diff --git a/.github/actions/install-ffmpeg-windows/action.yml b/.github/actions/install-ffmpeg-windows/action.yml
index 43dea7b92..9b55cc7dd 100644
--- a/.github/actions/install-ffmpeg-windows/action.yml
+++ b/.github/actions/install-ffmpeg-windows/action.yml
@@ -19,7 +19,7 @@ inputs:
   max-attempts:
     description: Max download attempts before failing.
     required: false
-    default: "3"
+    default: "8"
 
 runs:
   using: composite
@@ -44,7 +44,7 @@ runs:
           } catch {
             Write-Warning "Download failed: $($_.Exception.Message)"
             if ($attempt -eq $maxAttempts) { throw }
-            Start-Sleep -Seconds (10 * $attempt)
+            Start-Sleep -Seconds (30 * $attempt)
           }
         }
 
diff --git a/.github/actions/prepare-ffmpeg-bin/action.yml b/.github/actions/prepare-ffmpeg-bin/action.yml
new file mode 100644
index 000000000..de6540798
--- /dev/null
+++ b/.github/actions/prepare-ffmpeg-bin/action.yml
@@ -0,0 +1,28 @@
+name: Prepare FFMPEG_BIN for bun install
+description: >-
+  Copies the system ffmpeg binary to a writable temp location and sets
+  FFMPEG_BIN in the environment. ffmpeg-static's postinstall script checks
+  whether a file already exists at FFMPEG_BIN; if it does and process.exit(0)
+  is respected by the runtime, the CDN download is skipped entirely. If the
+  runtime intercepts process.exit(0) and the download proceeds anyway, using
+  a writable target prevents the EACCES failure that occurs when the
+  destination is a system path like /usr/bin/ffmpeg.
+
+runs:
+  using: composite
+  steps:
+    - name: Copy ffmpeg to writable path
+      shell: bash
+      run: |
+        FFMPEG=$(which ffmpeg 2>/dev/null || echo "")
+        if [ -n "$FFMPEG" ]; then
+          cp "$FFMPEG" "$RUNNER_TEMP/hf-ffmpeg"
+        else
+          # ffmpeg not pre-installed; write a stub so ffmpeg-static's postinstall
+          # finds a file at FFMPEG_BIN and exits early (statSync check) without
+          # attempting the CDN download. Jobs that need a real ffmpeg binary
+          # install it via apt before calling this action.
+          printf '#!/bin/sh\nexec ffmpeg "$@"\n' > "$RUNNER_TEMP/hf-ffmpeg"
+        fi
+        chmod +x "$RUNNER_TEMP/hf-ffmpeg"
+        echo "FFMPEG_BIN=$RUNNER_TEMP/hf-ffmpeg" >> "$GITHUB_ENV"
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 4f40a28af..92993fde1 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -67,6 +67,7 @@ jobs:
       - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
         with:
           node-version: 22
+      - uses: ./.github/actions/prepare-ffmpeg-bin
       - run: bun install --frozen-lockfile
       - run: bun run build
 
@@ -84,6 +85,7 @@ jobs:
       - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
         with:
           node-version: 22
+      - uses: ./.github/actions/prepare-ffmpeg-bin
       - run: bun install --frozen-lockfile
       - run: bun run lint
 
@@ -117,6 +119,7 @@ jobs:
       - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
         with:
           node-version: 22
+      - uses: ./.github/actions/prepare-ffmpeg-bin
       - run: bun install --frozen-lockfile
       - name: Run fallow audit
         id: audit
@@ -172,6 +175,7 @@ jobs:
       - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
         with:
           node-version: 22
+      - uses: ./.github/actions/prepare-ffmpeg-bin
       - run: bun install --frozen-lockfile
       - run: bun run format:check
 
@@ -189,6 +193,7 @@ jobs:
       - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
         with:
           node-version: 22
+      - uses: ./.github/actions/prepare-ffmpeg-bin
       - run: bun install --frozen-lockfile
       - run: bun run build
       - run: bun run --filter '*' typecheck
@@ -207,6 +212,7 @@ jobs:
       - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
         with:
           node-version: 22
+      - uses: ./.github/actions/prepare-ffmpeg-bin
       - run: bun install --frozen-lockfile
       - run: bun run test:scripts
       - run: bun run --cwd packages/core build:hyperframes-runtime
@@ -226,6 +232,7 @@ jobs:
       - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
         with:
           node-version: 22
+      - uses: ./.github/actions/prepare-ffmpeg-bin
       - run: bun install --frozen-lockfile
       - run: bun run --filter @hyperframes/core test:hyperframe-runtime-ci
 
@@ -243,6 +250,7 @@ jobs:
       - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
         with:
           node-version: 22
+      - uses: ./.github/actions/prepare-ffmpeg-bin
       - run: bun install --frozen-lockfile
       - run: bun run --cwd packages/core build:hyperframes-runtime
       - name: Start studio and check for runtime errors
@@ -308,6 +316,7 @@ jobs:
       - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
         with:
           node-version: 22
+      - uses: ./.github/actions/prepare-ffmpeg-bin
       - run: bun install --frozen-lockfile
       - run: bun run build
 
@@ -383,6 +392,7 @@ jobs:
         run: |
           sudo apt-get update
           sudo apt-get install -y ffmpeg
+      - uses: ./.github/actions/prepare-ffmpeg-bin
       - name: Install dependencies
         run: bun install --frozen-lockfile
       - name: Build monorepo
diff --git a/.github/workflows/windows-render.yml b/.github/workflows/windows-render.yml
index e040e2503..e8d9f5b63 100644
--- a/.github/workflows/windows-render.yml
+++ b/.github/workflows/windows-render.yml
@@ -108,6 +108,12 @@ jobs:
       - name: Install FFmpeg
         uses: ./.github/actions/install-ffmpeg-windows
 
+      - name: Set FFMPEG_BIN for bun install
+        shell: pwsh
+        run: |
+          $path = (Get-Command ffmpeg.exe).Source
+          "FFMPEG_BIN=$path" | Out-File -FilePath $env:GITHUB_ENV -Encoding utf8 -Append
+
       # -----------------------------------------------------------------
       # Verify FFmpeg feature inventory.
       #
@@ -394,6 +400,12 @@ jobs:
       - name: Install FFmpeg
         uses: ./.github/actions/install-ffmpeg-windows
 
+      - name: Set FFMPEG_BIN for bun install
+        shell: pwsh
+        run: |
+          $path = (Get-Command ffmpeg.exe).Source
+          "FFMPEG_BIN=$path" | Out-File -FilePath $env:GITHUB_ENV -Encoding utf8 -Append
+
       - name: Install Bun
         uses: oven-sh/setup-bun@0c5077e51419868618aeaa5fe8019c62421857d6 # v2