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Colorize high-quality video using LTX-2.3
fal-ai/ltx-2.3-quality/colorization
Colorize high-quality video using LTX-2.3
Inference
Commercial use
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Restore natural color to a grayscale / monochrome video.
The client provides a convenient way to interact with the model API.
npm install --save @fal-ai/clientThe @fal-ai/serverless-client package has been deprecated in favor of @fal-ai/client. Install the new package and update your imports — see client setup.
Set FAL_KEY as an environment variable in your runtime.
export FAL_KEY="YOUR_API_KEY"The client API handles the API submit protocol. It will handle the request status updates and return the result when the request is completed.
import { fal } from "@fal-ai/client";
const result = await fal.subscribe("fal-ai/ltx-2.3-quality/colorization", {
input: {
video_url: "https://v3b.fal.media/files/b/0a8824b1/sdm0KfmenrlywesfzY1Y1_if6euPp1.mp4"
},
logs: true,
onQueueUpdate: (update) => {
if (update.status === "IN_PROGRESS") {
update.logs.map((log) => log.message).forEach(console.log);
}
},
});
console.log(result.data);
console.log(result.requestId);The API uses an API Key for authentication. It is recommended you set the FAL_KEY environment variable in your runtime when possible.
import { fal } from "@fal-ai/client";
fal.config({
credentials: "YOUR_FAL_KEY"
});When running code on the client-side (e.g. in a browser, mobile app or GUI applications), make sure to not expose your FAL_KEY. Instead, use a server-side proxy to make requests to the API. For more information, check out our server-side integration guide.
The client API provides a convenient way to submit requests to the model.
import { fal } from "@fal-ai/client";
const { request_id } = await fal.queue.submit("fal-ai/ltx-2.3-quality/colorization", {
input: {
video_url: "https://v3b.fal.media/files/b/0a8824b1/sdm0KfmenrlywesfzY1Y1_if6euPp1.mp4"
},
webhookUrl: "https://optional.webhook.url/for/results",
});You can fetch the status of a request to check if it is completed or still in progress.
import { fal } from "@fal-ai/client";
const status = await fal.queue.status("fal-ai/ltx-2.3-quality/colorization", {
requestId: "764cabcf-b745-4b3e-ae38-1200304cf45b",
logs: true,
});Once the request is completed, you can fetch the result. See the Output Schema for the expected result format.
import { fal } from "@fal-ai/client";
const result = await fal.queue.result("fal-ai/ltx-2.3-quality/colorization", {
requestId: "764cabcf-b745-4b3e-ae38-1200304cf45b"
});
console.log(result.data);
console.log(result.requestId);Some attributes in the API accept file URLs as input. Whenever that's the case you can pass your own URL or a Base64 data URI.
You can pass a Base64 data URI as a file input. The API will handle the file decoding for you. Keep in mind that for large files, this alternative although convenient can impact the request performance.
You can also pass your own URLs as long as they are publicly accessible. Be aware that some hosts might block cross-site requests, rate-limit, or consider the request as a bot.
We provide a convenient file storage that allows you to upload files and use them in your requests. You can upload files using the client API and use the returned URL in your requests.
import { fal } from "@fal-ai/client";
const file = new File(["Hello, World!"], "hello.txt", { type: "text/plain" });
const url = await fal.storage.upload(file);The client will auto-upload the file for you if you pass a binary object (e.g. File, Data).
Read more about file handling in our file upload guide.
video_url string* requiredThe URL of the source video to transform.
prompt stringOptional short description of the video's content/scene. It is woven into the effect's trained caption to sharpen the result; leave empty to apply the effect with a generic description. Default value: ""
resolution ResolutionEnumOutput resolution (short side), preserving the source aspect ratio. The IC-LoRA control path caps the resolution x frames volume, so resolution trades against duration: 720p allows up to ~6s (sharper), 480p up to ~15s (softer but longer). A request above the budget is rejected with a clear error — pick 480p for longer clips. Output duration is num_frames / frames_per_second. Default value: "720p"
Possible enum values: 480p, 720p
num_frames integerThe number of output frames. Output duration is num_frames / frames_per_second. The IC-LoRA control budget caps the resolution x frames volume: roughly 6s at 720p or 15s at 480p; a request above it returns a 422 (lower num_frames, or use 480p). Default value: 121
frames_per_second floatFrames per second of the generated video. Default value: 24
num_inference_steps integerNumber of inference steps. Defaults to 15 and can be increased up to 30. Default value: 15
guidance_scale floatClassifier-free guidance scale. The default is tuned for fast, high-quality generation. Default value: 1
generate_audio booleanWhether to include audio in the returned video. When disabled, the final MP4 is returned without an audio track. Default value: true
negative_prompt stringThe negative prompt to steer generation away from. Default value: "color distortion, overexposure, static, blurry details, subtitles, style, artwork, painting, frame, still, dim overall tone, worst quality, low quality, JPEG compression artifacts, ugly, mutilated, extra fingers, poorly drawn hands, poorly drawn face, deformed, disfigured, malformed limbs, fused fingers, motionless frame, cluttered background, three legs, crowded background, walking backwards"
seed integerRandom seed for reproducibility. If None, a random seed is chosen.
enable_safety_checker booleanWhether to enable the safety checker. Default value: true
video_quality VideoQualityEnumThe quality preset of the generated video. Default value: "high"
Possible enum values: low, medium, high, maximum
video_write_mode VideoWriteModeEnumThe write mode of the generated video. Default value: "balanced"
Possible enum values: fast, balanced, small
sync_mode booleanIf True, the media is returned as a data URI inline in the response. Useful for short-lived requests and tests.
{
"video_url": "https://v3b.fal.media/files/b/0a8824b1/sdm0KfmenrlywesfzY1Y1_if6euPp1.mp4",
"resolution": "720p",
"num_frames": 121,
"frames_per_second": 24,
"num_inference_steps": 15,
"guidance_scale": 1,
"generate_audio": true,
"negative_prompt": "color distortion, overexposure, static, blurry details, subtitles, style, artwork, painting, frame, still, dim overall tone, worst quality, low quality, JPEG compression artifacts, ugly, mutilated, extra fingers, poorly drawn hands, poorly drawn face, deformed, disfigured, malformed limbs, fused fingers, motionless frame, cluttered background, three legs, crowded background, walking backwards",
"enable_safety_checker": true,
"video_quality": "high",
"video_write_mode": "balanced"
}The generated video.
seed integer* requiredThe seed actually used for generation.
prompt string* requiredThe prompt used for generation (after any expansion).
{
"video": {
"url": "",
"content_type": "image/png",
"file_name": "z9RV14K95DvU.png",
"file_size": 4404019
},
"prompt": ""
}url string* requiredThe URL where the file can be downloaded from.
content_type stringThe mime type of the file.
file_name stringThe name of the file. It will be auto-generated if not provided.
file_size integerThe size of the file in bytes.