External Codec Libvlcjni.so ((install)): Kmp

val args = arrayOf("-vvv", "--codec=avcodec") // force ffmpeg decoders libVLC = LibVLC(context, args) Look for logcat output:

// shared logic fun playExternalCodecFile(player: PlatformMediaPlayer) player.setDataSource("content://com.example/external_codec_sample.mkv") player.play()

This paper is structured as a technical brief suitable for developers integrating advanced playback capabilities into KMP applications (Android/iOS/Desktop). 1. Introduction Kotlin Multiplatform (KMP) allows sharing business logic across Android, iOS, and Desktop JVM targets. However, media playback with support for proprietary or less common codecs (e.g., E-AC-3, DTS, RV40, some MPEG-4 variants) remains a challenge because native platform players (ExoPlayer, AVFoundation, MediaPlayer) rely on system codecs. kmp external codec libvlcjni.so

libvlcjni.so loads decoders like libavcodec.so internally – external codecs work immediately. 3.3 iOS / Darwin Target iOS uses MobileVLCKit (Objective-C framework) which also bundles FFmpeg. A Kotlin/Native interop can be created, or use cinterop to call VLCKit, achieving identical external codec support. 4. Verifying External Codec Activation To confirm that libvlcjni.so is using its own decoders and not Android’s MediaCodec:

On Android, the libvlcjni.so ‑backed player will output audio correctly, whereas ExoPlayer would fail with No decoder for: audio/ac3 . libvlcjni.so provides KMP developers with a powerful, unified way to handle external codecs that are absent from platform decoders. By wrapping VLC’s engine in a KMP expect/actual pattern, you can achieve cross-platform playback with near‑identical behavior and extensive format support. However, media playback with support for proprietary or

actual fun setDataSource(path: String) val options = arrayOf("--codec=all", "--no-audio-time-stretch") libVLC = LibVLC(ApplicationProvider.getApplicationContext(), options) mediaPlayer = MediaPlayer(libVLC) val media = Media(libVLC, path) media.addOption(":no-audio-filter") // optional mediaPlayer.media = media

libvlc: using decoder module "avcodec" avcodec: using FFmpeg decoder for codec 'eac3' | Aspect | libvlcjni.so (Software) | MediaCodec (Hardware) | |--------|------------------------|------------------------| | CPU usage | High for 4K/HEVC | Low (GPU/DSP) | | Codec support | Full (hundreds) | Limited by device | | External codecs | Yes (built-in) | Rarely | | KMP compatibility | Works on Android, Linux, Windows | Android-only | A Kotlin/Native interop can be created, or use

Actual implementation: