06 August 2015 - DMG: downmix coefficients, repair options, and alerts

Field Name	Description	Allowed Values	Default Values
dc_repair	Corrects a DC offset	yes, no	no
phase_repair	Corrects a phase difference between the L and R channels	yes, no	no

Field Name	Description	Allowed Values	Default Values
dmg_alerts	Alerts provide information about a particular defect to the standard output. Silent Channel, DC Offset or Out of Phase Channel, for example	yes, no	no

Field Name	Description	Allowed Values	Default Values
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
The metadata does not contain downmix coefficients when the encoded audio is stereo.