Implement MediaCodec decoder pipeline and GPU encoder backend detection

[Copilot]

Wires up the two critical TODO stubs blocking the video streaming pipeline: Android-side MediaCodec decoding and PC-side hardware encoder detection.

Android MediaCodec decoder (DecoderController.kt)

• Full MediaCodec lifecycle: init on configure/surface-set, feed frames to input buffers, drain decoded output to Surface, release on teardown
• Thread-safe via synchronized; handles CodecException with auto-reinit on non-recoverable errors
• Fixed H.266/VVC MIME mapping (was silently aliased to H.264)

// Before: frames were silently dropped
fun onFrame(data: ByteArray) {
    if (data.isEmpty()) return
    // TODO: feed MediaCodec once decoder pipeline is wired.
}

// After: full decode + render pipeline
fun onFrame(data: ByteArray) {
    if (data.isEmpty()) return
    synchronized(lock) { feedDecoder(data) }
}

PC GPU encoder detection (encoder.rs)

• Replaced hardcoded backend list with real DXGI adapter enumeration (vendor IDs: NVIDIA→NVENC, AMD→AMF, Intel→QSV)
• Added MFTEnumEx probe for Media Foundation H.264 encoder availability
• Added codec_priority() and discover_capabilities() for spec-compliant codec selection (H.265→AV1→H.264→VP9)

Android codec capability discovery (CodecCapabilities.kt)

• Refactored to data-driven MIME→mask mapping; added EVC/LCEVC decoder probing

Tests

• 9 Kotlin unit tests for MIME mapping and decoder status
• 7 Rust tests for backend detection, priority ordering, and capability discovery

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• dl.google.com
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java /usr/lib/jvm/temurin-17-jdk-amd64/bin/java --add-opens=java.base/java.lang=ALL-UNNAMED --add-opens=java.base/java.lang.invoke=ALL-UNNAMED --add-opens=java.base/java.util=ALL-UNNAMED --add-opens=java.prefs/java.util.prefs=ALL-UNNAMED --add-exports=jdk.compiler/com.sun.tools.javac.api=ALL-UNNAMED --add-exports=jdk.compiler/com.sun.tools.javac.util=ALL-UNNAMED --add-opens=java.base/java.util=ALL-UNNAMED --add-opens=java.prefs/java.util.prefs=ALL-UNNAMED --add-opens=java.base/java.nio.charset=ALL-UNNAMED --add-opens=java.base/java.net=ALL-UNNAMED --add-opens=java.base/java.util.concurrent=ALL-UNNAMED --add-opens=java.base/java.util.concurrent.atomic=ALL-UNNAMED --add-opens=java.xml/javax.xml.namespace=ALL-UNNAMED --add-opens=java.base/java.time=ALL-UNNAMED -XX:MaxMetaspaceSize=384m -XX:+HeapDumpOnOutOfMemoryError -Xms256m -Xmx512m -Dfile.encoding=UTF-8 (dns block)
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java /usr/lib/jvm/temurin-17-jdk-amd64/bin/java --add-opens=java.base/java.util=ALL-UNNAMED --add-opens=java.base/java.lang=ALL-UNNAMED --add-opens=java.base/java.lang.invoke=ALL-UNNAMED --add-opens=java.prefs/java.util.prefs=ALL-UNNAMED --add-opens=java.base/java.nio.charset=ALL-UNNAMED --add-opens=java.base/java.net=ALL-UNNAMED --add-opens=java.base/java.util.concurrent.atomic=ALL-UNNAMED -XX:MaxMetaspaceSize=384m -XX:+HeapDumpOnOutOfMemoryError -Xms256m -Xmx512m -Dfile.encoding=UTF-8 -Duser.country -Duser.language=en -Duser.variant -cp /home/REDACTED/.gradle/wrapper/dists/gradle-8.2.1-bin/5hap6b9n41hkg4jeh2au2pllh/gradle-8.2.1/lib/gradle-launcher-8.2.1.jar -javaagent:/home/REDACTED/.gradle/wrapper/dists/gradle-8.2.1-bin/5hap6b9n41hkg4jeh2au2pllh/gradle-8.2.1/lib/agents/gradle-instrumentation-agent-8.2.1.jar org.gradle.launcher.daemon.bootstrap.GradleDaemon (dns block)
  • Triggering command: /usr/bin/curl curl -s -o /dev/null -w %{http_code} REDACTED de/node/bin/grep (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

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