registerByteArrayCallback

Usage

soundObject.registerByteArrayCallback(position, #callbackFunction, [castMemRef], [read-write/read-only flag])

Description

Byte array method; calls the callback method specified using #callbackFunction. The byte array is filled with the audio sample data received from the sound object.

Parameters

Parameter	Description	Default value
position	You can specify the #preFilter and #postFilter in this parameter. #`preFilter` specifies the audio PCM samples before applying the sound object filters. #`postFilter` specifies the audio PCM samples after applying the sound object filters.	Required
symCallback	Registers `callbackFunction` as the callback method for the audio data in the sound object.	Required
castMemRef	Specifies a cast member reference when the callback method is a member of the parent script. Do not specify the parameter if the callback method is in movieScript.	Optional
read-write/read-only flag	Specifies whether the callback is `#readOnly` or #`readWrite`. #readOnly - The audio bytearray data is read only in the callback method. #readWrite - The audio bytearray data is read and write in the callback method. So the data can be modified in the callback.	#readOnly

The callbackFunction implementation is as follows:

On callbackFunction byteArray, bitDepth, sampleRate, channelCount 
    Put  byteArray --Audio output implementation 
End

Note: Inside the callback handler, if there is any script that causes runtime errors (such as property not found), the error messages are not displayed, and the handler execution is aborted at the point of error. All the subsequent statements are not executed.

Examples

    -- BUTTON BEHAVIOR -- 
    global gSound     -- soundObject 
    global gMixer -- mixer object 
    global counter -- Counter to fill the silence 
    global fillSilence -- Flag to fill the silence 
    on mouseUp(me) 
    ------------------------------------------------------- 
    -- ACTION: Creates a soundObject from the Cast member. 
    -- The callback handler HAS to be in a Parent Script. 
    -- See the Movie Script for callback details. 
    -------------------------------------------------------------------- 
    gMixer = new(#mixer) 
    gSound = gMixer.createSoundObject("1", member(1)) 
    --Create the sound object from cast member 
    sPre = new script("Output") -- Output is a parent script 
    sPost = new script("Output") 
    sPre.countLimit = 50 -- Setting the Property value for filling the silence 
    sPost.countLimit = 10 
    fl = gSound.filterlist 
    fl.append(audioFilter(#reverbFilter)) -- Adding Reverb Filter 
    gSound.registerByteArraycallback(#preFilter, #audioOutput,sPre,#readWrite) 
    -- Registering the callback with preFilter, so that the bytes will be available 
    --before applying filters 
    -- Specifying the script reference as sPre, can specify it as movie script if it is 
    --empty 
    -- Specifying readWrite, so that the bytes can be modified in the callback method 
    gSound.registerByteArrayCallback(#postFilter, #audioOutput,sPost,#readWrite) 
    -- Registering the callback with postFilter, so that the bytes will be available 
    --after applying filters 
    gMixer.bufferSize = 200 -- Setting the bufferSize of mixer to 200 
    gMixer.play()   -- Play the sound 
    end

Callback method (parent script)

    -- PARENT SCRIPT named OUTPUT -- 
    global gSoundIOInstance -- instance of FileIO for reading sound file  
    global gSound -- soundObject 
    global counter -- Counter to  fill the  silence 
    global fillSilence -- Flag to fill the silence 
    property countLimit 
    --Callback Method 
    on audioOutput me, aByteArray, bitDepth, sampleFreq, numChannel  
     ------------ --------- ---------------- ------- 
    -- SOURCE: Called back from gSound whenever gSound has finished 
    --    playing its current contents. 
    -- INPUT: <aByteArray> will be the byteArray with audio data which has to be 
    -- modified and the byteArray to send back. 
    -- ACTION: Transfers the (remaining) contents of the file to 
    -- aByteArray 
    -- OUTPUT: Returns TRUE if there was any data to pas to aByteArray 
    -- FALSE if not. 
  -------------------------------------------------------------------- 
    if fillSilence = 1 then -- Checking the fillSilence flag 
    repeat with i = 1 to aByteArray.length -- Looping thru the bytes of audio data 
    aByteArray[i] = 0 -- Setting the byte to silence 
    --Modify the bytes before playing, here it is set to 0 means silence 
    end repeat 
    end if 
    put aByteArray 
    counter = counter + 1 -- Increasing the counter to keep filling the silence 
      if(counter > countLimit)then -- If the countLimit is reached stop filling the silence 
    counter = 0 
    fillSilence = 1 - fillSilence -- Toggling between silence & play 
    end if 
    end