NextLib

NextLib is a library for adding ffmpeg codecs to Media3.

Currently supported decoders

• Audio: Vorbis, Opus, Flac, Alac, pcm_mulaw, pcm_alaw, MP3, Amrnb, Amrwb, AAC, AC3, EAC3, dca, mlp, truehd
• Video: H.264, HEVC, VP8 and VP9 (FFmpeg built-in decoders), AV1 (dav1d)

Setup

Kotlin DSL:

dependencies {
    implementation("io.github.anilbeesetti:nextlib-media3ext:INSERT_VERSION_HERE") // To add media3 software decoders and extensions
    implementation("io.github.anilbeesetti:nextlib-mediainfo:INSERT_VERSION_HERE") // To get media info through ffmpeg
}

Groovy DSL:

dependencies {
    implementation "io.github.anilbeesetti:nextlib-media3ext:INSERT_VERSION_HERE" // To add media3 software decoders and extensions
    implementation "io.github.anilbeesetti:nextlib-mediainfo:INSERT_VERSION_HERE" // To get media info through ffmpeg
}

Basic usage

Use NextRenderersFactory as a drop-in DefaultRenderersFactory replacement to make the bundled FFmpeg decoders available to Media3:

val renderersFactory = NextRenderersFactory(applicationContext)

ExoPlayer.Builder(applicationContext)
    .setRenderersFactory(renderersFactory)
    .build()

Runtime decoder switching

Create a DecoderManager alongside NextRenderersFactory when the application needs to select video and audio decoders while keeping the same ExoPlayer instance:

val decoderManager = DecoderManager()
val renderersFactory = NextRenderersFactory(applicationContext)
    .setDecoderManager(decoderManager)
val player = ExoPlayer.Builder(applicationContext)
    .setRenderersFactory(renderersFactory)
    .build()

decoderManager.attach(player)
decoderManager.selectVideoDecoder(DecoderMode.HARDWARE)
decoderManager.selectAudioDecoder(DecoderMode.AUTO)

decoderManager.detach()
player.release()

Video and audio are selected independently. See media3ext/DECODER_SWITCHING.md for mode behavior, lifecycle, and application-owned error handling.

Building from source

Use macOS or Linux (WSL on Windows), JDK 17+, make, curl, tar, and pkg-config, Meson, Ninja, and NASM 2.14+ (brew install meson ninja nasm on macOS; sudo apt-get install meson ninja-build nasm on Ubuntu). On Apple Silicon, also install native yasm (brew install yasm) for the x86 ABIs; the pinned NDK bundles an Intel-only assembler. Install Android CLI and put android on PATH, or set ANDROID_CLI to its executable path. Set sdk.dir in local.properties or export ANDROID_HOME to your Android SDK.

./gradlew assembleRelease

Both modules depend on one :ffmpegSetup task, which installs missing NDK/CMake packages with Android CLI and builds the four supported ABIs before CMake runs. NDK and CMake versions come from gradle/libs.versions.toml. Existing SDK tools are reused; Android CLI is only needed when a package is missing. Complete any SDK license prompts during initial installation before running a headless build.

The build pins dav1d 1.5.4 and statically links it into FFmpeg's libavcodec.so for every ABI, with assembly optimizations and both 8-bit and high-bit-depth AV1 support. AV1 uses the libdav1d decoder in Media3 and in media-info/thumbnail lookups.

Gradle tracks the setup script, tool versions, and generated output so unchanged builds skip FFmpeg. To force rebuilding it:

./gradlew :ffmpegSetup --rerun-tasks

For standalone use, export ANDROID_HOME and run bash ffmpeg/setup.sh (always rebuilds). Run python3 ffmpeg/test_setup.py for setup regression checks without SDK downloads or native compilation.

To verify AV1 decoding and seeking on a disposable ARM64 Android emulator, build the library and run the native regression test (requires host FFmpeg with the libsvtav1 encoder):

ANDROID_NDK_HOME=/path/to/sdk/ndk/25.2.9519653 ANDROID_SERIAL=emulator-5554 \
  bash media3ext/src/test/cpp/run_av1_decoder_test.sh

This checks decoder discovery by both name and codec ID, 8-bit and 10-bit output, film-grain decoding, one output frame per sample with no delayed frames at EOS, and decoding again after a seek/flush. AV1 uses dav1d's low-delay mode to match Media3's SimpleDecoder input/output contract.

See AV1 verification for the Next Player playback checks and tested device coverage.