Add Docker setup, .env.example, updated .gitignore/CHANGELOG and ADRs 004-007 + arc42 template

backend/playout/Dockerfile

@@ -0,0 +1,25 @@
+FROM alpine:3.20
+
+# Install FFmpeg, curl for health checks, and basic tools
+RUN apk add --no-cache \
+    ffmpeg \
+    curl \
+    bash
+
+WORKDIR /app
+
+# Copy playout scripts and configuration
+COPY src/ /app/src/
+COPY config/ /app/config/
+COPY *.sh /app/
+
+RUN chmod +x /app/*.sh
+
+# Create directories for playlist and HLS output
+RUN mkdir -p /app/playlist /app/hls
+
+# Expose HLS directory (will be served by nginx)
+VOLUME ["/app/hls"]
+
+# Default command runs the playout loop
+CMD ["./start-playout.sh"]

backend/playout/start-playout.sh

@@ -0,0 +1,31 @@
+#!/bin/bash
+set -e
+
+echo "=== Linear Void Playout Service Starting ==="
+echo "Playlist path: $PLAYLIST_PATH"
+echo "HLS segment duration: ${HLS_SEGMENT_DURATION:-6}s"
+
+# Ensure playlist exists or create a demo one
+if [ ! -f "$PLAYLIST_PATH" ]; then
+  echo "Warning: Playlist not found at $PLAYLIST_PATH. Creating demo playlist."
+  cat > "$PLAYLIST_PATH" << EOF
+file '/app/media/demo1.mp4'
+file '/app/media/demo2.mp4'
+EOF
+fi
+
+# Run FFmpeg in a loop for continuous playback
+while true; do
+  echo "[$(date)] Starting FFmpeg playout..."
+  ffmpeg -re -f concat -safe 0 -i "$PLAYLIST_PATH" \
+    -c:v copy -c:a copy \
+    -f hls \
+    -hls_time ${HLS_SEGMENT_DURATION:-6} \
+    -hls_list_size ${HLS_WINDOW_SIZE:-24} \
+    -hls_flags delete_segments+append_list \
+    -hls_segment_filename "/app/hls/segment_%03d.ts" \
+    "/app/hls/playlist.m3u8" || echo "FFmpeg exited with error. Restarting in 5s..."
+
+  echo "Playout loop crashed or ended. Restarting in 5 seconds..."
+  sleep 5
+done