Update Dockerfile to include FFmpeg 8.0 installation with shared libraries and set LD_LIBRARY_PATH for runtime compatibility.

Dockerfile

@@ -38,13 +38,16 @@ COPY ./src /app/src
 # Create virtual environment and install dependencies (includes CUDA support via pyproject.toml)
 RUN uv sync
 
-# Stage 3: Final image
+# Stage 4: Final image
 FROM python:3.11-slim
 
 WORKDIR /app
 
 RUN apt-get update && apt-get install -y \
     bash \
+    wget \
+    tar \
+    xz-utils \
     && rm -rf /var/lib/apt/lists/*
 
 # Install uv in the final stage
@@ -53,6 +56,19 @@ RUN pip install uv
 # Copy virtual environment from backend-build stage
 COPY --from=backend-build /app/.venv /app/.venv
 
+# Download and install FFmpeg 8.0 with shared libraries into .venv (matching Windows installer approach)
+# Using BtbN FFmpeg builds which provide shared libraries
+RUN cd /tmp && \
+    wget -q https://github.com/BtbN/FFmpeg-Builds/releases/download/latest/ffmpeg-master-latest-linux64-gpl-shared.tar.xz -O ffmpeg.tar.xz && \
+    tar -xf ffmpeg.tar.xz && \
+    cp -a ffmpeg-master-latest-linux64-gpl-shared/bin/* /app/.venv/bin/ && \
+    cp -a ffmpeg-master-latest-linux64-gpl-shared/lib/* /app/.venv/lib/ && \
+    rm -rf ffmpeg-master-latest-linux64-gpl-shared ffmpeg.tar.xz && \
+    /app/.venv/bin/ffmpeg -version | head -n 1
+
+# Set LD_LIBRARY_PATH so torchcodec can find ffmpeg libraries at runtime
+ENV LD_LIBRARY_PATH=/app/.venv/lib:${LD_LIBRARY_PATH}
+
 # Copy Python source code
 COPY --from=backend-build /app/src /app/src