ppt-to-video

name	ppt-to-video
description	Convert PPT to video with AI voiceover and synced animations. Invoke when user asks to convert PPT/PPTX to video, create narrated video from slides, or add voiceover to presentation.

PPT to Video Converter

Convert PowerPoint presentations to narrated videos with AI-generated voiceover, preserving all slide animations and styles.

How It Works

1. Analyze PPT - Extract slide count, text content, and animation metadata
2. Generate TTS - Create AI voiceover for each slide using edge-tts (zh-CN-XiaoxiaoNeural)
3. Fix Animations - Modify PPTX XML to auto-play all animations (avoid click-trigger issues)
4. Record Slideshow - Launch WPS COM slideshow, capture screen at native resolution
5. Encode Video - FFmpeg encodes frames to 1920x1080 H.264
6. Merge Audio - Concatenate per-slide audio, merge with video
7. Output - Final MP4 video file (optional ZIP packaging)

Requirements

• Windows with WPS Office installed (WPS COM: KWpp.Application)
• Python 3.8+ with: edge-tts, mss, Pillow, lxml, pywin32
• FFmpeg + ffprobe (chocolatey: choco install ffmpeg)
• Screen resolution: 1920x1080 recommended

Usage

Basic Usage

User: 帮我把PPT转成视频，要有配音
User: Convert my PPT to video with voiceover

The skill will automatically:

1. Read the uploaded PPT file
2. Generate TTS audio for each slide
3. Record the PPT slideshow with animations
4. Output a synced MP4 video

Advanced Options

• Duration: Control per-slide timing by adjusting TTS text length
• Voice: Default zh-CN-XiaoxiaoNeural (female), can use zh-CN-YunxiNeural (male)
• Rate: Default +10%, adjust for faster/slower speech
• Subtitles: Optional, set ENABLE_SUBTITLES=true in script
• Resolution: Default 1920x1080, adjustable via TARGET_WIDTH/TARGET_HEIGHT

Technical Details

Key Design Decisions

1. WPS COM over PowerPoint COM: WPS KWpp.Application is more reliable in sandboxed environments. PowerPoint COM may fail due to license/activation issues.

2. Animation Auto-Play Fix: The critical step that prevents "PPT plays too fast" issue. We modify the PPTX XML to change delay="indefinite" to delay="0", making all click-triggered animations play automatically. This avoids the problem where extra clicks/spacebar presses accidentally advance slides.

3. Screen Capture: Use mss library for high-performance screen capture. Typical capture rate: 11-15 fps on 1920x1080. The video is encoded at the calculated fps to maintain perfect sync.

4. Audio Sync: Per-slide TTS audio is generated first. Slide durations are set to match audio durations exactly. The video is encoded with calc_fps = total_frames / total_duration to ensure frame count matches audio length.

5. Binary Copy: Due to potential filesystem permission issues, final video is binary-copied (read bytes, write bytes) rather than using file copy utilities.

Scripts

Script	Purpose
scripts/ppt_to_video.py	Main pipeline script - runs the full conversion
scripts/fix_ppt_animations.py	Standalone PPTX animation fixer

Output Paths

• Temporary files: c:\Users\Admin\.trae-cn\work\<session_id>\ppt_video\
  • audio/ - Per-slide MP3 files
  • frames/ - Captured JPEG frames
  • video.avi - OpenCV encoded video (if FFmpeg fails)
  • merged.mp3 - Concatenated audio
• Final output: d:\trae\wendang\ppt-video-final.mp4
• ZIP package: d:\trae\wendang\ppt-video-final.zip

Troubleshooting

Problem	Solution
PPT plays too fast	Ensure animation fix is applied (fix_ppt_animations.py)
WPS COM not found	Install WPS Office, verify KWpp.Application in registry
FFmpeg can't write files	Use OpenCV encoding fallback or pipe mode
Audio out of sync	Verify calc_fps = valid_frames / total_audio_duration
Empty video file	Binary-copy from C: to D: instead of direct write
Low fps	Close other apps, reduce monitor resolution to 1920x1080

Workflow Example

# 1. User uploads presentation.pptx
# 2. Skill reads PPT, extracts text
# 3. Generate TTS (12 slides → 12 MP3 files, ~2.5 min total)
# 4. Fix animations (XML: indefinite → 0)
# 5. Launch WPS slideshow, record 145s
# 6. Encode: 1888 frames @ 12.96fps → 1920x1080 H.264
# 7. Merge audio + video → final.mp4
# 8. Output: 4.47MB ZIP

Limitations

• Windows only (requires WPS COM)
• Screen capture fps depends on hardware (typically 11-15fps)
• TTS uses edge-tts (requires internet connection)
• No support for embedded video/audio in PPT slides
• Animations are auto-played (individual click timing is not preserved)