Skip to main content

Audio Encoder Settings

The following table lists the Audio Encoder controls and settings:

Audio Encoder SettingDefaultDescription/Values
CodecMPEG-2 ADTS

Select the audio compression algorithm:

  • MPEG-2 AAC-LC ADTS - Encodes audio using the ISO/IEC 13818-7 MPEG-2 AAC-LC algorithm with an ADTS header. (Default)
  • MPEG-4  AAC-LC LOAS/LATM - Encodes audio using the ISO/IEC 14496-3 MPEG-4 AACLC algorithm with a LOAS/LATM header.

  • 16 bit Pass-Through -  Passes raw PCM (Pulse-Code Modulation) audio through the audio encoder for lossless audio transmission. In MPEG-2 TS streams, this audio codec uses the SMPTE 302M format, and currently supports the carriage of 16 bits of PCM data transported in 2, 4, 6, or 8 audio channels (i.e. 1 to 4 audio channel pairs). 

    Note

    In PCM Pass-Through audio:  

    • When the audio channel mode is set to mono, the audio content is duplicated in both channels of the single channel pair being sent.
    • When the audio channel mode is set to 3.0, 5.0, or 7.0, there is an extra audio channel carried in the 302M channel pair bundles. This extra channel will have zeroed (silent) content.
    • The encoder can detect and pass through Dolby AC3 and E-AC3 audio. 



Input Interface SDI

Select the input interface for the audio encoder. Options are:

Note

On the Makito FX DisplayPort unit this parameter is read-only, as DisplayPort is the only input option. 

Channel Mode 

Stereo

General

The Channel Mode determines the audio channel layout (both the layout expected from the input, and the layout expected upon output on the decoder end), and the number of audio channels required to process the audio input.

Available channel modes depend on the chosen Input Interface. Options are:

Audio Channel Layouts

In order to ensure that your audio is processed properly, the audio channels in the upstream source should be configured as follows for each Channel Mode: 

Note

Generally, the encoder can process intelligible audio as long as each channel pair value is found in the channel mode, regardless of positioning.

The exception to this is LFE (Low-Frequency Effects, also known as the sub-woofer). The LFE must be the fourth channel in the input channel set, and the last audio object in the AAC elementary stream access unit when it is present (i.e. in modes 5.1 and 7.1) in order to produce intelligible audio.

AC3 & E-AC3 Audio

When passing through encoded AC3 or E-AC3 audio, the Channel Mode will determine what audio data is passed through, which varies based on the SMPTE 337 encapsulation mode used in the upstream source. These encapsulation modes can hold PCM Audio, non-PCM audio, or a combination of both. To prioritize AC3/E-AC3 (i.e. non-PCM audio) select the appropriate channel mode according to the table below. 

Bitrate128 kbps

The Audio Bitrate for the AAC encoder. Each Channel Mode supports a certain bitrate range. Users can select lower audio encoding bitrates for limited bandwidth streaming situations, or higher bitrates for higher quality audio encoding.

Note

This parameter is unused when the codec is 16 bit Pass-Through, instead, the bitrate is a fixed number determined by the number of channel pairs carried. 

  • Mono: 12 to 288 kbps
  • Stereo: 14 to 576 kbps
  • 3.0: 16-864 kbps
  • 4.0: 18-1152 kbps
  • 5.0: 20-1440 kbps
  • 5.1: 21-1440 kbps
  • 7.1:  25-2016 kbps
Sample Rate (kHz)48 kHzThe number of audio samples per second taken from the incoming signal. 48 kHz only.
AAC-LC AlgorithmMPEG-2 ADTS

The audio compression algorithm:

  • MPEG-2 ADTS - Encodes audio using the ISO/IEC 13818-7 MPEG-2 AAC-LC algorithm with an ADTS header.
  • MPEG-4 LOAS/LATM - Encodes audio using the ISO/IEC 14496-3 MPEG-4 AACLC algorithm with a LOAS/LATM header.
Languagen/a(Optional) To specify the language of the input, start typing in the desired language and select it from the list. The language values are three-letter codes, defined in ISO 639-2 (https://www.loc.gov/standards/iso639-2/php/code_list.php).

Statistics

n/a

Click Statistics icon

 to view statistics for the encoder. See Audio Encoder Statistics.

Mute/Unmute

n/a

Click the Mute/Unmute icon

/
to encode silence instead of the selected audio input (for example, this may be used when you do not wish to encode the audio but the decoder being used does not support decoding of video only streams), or to unmute a muted encoder. 

Start/Stop

n/a

Click the Start/Stop

/
icon to restart a stopped encoder or stop an active encoder.

Related Topics

JavaScript errors detected

Please note, these errors can depend on your browser setup.

If this problem persists, please contact our support.

Contact Support Close