Downmix

Down mixing parameters.

When changing the number of output channels from source material, the following settings control how source audio amplitude and positioning will be mixed into the requested output.

Parameter

Description

Allowed Values

Default Value

downmix_mode

Dolby Encoding Engine downmix mode

pl2, loro, ltrt

pl2

hybrid_downmix

Hybrid downmix

yes, no

none

dmix_preference

DMG audio-dmix-preference option

loro, ltrt, pl2, unknown

none

dmix_center_level

Sets Lt/Rt and Lo/Ro downmix(5.1-to-stereo) levels for the central channel.

+3.0, +1.5, 0.0, –1.5, –3.0, –4.5, –6.0, and –inf.

–3.0

dmix_center_level_ltrt

Overrides the Lt/Rt downmix level setting for the central channel when <dmix_center_level> is used.

+3.0, +1.5, 0.0, –1.5, –3.0, –4.5, –6.0, and –inf.

–3.0

dmix_center_level_loro

Overrides the Lo/Ro downmix level setting for the central channel when <dmix_center_level> is used.

+3.0, +1.5, 0.0, –1.5, –3.0, –4.5, –6.0, and –inf.

–3.0

dmix_surround_level

Sets Lt/Rt and Lo/Ro downmix(5.1-to-stereo) levels for Ls and Rs channels.

–1.5, –3.0, –4.5, –6.0, and –inf.

–3.0

dmix_surround_level_ltrt

Overrides the Lt/Rt downmix level setting for Ls and Rs channels when <dmix_surround_level> is used.

–1.5, –3.0, –4.5, –6.0, and –inf.

–3.0

dmix_surround_level_loro

Overrides the Lo/Ro downmix level setting for Ls and Rs channels when <dmix_surround_level> is used.

–1.5, –3.0, –4.5, –6.0, and –inf.

–3.0

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Note

The metadata does not contain downmix coefficients when the encoded audio is stereo.