NEWDolby Media Processing APIs are now the Dolby.io Media APIs Learn More >
X

Enhancing Media

Getting Started with the Media Enhance API

The Dolby.io Media Enhance API is designed to improve the sound of your media. Our algorithms analyze your media and make corrections to quickly improve and produce professional quality audio. By using this API you can automate typically labor intensive and specialized media processing tasks to improve:

  • Speech leveling
  • Noise reduction
  • Loudness correction
  • Speech isolation
  • Sibilance reduction
  • Plosive reduction
  • Dynamic equalization
  • Tone shaping

This tutorial will show you how to use the API to build a range of applications such as podcast tools, online learning platforms, interviews, or social video sharing.

Not a Developer?

To get started without writing any code, you can use the
Media Demo to upload a file and view the results.

Getting Started

To get started you'll follow these steps.

  1. Get your API key
  2. Prepare your media
  3. Make a Media Enhance request
  4. Check the results
  5. Review the output

1. Get Your API Key

In order to use the Media Enhance API you will need to have an API key. When you sign up for an account you are able to retrieve your API key from the Media APIs section of the dashboard. Your key is a globally unique identifier (guid) for your specific account applications that should be passed to all API requests as a header called x-api-key.

2. Prepare Your Media

Make your media available for enhancing:

a. Use your own cloud storage provider
b. Use our Dolby Media Input API

a. Use your own cloud storage provider

You will want to consider this option when you move your applications into production. Our services are able to work with many popular cloud storage services such as AWS S3, GCP Cloud Storage, or your own services with basic or token based authentication.

See the Media Input and Output guide for more detail on various storage options.

b. Use our Dolby Media Input API (optional)

The Media Input API was designed to give you a quick way to upload media while evaluating the Media APIs. We can securely store your media temporarily, any media you upload will be removed regularly so shouldn't be used for permanent storage.

Call Start Media Input to identify a shortcut url. It must begin with dlb:// but otherwise is your own personal unique identifier. Some valid examples:

  • dlb://example.mp4
  • dlb://input/your-favorite-podcast.mp4
  • dlb://usr/home/me/voice-memo.wav

You can think of this like an object key that is used to identify a file for your account. Once you call POST /media/input you'll be returned a new url in the response. This is a pre-signed URL to a cloud storage location you will use to upload the file. You do that by making a PUT request with your media.

The following examples use an environment variable to identify the api key (DOLBYIO_API_KEY) and the file path to your file (INPUT_MEDIA_LOCAL_PATH). You need to either set those variables for your environment or update the code samples with new values.

import os
import requests

# Set or replace these values

file_path = os.environ["INPUT_MEDIA_LOCAL_PATH"]
api_key = os.environ["DOLBYIO_API_KEY"]

# Declare your dlb:// location

url = "https://api.dolby.com/media/input"
headers = {
    "x-api-key": api_key,
    "Content-Type": "application/json",
    "Accept": "application/json",
}

body = {
    "url": "dlb://in/example.mp4",
}

response = requests.post(url, json=body, headers=headers)
response.raise_for_status()
data = response.json()
presigned_url = data["url"]

# Upload your media to the pre-signed url response

print("Uploading {0} to {1}".format(file_path, presigned_url))
with open(file_path, "rb") as input_file:
  requests.put(presigned_url, data=input_file)
// This example will read a file from your local computer
// and upload it to storage.  You'll need to install node, npm,
// and axios.

const fs = require("fs")
const axios = require("axios").default

// Set or replace these values

const file_path = process.env.INPUT_MEDIA_LOCAL_PATH
const api_key = process.env.DOLBYIO_API_KEY

// Declare your dlb:// location

const config = {
  method: "post",
  url: "https://api.dolby.com/media/input",
  headers: {
    "x-api-key": api_key,
    "Content-Type": "application/json",
    Accept: "application/json",
  },
  data: {
    url: "dlb://in/example.mp4",
  },
}

axios(config)
  .then(function(response) {
    // Upload your media to the pre-signed url response
    console.log(`Upload ${file_path} to ${response.data.url}`);

    const upload_config = {
      method: "put",
      url: response.data.url,
      data: fs.createReadStream(file_path),
      maxContentLength: Infinity,
      maxBodyLength: Infinity,
      headers: {
        "Content-Type": "application/octet-stream",
        "Content-Length": fs.statSync(file_path).size,
      },
    }
    axios(upload_config)
      .then(function() {
        console.log("File uploaded")
      })
      .catch(function(error) {
        console.log(error)
      })
  })
  .catch(function(error) {
    console.log(error)
  })
curl -X POST https://api.dolby.com/media/input \
  --header "x-api-key: $DOLBYIO_API_KEY" \
  --data '{
      "url": "dlb://in/example.mp4"
  }'

# Use the result in a second command replacing `$PRE_SIGNED_URL` with the response from the previous command:

curl -X PUT $PRE_SIGNED_URL -T ./your-local-media.mp4

Once the upload is complete, you'll be able to refer to this media with the dlb://in/example.mp4 shortcut.

3. Make a Media Enhance Request

The Media Enhance API requires both an input and an output parameter to begin enhancing your media. There are additional parameters that can be used to customize the results based on the type of content and preferences you might have beyond the basic example here.

Regardless of whether you chose to use your own cloud storage or he Dolby.io /media/input service, the Dolby.io API will need to be able to read the media. See the Media Input and Output guide for a more detailed explanation of various ways you can provide authentication details.

These are all valid input values:

Similarly, for output you can use any location which our APIs will be able to write to. As this is less common, specifying a dlb:// output location will create one on the fly. Here are some examples:

import os
import requests

# Set or replace these values
api_key = os.environ['DOLBYIO_API_KEY']
body = {
  "input" : "s3://dolbyio/public/shelby/airplane.original.mp4",
  "output" : "dlb://out/example-enhanced.mp4"
}

url = "https://api.dolby.com/media/enhance"
headers = {
  "x-api-key": api_key,
  "Content-Type": "application/json",
  "Accept": "application/json"
}

response = requests.post(url, json=body, headers=headers)
response.raise_for_status()
print(response.json())
const axios = require("axios").default

const config = {
  method: "post",
  url: "https://api.dolby.com/media/enhance",
  headers: {
    "x-api-key": process.env.DOLBYIO_API_KEY,
    "Content-Type": "application/json",
    Accept: "application/json",
  },
  data: {
    input: "s3://dolbyio/public/shelby/airplane.original.mp4",
    output: "dlb://out/example-enhanced.mp4",
  },
}

axios(config)
  .then(function(response) {
    console.log(response.data.job_id)
  })
  .catch(function(error) {
    console.log(error)
  })
curl -X POST https://api.dolby.com/media/enhance \
     --header "x-api-key: $DOLBYIO_API_KEY" \
     --data '{
         "input": "s3://dolbyio/public/shelby/airplane.original.mp4",
         "output": "dlb://out/example-enhanced.mp4"
     }'

The JSON response will include a unique job_id that you'll need to use to check on the status of media processing.

{"job_id":"b49955b4-9b64-4d8b-a4c6-2e3550472a33"}

You can explore the /media/enhance API Reference to learn more about other options to customize the behavior of the media processing.

4. Check the Job Status

It will take a few moments for the API to enhance your file. You'll need to check the status of the job. You can learn more about this in the How It Works section of the Introduction to learn more.

For this GET /media/enhance request you'll need to use the job id returned from the previous step. In these examples, it is specified as an environment variable that you'll need to set or replace in the code samples.

import os
import requests

url = "https://api.dolby.com/media/enhance"
headers = {
  "x-api-key": os.environ["DOLBYIO_API_KEY"],
  "Content-Type": "application/json",
  "Accept": "application/json"
}

params = {
  "job_id": os.environ["DOLBYIO_JOB_ID"]
}

response = requests.get(url, params=params, headers=headers)
response.raise_for_status()
print(response.json())
const axios = require("axios").default

const config = {
  method: "get",
  url: "https://api.dolby.com/media/enhance",
  headers: {
    "x-api-key": process.env.DOLBYIO_API_KEY,
    "Content-Type": "application/json",
    Accept: "application/json",
  },
  params: {
    job_id: process.env.DOLBYIO_JOB_ID,
  },
}

axios(config)
  .then(function(response) {
    console.log(JSON.stringify(response.data, null, 4))
  })
  .catch(function(error) {
    console.log(error)
  })
curl -X GET "https://api.dolby.com/media/enhance?job_id=$DOLBYIO_JOB_ID" \
     --header "x-api-key: $DOLBYIO_API_KEY"

While the job is still in progress, you will be able to see the status and progress values returned.

{
  "path": "/media/enhance",
  "status": "Running",
  "progress": 42
}

If you re-run and call again after a period of time you'll see the status changes and the output you originally specified will be ready for downloading.

{
  "path": "/media/enhance",
  "progress": 100,
  "result": {},
  "status": "Success"
}

5. Review Media

Once media processing is complete, the file will be PUT in the output location specified when the job was started. If you used the optional dlb://out/example.analysis.json location you can use the /media/output API to retrieve the file. It takes the url as the only parameter.

import os
import shutil
import requests

output_path = os.environ["OUTPUT_MEDIA_LOCAL_PATH"]

url = "https://api.dolby.com/media/output"
headers = {
    "x-api-key": os.environ["DOLBYIO_API_KEY"],
    "Content-Type": "application/json",
    "Accept": "application/json",
}

args = {
    "url": "dlb://out/example-enhanced.mp4",
}

with requests.get(url, params=args, headers=headers, stream=True) as response:
    response.raise_for_status()
    response.raw.decode_content = True
    print("Downloading from {0} into {1}".format(response.url, output_path))
    with open(output_path, "wb") as output_file:
        shutil.copyfileobj(response.raw, output_file)
const fs = require("fs")
const axios = require("axios").default

const output_path = process.env.OUTPUT_MEDIA_LOCAL_PATH

const config = {
  method: "get",
  url: "https://api.dolby.com/media/output",
  headers: {
    "x-api-key": process.env.DOLBYIO_API_KEY,
    "Content-Type": "application/json",
    "Accept": "application/json",
  },
  responseType: "stream",
  params: {
    url: "dlb://out/example-enhanced.mp4",
  },
}

axios(config)
  .then(function(response) {
    response.data.pipe(fs.createWriteStream(output_path))
    response.data.on("error", function(error) {
      console.log(error)
    })
    response.data.on("end", function() {
      console.log("File downloaded!")
    })
  })
  .catch(function(error) {
    console.log(error)
  })
# You specify the `-L` because the service will redirect you to a cloud storage location. 
# You shouldn't try to retrieve directly from the cloud storage as the location may change, 
# so use **/media/output** with the shortcut instead. 
# The `-O` is to just output the file to your local system with the same filename.

curl  -X GET https://api.dolby.com/media/output?url=dlb://out/example.analysis.json \
      -O -L \
      --header "x-api-key: $DOLBYIO_API_KEY"

Take a listen to the enhanced media.

Learn More

  • See the /media/enhance reference documentation
  • Explore the guides to build a better understanding

Did this page help you?