Handling loss of video input - MediaLive
How MediaLive handles video input lossConfiguring the replacement contentCustomizing delivery

Handling loss of video input

You can customize the way that MediaLive handles media when the video input into the channel is lost.

How MediaLive handles video input loss

When MediaLive is ingesting an input, it might detect that the video source has been lost. This loss causes MediaLive to start to follow the input loss behavior handling. MediaLive starts to encode replacement content (fill frames) on the output side. This handling ensures that the channel can continue to encode video content. (A key rule of MediaLive is that a running channel must always be encoding content.)

The channel follows the input loss handling until it recovers and goes back to normal encoding. The way that the channel recovers depends on whether you implement automatic input failover:

  • If you implement automatic input failover, the input loss handling will continue until the video black failover condition triggers the switch to another input (or until the input recovers.) If the second input fails, input loss handling will restart and continue until you have fixed the problem with both of the inputs.

  • If you don't implement automatic input failover, the input loss handling will continue until the input recovers or until you resolve the problem with the input.

The two features complement each other but work on different timing:

  • Input loss handling occurs as soon as an expected frame fails to arrive. For example, if the framerate of the input is 60 FPS, the handling will be triggered if a frame does not arrive within 17 Msecs of the previous frame. (17 Msecs is approximately 1 second divided by 60.)

  • The trigger for automatic input failover is longer and is configurable. A typical trigger is 1000 Msecs.

Input loss compared to input probing failure

Input loss handling occurs only after a previously healthy input becomes unhealthy.

It is also possible for an input to fail before that. When a channel starts and MediaLive begins to ingest the first input, it probes for the input—it attempts to detect the input and the sources. If the detection fails, then the input and the chanel fails immediately. You must resolve the problem and restart the channel. The problem might be that the input isn't present (this problem applies mostly to RTMP inputs), or the input exceeds the current channel specifications, or the input settings are wrong.

Default behaviour input loss handling

The default for input loss handling is the following:

  • Encoding the replacement content: Repeat and encode the last valid frame that was received. Repeat for 1000 Msecs. Then encode black frames for 1000 Msecs. Then encode a black slate indefinitely.

  • Delivering the content: The default handling is to emit (deliver) the encoded replacement content.

Customizing input loss handling

  • You can customize the timing of the replacement content, and you can customize the content of the slate..

  • In some output group types, you can change the delivery so that the encoded content isn't delivered.

Configuring the replacement content

You can customize the duration of the replacement content, and you can customize the image or color used for the slate. For example, you can change the slate to an image (such as Please stand by).

Note

This section assumes that you are familiar with creating or editing a channel, as described in Creating a channel from scratch.

  1. On the Create channel page of the MediaLive console, choose General settings. Expand Global configuration. Choose Enable global configuration, if necessary.

  2. In Input loss behavior, choose Input loss Behavior. More fields appear. These fields control the replacement content, as follows:

    • Encode the last valid frame for the time specified in Repeat Frame Msec. Zero means disabled (skip the repeat frame and go to the black frame). The value 1,000,000 means repeat the previous forever.

    • When Repeat Frame Msec expires, encode a black frame for the time specified in Black Frame Msec. Zero means disabled (skip the black frame and go to the slate). The value 1,000,000 means repeat black frames forever.

    • When Black Frame Msec expires, switch to sending a specified slate or color, as specified in Input Loss Image Type and then Input Loss Image Color or Input Loss Image Slate.

  3. Complete one or more fields to customize the behavior. For details about a field on the MediaLive console, choose the Info link next to the field.

Customizing delivery

You can change the default handling of the replacement content so that instead of delivering the encoded output, MediaLivediscards it. You can change the handling in the following types of output groups:

  • HLS

  • Microsoft Smooth

  • RTMP

  • UDP/TS

For all other types of output groups except MediaPackage, MediaLive always delivers the content. For a MediaPackage output group, MediaLive always pauses delivery.

Note

This section assumes that you are familiar with creating or editing a channel, as described in Creating a channel from scratch.

  1. On the Create channel page of the MediaLive console, choose the output group in the left navigation bar.

  2. In the Settings section for the output group, find the Input Loss Action field for that output group. Choose the option you want for all the outputs (including outputs that don't include video) in this output group. See the table after this step.

This table lists the delivery options for the output groups. Read across each row.

Type of output group Field Description

HLS

Microsoft Smooth

RTMP

 EMIT_OUTPUT Deliver the replacement content.

This is the default for these output groups.

HLS

Microsoft Smooth

RTMP

 PAUSE_OUTPUT Encode only the repeat frames, if the channel is configured to process them. After that content ends, stop delivery for all outputs in this output group.

Note that MediaLive keeps the underlying RTMP connection open.
UDP EMIT_PROGRAM Encode the replacement content, and deliver the program and all the tables for this output group.

This is the default for UDP.
UDP

DROP_TS

 Stop delivery of the entire transport stream in this output group.
UDP DROP_PROGRAM

Drop the program from the transport stream. MediaLive replaces the program with null packets, in order to meet the TS bitrate requirement.

Deliver the null packets and all the tables for this output group.

Recommendation

You should make sure that the delivery meets the expectations of the downstream system.

For example, if the channel is a standard channel (with two redundant pipelines), the downstream system might be set up to switch to the output from the second pipeline. In this case, it's best if you set up the output to stop emitting the output.

As another example, the channel might have only one pipeline. Furthermore, the downstream system might not behave well if it loses delivery from MediaLive. Therefore, it's best for you to set up to emit the output. The downstream system will remain stable, and you could set up MediaLive with a "Please stand by" slate to improve the experience for the person watching the video.