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NAME
sound.datatype -- root data type for sounds.
FUNCTION
The sound.datatype is the super-class for any sound related
classes.
METHODS
OM_NEW -- Create a new sound object.
OM_GET -- Obtain the value of an attribute.
OM_SET -- Set the values of multiple attributes.
OM_UPDATE -- Update the values of multiple attributes.
OM_DISPOSE -- Dispose of a sound object.
GM_LAYOUT -- Layout the object and notify the application of the
title and size.
GM_HITTEST -- Determine if the object has been hit with the
mouse.
GM_GOACTIVE -- Tell the object to go active. On SELECTDOWN, the
sound will start playing.
GM_HANDLEINPUT -- Handle input. Currently input (other than
SELECTDOWN) doesn't affect the sound.
GM_RENDER -- cause the graphic to render. currently the graphic
for the sound is just a static icon.
DTM_TRIGGER -- cause an event to occur. currently the only
trigger event is STM_PLAY, which will cause the sound to start
playing.
NOTE: Subclasses which support streaming data access may
support more than just the STM_PLAY event.
DTM_COPY -- Copy the entire sound to the clipboard as 8SVX.
NOTE: Up to and including V40 sound.datatype never stored
a valid voiceheader with the file. this was fixed in v44.
Subclasses which support streaming data access may not
support this method.
DTM_WRITE -- write the entire sound to a file as 8svx.
NOTE: Up to and including V40 sound.datatype never stored
a valid voiceheader with the file. this was fixed in v44.
Subclasses which support streaming data access may not
support this method.
TAGS
SDTA_VoiceHeader (struct voiceheader *) -- set and get the base
information for the sound. voiceheader is defined in
<datatypes/soundclass.h>.
NOTE: Up to and including V40 sound.datatype never returned
a valid voiceheader for om_get and the voiceheader data
was ignored in the OM_NEW/OM_SET cases. This was fixed
in V44.
Applicability is (ISG).
SDTA_Sample (BYTE *) -- Set and get the sound data. Starting
with V40 the sample data does not need to be in CHIP memory.
Starting with V44 the sample data does not need to start
on a WORD-aligned address. Setting SDTA_Sample to NULL
will stop sound replay if sound.datatype was started
playing with a non-NULL SDTA_Sample parameter.
The SDTA_Sample parameter selects mono playback on any
sound channel that is currently available.
NOTE: For streaming sound playback, SDTA_LeftSample,
SDTA_RightSample, and SDTA_Sample will all be
NULL (V44).
Applicability is (ISG).
SDTA_SampleLength (ULONG) -- Length of the sound data in bytes.
Starting with V44 the sample data does not need to be
an even number of bytes. Setting SDTA_SampleLength to 0
will stop sound replay.
Applicability is (ISG).
SDTA_Period (UWORD) -- Set and get the period of the sound
(in timing intervals per sample). This attribute can be
used to affect a playing sound. Please note that the
Amiga audio hardware does not reliably support playback
periods shorter than 124; sound.datatype will limit the
period to valid intervals (V44).
Default for this tag is 394. Applicability is (ISG).
SDTA_Volume (UWORD) -- Set and get the volume of the sound. This
attribute can be used to affect a playing sound.
Valid range is from 0 to 64. Default for this tag is 64.
Applicability is (ISG).
SDTA_Cycles (UWORD) -- Set and get the number of cycles the
sound will be played.
Default for this tag is 1. Applicability is (ISG).
The following tags are new for V40.
SDTA_SignalTask (struct task *) -- task to signal when the
is complete, or if SDTA_Continuous is TRUE, when
the next buffer is needed.
Default for this tag is NULL. Applicability is (IS).
SDTA_SignalBit (ULONG) -- signal mask to use with sdta_signaltask
or 0 to disable.
NOTE: Due to a bug in sound.datatype V40 SDTA_SignalBit was
actually implemented as a signal mask as opposed to a
bit number. The documentation now reflects this. If you
intend to use a signal bit number instead of the mask,
use the new V44 tag SDTA_SignalBitNumber below.
Default for this tag is 0. Applicability is (IS).
SDTA_Continuous (BOOL) -- Used to indicate that the sound
datatype will be fed a continuous stream of data.
Default for this tag is FALSE. Applicability is (I).
The following tags are new for V44.
SDTA_SignalBitMask (ULONG) -- signal mask to use with sdta_signaltask
or 0 to disable. This tag is an alias for SDTA_SignalBit.
Default for this tag is 0. Applicability is (IS).
SDTA_SignalBitNumber (BYTE) -- signal bit to use with sdta_signaltask
or -1 to disable.
Default for this tag is -1. Applicability is (IS).
SDTA_SamplesPerSec (UWORD) -- Set and get the replay frequency of
a sound (in Hz). This attribute can be used to affect a playing
sound. Unlike the SDTA_Period tag, which serves the same purpose,
this tag automatically takes the system clock value into account.
Please note that the Amiga audio hardware does not reliably
support playback rates beyond 28,000 samples per second;
sound.datatype will limit the replay frequency to valid
intervals.
Applicability is (ISG).
SDTA_ReplayPeriod (struct timeval *) -- get the replay period,
i.e. the time it takes for the complete sound to be played.
If the sample size has not been set yet, the timeval tv_sec
and tv_micro members will be set to 0. If the sample is to
be played continuously, both timeval members will be set
to 0xFFFFFFFF.
Applicability is (G).
SDTA_Pan (BYTE) -- Set the stereo panning; this must be set to
a number in the range of -64..64. A value of -64 will
pan the sound to the left channel, silencing the right
channel; a value of 64 will pan the sound to the right
channel and silence the left channel. To center playback,
use a panning value of 0. The panning value only takes
effect if a stereo sound is being played.
Default for this tag is 0. Applicability is (IS).
SDTA_FreeSampleData (BOOL) -- This tag controls whether
sound.datatype will call freevec() on the sample data
attached to an object. If the SDTA_Continuous attribute was
set to TRUE, sound.datatype will never free any data attached
to an object. It is safe to attach the same sample to
more than one channel as sound.datatype will make sure that
no sample data is freed twice.
Default for this tag is FALSE. Applicability is (IS).
SDTA_LeftSample (BYTE *) -- Set and get the left channel sound data.
The sample data does not need to be in CHIP memory and does
not need to start on a WORD-aligned address. Setting
SDTA_LeftSample to NULL will stop sound replay if sound.datatype
was started playing with a non-NULL SDTA_LeftSample parameter.
The SDTA_LeftSample parameter alone selects mono playback on
any left sound channel that is currently available. Used together
with the SDTA_RightSample parameter, stereo playback on any
available stereo channels is selected.
The SDTA_LeftSample parameter takes precedence over the
the SDTA_Sample parameter.
NOTE: For streaming sound playback, SDTA_LeftSample,
SDTA_RightSample, and SDTA_Sample will all be
NULL (V44).
Applicability is (ISG).
SDTA_RightSample (BYTE *) -- Set and get the right channel sound data
.
The sample data does not need to be in CHIP memory and does
not need to start on a WORD-aligned address. Setting
SDTA_RightSample to NULL will stop sound replay if sound.datatype
was started playing with a non-NULL SDTA_RightSample parameter.
The SDTA_RightSample parameter alone selects mono playback on
any right sound channel that is currently available. Used
together with the SDTA_LeftSample parameter, stereo playback
on any available stereo channels is selected.
The SDTA_RightSample parameter takes precedence over the
the SDTA_Sample parameter.
NOTE: For streaming sound playback, SDTA_LeftSample,
SDTA_RightSample, and SDTA_Sample will all be
NULL (V44).
Applicability is (ISG).
SDTA_SyncSampleChange (BOOL) -- If SDTA_Continuous was set to TRUE,
sound.datatype will expect a continuous stream of data to be
played. By specifying "SDTA_SyncSampleChange,TRUE" you request
that new sound data will be played only if the old data has
been played completely (otherwise, playback would restart
immediately with the new sound). If playback is currently in
progress, the task to change the sample data will be made to
wait until playback of the old sound has finished.
Default for this tag is FALSE. Applicability is (IS).
DTA_Immediate (BOOL) -- Select and query whether playback should
start immediately after the object has passed the layout
process.
Default for this tag is FALSE. Applicability is (ISG).
DTA_Repeat (BOOL) -- Select and query whether playback should
loop indefinitely, regardless of the current SDTA_Cycles
settings.
Default for this tag is FALSE. Applicability is (ISG).
NOTES
You cannot switch between mono and stereo playback on the fly while
the sound is still playing. First, stop the sound, then change the
SDTA_Sample/SDTA_LeftSample/SDTA_LeftSample attributes.
The sound.datatype implementation has been cleaned up for V44 to
allow for streaming subclasses to be written. Such subclasses will
always return NULL when their SDTA_LeftSample, SDTA_RightSample and
SDTA_Sample attributes are queried. However, they will never return
0 for the SDTA_SampleLength and SDTA_SamplesPerSec attributes since
these can be used to calculate the length of the entire sample.
Streaming subclasses will respond to the DTM_TRIGGER method, to
start, stop playback, etc. but may not support any other methods
which rely upon the entire sample to reside in memory.