Audio Track Naming and Channel Designators

Certain file formats allow for audio tracks and channels to be identified with specific names and/or designated sound field assignments. Having this information in a file enables media players to properly direct audio to the appropriate speakers, or to apply processing (i.e. downmix) to the audio when needed.

Track Name

One of the options in a transcode task’s target settings for an audio track is to include a track_name value. In the example below, there are two audio tracks, with the first track to be named “LEFT TOTAL” and the second track named “RIGHT TOTAL”.

"audio": [
  {
    "codec": "pcm",
    "channels": 1,
    "track_name": "LEFT TOTAL",
    "sample_rate": 48000,
    "sample_size": 24
  },
  {
    "codec": "pcm",
    "channels": 1,
    "track_name": "RIGHT TOTAL",
    "sample_rate": 48000,
    "sample_size": 24
  }
]

The resulting file produced here would be reported in the Hybrik’s Storage Browser as shown:

Channel Designator

The next example includes the channel_designators settings for both of the audio tracks. When applied, the resulting file will contain the channel information which can be accessed during downstream processing and/or playback. Here are two common examples for both a stereo and 5.1 audio tracks:

{
  "audio": [
    {
      "codec": "pcm",
      "channels": 2,
      "sample_rate": 48000,
      "sample_size": 24,
      "track_name": "Stereo",
      "channel_designators": [
        "left_total",
        "right_total"
      ]
    },
    {
      "codec": "pcm",
      "channels": 6,
      "sample_rate": 48000,
      "sample_size": 24,
      "track_name": "5.1",
      "channel_designators": [
        "left",
        "right",
        "center",
        "lfe_screen",
        "left_surround",
        "right_surround"
      ]
    }
  ]
}

The channel assignments for the resulting file are reported in Hybrik’s Storage Browser as well as in common tools such as MediaInfo. Here’s an example screenshot from the Storage Browser:

Examples

A complete sample job which includes a source and transcode task set using the example above can be found here

• Audio Track Naming Example
• Audio Track Naming Example Interleaved to Discrete