Live input redundancy AWS Elemental MediaPackage processing flow
Achieve input redundancy in AWS Elemental MediaPackage by sending two streams to separate ingest domains on a channel in MediaPackage. One of the streams becomes the primary, active source of content for the endpoints, while the other continues to passively receive content. If MediaPackage stops receiving content from the active stream, it switches over to the other ingest stream so that content playback isn't interrupted.
If you use MediaPackage with AWS Elemental MediaLive (for example), here's the flow of input redundancy:
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You create a channel group in MediaPackage, as described in Creating a channel group in AWS Elemental MediaPackage. When MediaPackage provisions the channel group, it creates an egress domain for all channels and origin endpoints within the channel group.
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You create a channel within the channel group as described in Creating a channel in AWS Elemental MediaPackage. When MediaPackage provisions the channel, it creates two ingest domains for the channel. If you're not using input redundancy, you can send a stream to either ingest domain. There's no requirement that you send content to both domains.
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You create an origin endpoint within the channel as described in Creating an origin endpoint in AWS Elemental MediaPackage.
Important
If you use short output segments, depending on your playback device, you might see buffering when MediaPackage switches inputs. You can reduce buffering by using the time delay feature on the endpoint. Be aware that using a time delay introduces latency to end-to-end delivery of the content. For information about enabling time delay, see Creating an origin endpoint in AWS Elemental MediaPackage.
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You create an input and channel in AWS Elemental MediaLive, and you add a MediaPackage output group to the channel in MediaLive. For more information, see Creating a Channel from Scratch in the AWS Elemental MediaLive User Guide.
If you use an HLS output group in AWS Elemental MediaLive, the input loss action on the HLS group's settings must be set to pause the output if the service doesn't receive input. If MediaLive sends a black frame or some other filler frame when it's missing input, then MediaPackage can't tell when segments are missing, and subsequently can't perform failover. For more information about setting the input loss action in MediaLive, see Fields for the HLS Group in the AWS Elemental MediaLive User Guide.
Important
If you use a different encoder (not AWS Elemental MediaLive) and you send two separate streams to the same channel in MediaPackage, the streams must have identical encoder settings and manifest names. Otherwise, input redundancy might not work correctly and playback could be interrupted if the inputs switch.
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You start the channel in AWS Elemental MediaLive to send the streams to MediaPackage.
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MediaPackage receives content on both of the ingest URLs, but only one of the streams is used for source content at a time. If the active stream is missing any segments, then MediaPackage automatically fails over to the other stream. MediaPackage continues to use this stream until failover is needed again.
The formula that's used to determine if an input is missing segments is based on the segment lengths on the inputs and the endpoints. If an input is missing segments and quickly recovers, an endpoint with longer segment lengths won't switch inputs. This might result in different endpoints on the channel using different inputs (if one endpoint switches and the other doesn't). This is expected behavior and should not affect the content workflow.
