Audio Encoder Settings

The following table lists the Audio Encoder controls and settings:

Audio Encoder Setting	Default	Description/Values
Codec	MPEG-2 ADTS	The audio compression algorithm. Options are: MPEG-2 ADTS - Encodes audio using the ISO/IEC 13818-7 MPEG-2 AAC-LC algorithm with an ADTS header. (Default) MPEG-4 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 virtually 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-1	The input audio source. Options are: SDI-1 SDI-2 SDI-3 SDI-4
Input Interface	SDI-1	Analog (Makito X4 Rugged only)
Channel Mode	Stereo	General The Channel Mode determines the audio channel layout (both the layout expected from the SDI input, and the layout expected upon output on the decoder end), and the number of audio channels required to process the audio input. Options are: Stereo Mono Left Mono Right 3.0 (3 ch) 4.0 (4 ch) 5.0 (5 ch) 5.1 (6 ch) 7.0 (7 ch) Note Channel Mode 7.0 is only available when the Codec is set to 16 bit Pass-Through. 7.1 (8ch) Important It is recommended not to exceed 100 channels when configuring multiple audio encoders. Encoding more than 100 audio channels may compromise system performance.
		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.
Bitrate	128 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. Options are: Mono: 12-288 kbps Stereo: 14-576 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
Input Channels	Ch 1-2	The channels at which the audio input will start and end. The Input Channel ranges will change automatically depending on the required number of audio channels in the selected Channel Mode.
Sample Rate (kHz)	48 kHz	The number of audio samples per second taken from the incoming signal. Possible values are: 48 kHz 16 kHz (Analog Inputs only)
0 dBFS Audio Level (dBu)	+6 dBu	(Analog Input only) Adjusts the maximum analog Audio Input signal level (0 dBfs) from 0 to +6dBU. Note This is useful in applications such as broadcast and streaming to allow higher audio headroom.
Language	n/a	(Optional) To specify the language of the input, start typing letters and select the language from the list. The language values are three-character codes, defined in ISO 639-2 (https://www.loc.gov/standards/iso639-2/php/code_list.php).
Statistics	n/a	Click the Statistics icon to view statistics for the encoder. See Audio Encoder Statistics.
Mute/Unmute	n/a	Click the Mute/Unmute icon / to turn the selected audio input on or off. A muted stream will encode silence instead of audio input. This may be used, for example when you do not wish to encode the audio but the decoder being used does not support decoding of video only streams.
Stop/Start	n/a	Click the Stop/Start icon / to stop or start an active audio encoder.

Related Topics

General

Audio Channel Layouts

AC3 & E-AC3 Audio