Start and End Frame Video API

Create controlled video transitions with start and end frame inputs.

Start and End Frame Video API

Some video models support frames_to_video with a required start_frame and optional end_frame. Use this workflow when the beginning and final composition both matter.

Good use cases

  • Product transformation clips
  • Before/after interiors
  • Character movement between two poses
  • Controlled brand transitions

Example with Veo 3.1 Fast

curl https://buble.ai/api/v1/generations \
  -H "Authorization: Bearer $BUBLE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "google/veo3.1-fast",
    "mode": "frames_to_video",
    "prompt": "Create an elegant transformation from the first frame to the final frame with smooth cinematic camera movement and realistic lighting continuity",
    "start_frame": "https://example.com/start.png",
    "end_frame": "https://example.com/end.png",
    "duration": "8s",
    "resolution": "720p",
    "aspect_ratio": "16:9"
  }'

Models with start/end frame support

  • google/veo3.1-fast
  • google/veo3.1-quality
  • doubao/seedance-2.0-fast
  • doubao/seedance-2.0
  • doubao/seedance-1.5-pro
  • kling/kling-v3

min_files: 1 means the start frame is enough. Add end_frame only when you need a controlled ending.