feat: add TTS narration + single combined promo video

Author: srpatcha

.github/workflows/video-build.yml

@@ -28,45 +28,47 @@ jobs:
         with:
           python-version: '3.11'
 
-      - name: Install Manim & dependencies
+      - name: Install Manim, gTTS & dependencies
         run: |
           sudo apt-get update
           sudo apt-get install -y ffmpeg libcairo2-dev libpango1.0-dev
-          pip install manim==0.18.1
+          pip install manim==0.18.1 gTTS
 
-      - name: Render promo video (1080p)
+      - name: Generate narration audio
         run: |
           cd promo
-          manim render -qh --format mp4 promo_scene.py ProductPromo
-          echo "Video rendered"
+          python generate_audio.py
+          ls -lh narration.mp3
 
-      - name: Render social media variants
+      - name: Render promo video (1080p)
         run: |
           cd promo
-          # Square (1080x1080) for Instagram/LinkedIn
-          manim render -qh --format mp4 \
-            --resolution 1080,1080 \
-            promo_scene.py ProductPromo \
-            -o eIPC_square.mp4 || true
-          echo "Social variants rendered"
+          manim render -qh --format mp4 promo_scene.py ProductPromo
 
-      - name: List outputs
+      - name: Merge video + audio into final MP4
         run: |
-          echo "=== Generated Videos ==="
-          find promo/media -name "*.mp4" -exec ls -lh {} \;
+          cd promo
+          VIDEO=$(find media/videos -name "ProductPromo.mp4" | head -1)
+          ffmpeg -y -i "$VIDEO" -i narration.mp3 \
+            -c:v copy -c:a aac -b:a 192k \
+            -map 0:v:0 -map 1:a:0 \
+            -shortest \
+            eIPC_v1.0_promo.mp4
+          echo "Final video:"
+          ls -lh eIPC_v1.0_promo.mp4
 
-      - name: Upload video artifacts
+      - name: Upload final video
         uses: actions/upload-artifact@v4
         with:
-          name: promo-videos
-          path: promo/media/videos/**/*.mp4
+          name: eIPC-promo-video
+          path: promo/eIPC_v1.0_promo.mp4
           retention-days: 90
 
       - name: Attach to release
         if: github.event_name == 'release'
         uses: softprops/action-gh-release@v2
         with:
-          files: promo/media/videos/**/*.mp4
+          files: promo/eIPC_v1.0_promo.mp4
           tag_name: ${{ github.event.release.tag_name }}
           fail_on_unmatched_files: false
         env:
@@ -81,9 +83,8 @@ jobs:
       - name: Report
         run: |
           echo "## Promo Video Build" >> $GITHUB_STEP_SUMMARY
-          echo "" >> $GITHUB_STEP_SUMMARY
           echo "| Detail | Value |" >> $GITHUB_STEP_SUMMARY
           echo "|--------|-------|" >> $GITHUB_STEP_SUMMARY
           echo "| Product | eIPC |" >> $GITHUB_STEP_SUMMARY
+          echo "| Audio | gTTS narration |" >> $GITHUB_STEP_SUMMARY
           echo "| Render | ${{ needs.render-video.result }} |" >> $GITHUB_STEP_SUMMARY
-          echo "| Trigger | ${{ github.event_name }} |" >> $GITHUB_STEP_SUMMARY

promo/generate_audio.py

@@ -0,0 +1,10 @@
+"""Generate narration audio using Google Text-to-Speech."""
+from gtts import gTTS
+
+NARRATION = (
+    "Introducing eIPC. Embedded inter-process communication done right. Feature one: Shared memory channels deliver microsecond latency between processes. Feature two: Zero-copy message passing eliminates data duplication overhead. Feature three: Cross-platform portability runs on Linux, RTOS, and bare metal. eIPC. Open source and lightning fast. Visit github dot com slash embeddedos-org slash eIPC."
+)
+
+tts = gTTS(text=NARRATION, lang="en", slow=False)
+tts.save("narration.mp3")
+print(f"Generated narration.mp3 ({len(NARRATION)} chars)")