KBTVCaster

Project Overview

If you want to receive phone-pushed videos on the TV without being locked into commercial casting apps, KBTVCaster takes the approach of turning an ordinary Android TV into a protocol receiver: full DLNA/UPnP media push support, with AirPlay screen mirroring built in as an experimental feature. It is built on Kotlin and Media3 ExoPlayer, uses a source-vendored Cling UPnP stack, and wraps the UxPlay kernel behind a thin JNI bridge for mirroring.

Item	Value
Platform	Android TV / boxes (Android 6.0, API 23+)
Protocols	DLNA / UPnP (full), AirPlay mirroring (experimental)
Stack	Kotlin 1.9, Media3 ExoPlayer, Cling, UxPlay, oboe
Architectures	arm64-v8a / x86_64 / x86
License	GPLv3

Tap on the phone, play on the TV — mirroring is on its way too.

Key Features

• DLNA media push: hit the cast button in any phone video app; direct mp4 / mkv links and HLS (m3u8) streams both play, including Baidu Netdisk UA adaptation
• Full remote mapping: play, pause, seek and volume all via D-Pad; a foreground service keeps it resident with boot-time autostart
• AirPlay screen mirroring: mirror straight from the iPhone Control Center; video decodes via MediaCodec and audio via an AAC-ELD/LC + ALAC chain, non-DRM content only
• Protocol abstraction: every cast protocol implements a unified CastProtocol interface that forwards PlaybackCommand only, so adding one is a single implementation
• Log-based troubleshooting: adb logcat -s "CastCoordinator:*" pinpoints discovery and playback issues

How to Use

1. Install and open the APK on the TV; a "Kaiji Casting" standby screen appears
2. Put the phone and TV on the same WiFi (router AP isolation blocks discovery)
3. Tap the cast button on a video page and choose the device "凯机投屏"
4. Mirroring: install the airplay build on the TV, open Control Center → Screen Mirroring on the iPhone and pick KBTVCaster; the picture appears in about 10 seconds

Installation

Releases provide two officially signed APKs: app-release.apk is the DLNA stable build (mirroring protocol not registered), and app-release-airplay.apk additionally enables mirroring. Install over network ADB (adb connect <TV_IP>:5555) or sideload from a USB drive. For a slim build add -Pkbtv.build.abi=arm64-v8a to produce a single-architecture package of about 19 MB.

System Requirements

Item	Requirement
OS	Android 6.0 (API 23) and above
Architecture	arm64-v8a / x86_64 / x86
Network	Phone, computer and TV on the same LAN

Notes

• Mirroring is experimental: the protocol is not registered by default and only ships in the airplay build; the audio decode chain is wired but still being tuned on real devices and may be silent
• Non-DRM only: AirPlay mirroring is based on UxPlay and cannot mirror protected content
• Device not found: confirm the same WiFi, AP isolation off, and the app running in the foreground