Operation Manual

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option is offered in addition to the previous choices. Note that AAC-LC requires
additional licensing. The two variants for this control are depicted below.
If the Output Protocol in the Encoder Connections Tab is set to RTMP, this field is forced
to AAC-LC and becomes not editable. The reason is that the RTMP protocol has no
support for MPEG-1 Layer II audio at 48 kHz sampling. It also has no support for Dolby.
 Mode: The available choices for this parameter depend on the Audio Encoding selection,
as follows:
o MPEG-1 Layer II: the available modes are Stereo or Single Channel. If you
select Single Channel (Mono), only the audio connected to the Left input will be
encoded.
o AAC-LC: the available modes are Stereo, Mono, or Dual Mono. If you select
Mono, only the audio connected to the Left input will be encoded.
o Dolby Passthrough: This parameter is not displayed.
 Audio Bit Rate: The format of this parameter is a function of the Audio Encoding
setting. For MPEG-1 Layer II, this parameter is a drop-down list of valid discrete bit
rates; the values in the list are also a function of the Mode Setting. For AAC-LC, the
range is 112 to 512 kb/s for Stereo and Dual Mono, and 56 to 256 kb/s for Mono. This
parameter is not displayed for Dolby Passthrough as the B264 will automatically detect
the incoming audio bit rate.
 Peak Audio Bit Rate: This parameter is only displayed for AAC-LC. It must be set at
least 1 kb/s higher than the Audio Bit Rate. The maximum value is 288 kb/s for Mono,
and 576 kb/s for Stereo and Dual Mono.
 Sample Rate: This field is for information purposes only. The B264 only supports
48 kHz audio sample rate.