Elemental MediaConvert createJob cache control settings

Question

I am converting mp4 videos in s3 into resized version and uploading to s3 using aws elemental mediaconvert. Is there a setting in the elemental media convert job which I can use to set the CacheControl max-age header so that it gets applied to the resized version of the video?

One of the job setting that I use is shared below

          {
        ContainerSettings: {
          Container: "MP4",
          Mp4Settings: {
            CslgAtom: "INCLUDE",
            FreeSpaceBox: "EXCLUDE",
            MoovPlacement: "PROGRESSIVE_DOWNLOAD",
          },
        },
        VideoDescription: {
          Width: 720,
          ScalingBehavior: "DEFAULT",
          Height: 1280,
          TimecodeInsertion: "DISABLED",
          AntiAlias: "ENABLED",
          Sharpness: 50,
          CodecSettings: {
            Codec: "H_264",
            H264Settings: {
              InterlaceMode: "PROGRESSIVE",
              NumberReferenceFrames: 3,
              Syntax: "DEFAULT",
              Softness: 0,
              GopClosedCadence: 1,
              GopSize: 90,
              Slices: 1,
              GopBReference: "DISABLED",
              MaxBitrate: 3000000,
              SlowPal: "DISABLED",
              SpatialAdaptiveQuantization: "ENABLED",
              TemporalAdaptiveQuantization: "ENABLED",
              FlickerAdaptiveQuantization: "DISABLED",
              EntropyEncoding: "CABAC",
              FramerateControl: "INITIALIZE_FROM_SOURCE",
              RateControlMode: "QVBR",
              QvbrSettings: {
                QvbrQualityLevel: 7,
              },
              CodecProfile: "MAIN",
              Telecine: "NONE",
              MinIInterval: 0,
              AdaptiveQuantization: "HIGH",
              CodecLevel: "AUTO",
              FieldEncoding: "PAFF",
              SceneChangeDetect: "ENABLED",
              QualityTuningLevel: "SINGLE_PASS",
              FramerateConversionAlgorithm: "DUPLICATE_DROP",
              UnregisteredSeiTimecode: "DISABLED",
              GopSizeUnits: "FRAMES",
              ParControl: "INITIALIZE_FROM_SOURCE",
              NumberBFramesBetweenReferenceFrames: 2,
              RepeatPps: "DISABLED",
            },
          },
          AfdSignaling: "NONE",
          DropFrameTimecode: "ENABLED",
          RespondToAfd: "NONE",
          ColorMetadata: "INSERT",
        },
        AudioDescriptions: [
          {
            AudioTypeControl: "FOLLOW_INPUT",
            CodecSettings: {
              Codec: "AAC",
              AacSettings: {
                AudioDescriptionBroadcasterMix: "NORMAL",
                Bitrate: 96000,
                RateControlMode: "CBR",
                CodecProfile: "LC",
                CodingMode: "CODING_MODE_2_0",
                RawFormat: "NONE",
                SampleRate: 48000,
                Specification: "MPEG4",
              },
            },
            LanguageCodeControl: "FOLLOW_INPUT",
          },
        ],
        Extension: ".mp4",
      },
    ],
    OutputGroupSettings: {
      Type: "FILE_GROUP_SETTINGS",
      FileGroupSettings: {
        Destination: "",
        DestinationSettings: {
          S3Settings: {
            AccessControl: {
              CannedAcl: "PUBLIC_READ",
            },
          },
        },
      },
    },
  }

Answer 1

MediaConvert does not presently have a setting that allows adding user metadata (e.g. HTTP headers) to its outputs.

This needs to be implemented as a 'post processing' step to your workflow.

Since MediaConvert uses Amazon S3 as its output destination, you would typically set object metadata (i.e. Cache-Control headers) in Amazon S3 at the time you upload the object. Once the object is uploaded, you cannot modify object metadata. The only way to modify object metadata is to make a copy of the object and set the metadata.

There are a few approaches to do this:

A. You can add cache-control headers to your objects using the Amazon S3 console. The console handles the copying of the object with the new metadata behind the scenes.

Adding headers to your objects using the Amazon S3 console : https://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/Expiration.html#ExpirationAddingHeadersInS3 Editing object metadata in the Amazon S3 console : https://docs.aws.amazon.com/AmazonS3/latest/userguide/add-object-metadata.html

B. You can automate adding metadata by: Configuring an S3 Event notification on your destination S3 bucket, that monitors for 'New object created events' and subsequently triggers Lambda function. The Lambda function code then makes a copy of the recently created object (mp4 file) and sets the metadata.

Amazon S3 Event Notifications : https://docs.aws.amazon.com/AmazonS3/latest/userguide/NotificationHowTo.html

Tutorial: Using an Amazon S3 trigger to invoke a Lambda function : https://docs.aws.amazon.com/lambda/latest/dg/with-s3-example.html

C. Since you are looking to set Cache-Control headers on your objects, I assume that also intend to make your transcoded videos available via a browser or shared cache (e.g. CDN). Should you be using a CDN like CloudFront, you can opt to configure CloudFront to add one or more HTTP headers to the responses that it sends to viewers. Making these changes doesn't require writing code or changing the origin. The HTTP headers that you can add include the Cache-Control header.

Adding HTTP headers to CloudFront responses : https://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/adding-response-headers.html

To do so:

1. Go to AWS Console and navigate to the CloudFront distribution.
2. Go to Behaviors Tab
3. Select the respective / default behavior and go for the edit option to edit that behavior
4. There you can see the option Response headers policy – optional
5. You can make use of an existing response headers policy or create a new one
6. Go to Policies - Response Headers and click on "Create response header policy" under custom policies. If you have an existing policy edit it.
7. For me I have a policy already, so I edited that policy
8. Go for Custom headers – optional
9. Add the Cache-Control header along with the max-age value you want. This value can be set to override origin if you want it.

10. In your respective / default behavior, under the Response headers policy select the one you just created or edited.