AWS-Fast-Channels

This SAM project deploys an end to end FAST channel solution primarily using MediaTailor's Channel Assembly feature to produce linear HLS and DASH streams. Rather than running a Live Encoding processes, this solution prepares the media as if it were VOD and then uses playlist manipulation available through Channel Assembly to create 24x7 live streams.

At deployment, you will first define two buckets. The input bucket is where you can drop your mezzanine input VODs (such as MP4s, MXF, MOV etc). This will trigger a MediaConvert job to prepare your media into HLS, DASH and CMAF streaming formats. Once the MediaConvert job is complete, the output will be ingested into MediaPackage-Vod and MediaTailor-ChannelAssembly.

Additionally, a custom resource of the AdBreakSlates will be generated upon deployment. This will allow you to insert ad breaks to your channel output. You can configure additional AdBreak times by modifying the template.yaml file

A SampleChannel is also created. This is where you can start adding Programs to create a schedule. See the MediaTailor Channel Assembly Quickstart guide to adding Programs for more information: https://docs.aws.amazon.com/mediatailor/latest/ug/channel-assembly-getting-started.html#ca-getting-started-create-programs

An AdServer Url can also be defined if you already have an Ad Server. By default a dummy ad server is used that will respond with ads so you can test an end to end workflow

You may also define add opportunities by adding Tags to the S3 object that is uploaded. By default the tag name is AdOffsets but this can be customized in the parameters. Your AdOffsets Tag Value should be a space delimited list of millisecond offsets from the start of the media. For example, to place an ad opportunity at 30s, 90s and 120s insert a value of 30000 90000 120000. This will force MediaConvert to create an i-frame and segment boundary at these positions so that you can use the same offset values when creating Programs in Channel Assembly.

Features

• Fully automated set-up of S3, MediaConvert, MediaPackage, CloudFront and MediaTailor
• Frame-accurate ad insertion
• Follows best practice guidelines including securing MediaPackage Origin and Caching configuration
• Custom Resource to automatically generate AdBreak slates
• Alerts to media processing via email

Diagram

Deployment

cd deployment
sam build --template-file fast-on-aws.deployment
sam deploy --guided --capabilities CAPABILITY_IAM CAPABILITY_AUTO_EXPAND

Make sure you have SAM installed: https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/install-sam-cli.html#install-sam-cli-instructions

Once deployed, you can add some video content to the input bucket that is created. You can find the name of the bucket in the Ouputs section of the CloudFormation deployment:

aws s3 cp ${my_movie} s3://${input_bucket_generated}

You will then recieve an email from the SNS topic when the content is available for playback as a VOD, along with the MediaTailor Ad Insertion URLs.

To add ${my_movie} to a linear channel, find the Channel named *-MediaTailorSampleChannel and add a new Program referencing ${my_movie} in the SourceLocation named *-MediaTailorSourceLocation.

If you would like to insert ad breaks, use the AdBreakSlates_* VOD Sources in the same SourceLocation. This slates will be replaced by the MediaTailor Ad Insertion configuration with the Ad Server VAST response.

Optional

Before you build, you can customize the list of bit rate presets you wish to use by running the generate_presets.py script.

cd source/scripts
python3 generate_presets.py

You can customize the presets generated by modifying the assets/presets.csv file. See further instructions in the SCRIPTS.md readme.

Adding Programs to your Channel

This project will automatically create a sample Channel Assembly channel: ${AWS::StackName}-MediaTailorSampleChannel. Once an asset is processed it will also be imported as a Channel Assembly Vod Source resource and scheduled to the Sample Channel with the Ad Breaks. You can create Channel Assembly Program resources to schedule a Vod Source to play on a new channel if you wish.

Make sure you start a channel before trying to playback.

Check the CloudFormation Outputs for the SSAI Url to the Channel.

Here is an example to generate programs. You can use the same AdbreakOffsets as defined in the S3 upload.

import boto3

client = boto3.client('mediatailor')

source_location_name = 'source_location_name'
channel_name = 'sample_channel_name'
vod_source_name  = 'my_source'

def generate_adbreaks(offsets_millis, source_location_name):
    adbreaks = []
    count = 0

    for offset_millis in offsets_millis:
        adbreak = {
            'Slate': {
                'SourceLocationName': source_location_name,
                'VodSourceName': 'AdBreakSlate30000'
            },
            'MessageType': 'SPLICE_INSERT',
            'OffsetMillis': offset_millis,
            'SpliceInsertMessage': {
                'AvailNum': count,
                'AvailsExpected': count,
                'SpliceEventId': count,
                'UniqueProgramId': count
            }
        }
        adbreaks.append(adbreak)
        count += 1

    return adbreaks

adbreaks = generate_adbreaks([0, 30000, 60000, 90000, 120000], source_location_name)
response = client.create_program(
    AdBreaks=adbreaks,
    ChannelName=channel_name,
    ProgramName=vod_source_name,
    SourceLocationName=source_location_name,
    VodSourceName=vod_source_name,
    ScheduleConfiguration={
        'Transition': {
            'RelativePosition': 'BEFORE_PROGRAM',
            'Type': 'RELATIVE'
        }
    },
)
print(response)

Ad Insertion

VOD

If you add ad break offset values to the AdOffsets named Tag to the input S3 media file, MediaConvert will automatically create zero duration Ad Breaks at these locations. In the outputted HLS playlists, the following tags will appears:

#EXT-X-CUE-OUT: 0
#EXT-X-CUE-IN

If you request the vod source via the ${StackName}-PlaybackConfiguration-Vod MediaTailor Playback Configuration, dynamically generated ad breaks will be automatically inserted at those add opportunities, based on the VAST response from the ad server. By default, a dummy VAST response is configured to simulate ad playback.

For example, if your asset in MediaPackage-Vod has the following URL: https://e3250800c185df7ae473c3fd9c7a91aa.egress.mediapackage-vod.us-west-2.amazonaws.com/out/v1/24247f7e7f2942509058713671dce466/209b7701f2224791a9a44440e6e5b9e0/e2fdd7d6ae5f4e41ac57089be4de2d02/index.m3u8

Replace the hostname component with the MediaTailor HLS Playback URL: https://1eba27f282c44ac1a5116e0f33924433.mediatailor.us-west-2.amazonaws.com/v1/master/1bab6b4238868b752a9e9daae3e2a4911f2a2fc9/fast-on-aws5-PlaybackConfiguration-Vod/out/v1/24247f7e7f2942509058713671dce466/209b7701f2224791a9a44440e6e5b9e0/e2fdd7d6ae5f4e41ac57089be4de2d02/index.m3u8

LIVE

The Output of the CloudFormation deployment will contain the URLs of the Channel Assembly channels behind an SSAI playback configuration.

Notes:

• Currently MediaTailor Ad Insertion does not support CMAF outputs withou a custom transcode profile
• Currently HEVC only works in CMAF ouputs when using HLS in Apple iOS
• Ergo, HEVC and CMAF with SSAI is not currently advisable.
• The CloudFormation resources will take some time to deploy due to sequentially creating MediaConvert Presets. This is to avoid hitting TPS limits on creation.
  • CloudFront distribution also takes some time to create

FAQs

How much will this solution cost?

This solution will incur the following costs as per your AWS usage rates:

• S3 Storage
• MediaPackage Packaged Bytes Out
• MediaConvert Transcode Minutes
• MediaTailor Channel Assembly Hours
• MediaTailor Ad Insertion
• MediaTailor Ad Delivery Bytes Out
• CloudFront CDN Bytes Out

How can I change the bit rate ladder?

within the template.yaml you can configure the Presets with Type: AWS::MediaConvert::Preset. Make sure to also update the job template (Type: AWS::MediaConvert::JobTemplate) if you remove or add presets. Included in the repo is a script in the MediaConvertJobTemplate directory which will generate Presets and associated Template for you. Simply modify the included presets.csv and execute generate_presets.py. You will need the python3 package troposphere installed.

How can I delete the resources created by this SAM?

firstly make sure the following resources are empty (i.e. contain no resources but still exist)

• SourceLocation (i.e delete all VodSources)
• input and output s3 buckets (i.e. delete all objects in the bucket)
• MediaPackage PackagingGroup (i.e. delete all VOD Assets associated with the given Packaging Group)

How can I access the streams?

The SAM project will emit an Output with the prefix URLs to the SampleChannel Ad Insertion hostname. Make sure the channel is in running before you request the stream.