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Devices:
cd.device
CD_ADDCHANGEINT
CD_ADDFRAMEINT
CD_ATTENUATE
CD_CHANGENUM
CD_CHANGESTATE
CD_CONFIG
CD_EJECT
CD_GETGEOMETRY
CD_INFO
CD_MOTOR
CD_PAUSE
CD_PLAYLSN
CD_PLAYMSF
CD_PLAYTRACK
CD_PROTSTATUS
CD_QCODELSN
CD_QCODEMSF
CD_READ
CD_READXL
CD_REMCHANGEINT
CD_REMFRAMEINT
CD_SEARCH
CD_SEEK
CD_TOCLSN
CD_TOCMSF
CloseDevice
OpenDevice
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Docs » Autodocs » cd.device » CD_ATTENUATE
CD_ATTENUATE -- Attenuate CD audio volume (immediately or gradually)
IO REQUEST
io_Device preset by the call to OpenDevice()
io_Unit preset by the call to OpenDevice()
io_Command CD_ATTENUATE
io_Data NULL
io_Length duration of volume fade in frames
io_Offset target volume level (0 - 0x7FFF) (-1 = status only)
io_Error Returns an error if drive does not support attenuation
io_Actual current volume level (fade may be monitored)
This command will ramp the CD audio volume up or down from its
current value to the value contained in io_Offset. The range is 0
(silence) to 0x7FFF (full volume). If -1 is specified as the target,
the attenuation will not be modified; the current attenuation value
will be returned in io_Actual.
io_Length contains the duration of the fade. In seconds, this is
io_Length divided by the current frame rate (usually 75).
Note that this command returns before the fade has completed. Thus,
once started, a fade cannot be aborted. You can, however, send a
new CD_ATTENUATE command, which will immediately override any fade
currently in progress. An io_Length of zero means attenuate
immediately.
If a gradual attenuation command is sent before the play command, the
fade will begin as soon as the play command is sent.
This command has no effect on Amiga audio volume, only CD audio.
If the drive does not support volume attenuation, but does support
mute, a value of under $0800 should be considered mute, and equal
to or above should be full volume. If chunky attenuation is
supported, the drive should do the best it can. If the drive does
not support volume attenuation at all, an error should be returned.
Even if only mute is supported, if gradual attenuation is requested,
the device should still emulate the fade command and mute based on
the $0800 boundary.
CD_INFO()
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