Turning on R8 immediately surfaced a latent runtime bug: the ffmpeg-kit-next
wrapper references com.arthenica.smartexception.java.Exceptions from
AbstractSession.fail() in eighteen places, but a local .aar carries no
transitive dependencies, so nothing was pulling it in. Debug builds tolerate
this through lazy class loading -- the class is only touched on an error
path -- so it would have shipped as a crash the first time an FFmpeg
conversion failed. Declared explicitly now.
Keep rules cover the JNI boundary. The native library resolves classes and
methods by name, which R8 cannot see, so without them the FFmpeg calls fail
with NoSuchMethodError in release builds only. Workers are kept too, since
WorkManager reconstructs them reflectively from a class name persisted in its
database, and a rename breaks jobs enqueued before the update.
Verified on the produced artifacts rather than assumed: all 22 native
libraries survive minification and every one is still 16 KB aligned inside
the APK. Release is 82 MB against 115 MB for debug; the AAB is 40 MB and Play
splits it per ABI.
The privacy policy lists every permission, including the three WorkManager
adds automatically (WAKE_LOCK, RECEIVE_BOOT_COMPLETED, ACCESS_NETWORK_STATE).
Checking the merged manifest showed those, and a policy that omitted them
would look dishonest to anyone who inspected the app. INTERNET is genuinely
absent, so "files stay on the device" is enforced by the OS rather than a
promise.
CI runs unit tests on every push and builds the FFmpeg AAR only for release
tags, since that is a full cross-compile. Releases attach the FFmpeg
corresponding source next to the APK: GPL-3.0 requires it, and FFmpeg's
instruction to host it "on the same webserver" cannot be satisfied by a Play
listing.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
The generated scaffold was a Views-based Material 2 shell with no activity,
no Kotlin sources, and a placeholder package. Replace it with the real base
the conversion work builds on.
Build configuration, with three AGP 9 specifics that contradict most
tutorials still in circulation:
- AGP 9 has built-in Kotlin. Applying org.jetbrains.kotlin.android now fails
the build, so the absence of that plugin is deliberate, not an oversight.
- The Compose compiler plugin is still separate and must be applied, pinned
to 2.2.10 to match the kotlin-gradle-plugin AGP 9.3.1 brings transitively.
Pinning it to the newest Kotlin release instead would mismatch.
- android.kotlinOptions {} was removed; jvm configuration moves to a
top-level kotlin { compilerOptions {} }.
Java compatibility goes 11 -> 17 (AGP 9 requires JDK 17), abiFilters
restrict packaging to arm64-v8a and x86_64, and jniLibs packaging is set
uncompressed so the APK zip-aligns native libraries on 16 KB boundaries.
Every dependency version in the catalog was checked to resolve against
Google Maven rather than copied from documentation. Note that KSP has moved
to standalone versioning (2.3.11) and no longer uses the old
<kotlin>-<ksp> scheme; it is catalogued but left unapplied until Room lands.
Set applicationId to dev.jasonmross.mediaconverter. com.example.* is
rejected by the Play Console, and the application ID is permanent once
published, so it has to be right before the first upload. The display name
is just a string resource and stays changeable.
Document the split license posture: source is MIT, but the distributed
binary will be GPL-3.0 because it bundles FFmpeg built with x264/x265.
LICENSES/README.md records why, including that libass is ISC rather than
GPL, so subtitle burn-in is not what forces the GPL choice.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
JMR-devandClaude Opus 5