Name: Audio to Waveform API: Turn Audio into Waveform Videos
Brand: magicapi
SKU: api-magicapi-audio-to-waveform-video-fofr-audio-to-waveform
Availability: InStock
Author: API Market

Shashank Agarwal

# 🎵 Audio Waveform Video Generator API (fofr Audio to Waveform)

## Overview
Audio to Waveform from fofr creates a waveform video from an audio file.

Send an `audio` URL and optionally set the background and bar colours, the number and width of the bars, the bar opacity and a caption. Each request returns the URL of one MP4 video.

## Features
- **Colours**: `bg_color` (default `#000000`) and `bars_color` (default `#ffffff`) take hex colour strings.
- **Bar layout**: `bar_count` sets the number of bars (default 100) and `bar_width` their width, where 1 is full width and 0.5 half width (default 0.4).
- **Opacity**: `fg_alpha` sets the opacity of the waveform (default 0.75).
- **Caption**: `caption_text` adds a caption to the video; leave it empty (the default) for none.
- **MP4 output**: each request returns one MP4 video URL.

## Use Cases
1. **Podcast clips**: turn audio excerpts into videos that can be posted where only video is accepted.
2. **Music previews**: share tracks as short waveform videos with the track description as the caption.
3. **Voice notes and announcements**: post spoken updates as video.
4. **Branded audio posts**: match the bar and background colours to your brand.

## Visual Examples
### Example Input
[Listen to the example input audio](https://blog.api.market/wp-content/uploads/2026/10/audio-to-waveform-input-api-market.wav)

The request set every styling field to its default value and added a caption.

```json
{
  "audio": "https://blog.api.market/wp-content/uploads/2026/10/audio-to-waveform-input-api-market.wav",
  "bg_color": "#000000",
  "fg_alpha": 0.75,
  "bar_count": 100,
  "bar_width": 0.4,
  "bars_color": "#ffffff",
  "caption_text": "80s trancecore, driving rhythm section, ambient textures, boomwhackers, persian scale mode, tribute recording"
}
```

### Example Output
[Watch the example output](https://blog.api.market/wp-content/uploads/2026/10/audio-to-waveform-output-b724xg5p-api-market.mp4)

White bars on a black background with the caption text, rendered in 2.53 seconds of processing.

## Input Parameters
| Field | Type | Required | Default | Allowed values | Description |
| --- | --- | --- | --- | --- | --- |
| `audio` | string (URL) | Yes |  |  | URL of the audio file to create the waveform from |
| `bg_color` | string | No | `#000000` |  | Background colour of the waveform video, as a hex colour |
| `fg_alpha` | number | No | `0.75` |  | Opacity of the foreground waveform |
| `bars_color` | string | No | `#ffffff` |  | Colour of the waveform bars, as a hex colour |
| `bar_count` | integer | No | `100` |  | Number of bars in the waveform |
| `bar_width` | number | No | `0.4` |  | Width of the bars. 1 represents full width, 0.5 half width, and so on. |
| `caption_text` | string | No | `""` |  | Caption text for the video |

## Pricing
- **Pay As You Go (PAYG) pricing**: you only pay for what you use.
- **Price**: $0.001 per API unit.
- **1 API unit = 1 request with up to 9 seconds of processing.** A longer request uses one more unit per started 9-second block (for example, 10 seconds of processing uses 2 units, $0.002).
- **Example cost**: the example took 2.53 seconds of processing, which is 1 unit, $0.001.
- **Failed or cancelled predictions are not billed.**
- **GET requests to check prediction status** are free and don't count toward API unit usage.
- **No monthly subscription fee.**

## API Documentation

### Base URL
All API requests go to: `https://prod.api.market/api/v1/magicapi/audio-to-waveform-video-fofr-audio-to-waveform`

### Authentication
Send your api.market API key in the `x-api-market-key` header:
```
x-api-market-key: YOUR_API_MARKET_KEY
```

### Asynchronous Processing
**IMPORTANT**: This API is asynchronous. The flow is:
1. Send a POST request to `/predictions`. A successful request returns **201 Created** with a prediction `id` and a `status` of `starting` or `processing`.
2. Poll GET `/predictions/{id}` with that ID.
3. Keep polling while `status` is `starting` or `processing`.
4. Stop when `status` is `succeeded` (read `output`), `failed` or `canceled` (read `error`).

A polling interval of 1 second and an overall timeout of 600 seconds (10 minutes) work well.

### Endpoints

#### Create a Prediction
```bash
curl -X POST "https://prod.api.market/api/v1/magicapi/audio-to-waveform-video-fofr-audio-to-waveform/predictions" \
  -H "Content-Type: application/json" \
  -H "x-api-market-key: YOUR_API_MARKET_KEY" \
  -d '{
    "version": "116cf9b97d0a117cfe64310637bf99ae8542cc35d813744c6ab178a3e134ff5a",
    "input": {
      "audio": "https://blog.api.market/wp-content/uploads/2026/10/audio-to-waveform-input-api-market.wav",
      "bg_color": "#000000",
      "fg_alpha": 0.75,
      "bar_count": 100,
      "bar_width": 0.4,
      "bars_color": "#ffffff",
      "caption_text": "80s trancecore, driving rhythm section, ambient textures, boomwhackers, persian scale mode, tribute recording"
    }
  }'
```

Response (201 Created):
```json
{
  "id": "b724xg5pfdrmw0d1ccp9k9ddkm",
  "version": "116cf9b97d0a117cfe64310637bf99ae8542cc35d813744c6ab178a3e134ff5a",
  "status": "starting",
  "created_at": "2026-10-22T10:33:57.249Z"
}
```

#### Check Prediction Status
```bash
curl -X GET "https://prod.api.market/api/v1/magicapi/audio-to-waveform-video-fofr-audio-to-waveform/predictions/{id}" \
  -H "x-api-market-key: YOUR_API_MARKET_KEY"
```

Response when the prediction has finished (200 OK):
```json
{
  "id": "b724xg5pfdrmw0d1ccp9k9ddkm",
  "status": "succeeded",
  "output": "https://blog.api.market/wp-content/uploads/2026/10/audio-to-waveform-output-b724xg5p-api-market.mp4",
  "error": null,
  "created_at": "2026-10-22T10:33:57.249Z",
  "started_at": "2026-10-22T10:34:16.897Z",
  "completed_at": "2026-10-22T10:34:20.427Z"
}
```

`output` is a single URL string pointing to the MP4 waveform video.

### Status Codes
- **201 Created**: prediction created (POST `/predictions`). This is the normal success response.
- **200 OK**: prediction details returned (GET `/predictions/{id}`).
- **400 Bad Request**: invalid input, for example a missing `audio` or a `bar_count` that is not an integer.
- **401 Unauthorized**: missing or invalid API key.
- **404 Not Found**: no prediction with that ID.
- **429 Too Many Requests**: rate limit exceeded.
- **500 Internal Server Error** or **503 Service Unavailable**: temporary server problem; retry later.

## Rate Limits
All plans allow 10 requests per second. Requests above that return `429 Too Many Requests`; back off before retrying and honour any `Retry-After` header. Polling a prediction with GET is free but still counts toward the per-second limit, so poll every 1 to 5 seconds rather than in a tight loop.

## Error Handling
- Check the HTTP status code of every request and read the response body for the error message.
- A prediction can also end with `status` set to `failed`; the `error` field then explains why. Failed predictions are not billed.
- Retry 429, 500 and 503 responses with exponential backoff. Fix the input before retrying a 400.

## Implementation Guide
### Example Code

#### JavaScript
```javascript
const apiKey = "YOUR_API_MARKET_KEY";
const baseUrl = "https://prod.api.market/api/v1/magicapi/audio-to-waveform-video-fofr-audio-to-waveform";

async function createAndWaitForPrediction(input) {
  const response = await fetch(`${baseUrl}/predictions`, {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
      "x-api-market-key": apiKey
    },
    body: JSON.stringify({ version: "116cf9b97d0a117cfe64310637bf99ae8542cc35d813744c6ab178a3e134ff5a", input })
  });

  if (response.status !== 201) {
    throw new Error(`API error: ${response.status} ${await response.text()}`);
  }

  const prediction = await response.json();
  return pollForResults(prediction.id);
}

const delay = (ms) => new Promise((resolve) => setTimeout(resolve, ms));

async function pollForResults(predictionId) {
  const maxTimeout = 600000;
  const pollInterval = 1000;
  const startTime = Date.now();

  while (Date.now() - startTime < maxTimeout) {
    const response = await fetch(`${baseUrl}/predictions/${predictionId}`, {
      headers: { "x-api-market-key": apiKey }
    });

    if (!response.ok) {
      throw new Error(`API error: ${response.status} ${await response.text()}`);
    }

    const prediction = await response.json();

    if (prediction.status === "succeeded") {
      return prediction.output;
    }

    if (prediction.status === "failed" || prediction.status === "canceled") {
      throw new Error(`Prediction ${prediction.status}: ${prediction.error || "Unknown error"}`);
    }

    await delay(pollInterval);
  }

  throw new Error("Prediction timed out after 10 minutes");
}

createAndWaitForPrediction({
  "audio": "https://blog.api.market/wp-content/uploads/2026/10/audio-to-waveform-input-api-market.wav",
  "bg_color": "#000000",
  "fg_alpha": 0.75,
  "bar_count": 100,
  "bar_width": 0.4,
  "bars_color": "#ffffff",
  "caption_text": "80s trancecore, driving rhythm section, ambient textures, boomwhackers, persian scale mode, tribute recording"
}).then((output) => console.log(output));
```

#### Python
```python
import time
import requests

API_KEY = "YOUR_API_MARKET_KEY"
BASE_URL = "https://prod.api.market/api/v1/magicapi/audio-to-waveform-video-fofr-audio-to-waveform"


def create_and_wait_for_prediction(input_data):
    headers = {"Content-Type": "application/json", "x-api-market-key": API_KEY}
    response = requests.post(
        f"{BASE_URL}/predictions",
        headers=headers,
        json={"version": "116cf9b97d0a117cfe64310637bf99ae8542cc35d813744c6ab178a3e134ff5a", "input": input_data},
    )

    if response.status_code != 201:
        raise Exception(f"API error: {response.status_code} {response.text}")

    return poll_for_results(response.json()["id"])


def poll_for_results(prediction_id):
    max_timeout = 600
    poll_interval = 1
    headers = {"x-api-market-key": API_KEY}
    start_time = time.time()

    while time.time() - start_time < max_timeout:
        response = requests.get(f"{BASE_URL}/predictions/{prediction_id}", headers=headers)

        if response.status_code != 200:
            raise Exception(f"API error: {response.status_code} {response.text}")

        prediction = response.json()

        if prediction["status"] == "succeeded":
            return prediction["output"]

        if prediction["status"] in ("failed", "canceled"):
            raise Exception(f"Prediction {prediction['status']}: {prediction.get('error') or 'Unknown error'}")

        time.sleep(poll_interval)

    raise Exception("Prediction timed out after 10 minutes")


output = create_and_wait_for_prediction({
    "audio": "https://blog.api.market/wp-content/uploads/2026/10/audio-to-waveform-input-api-market.wav",
    "bg_color": "#000000",
    "fg_alpha": 0.75,
    "bar_count": 100,
    "bar_width": 0.4,
    "bars_color": "#ffffff",
    "caption_text": "80s trancecore, driving rhythm section, ambient textures, boomwhackers, persian scale mode, tribute recording"
})
print(output)
```

## FAQ
- **What colour format do `bg_color` and `bars_color` take?**
  - Hex colour strings such as `#000000` and `#ffffff`, as in the defaults.
- **Can I leave out the caption?**
  - Yes. `caption_text` defaults to an empty string, which adds no caption.
- **How do `bar_count` and `bar_width` work together?**
  - `bar_count` sets how many bars are drawn; `bar_width` sets how much of each bar's slot it fills, from 1 (full width) down to thinner bars with gaps.
- **What does a request cost?**
  - $0.001 for up to 9 seconds of processing. The example took 2.53 seconds.
- **Is the 201 response from POST an error?**
  - No. 201 Created means the prediction was accepted. Use the returned `id` to poll GET `/predictions/{id}` until `status` is `succeeded`, `failed` or `canceled`.

## Contact Us
If you have any questions, reach out to us through the chat on the bottom right of the page. You can also email our support team at hello@magicapi.com.


Create waveform videos from audio files with fofr Audio to Waveform: set colours, bar count, bar width, opacity and a caption. Pay as you go, no monthly fee.