lightricks/ltx-2-19b/extend-video

Name: LTX-2 19B
Author: Lightricks

Ltx 2 19b Extend Video by Lightricks - AI-powered video editing and transformation. Apply style transfer, motion control, lip-sync, and visual effects to existing videos with natural language instructions.

Input

Prompt(string)

The prompt to generate the video from.

Image URL or upload(string)

Upload

PNG, JPEG, WebP, or GIF · 20 MiB maximum

The URL of the image to use as the end of the extended video.

Video URL(string)

The URL of the video to extend.

Generate Audio(boolean)

Whether to generate audio for the video.

Guidance Scale(number)

110

The guidance scale to use. Range: 1 to 10.

Number of Inference Steps(integer)

850

The number of inference steps to use. Range: 8 to 50.

Seed(integer)

The seed for the random number generator.

FPS(number)

160

The frames per second of the generated video. Range: 1 to 60.

Video Quality(string)

The quality of the generated video. Allowed values: low, medium, high, maximum.

Number of Context Frames(integer)

0121

The number of frames to use as context for the extension. Range: 0 to 121.

Number of Frames(integer)

9481

The number of frames to generate. Range: 9 to 481.

End Image Strength(number)

The strength of the end image to use for the video generation. Range: 0 to 1.

Extend Direction(string)

Direction to extend the video. 'forward' extends from the end of the video, 'backward' extends from the beginning. Allowed values: forward, backward.

Camera LoRA Scale(number)

The scale of the camera LoRA to use. This allows you to control the camera movement of the generated video more accurately than just prompting the model to move the camera. Range: 0 to 1.

Use Multi-Scale(boolean)

Whether to use multi-scale generation. If True, the model will generate the video at a smaller scale first, then use the smaller video to guide the generation of a video at or above your requested size. This results in better coherence and details.

Camera LoRA(string)

The camera LoRA to use. This allows you to control the camera movement of the generated video more accurately than just prompting the model to move the camera. Allowed values: dolly_in, dolly_out, dolly_left, dolly_right, jib_up, jib_down, static, none.

Video Strength(number)

Video conditioning strength. Lower values represent more freedom given to the model to change the video content. Range: 0 to 1.

Video Output Type(string)

The output type of the generated video. Allowed values: X264 (.mp4), VP9 (.webm), PRORES4444 (.mov), GIF (.gif).

Match Input FPS(boolean)

When true, match the output FPS to the input video's FPS instead of using the default target FPS.

Video Write Mode(string)

The write mode of the generated video. Allowed values: fast, balanced, small.

Video Size(string)

The size of the generated video. Allowed values: auto, square_hd, square, portrait_4_3, portrait_16_9, landscape_4_3, landscape_16_9.

Audio Strength(number)

Audio conditioning strength. Lower values represent more freedom given to the model to change the audio content. Range: 0 to 1.

Idle

Example output — click Run to generate your own

Production endpoint

Send your first request

OpenAI-compatible endpoint with unified authentication and usage tracking.

POSThttps://api.sandbase.ai/v1/run

Model IDlightricks/ltx-2-19b/extend-video

Input Schema

22 parameters · 1 required · 21 optional

Parameter	Type	Required	Description
`prompt`	string	Required	The prompt to generate the video from.
`fps`	number	Optional	The frames per second of the generated video. · Min: 1 · Max: 60 · Default: 25
`seed`	integer	Optional	The seed for the random number generator.
`video`	string	Optional	The URL of the video to extend.
`end_image`	string	Optional	The URL of the image to use as the end of the extended video.
`num_frames`	integer	Optional	The number of frames to generate. · Min: 9 · Max: 481 · Default: 121
`video_size`	string	Optional	The size of the generated video. · Options: auto, square_hd, square, portrait_4_3, portrait_16_9, landscape_4_3, landscape_16_9 · Default: "auto" autosquare_hdsquareportrait_4_3portrait_16_9landscape_4_3landscape_16_9
`camera_lora`	string	Optional	The camera LoRA to use. This allows you to control the camera movement of the generated video more accurately than just prompting the model to move the camera. · Options: dolly_in, dolly_out, dolly_left, dolly_right, jib_up, jib_down, static, none · Default: "none" dolly_indolly_outdolly_leftdolly_rightjib_upjib_downstaticnone
`video_quality`	string	Optional	The quality of the generated video. · Options: low, medium, high, maximum · Default: "high" lowmediumhighmaximum
`audio_strength`	number	Optional	Audio conditioning strength. Lower values represent more freedom given to the model to change the audio content. · Min: 0 · Max: 1 · Default: 1
`generate_audio`	boolean	Optional	Whether to generate audio for the video. · Default: true
`guidance_scale`	number	Optional	The guidance scale to use. · Min: 1 · Max: 10 · Default: 3
`use_multiscale`	boolean	Optional	Whether to use multi-scale generation. If True, the model will generate the video at a smaller scale first, then use the smaller video to guide the generation of a video at or above your requested size. This results in better coherence and details. · Default: true
`video_strength`	number	Optional	Video conditioning strength. Lower values represent more freedom given to the model to change the video content. · Min: 0 · Max: 1 · Default: 1
`match_input_fps`	boolean	Optional	When true, match the output FPS to the input video's FPS instead of using the default target FPS. · Default: true
`extend_direction`	string	Optional	Direction to extend the video. 'forward' extends from the end of the video, 'backward' extends from the beginning. · Options: forward, backward · Default: "forward" forwardbackward
`video_write_mode`	string	Optional	The write mode of the generated video. · Options: fast, balanced, small · Default: "balanced" fastbalancedsmall
`camera_lora_scale`	number	Optional	The scale of the camera LoRA to use. This allows you to control the camera movement of the generated video more accurately than just prompting the model to move the camera. · Min: 0 · Max: 1 · Default: 1
`video_output_type`	string	Optional	The output type of the generated video. · Options: X264 (.mp4), VP9 (.webm), PRORES4444 (.mov), GIF (.gif) · Default: "X264 (.mp4)" X264 (.mp4)VP9 (.webm)PRORES4444 (.mov)GIF (.gif)
`end_image_strength`	number	Optional	The strength of the end image to use for the video generation. · Min: 0 · Max: 1 · Default: 1
`num_context_frames`	integer	Optional	The number of frames to use as context for the extension. · Min: 0 · Max: 121 · Default: 25
`num_inference_steps`	integer	Optional	The number of inference steps to use. · Min: 8 · Max: 50 · Default: 40

Output Schema

Field	Type	Description
`id`	string	Unique identifier for the generation task
`status`	string	Task status: pending, running, completed, failed, timeout
`model`	string	Model used for the generation
`outputs`	array	Array of output items
`outputs[].url`	string	URL of the generated artifact
`outputs[].content_type`	string	MIME type (e.g. image/png, video/mp4)
`error`	object \| null	Error details if failed, null on success
`error.type`	string	Machine-readable error type code
`error.message`	string	Human-readable error description

Async Workflow

This model uses asynchronous execution. Submit a request and poll for the result.

Submit — POST to /v1/run, receive an id
Poll — GET /v1/run/{id} until status is completed, failed, or timeout
Retrieve — Read outputs from the completed response

Code Examples

Ready-to-run snippets

# Step 1: Submit
curl -X POST https://api.sandbase.ai/v1/run \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
  "model": "lightricks/ltx-2-19b/extend-video",
  "fps": 25,
  "video": "https://static.sandbase.ai/examples/lightricks/ltx-2-19b/extend-video/input_video_0.mp4",
  "prompt": "Continue the scene naturally, maintaining the same style and motion.",
  "num_frames": 121,
  "video_size": "auto",
  "camera_lora": "none",
  "video_quality": "high",
  "audio_strength": 1,
  "generate_audio": true,
  "guidance_scale": 3,
  "use_multiscale": true,
  "video_strength": 1,
  "match_input_fps": true,
  "extend_direction": "forward",
  "video_write_mode": "balanced",
  "camera_lora_scale": 1,
  "video_output_type": "X264 (.mp4)",
  "end_image_strength": 1,
  "num_context_frames": 25,
  "num_inference_steps": 40
}'

# Step 2: Poll result (replace <id>)
curl https://api.sandbase.ai/v1/run/<id> \
  -H "Authorization: Bearer YOUR_API_KEY"

← Back to LTX-2 19B

API README

LTX-2 19B

LTX-2 19B is a video continuation endpoint in the LTX 2 19B family. It is built for creators who need to turn a concrete creative brief into a controlled visual sequence: the request establishes the source material, the intended subject behavior, the camera language, and the atmosphere of the finished shot. The standard route keeps that workflow explicit instead of hiding its input assumptions behind a generic video-generation label.

In practice, this route accepts video, end image as creative context and exposes num frames, video size, generate audio, video strength, camera lora for delivery planning. That makes it suitable for shot-based pipelines where teams must preserve a source, direct a transformation, or control the final format without losing sight of the model's central task. Write prompts as a compact shot plan—subject, action, setting, camera, light, and timing—then use the structured fields for constraints that should remain deterministic across iterations.

Highlights

Continuation beyond the cut. The video input supplies the existing timeline and the prompt directs what happens after its current endpoint.
Controlled transition target. end_image can anchor the final composition of the newly extended segment.
Continuity-versus-change balance. video_strength tunes how strongly the extension follows the incoming visuals.
LTX 2 19B audio carried into the extension. audio_strength and generate_audio coordinate soundtrack continuity where documented. This behavior is exposed on the named 19B route. For lightricks/ltx-2-19b/extend-video, this task-specific control is documented alongside the route’s own required inputs.

Pricing

Billing unit	Price
Base request	`$0.001800`

When to Use

Scenario	Recommendation
Choose this route	Use it when the deliverable specifically calls for video continuation, rather than a neighboring generation mode.
Prepare the source	Provide video in the format described by the request schema.
Direct the shot	Describe the subject, action, environment, camera movement, lighting, and temporal progression in that order.
Control continuity	Use endpoint frames, reference media, strength, or audio controls when those fields are available instead of burying hard constraints in prose.
Plan delivery	Set duration, frame count, resolution, and aspect ratio explicitly when the schema exposes them, then compare iterations with a stable seed where supported.

Prompt Guide

For video continuation, describe one coherent shot rather than a list of visual keywords. Put the main subject and action first, follow with location and staging, then add camera movement, lens or framing, lighting, mood, and any timed change. Keep URLs and hard delivery choices in their dedicated fields.

{
  "prompt": "Continue the scene naturally, maintaining the same style and motion.",
  "generate_audio": true,
  "video": "https://static.sandbase.ai/examples/lightricks/ltx-2-19b/extend-video/input_video_0.mp4",
  "end_image": "https://example.com/reference.jpg"
}

Technical Specs

Specification	Value
Model ID	`lightricks/ltx-2-19b/extend-video`
Required inputs	`prompt`
Execution	Asynchronous generation job
Request controls	22 documented fields
Output	`url`, `content_type`

Request fields

Field	Type and constraints
`fps`	number; Optional; Range: 1–60; Default: 25
`seed`	integer; Optional
`video`	string; Optional
`prompt`	string; Required
`end_image`	string; Optional
`num_frames`	integer; Optional; Range: 9–481; Default: 121
`video_size`	string; Optional; Options: auto, square_hd, square, portrait_4_3, portrait_16_9, landscape_4_3, landscape_16_9; Default: "auto"
`camera_lora`	string; Optional; Options: dolly_in, dolly_out, dolly_left, dolly_right, jib_up, jib_down, static, none; Default: "none"
`video_quality`	string; Optional; Options: low, medium, high, maximum; Default: "high"
`audio_strength`	number; Optional; Range: 0–1; Default: 1
`generate_audio`	boolean; Optional; Default: true
`guidance_scale`	number; Optional; Range: 1–10; Default: 3
`use_multiscale`	boolean; Optional; Default: true
`video_strength`	number; Optional; Range: 0–1; Default: 1
`match_input_fps`	boolean; Optional; Default: true
`extend_direction`	string; Optional; Options: forward, backward; Default: "forward"
`video_write_mode`	string; Optional; Options: fast, balanced, small; Default: "balanced"
`camera_lora_scale`	number; Optional; Range: 0–1; Default: 1
`video_output_type`	string; Optional; Options: X264 (.mp4), VP9 (.webm), PRORES4444 (.mov), GIF (.gif); Default: "X264 (.mp4)"
`end_image_strength`	number; Optional; Range: 0–1; Default: 1
`num_context_frames`	integer; Optional; Range: 0–121; Default: 25
`num_inference_steps`	integer; Optional; Range: 8–50; Default: 40