diff --git a/api/Dockerfile b/api/Dockerfile
index a56dd9e..e1a7463 100644
--- a/api/Dockerfile
+++ b/api/Dockerfile
@@ -58,15 +58,57 @@ RUN npm ci --omit=dev && npm cache clean --force
 
 # Stage 3: Static ffmpeg binary (avoids apt ffmpeg pulling mesa/libllvm for
 # hardware acceleration we don't use server-side).
+#
+# Resilient download: johnvansickle.com is the primary source but it's a single
+# self-hosted host with no CDN and goes down intermittently. Use bounded-timeout
+# retries, then fall back to a pinned BtbN/FFmpeg-Builds autobuild. Every archive
+# is SHA256-verified before extraction. The two sources have different internal
+# layouts, so locate the binaries with `find` rather than a fixed strip path.
 FROM debian:trixie-slim AS ffmpeg-static
 ARG TARGETARCH
 RUN apt-get update && apt-get install -y --no-install-recommends \
         curl ca-certificates xz-utils \
-    && curl -fsSL -o /tmp/ffmpeg.tar.xz "https://johnvansickle.com/ffmpeg/releases/ffmpeg-release-${TARGETARCH}-static.tar.xz" \
+    && rm -rf /var/lib/apt/lists/* \
+    && case "${TARGETARCH}" in \
+         amd64) \
+           primary_url="https://johnvansickle.com/ffmpeg/releases/ffmpeg-release-amd64-static.tar.xz" ; \
+           primary_sha256="abda8d77ce8309141f83ab8edf0596834087c52467f6badf376a6a2a4c87cf67" ; \
+           fallback_url="https://github.com/BtbN/FFmpeg-Builds/releases/download/autobuild-2026-05-30-13-19/ffmpeg-N-124681-gb8c5376eb4-linux64-gpl.tar.xz" ; \
+           fallback_sha256="6cfd689ee95ff128e89080af10c93f16e48760eb2acc124c5c8258dc922cc13b" ; \
+           ;; \
+         arm64) \
+           primary_url="https://johnvansickle.com/ffmpeg/releases/ffmpeg-release-arm64-static.tar.xz" ; \
+           primary_sha256="f4149bb2b0784e30e99bdda85471c9b5930d3402014e934a5098b41d0f7201b1" ; \
+           fallback_url="https://github.com/BtbN/FFmpeg-Builds/releases/download/autobuild-2026-05-30-13-19/ffmpeg-N-124681-gb8c5376eb4-linuxarm64-gpl.tar.xz" ; \
+           fallback_sha256="b90a31f1d0b030f5d8a3d11cfec736e369bd5a1371b19bf65421a07f72b1d547" ; \
+           ;; \
+         *) echo "unsupported TARGETARCH: ${TARGETARCH}" >&2; exit 1 ;; \
+       esac \
     && mkdir -p /tmp/ffmpeg \
-    && tar -xJf /tmp/ffmpeg.tar.xz -C /tmp/ffmpeg --strip-components=1 \
-    && mv /tmp/ffmpeg/ffmpeg /tmp/ffmpeg/ffprobe /usr/local/bin/ \
-    && chmod +x /usr/local/bin/ffmpeg /usr/local/bin/ffprobe
+    && ok= \
+    && for source in \
+         "primary ${primary_sha256} ${primary_url}" \
+         "fallback ${fallback_sha256} ${fallback_url}" ; do \
+         source_name="${source%% *}" ; \
+         source_data="${source#* }" ; \
+         sha256="${source_data%% *}" ; \
+         url="${source_data#* }" ; \
+         echo "Downloading ffmpeg (${source_name}) from ${url}" ; \
+         if curl -fsSL --connect-timeout 20 --max-time 300 \
+                 --retry 3 --retry-delay 5 --retry-all-errors \
+                 -o /tmp/ffmpeg.tar.xz "${url}" \
+             && echo "${sha256}  /tmp/ffmpeg.tar.xz" | sha256sum -c - ; then ok=1 ; break ; fi ; \
+         rm -f /tmp/ffmpeg.tar.xz ; \
+         echo "ffmpeg source failed, trying next: ${url}" >&2 ; \
+       done \
+    && [ -n "${ok}" ] || { echo "all ffmpeg download sources failed" >&2 ; exit 1 ; } \
+    && tar -xJf /tmp/ffmpeg.tar.xz -C /tmp/ffmpeg \
+    && ffmpeg_bin="$(find /tmp/ffmpeg -type f -name ffmpeg | head -n1)" \
+    && ffprobe_bin="$(find /tmp/ffmpeg -type f -name ffprobe | head -n1)" \
+    && [ -n "${ffmpeg_bin}" ] && [ -n "${ffprobe_bin}" ] \
+    && mv "${ffmpeg_bin}" "${ffprobe_bin}" /usr/local/bin/ \
+    && chmod +x /usr/local/bin/ffmpeg /usr/local/bin/ffprobe \
+    && rm -rf /tmp/ffmpeg /tmp/ffmpeg.tar.xz
 
 # Stage 4: Runtime - Minimal image with only runtime dependencies
 FROM python:3.13-slim AS runner