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LTX-2.3 22B · Extend Video

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Model id ltx-2.3-22b/extend-video
# Run the model; wait up to 20 s for the finished result in the same call
curl -X POST "https://api.doitong.com/v1/run/ltx-2.3-22b/extend-video?wait=20" \
  -H "Authorization: Bearer $DOITONG_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
    "video": "https://content.doitong.com/video/showcase/v3/gen_fox_cartoon.mp4"
  }'

# Still "queued" or "running"? Poll with the id from the response:
curl "https://api.doitong.com/v1/requests/REQUEST_ID?wait=20" \
  -H "Authorization: Bearer $DOITONG_API_KEY"

Files like the example: $0.18 180 API credits your files are measured before the run Run it on this page

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Lightricks · Video

Your first result goes here

Build a request below and run it with your API key. Outputs are copied to our storage, kept forever or 7 days for free.

Build a request

Controls are generated from the model schema. The code and the price update as you change them.

•required

Prompt used as the basis for video generation.

•required video_url
Drop a file, or

URL pointing to the video that will be extended.

video_size default auto

Dimensions of the generated video.

default 121

Frame count for the generated output.

Advanced negative_prompt · end_image · scheduler · acceleration · camera_lora · video_output_type · video_quality · video_write_mode · extend_direction · fps · num_inference_steps · video_cfg_scale · video_stg_scale · video_rescaling_scale · video_modality_scale · audio_cfg_scale · audio_stg_scale · audio_rescaling_scale · audio_modality_scale · gradient_estimation_gamma · camera_lora_scale · distill_lora_first_pass_scale · distill_lora_second_pass_scale · num_context_frames · video_strength · audio_strength · end_image_strength · seed · use_multiscale · match_input_fps · use_restart_sampling · enable_prompt_expansion · enable_safety_checker
default news broadcast, 3d an...

Negative prompt used during video generation.

end_image_url
Drop a file, or

Provide a final-frame image by URL to define how the extended video ends.

scheduler default ltx2

Scheduler selection.

acceleration default regular

Acceleration level applied to processing.

camera_lora default none

Camera LoRA selection for controlling movement in the generated video more precisely than camera-motion prompts alone.

video_output_type default X264 (.mp4)

Output type for the resulting video.

video_quality default high

Quality level for the resulting video.

video_write_mode default balanced

Write mode for the resulting video.

extend_direction default forward

Side of the video to extend: choose 'backward' to add content before its beginning or 'forward' to add content after its end.

default 24

Output video frame rate, measured in frames per second.

default 40

Count of inference steps performed.

default 3

Video guidance setting: raise it for greater consistency and focus in the generated content. Uses classifier-free guidance (CFG).

default 0

Video consistency and focus control through the Spatiotemporal Guidance (STG) scale; increase the setting to strengthen both qualities.

default 0.7

Video rescaling adjustment for balancing classifier-free against spatiotemporal guidance as a ratio.

default 3

Video modality adjustment for balancing the video and audio contributions as a ratio.

default 7

Audio guidance setting: raise it for greater consistency and focus in the generated content. Uses classifier-free guidance (CFG).

default 0

Audio consistency and focus control through the Spatiotemporal Guidance (STG) scale; increase the setting to strengthen both qualities.

default 0.7

Audio rescaling adjustment for balancing classifier-free against spatiotemporal guidance as a ratio.

default 3

Audio modality adjustment for balancing the video and audio contributions as a ratio.

default 2

Denoising gradient-estimation setting: 0 turns estimation off; otherwise, the value specifies gamma.

default 1

Camera LoRA strength for controlling movement in the generated video more precisely than camera-motion prompts alone.

default 0.2

Control first-pass distill LoRA scaling, using 0 to turn it off.

default 0.5

Control distill LoRA scaling for every pass after the first.

default 25

Frame count used to provide context when extending the video.

default 1

Freedom to alter video content is controlled by this conditioning strength: smaller settings allow the model greater latitude.

default 1

Freedom to alter audio content is controlled by this conditioning strength: smaller settings allow the model greater latitude.

default 1

Control how much the end image influences the generated video.

Seed value that initializes random-number generation.

POST /run/ltx-2.3-22b/extend-video?wait=20 quote → $0.18
# Run the model; wait up to 20 s for the finished result in the same call
curl -X POST "https://api.doitong.com/v1/run/ltx-2.3-22b/extend-video?wait=20" \
  -H "Authorization: Bearer $DOITONG_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
    "video": "https://content.doitong.com/video/showcase/v3/gen_fox_cartoon.mp4"
  }'

# Still "queued" or "running"? Poll with the id from the response:
curl "https://api.doitong.com/v1/requests/REQUEST_ID?wait=20" \
  -H "Authorization: Bearer $DOITONG_API_KEY"

Run this request

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About LTX-2.3 22B · Extend Video

Takes `video_url` and a `prompt` and generates a continuation of `num_frames` frames (9 to 481). An optional `end_image_url` sets where the extension finishes. `match_input_fps` keeps the source frame rate, `generate_audio` adds sound, and `video_size` defaults to auto. Output can be mp4, webm, mov or GIF.

Parameters

Send either the canonical name or the native name, not both. Canonical names

NameType DefaultAllowed Description
promptrequired
Typestring
Prompt used as the basis for video generation.
video_urlrequired video
Typeurl · video
URL pointing to the video that will be extended.
end_image_urloptional end_image
Typeurl · image
Provide a final-frame image by URL to define how the extended video ends.
num_framesoptional
Typeinteger
Default121
9 – 481
Frame count for the generated output.
video_sizeoptional
Typeobject
Defaultauto
autosquare_hdsquareportrait_4_3portrait_16_9landscape_4_3landscape_16_9
Dimensions of the generated video.
generate_audiooptional
Typeboolean
Defaulttrue
Controls whether the video includes generated audio.
use_multiscaleoptional
Typeboolean
Defaulttrue
Multi-scale generation toggle for improved coherence and detail. With True, a preliminary smaller video guides a second generation whose size meets or exceeds the requested dimensions.
match_input_fpsoptional
Typeboolean
Defaulttrue
Output frame-rate override that replaces the default target FPS with the source video's FPS when enabled.
fpsoptional
Typenumber
Default24
1 – 60
Output video frame rate, measured in frames per second.
num_inference_stepsoptional
Typeinteger
Default40
8 – 50
Count of inference steps performed.
video_cfg_scaleoptional
Typenumber
Default3
1 – 20
Video guidance setting: raise it for greater consistency and focus in the generated content. Uses classifier-free guidance (CFG).
video_stg_scaleoptional
Typenumber
Default0
0 – 20
Video consistency and focus control through the Spatiotemporal Guidance (STG) scale; increase the setting to strengthen both qualities.
video_rescaling_scaleoptional
Typenumber
Default0.7
0 – 1
Video rescaling adjustment for balancing classifier-free against spatiotemporal guidance as a ratio.
video_modality_scaleoptional
Typenumber
Default3
0 – 10
Video modality adjustment for balancing the video and audio contributions as a ratio.
audio_cfg_scaleoptional
Typenumber
Default7
1 – 20
Audio guidance setting: raise it for greater consistency and focus in the generated content. Uses classifier-free guidance (CFG).
audio_stg_scaleoptional
Typenumber
Default0
0 – 20
Audio consistency and focus control through the Spatiotemporal Guidance (STG) scale; increase the setting to strengthen both qualities.
audio_rescaling_scaleoptional
Typenumber
Default0.7
0 – 1
Audio rescaling adjustment for balancing classifier-free against spatiotemporal guidance as a ratio.
audio_modality_scaleoptional
Typenumber
Default3
0 – 10
Audio modality adjustment for balancing the video and audio contributions as a ratio.
gradient_estimation_gammaoptional
Typenumber
Default2
0 – 10
Denoising gradient-estimation setting: 0 turns estimation off; otherwise, the value specifies gamma.
use_restart_samplingoptional
Typeboolean
Defaultfalse
Restart sampling toggle for potentially better video quality: enabling it introduces a little noise at every denoising step.
scheduleroptional
Typeenum
Defaultltx2
ltx2linear_quadraticbeta
Scheduler selection.
accelerationoptional
Typeenum
Defaultregular
noneregularhighfull
Acceleration level applied to processing.
camera_loraoptional
Typeenum
Defaultnone
dolly_indolly_outdolly_leftdolly_rightjib_upjib_downstaticnone
Camera LoRA selection for controlling movement in the generated video more precisely than camera-motion prompts alone.
camera_lora_scaleoptional
Typenumber
Default1
0 – 1
Camera LoRA strength for controlling movement in the generated video more precisely than camera-motion prompts alone.
negative_promptoptional
Typestring
Defaultnews broadcast, 3d animation, computer graphics, pc game, console game, video game, cartoon, childish, watermark, logo, text, on screen text, subtitles, titles, signature, slowmo, static
Negative prompt used during video generation.
seedoptional
Typeinteger | null
Seed value that initializes random-number generation.
enable_prompt_expansionoptional
Typeboolean
Defaulttrue
Controls whether prompt expansion is enabled.
enable_safety_checkeroptional
Typeboolean
Defaulttrue
Controls whether safety checking is enabled.
video_output_typeoptional
Typeenum
DefaultX264 (.mp4)
X264 (.mp4)VP9 (.webm)PRORES4444 (.mov)GIF (.gif)
Output type for the resulting video.
video_qualityoptional
Typeenum
Defaulthigh
lowmediumhighmaximum
Quality level for the resulting video.
video_write_modeoptional
Typeenum
Defaultbalanced
fastbalancedsmall
Write mode for the resulting video.
distill_lora_first_pass_scaleoptional
Typenumber
Default0.2
0 – 1
Control first-pass distill LoRA scaling, using 0 to turn it off.
distill_lora_second_pass_scaleoptional
Typenumber
Default0.5
0 – 1
Control distill LoRA scaling for every pass after the first.
extend_directionoptional
Typeenum
Defaultforward
forwardbackward
Side of the video to extend: choose 'backward' to add content before its beginning or 'forward' to add content after its end.
num_context_framesoptional
Typeinteger
Default25
0 – 121
Frame count used to provide context when extending the video.
video_strengthoptional
Typenumber
Default1
0 – 1
Freedom to alter video content is controlled by this conditioning strength: smaller settings allow the model greater latitude.
audio_strengthoptional
Typenumber
Default1
0 – 1
Freedom to alter audio content is controlled by this conditioning strength: smaller settings allow the model greater latitude.
end_image_strengthoptional
Typenumber
Default1
0 – 1
Control how much the end image influences the generated video.
required Canonical name, also accepted

File parameters take a public https:// URL, a data: URI up to 10 MB, or the file_url of an upload. Files

Output

GET /requests/req_8k2m4q7x1z9c3v5b6n0p2r4t
{
  "id": "req_8k2m4q7x1z9c3v5b6n0p2r4t",
  "object": "request",
  "model": "ltx-2.3-22b/extend-video",
  "status": "succeeded",
  "created_at": "2026-10-20T12:00:00Z",
  "started_at": "2026-10-20T12:00:02Z",
  "completed_at": "2026-10-20T12:00:09Z",
  "queue_position": null,
  "cost": {
    "credits": 180,
    "usd": "0.18",
    "charged": 180,
    "refunded": 0
  },
  "input": {
    "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
    "video_url": "https://content.doitong.com/video/showcase/v3/gen_fox_cartoon.mp4"
  },
  "output": {
    "video": {
      "url": "https://content.doitong.com/dev-api/2026/10/20/req_8k2m4q7x1z9c3v5b6n0p2r4t/0-output.mp4",
      "content_type": "video/mp4",
      "file_name": "0-output.mp4",
      "file_size": 1843200,
      "width": 1024,
      "height": 768,
      "fps": 1.0,
      "duration": 5,
      "num_frames": 1
    },
    "seed": 42,
    "prompt": "A woman stands still amid a busy neon-lit street at night. The camera slowly dollies in toward her face as people blur past, their motion emphasizing her calm presence. City lights flicker and reflections shift across her denim jacket."
  },
  "outputs": [
    {
      "type": "video",
      "url": "https://content.doitong.com/dev-api/2026/10/20/req_8k2m4q7x1z9c3v5b6n0p2r4t/0-output.mp4",
      "content_type": "video/mp4",
      "file_size": 1843200,
      "width": 1280,
      "height": 720,
      "duration": 5,
      "stored": true
    }
  ],
  "error": null,
  "metrics": {
    "inference_seconds": 6.8
  },
  "urls": {
    "self": "https://api.doitong.com/v1/requests/req_8k2m4q7x1z9c3v5b6n0p2r4t",
    "cancel": "https://api.doitong.com/v1/requests/req_8k2m4q7x1z9c3v5b6n0p2r4t/cancel"
  }
}
Your files, your choiceEvery outputs[].url is a copy on our storage: kept forever (paid per GB-month) or 7 days for free, by your account setting or ?storage=.
Same shape on every modeltype, url, content_type, width, height and duration, for images, video and audio alike. output is the model’s own result object.
Fields of output
video
object {url, content_type, file_name, file_size, width, height, fps, duration, num_frames}Video produced by the model.
seed
integerSeed value used to initialize random number generation.
prompt
stringPrompt used to guide generation.

More models: Video to Video

For AI agents: this page as Markdown is at https://doitong.com/developers/models/ltx-2.3-22b/extend-video.md. All models and guides: https://doitong.com/developers/llms.txt