JMR-devandClaude Opus 5
b082cea889
There is no usable prebuilt FFmpeg for Android any more. arthenica/ffmpeg-kit is archived and its binaries were deleted from Maven Central, so every com.arthenica:ffmpeg-kit-* coordinate 404s and all of its release tags have zero assets. Maven Central's search index still lists the old versions, which misleads; the files behind those entries are gone. The successor, ffmpeg-kit-next, is source-only by design. Building it ourselves is the only remaining option, not a preference. ffmpeg-kit-next is Nix-only -- there is no plain android.sh, only nix-android.sh and a flake -- so the toolchain lives in a container rather than on the developer's machine. The recipe doubles as the reproducibility artifact F-Droid expects and as the GPL corresponding-source obligation. Four problems this path hits, none of them documented upstream: - The nixos/nix base image already ships bash, coreutils and git; installing them collides with the existing profile entries and fails the image build. - Upstream scripts use #!/bin/bash but the image provides only /bin/sh, so start-android.sh dies with "cannot execute: required file not found" after the entire toolchain has been built. - Gradle's AAPT2 comes from Maven as a prebuilt binary linked against FHS paths that do not exist under Nix, failing with "Daemon startup failed" after the whole native build succeeds. Nixpkgs' Android SDK ships an already-patched aapt2, so Gradle is pointed at that. - A bare '*.aar' find also collects every AAR Gradle unpacked into its own caches, so the copy is scoped to the ffmpeg-kit outputs. The NDK stays at r27d as the flake pins it. Do not "upgrade" to r28+: android/jni/Android.mk applies -Wl,-z,max-page-size=16384 manually precisely because r27 predates automatic alignment, and the result is verified 16 KB compliant as-is. Verified against the produced artifact: every .so on both ABIs reports LOAD align 0x4000, libraries are separate rather than a static monolith as the GPL relinking obligation requires, and the embedded configure line confirms --enable-gpl --enable-version3 with x264, x265, SVT-AV1, LAME, libass and the MediaCodec wrappers. Note that --enable-small and --enable-lto internalize symbols, so absence from strings output proves nothing; check the configure line instead. The 35 MB AAR itself is gitignored. F-Droid strips checked-in prebuilt native libraries, and the recipe is the artifact of record. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Local FFmpeg AAR
ffmpeg-kit-next-*.aar is built, not committed. Build it with:
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 .aar is deliberately gitignored. It is a ~35 MB binary blob, and F-Droid's build
process strips checked-in prebuilt native libraries — committing it would break the
F-Droid build and bloat the repository. The reproducible recipe in tools/ffmpeg/ is
the artifact of record, and it also serves as the GPL corresponding-source obligation.