JMR-dev/LibreMediaConverter
1
0
Fork 0
Code Issues 16 Pull Requests Actions Packages Projects Releases Wiki Activity

Enable R8 and add release, store and F-Droid infrastructure

Browse Source 
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>
This commit is contained in:
JMR-dev
2026-08-19 22:45:40 -05:00
co-authored by Claude Opus 5
parent 0c352cdcfb
commit bb969ece64
10 changed files with 305 additions and 20 deletions
Download Patch File Download Diff File Expand all files Collapse all files
.github/workflows/build.yml
+117
View File
@@ -0,0 +1,117 @@
name: Build
on:
push:
branches: [main]
pull_request:
jobs:
test:
name: Unit tests and lint
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v4
- uses: actions/setup-java@v4
with:
distribution: temurin
java-version: '17' # AGP 9 requires JDK 17
- uses: gradle/actions/setup-gradle@v4
# The FFmpeg AAR is not committed, so provide a stub for jobs that only need
# to compile and run JVM tests. Anything that actually calls into FFmpeg is an
# instrumented test and does not run here.
- name: Stub the FFmpeg AAR
run: |
mkdir -p app/libs
if [ ! -f app/libs/ffmpeg-kit-next-8.1.1.aar ]; then
echo "::warning::Using an empty FFmpeg AAR stub; instrumented tests are skipped."
mkdir -p /tmp/stub/jni && printf '<manifest package="com.arthenica.ffmpegkit"/>' > /tmp/stub/AndroidManifest.xml
(cd /tmp/stub && zip -qr ffmpeg-kit-next-8.1.1.aar .)
cp /tmp/stub/ffmpeg-kit-next-8.1.1.aar app/libs/
fi
- name: Unit tests
run: ./gradlew testDebugUnitTest
- name: Upload test report
if: always()
uses: actions/upload-artifact@v4
with:
name: unit-test-report
path: app/build/reports/tests/
ffmpeg:
name: Build FFmpeg AAR
runs-on: ubuntu-latest
# Expensive (a full cross-compile of FFmpeg, x264, x265 and friends), so it runs
# only for releases rather than on every push.
if: startsWith(github.ref, 'refs/tags/v')
steps:
- uses: actions/checkout@v4
- name: Build the AAR in a container
run: |
cd tools/ffmpeg
podman build -t ffmpeg-kit-builder:ci -f Containerfile . || \
docker build -t ffmpeg-kit-builder:ci -f Containerfile .
mkdir -p out
(podman run --rm -v "$PWD/out":/work/out:Z ffmpeg-kit-builder:ci full || \
docker run --rm -v "$PWD/out":/work/out ffmpeg-kit-builder:ci full)
- uses: actions/upload-artifact@v4
with:
name: ffmpeg-aar
path: tools/ffmpeg/out/ffmpeg-kit-next-*.aar
release:
name: Release
needs: [test, ffmpeg]
runs-on: ubuntu-latest
if: startsWith(github.ref, 'refs/tags/v')
steps:
- uses: actions/checkout@v4
- uses: actions/setup-java@v4
with:
distribution: temurin
java-version: '17'
- uses: gradle/actions/setup-gradle@v4
- uses: actions/download-artifact@v4
with:
name: ffmpeg-aar
path: app/libs/
- name: Build release artifacts
run: ./gradlew assembleRelease bundleRelease
# GPL-3.0 requires that complete corresponding source accompany the binary.
# FFmpeg's guidance says to host it on the same server as the binary; for a Play
# listing that is impossible, so it is attached to the GitHub release next to the
# APK and linked from both the store listing and the in-app About screen.
- name: Assemble corresponding source
run: |
mkdir -p release-source
cp -r tools/ffmpeg release-source/
{
echo "FFmpeg corresponding source for ${GITHUB_REF_NAME}"
echo
echo "Upstream: https://github.com/arthenica/ffmpeg-kit-next"
echo "Tag: v8.1.1 (FFmpeg 8.1.2)"
echo
echo "The exact configure line used is printed in the build log and is"
echo "reproduced by running tools/ffmpeg as documented in its README."
} > release-source/README.txt
tar czf ffmpeg-corresponding-source.tar.gz release-source
- uses: softprops/action-gh-release@v2
with:
files: |
app/build/outputs/apk/release/*.apk
app/build/outputs/bundle/release/*.aab
ffmpeg-corresponding-source.tar.gz
LICENSE
LICENSES/README.md
PRIVACY.md
+55
View File
@@ -0,0 +1,55 @@
# Privacy Policy
**Media Converter does not collect any data.**
That is the whole policy, but here is what it means concretely.
## No data leaves your device
The app has **no network access**. It does not declare the `INTERNET` permission, so it
is not merely a promise not to transmit anything — the operating system will not let it.
Your files are converted on your device and stay there.
## No analytics, advertising or tracking
There is no analytics SDK, no crash reporter, no advertising identifier, and no
third-party service of any kind.
## What the app accesses, and why
| Access | Why |
|---|---|
| Files you explicitly pick | Read as conversion input. The app uses the system file picker and can only see files you choose. It never scans your storage. |
| The destination you choose for output | Write the converted file. Again, only where you point it. |
| Notifications | Show conversion progress so you can leave the app while a long job runs. Optional; conversions work without it. |
The app does not request storage permissions. It uses the Storage Access Framework,
which grants access only to the individual files you select.
## The full permission list
Inspecting the app will show a few permissions that are not in the table above. They are
added automatically by the Jetpack WorkManager library, which runs conversions in the
background. Listing them here rather than leaving you to wonder:
| Permission | Origin | What it does here |
|---|---|---|
| `FOREGROUND_SERVICE`, `FOREGROUND_SERVICE_MEDIA_PROCESSING`, `FOREGROUND_SERVICE_DATA_SYNC` | Ours | Keep a conversion running when the app is not in the foreground. Android requires a declared service type for this. |
| `POST_NOTIFICATIONS` | Ours | Show conversion progress. Optional. |
| `WAKE_LOCK` | WorkManager | Stop the device sleeping mid-conversion. |
| `RECEIVE_BOOT_COMPLETED` | WorkManager | Restore an unfinished job queue after a restart. |
| `ACCESS_NETWORK_STATE` | WorkManager | WorkManager can gate jobs on connectivity. **This app does not use that feature**, and the permission only allows reading whether a network exists — it does not permit any network communication. |
Notably absent is `INTERNET`. Without it the operating system will not allow the app to
open a network connection at all, so "your files stay on your device" is enforced by
Android rather than resting on our word.
## Where files are stored
Conversions are written to the app's private cache while they run, then copied to the
location you choose. The temporary copy is deleted afterwards. Uninstalling the app
removes everything in its private storage.
## Contact
Report issues at the project's repository.
README.md
+54 -7
View File
@@ -5,8 +5,9 @@ compression, audio extraction and conversion, GIF and frame export, and file mer
Android 13+ (API 33). Built with Jetpack Compose and Material 3.
> **Status: early development.** The project scaffold and UI shell exist; the conversion
> pipeline is being built out. Not yet usable.
> **Status: working, unreleased.** Both conversion engines, the router, the background
> job queue and the join flow are implemented and building. The FFmpeg format tests have
> been written but not yet executed on a device.
## Licensing at a glance
@@ -65,16 +66,62 @@ extension appears in any Android Vulkan Profile tier.
So this app is hardware accelerated via MediaCodec, and GPU accelerated for effects via
GL shaders. Both are real; neither is "the GPU decoding video."
## Features
| | Formats |
|---|---|
| Video out | MP4 (H.264/H.265), MKV (H.264/H.265), WebM (VP9) |
| Audio out | MP3, AAC/M4A, FLAC, Opus, WAV |
| Images | GIF, PNG frame sequences |
| Other | Join several files into one |
Conversions run as durable background work, so they survive leaving the app and are
restored after a restart.
## Building
Requires JDK 17+ and the Android SDK with API 37.
Requires JDK 17+ (AGP 9 will not run on older) and the Android SDK with API 37.
```
./gradlew :app:assembleDebug
The FFmpeg AAR is **not committed** — it is a 35 MB binary, and F-Droid strips
checked-in native libraries. Build it first:
```sh
cd tools/ffmpeg
podman build -t ffmpeg-kit-builder:local -f Containerfile .
mkdir -p out
podman run --name ffmpeg-build -v "$PWD/out":/work/out:Z \
localhost/ffmpeg-kit-builder:local full
cp out/ffmpeg-kit-next-*.aar ../../app/libs/
```
The FFmpeg native library is built separately from source; that build is not yet wired
into this repository.
Then:
```sh
./gradlew :app:assembleDebug # debug APK
./gradlew :app:testDebugUnitTest # JVM tests
./gradlew :app:connectedDebugAndroidTest # device tests, needs a running device
./gradlew :app:assembleRelease # R8-minified release
```
See [`tools/ffmpeg/README.md`](tools/ffmpeg/README.md) for why the build is
containerised and which flags matter.
## Testing
Unit tests cover the parts that decide correctness without needing hardware: the
routing matrix, the FFmpeg argument builder, and the stream-copy-versus-re-encode
planner. They run against fabricated device profiles, so branches like "this device
cannot encode HEVC" are reachable regardless of what the test machine is.
Instrumented tests cover the parts that only a device can prove: real hardware
transcoding, the foreground service type, and each FFmpeg output format asserted
against the produced file rather than the exit code.
## Privacy
The app has **no `INTERNET` permission**, so it cannot open a network connection at all.
Nothing is uploaded, and there is no analytics or advertising. See [PRIVACY.md](PRIVACY.md),
which also explains the permissions WorkManager adds automatically.
## Contributing
app/build.gradle.kts
+7 -2
View File
@@ -35,8 +35,10 @@ android {
buildTypes {
release {
optimization {
// Left off until the JNI keep rules land with FFmpeg (see plan, Phase 6).
enable = false
// R8 full mode. Keep rules for the JNI boundary live in
// src/main/keepRules/rules.keep -- without them the native FFmpeg
// calls break at runtime in release builds only.
enable = true
}
}
}
@@ -78,6 +80,9 @@ dependencies {
// archived and delisted, and ffmpeg-kit-next is source-only by design.
// The AAR is gitignored; see app/libs/README.md to produce it.
implementation(files("libs/ffmpeg-kit-next-8.1.1.aar"))
// A local .aar carries no transitive dependencies, so the wrapper's own runtime
// dependency has to be declared here explicitly.
implementation(libs.smart.exception.java)
// Durable job queue. WorkManager survives process death, which is what makes the
// queue resumable after the foreground-service timeout fires.
app/src/main/keepRules/rules.keep
+38 -11
View File
@@ -1,12 +1,39 @@
# Add project specific R8 rules here.
# AGP will combine all keep rule files in src/main/keepRules to pass to R8
#
# For more details, see
# https://d.android.com/r/tools/r8/keep-rules
# R8 keep rules.
# AGP combines every file under src/<variant>/keepRules and passes them to R8.
# If your project uses WebView with JS, uncomment the following
# and specify the fully qualified class name to the JavaScript interface
# class:
#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
# public *;
#}
# --- FFmpegKit JNI boundary -------------------------------------------------
# The native library looks these classes and members up by name through JNI.
# R8 cannot see those references, so without explicit keeps it will rename or
# remove them and the native calls fail at runtime with NoSuchMethodError --
# only in release builds, and only once a conversion is actually attempted.
-keep class com.arthenica.ffmpegkit.** { *; }
-keep class com.arthenica.smartexception.** { *; }
# Callback types the native layer instantiates and invokes.
-keep interface com.arthenica.ffmpegkit.FFmpegSessionCompleteCallback { *; }
-keep interface com.arthenica.ffmpegkit.FFprobeSessionCompleteCallback { *; }
-keep interface com.arthenica.ffmpegkit.MediaInformationSessionCompleteCallback { *; }
-keep interface com.arthenica.ffmpegkit.LogCallback { *; }
-keep interface com.arthenica.ffmpegkit.StatisticsCallback { *; }
# Any method the native side calls back into.
-keepclasseswithmembernames class * {
native <methods>;
}
# --- WorkManager ------------------------------------------------------------
# Workers are constructed reflectively from a class name stored in the WorkManager
# database, so a renamed worker breaks jobs that were enqueued before the update.
-keep class * extends androidx.work.ListenableWorker {
public <init>(android.content.Context, androidx.work.WorkerParameters);
}
# --- Media3 -----------------------------------------------------------------
# Transformer selects codecs and muxers reflectively in places.
-keep class androidx.media3.** { *; }
-dontwarn androidx.media3.**
# Keep the source file and line numbers so release crash reports stay readable,
# then hide the original file name.
-keepattributes SourceFile,LineNumberTable
-renamesourcefileattribute SourceFile
fastlane/metadata/android/en-US/changelogs/1.txt
+7
View File
@@ -0,0 +1,7 @@
First release.
* Video conversion between MP4, MKV and WebM
* Audio extraction to MP3, AAC, FLAC, Opus and WAV
* GIF and PNG frame export
* Joining several files into one
* Hardware acceleration where the device supports it, with a visible fallback
fastlane/metadata/android/en-US/full_description.txt
+18
View File
@@ -0,0 +1,18 @@
A media converter that runs entirely on your device. Nothing is uploaded anywhere.
Convert video between MP4, MKV and WebM. Extract and convert audio to MP3, AAC,
FLAC, Opus or WAV. Export GIFs and PNG frame sequences. Join several clips into one
file.
Two conversion engines work together. Common video jobs run on your device's video
hardware, which is several times faster than software encoding and much easier on the
battery. Everything the hardware cannot do — Matroska, MP3, GIF, frame export, and the
highest quality settings — runs through a bundled FFmpeg build. The app tells you which
one it used and why, and lets you force software encoding if you prefer.
Quality settings:
* Fast — hardware accelerated, ideal for sharing and batches
* Best quality — software encoding with CRF rate control, for archiving
Free and open source. No advertising, no analytics, no network access.
fastlane/metadata/android/en-US/short_description.txt
+1
View File
@@ -0,0 +1 @@
Convert video and audio on your device. No ads, no tracking, no uploads.
fastlane/metadata/android/en-US/title.txt
+1
View File
@@ -0,0 +1 @@
Media Converter
gradle/libs.versions.toml
+7
View File
@@ -24,6 +24,7 @@ annotation = "1.10.0"
junit = "4.13.2"
androidxJunit = "1.3.0"
espressoCore = "3.7.0"
smartException = "0.2.1"
[libraries]
androidx-core-ktx = { group = "androidx.core", name = "core-ktx", version.ref = "coreKtx" }
@@ -63,6 +64,12 @@ androidx-room-runtime = { group = "androidx.room", name = "room-runtime", versio
androidx-room-ktx = { group = "androidx.room", name = "room-ktx", version.ref = "room" }
androidx-room-compiler = { group = "androidx.room", name = "room-compiler", version.ref = "room" }
# Required at runtime by the ffmpeg-kit-next wrapper: AbstractSession.fail()
# references smartexception.java.Exceptions. Debug builds tolerate its absence through
# lazy class loading, so this only surfaces as a crash on the first FFmpeg error --
# or, as it did here, as an R8 missing-class error.
smart-exception-java = { group = "com.arthenica", name = "smart-exception-java", version.ref = "smartException" }
junit = { group = "junit", name = "junit", version.ref = "junit" }
androidx-junit = { group = "androidx.test.ext", name = "junit", version.ref = "androidxJunit" }
androidx-espresso-core = { group = "androidx.test.espresso", name = "espresso-core", version.ref = "espressoCore" }