calls out
as easy to get wrong, are not reachable through it."
That objection is about the shadow. It does not apply to a function taking its own entry
type, which #133 did not evaluate. capabilitiesFrom(enumerate: () -> Sequence<CodecEntry>)
holds every rule; the edge keeps only the mapping from MediaCodecList onto CodecEntry.
The parameter is a Sequence rather than a List on purpose. runCatching has always wrapped
the *iteration*, so a MediaCodecInfo whose properties throw partway leaves the codecs
already read in place. A List parameter would move that throw outside the loop and turn a
partial answer into an empty one -- a behaviour change smuggled in as a refactor. There is
now a test for the partial case, and swapping the Sequence for an eager toList() reddens it.
The behaviour change this DOES make is one line of log, and it is the reason the seam was
worth cutting at all. The fallback said "Codec enumeration failed; assuming permissive" and
returned empty sets -- but "video/avc" in emptySet() is false, so canEncode and canDecode
answer no to everything and every job routes to FFmpeg. That is the restrictive answer, and
it is the right one: FFmpeg does whatever Media3 does, only slower. The code stays; the
message and the class KDoc now describe it.
Seven tests. One of them was wrong first and the mutation is what said so: the alias case
originally listed the alias *after* the codec it aliases and passed with the skip deleted,
because canonicalName is shared and the dedup catches the second entry either way. The two
rules overlap, so a fixture that does not separate them tests neither. Order separates
them -- an alias arriving first claims the canonical name in `seen` and gets its own types
credited, and the real codec is then dropped by the dedup. That is now the test, and it
also says what the rule is worth: with a Set accumulator, an alias declaring the same types
as its codec changes nothing, so the skip earns its place only when the two disagree.
Mutations, each run and restored, each reddening the test that owns it:
drop !isSoftwareOnly from the encoder predicate 1 red
remove the alias skip 1 red (0 before the fixture was fixed)
remove the canonical-name dedup 1 red
remove the video/ prefix filter 1 red
apply the hardware predicate to decoders too 1 red
make the failure fallback permissive 2 red
eager toList() instead of the lazy Sequence 1 red
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
JMR-devandClaude Opus 5
6d700f0014