Step 2: Map the output encodes to the sources - MediaLive
Example of mapping

Step 2: Map the output encodes to the sources

In the first step of planning the channel, you identified the number of encodes you need in each output group. You must now determine which assets from the source you can use to produce those encodes.

Result of this procedure

After you have performed this procedure, you will have identified the following key components that you will create in the channel:

  • The video input selectors

  • The audio input selectors

  • The captions input selectors

Identifying these components is the last step in planning the input side of the channel.

To map the output to the sources

  1. Obtain the list of output encodes you want to produce. You created this list in the previous step. It is useful to organize this list into a table. For example:

    Example
    Output group Type of encode Encode nickname

    Characteristics of the encode
    HLS Video VideoA

    AVC 1920x1080, 5 Mbps
    VideoB

    AVC 1280x720, 3 Mbps
    VideoC AVC 320x240, 750 Kbps
    Audio AudioA AAC 2.0 in English at 192000 bps
    AudioB AAC 2.0 in French at 192000 bps
    Captions CaptionsA

    WebVTT (object-style) converted from embedded, in English
    CaptionsB WebVTT (object-style) converted from embedded, in French
    RTMP Video VideoD AVC 1920x1080, 5Mbps
    Audio AudioC Dolby Digital 5.1 in Spanish
    Captions CaptionsC RTMP CaptionInfo (converted from embedded) in Spanish
    Archive Video VideoE AVC, 1920x1080, 8.5 Mbps
    Audio AudioD Dolby Digital 2.0 in Spanish
    AudioE Dolby Digital 2.0 in French
    AudioF Dolby Digital 2.0 in English
    Captions CaptionsD DVB-Sub (object-style) converted from Teletext, in 6 languages.

  2. Obtain the list of sources that you created when you assessed the source content and collected identifiers. For an example of such a list, see Step 4: Assess the upstream system .

  3. In your table of output encodes, add two more columns, labeled Source and Identifier in source.

  4. For each encode (column 2), find a line in the list of sources that can produce that encode. Add the source codec and the identifier of that source codec. This example shows a completed table.

    Example
    Output group Type of encode Encode nickname

    Characteristics of the encode

    		 Source Identifier in source
    HLS Video VideoA

    AVC 1920x1080, 5 Mbps

    		 HEVC PID 600
    VideoB

    AVC 1280x720, 3 Mbps

    		 HEVC PID 600
    VideoC AVC 320x240, 750 Kbps HEVC PID 600
    Audio AudioA AAC 2.0 in English at 192000 bps AAC 2.0 PID 759
    AudioB AAC 2.0 in French at 192000 bps AAC 2.0 PID 747
    Captions CaptionsA

    WebVTT (object-style) converted from embedded, in English

    		 Embedded Channel 4
    CaptionsB WebVTT (object-style) converted from embedded, in French Embedded Channel 2
    RTMP Video VideoD AVC 1920x1080, 5Mbps HEVC PID 600
    Audio AudioC Dolby Digital 5.1 in Spanish Dolby Digital 5.1 PID 720
    Captions CaptionsC RTMP CaptionInfo (converted from embedded) in Spanish Embedded Channel 3
    Archive Video VideoE AVC, 1920x1080, 5 Mbps HEVC PID 600
    Audio AudioD Dolby Digital 2.0 in Spanish AAC 2.0 PID 746
    AudioE Dolby Digital 2.0 in French AAC 2.0 PID 747
    AudioF Dolby Digital 2.0 in English AAC 2.0 PID 759
    Captions CaptionsD DVB-Sub (object-style) converted from Teletext, in 6 languages. Teletext PID 815

    You will use this information when you create the channel:

  5. After you have identified the source assets, group those assets that are being used more than once, to remove the duplicates.

  6. Label each asset by its type—video, audio, or captions.

    Example
    Input asset Asset nickname Source Characteristics Identifier in Source
    video 1 Video1 Video HEVC PID 600
    audio 1 Audio1 Audio AAC 2.0 Spanish PID 746
    audio 2 Audio2 AAC 2.0 French PID 747
    audio 3 Audio3 AAC 2.0 English PID 759
    audio 4 Audio4 Dolby Digital 5.1 Spanish PID 720
    captions 1 Captions1 Captions Embedded French Channel 2
    captions 2 Captions2 Embedded Spanish Channel 3
    captions 3 Captions3 Embedded English Channel 4
    captions 4 Captions4 Teletext, all languages PID 815

Example of mapping

The following diagrams illustrate the mapping of the output encodes back to source assets. The first diagram shows the outputs (at the top) and the sources (at the bottom). The other three diagrams shows the same outputs and sources with the mappings for video, for audio, and for captions.

Encodes and assets

Mapping video encodes to assets

Mapping audio encodes to assets

Mapping captions encodes to assets