How to apply fade-in/fade-out operation on an audio file in Azure Media Services?

Question

Hi, We have a use case wherein we want to apply fade-in/fade out filters on an audio file.
Along with this, we also want to increase/decrease the volume of an audio file stored in azure media services.

Wanted to know whether it is possible to perform the above two operations on audio file in Azure Media Services.

I have came across this documentation [https://learn.microsoft.com/en-us/rest/api/media/transforms/create-or-update which does explain how to create transform and also mentions about AudioOverlay property.

I have created a transform using it but it is not producing the intended output.
Any help here in this regard will be greatly appreciated.

Thanks

Answer 1

Hello @Tarun Vashisth , and thank you for reaching out. The short answer is yes, both operations should be possible.

I'm not sure if you are using a custom transform or built-in transform, but it should be possible with both. You can accomplish that as following:

First step: -

Create a Transform with AudioOverlay as below:

   {
     "@odata.type": "#Microsoft.Media.StandardEncoderPreset",
     "filters": {
       "rotation": "Auto",
       "overlays": [
         {
           "@odata.type": "#Microsoft.Media.AudioOverlay",
           "inputLabel": "audioOverlay",
           "start": "PT5S",
           "end": "PT15S",
           "fadeInDuration": "PT5S",
           "fadeOutDuration": "PT5S",
           "audioGainLevel": 0.5
         }
       ]
     },
     "codecs": [
       {
         "@odata.type": "#Microsoft.Media.AacAudio",
         "channels": 2,
         "samplingRate": 48000,
         "bitrate": 128000,
         "profile": "AacLc"
       },
       {
         "@odata.type": "#Microsoft.Media.H264Video",
         "keyFrameInterval": "PT2S",
         "stretchMode": "AutoSize",
         "syncMode": "Auto",
         "sceneChangeDetection": false,
         "rateControlMode": "ABR",
         "complexity": "Balanced",
         "layers": [
           {
             "width": "1280",
             "height": "720",
             "label": "1280x720",
             "bitrate": 4500000,
             "maxBitrate": 4500000,
             "bFrames": 3,
             "frameRate": "0",
             "slices": 0,
             "adaptiveBFrame": true,
             "profile": "Auto",
             "level": "auto",
             "bufferWindow": "PT5S",
             "referenceFrames": 3,
             "crf": 23,
             "entropyMode": "Cabac"
           }
         ]
       }
     ],
     "formats": [
       {
         "@odata.type": "#Microsoft.Media.Mp4Format",
         "filenamePattern": "Video-{Basename}-{Label}-{Bitrate}{Extension}",
         "outputFiles": []
       }
     ]
   }

You can control the overlay:

• fadeInDuration & fadeOutDuration: To control the fade transition period
• start & end: Control the start and end of the audio fade
• audioGainLevel: You can use it to control the audio volume. Value between 0 - 1.0 For more information you can check our RestFul API documentation here [https://learn.microsoft.com/en-us/rest/api/media/jobs/create?tabs=HTTP#audiooverlay

Second step: -

When you submit the job, you should send the overlay audio asset. We do not have a sample for audio overlay, but we have a sample here [https://github.com/Azure-Samples/media-services-v3-dotnet/blob/main/VideoEncoding/Encoding_OverlayImage/Program.cs for image overlay which you can use as a starting point. The most important part is the below

List<JobInput> jobInputs = new List<JobInput>() {
     new JobInputAsset(assetName: inputAssetName),
     new JobInputAsset(assetName: overlayAssetName, label: OverlayLabel)
};

Notice how you submit 2 assets as input, the first input asset is the video to be encoded, and the second one is the audio overlay, and the label should match what you set in your transform "audioOverlay" in the above example.

The request payload will look something as below:

PUT https://management.azure.com/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/contosoresources/providers/Microsoft.Media/mediaServices/mediaservices/transforms/createdTransform/jobs/job1?api-version=2021-06-01

{
  "properties": {
    "input": {
      "@odata.type": "#Microsoft.Media.JobInputs",
      "inputs": [
        {
          "@odata.type": "#Microsoft.Media.JobInputAsset",
          "assetName": "Ignite"
        },
        {
          "@odata.type": "#Microsoft.Media.JobInputAsset",
          "assetName": "AudioSampleMP3-1m26s",
          "label": "audioOverlay"
        }
      ]
    },
    "outputs": [
      {
        "@odata.type": "#Microsoft.Media.JobOutputAsset",
        "assetName": "AudioFadeInFadeOut-20230126133224"
      }
    ]
  }
}

For more information about the Job creation, you can check the documentation here [https://learn.microsoft.com/en-us/rest/api/media/jobs/create?tabs=HTTP

Answer 2

@Tarun Vashisth , To benefit the community, posting from our offline discussion. @Ebraheem Al-Muneyeer (MSFT)

Use-case: Changing the volume of an audio file and applying fade-in/fade out on the same, via APIs
Is possible to change the volume of an audio file and apply fade-in/out operation on it using Azure Media Services?
-- This is not supported at the moment, you can only apply the effect on the audio-overlay.
Thanks for your feedback!