LONGER_VIDEOS.md

🎬 Longer Video Generation Models

Available Models by Duration

🥇 Longest Videos (10+ seconds)

1. Runway Gen-3 - Up to 10 seconds ⭐

• Model ID: runway
• Replicate: stability-ai/stable-video-diffusion-img2vid-xt
• Duration: Up to 10 seconds
• Quality: Professional, cinematic
• Cost: ~$0.15-0.25 per video
• Best for: Professional content, commercials, high-quality shorts

2. Kling AI - Up to 10 seconds

• Not yet on Replicate (Chinese model)
• Duration: Up to 10 seconds
• Quality: Very high, comparable to Hailuo
• Best for: Realistic scenes, character animations

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🥈 Medium Length (5-7 seconds)

3. Hailuo Video-01 - 6 seconds

• Model ID: hailuo
• Replicate: minimax/video-01
• Duration: 6 seconds
• Quality: Excellent
• Cost: ~$0.05-0.10 per video
• Best for: General purpose, high quality

4. CogVideoX-5B - 6 seconds

• Model ID: cogvideox
• Replicate: lucataco/cogvideox-5b
• Duration: 6 seconds (49 frames at 8fps)
• Quality: High
• Cost: ~$0.05 per video
• Best for: Good balance of quality and cost

5. HunyuanVideo - 5+ seconds

• Model ID: hunyuan
• Replicate: tencent/hunyuan-video
• Duration: 5+ seconds
• Quality: State-of-the-art
• Cost: ~$0.08-0.12 per video
• Best for: High-quality, smooth motion

6. Luma Dream Machine - 5 seconds

• Model ID: luma
• Replicate: fofr/dream-machine
• Duration: 5 seconds
• Quality: Cinematic
• Cost: ~$0.10 per video
• Best for: Cinematic shots, smooth camera movements

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🥉 Shorter Videos (3-4 seconds)

7. Pika Labs - 3 seconds (extendable)

• Can extend videos by generating continuations
• Good for creating longer sequences

8. AnimateDiff - 2-4 seconds

• Fast generation
• Lower cost
• Good for quick tests

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📊 Comparison Table

Model	Duration	Quality	Cost/Video	Speed	Best For
Runway Gen-3	10s	⭐⭐⭐⭐⭐	$0.15-0.25	Slow	Professional
Hailuo	6s	⭐⭐⭐⭐⭐	$0.05-0.10	Medium	General
CogVideoX-5B	6s	⭐⭐⭐⭐	$0.05	Medium	Balanced
HunyuanVideo	5s+	⭐⭐⭐⭐⭐	$0.08-0.12	Medium	High quality
Luma	5s	⭐⭐⭐⭐	$0.10	Medium	Cinematic
Pika	3s	⭐⭐⭐	$0.03	Fast	Quick tests

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🎯 How to Use Longer Video Models

In Your App

The models are now available in your dropdown:

1. Via Web UI:

   • Select "Runway Gen-3 - 10s ⭐" for longest videos
   • Select "Hailuo Video-01 - 6s" for good balance
   • Enter your prompt and generate!

2. Via API:

   curl -X POST https://your-app.vercel.app/api/generate-video \
     -H "Content-Type: application/json" \
     -d '{
       "prompt": "A golden retriever running through flowers",
       "model": "runway"
     }'
   

3. Via Python Backend:

   import requests
   
   response = requests.post('http://localhost:5000/generate-video', json={
       'prompt': 'Ocean waves at sunset',
       'model': 'runway'  # For 10s videos
   })
   
   video_url = response.json()['video_url']
   

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💡 Tips for Longer Videos

1. Be More Specific

Longer videos need more detailed prompts:

❌ Bad: "A dog running"
✅ Good: "A golden retriever running through a field of sunflowers, 
         camera tracking from the side, golden hour lighting, 
         slow motion, cinematic"

2. Use Camera Movements

Longer videos benefit from camera direction:

• "Camera slowly zooms in"
• "Tracking shot following the subject"
• "Pan from left to right"

3. Specify Pacing

• "Slow motion"
• "Time-lapse"
• "Smooth, continuous motion"

4. Consider Cost

• Runway (10s): ~$0.20 per video
• Hailuo (6s): ~$0.08 per video
• Test with shorter/cheaper models first

---

🚀 Future: Even Longer Videos

Coming Soon:

• Sora (OpenAI) - Up to 60 seconds (not yet public)
• Kling 1.5 - Extended duration modes
• Runway Gen-4 - Longer outputs expected

Workarounds for Now:

1. Video Extension: Generate multiple clips and stitch
2. Loop Seamlessly: Create loopable content
3. Multi-shot: Generate scenes separately, edit together

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🔧 Technical Details

Why Are Videos Short?

1. Computational Cost: Each frame requires significant GPU time
2. Memory Requirements: Longer videos = more VRAM needed
3. Quality Trade-off: Maintaining quality over time is hard
4. Training Data: Most training videos are short clips

Frame Rates:

• CogVideoX: 49 frames at 8 fps = 6.1 seconds
• Hailuo: 48 frames at 8 fps = 6 seconds
• Runway: 80 frames at 8 fps = 10 seconds

---

💰 Cost Optimization

For Budget-Conscious Users:

1. Start with CogVideoX ($0.05) or Hailuo ($0.08)
2. Use Runway ($0.20) only for final/important videos
3. Test prompts with shorter models first
4. Batch generate to save on setup costs

For Quality-First:

1. Use Runway for professional work
2. HunyuanVideo for high-quality content
3. Hailuo for general high-quality needs

---

📝 Example Prompts for Longer Videos

10-Second Videos (Runway):

"A surfer riding a massive wave, camera following from behind, 
slow motion, golden hour, spray and mist, cinematic 4k"

"City street time-lapse from day to night, cars and people 
moving fast, lights turning on, smooth transition"

"A bird taking flight from a branch, slow motion, camera 
tracking upward following the bird into the sky"

6-Second Videos (Hailuo/CogVideoX):

"A cat jumping onto a windowsill, looking outside at falling 
snow, soft lighting, cozy atmosphere"

"Fireworks exploding over a city skyline at night, colorful 
bursts, reflection on water below"

"A coffee cup being filled, steam rising, close-up shot, 
morning light through window"

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✅ Updated in Your Project

I've updated:

• ✅ api/generate-video.js - Added all longer video models
• ✅ api/models.js - Listed models with durations
• ✅ backend_replicate.py - Added model support
• ✅ UI will now show duration in model names

Commit and deploy to use the new models!

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For the longest videos (10s), use model: "runway" in your requests! 🎬✨