Mirelo SFX 2.0 Video-to-Video API on WaveSpeedAI

Name: Mirelo SFX 2.0 Video-to-Video
Brand: mirelo-ai
SKU: mirelo-ai/sfx-2.0/video-to-video
Price: 0.016 USD
Availability: InStock

README

Mirelo SFX 2.0 Video-to-Video

Mirelo SFX 2.0 Video-to-Video adds synchronized sound effects and ambience to an existing video while keeping the original visual footage. The model analyzes the action in the source video, generates matching audio, and returns the video with its new soundtrack.

Use optional text guidance to describe the sounds you want, add a negative prompt to exclude unwanted audio elements, and preserve existing speech when dialogue should remain in the final soundtrack.

Why Choose This?

Video-synchronized sound generation
Generate sound effects and ambience that follow the timing and action of the source footage.
Original visuals preserved
Add generated audio without creating or modifying the video frames.
Prompt-guided sound design
Describe the desired sound effects, environment, atmosphere, and audio direction.
Negative prompt control
Specify sounds, voices, music, or other elements that should be avoided.
Speech preservation
Keep existing dialogue while generating a new surrounding soundscape.
Up to 10 minutes
Request synchronized sound generation from 1 to 600 seconds.

Parameters

Parameter	Required	Description
video	Yes	Input video URL used to guide synchronized sound generation. Minimum video length: `1` second.
prompt	No	Optional guidance describing the desired soundtrack, sound effects, ambience, or environment. Maximum `2000` characters.
negative_prompt	No	Optional description of sounds or elements to avoid. Maximum `1000` characters.
preserve_speech	No	Preserve existing speech while generating other sounds around it. Default: `true`.
duration	No	Requested sound-generation duration in seconds. Range: `1–600`. Default: `10`. Generation cannot continue beyond the source video length.
seed	No	Optional integer seed from `0` to `2147483647`. Omit for random generation.

How to Use

Provide a source video — Upload a video or supply its URL.
Add sound guidance optional — Describe the effects, ambience, and soundtrack direction in prompt.
Add exclusions optional — Use negative_prompt to specify sounds that should be avoided.
Configure speech preservation — Keep preserve_speech=true when existing dialogue should remain.
Set duration — Choose the requested sound-generation length from 1 to 600 seconds.
Set seed optional — Use a fixed seed when reproducibility is needed.
Submit — Generate and retrieve the video with its synchronized soundtrack.

Pricing

Pricing is based on the requested duration.

The rate is $0.016 per requested second.

Duration	Price
1s	$0.016
5s	$0.080
10s	$0.160
30s	$0.480
60s	$0.960
600s	$9.600

Billing uses the requested duration.

If the source video is shorter than the requested duration, sound generation stops at the end of the source video, but billing still uses the requested duration. Set duration no longer than the usable source clip when additional requested time is unnecessary.

Best Use Cases

Film and cinematic sound design — Add synchronized ambience, impacts, movement, and environmental effects to footage.
Gameplay videos — Generate action-matched effects for movement, combat, objects, and environments.
Product videos — Add mechanical, interaction, and environmental sounds to product demonstrations.
Social media content — Create richer sound design for short-form visual content.
Foley-style workflows — Generate footsteps, impacts, object handling, fabric movement, and other action-based effects.
Alternate soundtrack exploration — Test different sound directions without changing the source visuals.
Speech-preserving sound design — Keep dialogue while rebuilding the surrounding soundscape.

Pro Tips

Describe concrete sound sources, timing, intensity, movement, and environment.
Explain how sounds should correspond to visible actions when synchronization matters.
Use negative_prompt to reduce unwanted music, voices, or background elements.
Keep preserve_speech=true when source dialogue should remain in the final video.
Set preserve_speech=false when you want the generated soundtrack focused on sound effects only.
Match duration to the usable source-video length to avoid paying for requested time beyond the available footage.
Start with shorter generations when testing a new sound direction.
Keep prompts focused when precise synchronization is more important than a complex soundscape.

Notes

video is required.
The source video must be at least 1 second long.
duration supports 1–600 seconds and defaults to 10.
Sound generation cannot continue beyond the source video length.
Billing still uses the requested duration when it exceeds the available source-video duration.
preserve_speech defaults to true.
preserve_speech=true preserves existing speech, not all original background audio.
Generation longer than 10 seconds is processed in consecutive windows.
The endpoint returns the source video with generated audio rather than standalone audio.

Related Models

Mirelo SFX 2.0 Text-to-Audio — Generate sound effects and ambience directly from text descriptions.
Mirelo SFX 2.0 Video-to-Audio — Generate synchronized standalone audio from an input video.
Mirelo SFX 2.0 Video-to-Video — Add synchronized generated sound effects to an existing video and return the completed video.

Sfx 2.0 Video To Video API — Quick start

Grab a WaveSpeedAI API key, then call POST https://api.wavespeed.ai/api/v3/mirelo-ai/sfx-2.0/video-to-video with your input as JSON. The endpoint returns a prediction id. Start polling the result endpoint around every 2 seconds, increase the interval for long-running tasks, and stop on any terminal status. On completed, read output values from data.outputs. Examples for Sfx 2.0 Video To Video below.

HTTP example

set -euo pipefail

: "${WAVESPEED_API_KEY:?Set WAVESPEED_API_KEY}"

REQUEST_BODY=$(cat <<'JSON'
{
    "video": "https://interactive-examples.mdn.mozilla.net/media/cc0-videos/flower.mp4",
    "preserve_speech": true,
    "duration": 10
}
JSON
)

# 1. Submit the prediction.
SUBMIT_RESPONSE=$(curl --silent --show-error --fail-with-body \
  -X POST "https://api.wavespeed.ai/api/v3/mirelo-ai/sfx-2.0/video-to-video" \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $WAVESPEED_API_KEY" \
  -d "$REQUEST_BODY")

TASK=$(printf '%s' "$SUBMIT_RESPONSE" | jq 'if has("data") then .data else . end')
PREDICTION_ID=$(printf '%s' "$TASK" | jq -r '.id')
if [ -z "$PREDICTION_ID" ] || [ "$PREDICTION_ID" = "null" ]; then
  printf 'Submission response did not contain a prediction id
' >&2
  exit 1
fi
RESULT_URL="https://api.wavespeed.ai/api/v3/predictions/$PREDICTION_ID/result"

# 2. Poll until the prediction finishes.
while true; do
  RESPONSE=$(curl --silent --show-error --fail-with-body "$RESULT_URL" \
    -H "Authorization: Bearer $WAVESPEED_API_KEY")
  RESULT=$(printf '%s' "$RESPONSE" | jq 'if has("data") then .data else . end')
  STATUS=$(printf '%s' "$RESULT" | jq -r '.status')
  case "$STATUS" in
    completed) printf '%s\n' "$RESULT" | jq '.outputs'; break ;;
    failed|cancelled|timeout|deleted) printf '%s\n' "$RESULT" | jq . >&2; exit 1 ;;
    *) sleep 2 ;;
  esac
done

Node.js example

const submitUrl = "https://api.wavespeed.ai/api/v3/mirelo-ai/sfx-2.0/video-to-video";
const apiKey = process.env.WAVESPEED_API_KEY;
if (!apiKey) throw new Error('Set WAVESPEED_API_KEY');

async function requestJson(url, options = {}) {
  const response = await fetch(url, options);
  if (!response.ok) throw new Error(await response.text());
  return response.json();
}

// 1. Submit the prediction.
const body = await requestJson(submitUrl, {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${apiKey}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
        "video": "https://interactive-examples.mdn.mozilla.net/media/cc0-videos/flower.mp4",
        "preserve_speech": true,
        "duration": 10
}),
});
const task = body.data ?? body;
if (!task.id) throw new Error("Submission response did not contain a prediction id");
const resultUrl = `https://api.wavespeed.ai/api/v3/predictions/${task.id}/result`;

// 2. Poll until the prediction finishes.
while (true) {
  const resultBody = await requestJson(resultUrl, {
    headers: { "Authorization": `Bearer ${apiKey}` },
  });
  const result = resultBody.data ?? resultBody;
  if (result.status === "completed") {
    console.log(result.outputs);
    break;
  }
  if (["failed", "cancelled", "timeout", "deleted"].includes(result.status)) throw new Error(JSON.stringify(result));
  await new Promise(resolve => setTimeout(resolve, 2000));
}

Python example

import json
import os
import time
from urllib.request import Request, urlopen

api_key = os.environ["WAVESPEED_API_KEY"]
headers = {"Authorization": f"Bearer {api_key}", "Content-Type": "application/json"}
payload = {
    "video": "https://interactive-examples.mdn.mozilla.net/media/cc0-videos/flower.mp4",
    "preserve_speech": True,
    "duration": 10
}

def request_json(url, data=None):
    request = Request(url, data=data, headers=headers, method="POST" if data else "GET")
    with urlopen(request) as response:
        return json.load(response)

# 1. Submit the prediction.
body = request_json("https://api.wavespeed.ai/api/v3/mirelo-ai/sfx-2.0/video-to-video", json.dumps(payload).encode())
task = body.get("data", body)
if not task.get("id"):
    raise RuntimeError("Submission response did not contain a prediction id")
result_url = f"https://api.wavespeed.ai/api/v3/predictions/{task['id']}/result"

# 2. Poll until the prediction finishes.
while True:
    result_body = request_json(result_url)
    result = result_body.get("data", result_body)
    status = result.get("status")
    if status == "completed":
        print(result.get("outputs", []))
        break
    if status in {"failed", "cancelled", "timeout", "deleted"}:
        raise RuntimeError(result)
    time.sleep(2)

Sfx 2.0 Video To Video API — Frequently asked questions

What is the Sfx 2.0 Video To Video API?

Sfx 2.0 Video To Video is a Mirelo Ai model for video sound design, exposed as a REST API on WaveSpeedAI. Mirelo SFX 2.0 Video-to-Video adds synchronized AI-generated sound effects to an input video and returns the original video with its new soundtrack, preserving the source visuals while enhancing sound design for film, social content, games, ads, and post-production workflows. Ready-to-use REST inference API, best performance, no coldstarts, affordable pricing. You can call it programmatically or try it from the playground above.

How do I call the Sfx 2.0 Video To Video API?

POST your input parameters to the model's REST endpoint (shown in the API tab of this playground) with your WaveSpeedAI API key in the Authorization header. Submission returns a prediction ID. Poll the result endpoint starting around every 2 seconds, increase the interval for long-running tasks, and stop on any terminal status. The playground generates Python, JavaScript, and cURL examples for submitting requests and polling results. Full request/response shape is documented at https://wavespeed.ai/docs/docs-api/mirelo-ai/mirelo-ai-sfx-2.0-video-to-video.

How much does Sfx 2.0 Video To Video cost per run?

Sfx 2.0 Video To Video starts at $0.016 per run. That figure is the base price — the final charge scales with the parameters you set in the form (output size, length, count, references, or whatever knobs this model exposes), so a higher-quality or larger output costs more than a minimal one. The exact cost for your current input is shown live next to the Generate button before you submit, and the actual per-call charge is recorded on the prediction afterwards.

What inputs does Sfx 2.0 Video To Video accept?

Key inputs: `prompt`, `video`, `duration`, `seed`, `negative_prompt`, `preserve_speech`. The full JSON schema (types, defaults, allowed values) is rendered above the Generate button and mirrored in the API reference at https://wavespeed.ai/docs/docs-api/mirelo-ai/mirelo-ai-sfx-2.0-video-to-video.

How do I get started with the Sfx 2.0 Video To Video API?

Sign up for a free WaveSpeedAI account to claim starter credits, copy your API key from /accesskey, then call the endpoint shown in the API tab of the playground. The playground also auto-generates a code sample in Python, JavaScript, or cURL for the parameters you've set.

Can I use Sfx 2.0 Video To Video outputs commercially?

Commercial usage rights depend on the model's license, set by its provider (Mirelo Ai). Check the provider's applicable terms and WaveSpeedAI's Terms of Service before commercial use.

mirelo-ai/sfx-2.0/video-to-video

ExamplesView all

Related Models

README

Mirelo SFX 2.0 Video-to-Video

Why Choose This?

Parameters

How to Use

Pricing

Best Use Cases

Pro Tips

Notes

Related Models

Sfx 2.0 Video To Video API — Quick start

Sfx 2.0 Video To Video API — Frequently asked questions

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