Setting up a multiplex

There are three components involved in an MPTS: a MediaLive multiplex, MediaLive programs, and MediaLive channels (and their attached MediaLive inputs). You must create these components in this order:

• Create the MediaLive multiplex.

• Create programs in that multiplex. A program can't exist on its own; it always exists in a multiplex.

• Create one channel and attach it to the program. A multiplex channel can't exist on its own; it always exists in a program.

Step 1: Plan the availability zones

Identify two AWS Availability Zones for the multiplex. AWS Elemental MediaLive runs the pipelines for the multiplex in those two zones. Follow these guidelines:

• If the multiplex will include a MediaConnect input and that input already exists, then make a note of the region and Availability Zones of the flows in that input. In the steps below, you will set up the multiplex to use the same region and Availability Zones.

• If the multiplex will include a MediaConnect input and that input doesn't already exists, then decide choose a region and Availability Zones. The flows and the multiplex must use the same region and Availability Zones.

• If the multiplex won't include a MediaConnect input, then choose a region and Availability Zones for the two pipelines in the multiplex.

Step 2: Create the multiplex

Create the multiplex. Make sure to create the multiplex in the identified region and Availability Zones. For more information, see Creating a multiplex and program.

Step 3: Create the inputs

You must create the inputs for the channels that you will create. As with any channel, you must create the inputs before you create each channel.

• Follow the regular procedure for creating the input.

• Inputs for the channels that are used in a multiplex can be MP4 inputs or MediaConnect inputs.

• For MediaConnect inputs, make sure that you follow these rules:

  • The flows in the MediaConnect inputs must use the region and zones that you identified in step 1.

  • All the MediaConnect inputs must use these same two zones.

Step 4: Create the programs

Create the programs to add to the multiplex. For more information, see Creating a multiplex and program. You can add up to 20 programs per multiplex. The multiplex must already exist.

Step 5: Create the channels

Create a channel for each program. The program must already exist.

Using the console, there are two ways to create the channel for a program:

• From the Program details page. After you create each program, details about the program appear, including a link to immediately create a channel for the program. If you choose this link, the Create channel page appears, with many fields already set to the value that is applicable to a channel used in a multiplex. For a summary of the fields that MediaLive sets for you, see Restrictions.

• From the navigation pane. You can create a channel in the usual way, by choosing Channel from the navigation pane. For information about setting some of the fields, see Restrictions.

For more information about completing the channel fields, see Creating a channel from scratch.

Restrictions

There are some restrictions on the configuration of a channel that is used in a multiplex:

Restrictions in the Output Group

The channel can contain only one output group, of type Multiplex. This type follows the rules of a UDP output group. It can contain only one output.

Restrictions in the Output

The following restrictions apply to the output fields.

Field	Value
In Multiplex destination, the Multiplex program field	From the list, choose the multiplex program that this channel belongs to.
In Stream settings, for Video	The output can contain one, and only one, video asset.
In Stream settings, for Audio	The output can contain zero or more audio assets.
In Stream settings, for Captions	The output can contain zero or more captions assets.

Restrictions in the Video

The following rules apply to the fields in the video.

Field	Value
Width and Height (resolution)	Set values for both the width and height. The width can be up to1920 pixels. The height can be up to1080.
Codec settings	Choose H.264 (AVC) or H.265 (HEVC).
In Aspect Ratio, the PAR control field	Set a value. This is required. Don't set up to follow the aspect ratio from the source.
In Rate control, the Rate control mode field	Choose Multiplex.
In Rate control, the Buffer size field	Keep blank.
In Frame rate, the Framerate field	Set a value. This is required. Don't set up to follow the frame rate from the source. The numerator and denominator must result in a decimal value in this range: Lowest supported rate is 23.97 frames per second (2400/1001). Highest supported rate is 60 frames per second.
In GOP structure	For GOP size units, choose FRAMES. Then set GOP structure to 6 or greater. Or for GOP size units, choose SECONDS. Then set GOP structure to 0.1 or greater.
In Codec details, the Profile field	If the codec is H.264, choose one of these profiles: BASELINE HIGH MAIN If the codec is H.265, choose one of these profiles: BASELINE HIGH HIGH_10BIT MAIN

Features That Are Not Restricted

There are some features of the channel that you can set up in the same way as you would set them up in a regular channel:

• For video configuration fields not mentioned in the table earlier in this section, you can set the field to suit your workflow.

• For audio, you can set up as you would set up in a UDP output group in a regular channel.

• For captions, you can set up as you would set up in a UDP output group in a regular channel. Specifically, make sure that the input captions and output captions follow the rules for a UDP output group. See Supported captions.

• For other features, if the feature is available for a UDP output group, then it is available for a channel in a multiplex.