The two FFmpeg engines were done in ad2a75d and d293646. This is
Media3Engine.transcode's invokeOnCancellation, which posts
transformer.cancel() onto the engine's own HandlerThread because cancel()
has the same single-thread requirement as start().
The assertion is the output file here, where it could not be for FFmpeg.
That side deletes the partial on cancellation, and on POSIX ffmpeg keeps
writing to the unlinked inode, so the path stays gone whether or not the
cancel landed -- it asserts the session's return code instead. Media3Engine
deletes nothing, the partial being ConversionWorker's to clean up, so the
file is the evidence.
A cancelled export reports itself two ways and both mean interrupted: no
video track, or MediaExtractor refusing the file outright with "Failed to
instantiate extractor" because there is no moov atom. The first version
treated only the null as success and the exception failed the test, which
is how that was measured. Only a playable file counts as a miss.
The wait before reading is several times the export's own length, so a
cancel that did not land has certainly finished by then: the failure
direction is "the file became playable", never "we did not wait long
enough". The attempt is retried for the reason the other two engines
measured -- a 3 s 320x240 export outruns a naive cancel on a loaded runner
-- and an export that never wrote a file at all is recorded as
inconclusive rather than allowed to pass as a cancellation.
It carries @FailsOnEmulatorApi37, so FAILS_ON_EMULATOR_API37_BASELINE moves
3 -> 4 in this diff. That file also said removing the marker would grow the
gating leg "by two", which has been wrong since the third marker landed; it
now names the constant instead of restating it.
Verified on a local API 34 emulator: 68 tests, 0 failures, 3 skipped; and
with transformer.cancel() removed all five attempts produce a playable
video/hevc and the test fails, naming each one.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>