<< Chapter < Page Chapter >> Page >
Listing 1 . Beginning of the class named SquareWave.
import java.io.*; import java.nio.*;import java.util.*; public class SquareWave extends AudioSignalGenerator02{public SquareWave(AudioFormatParameters01 audioParams,String[] args,byte[] melody){super(audioParams,args,melody); }//end constructor

Beginning of the getMelody method

This method returns an array containing three seconds of monaural audio data for a square wave at 1000 Hz.

Listing 2 shows the beginning of the overridden getMelody method. (Recall that an abstract version of this method is inherited from the class named AudioSignalGenerator02 -- see Listing 9 )

The code in Listing 2 is essentially the same as the corresponding WhiteNoise code from the earlier module. Therefore, I won't discuss it further in this module.

Listing 2 . Beginning of the getMelody method.
byte[] getMelody(){//Recall that the default for channels is 1 for mono. System.out.println("audioParams.channels = " + audioParams.channels);//Each channel requires two 8-bit bytes per 16-bit sample.int bytesPerSampPerChan = 2;//Override the default sample rate. Allowable sample rates are 8000,11025, // 16000,22050,44100 samples per second.audioParams.sampleRate = 8000.0F;// Set the length of the melody in seconds double lengthInSeconds = 3.0;//Create an output data array sufficient to contain the melody// at "sampleRate" samples per second, "bytesPerSampPerChan" bytes per // sample per channel and "channels" channels.melody = new byte[(int)(lengthInSeconds*audioParams.sampleRate* bytesPerSampPerChan*audioParams.channels)]; System.out.println("melody.length = " + melody.length);

Required audio data format

As you learned in earlier modules, an object of the AudioPlayOrFile01 class accepts an object of the AudioFormatParameters01 class along with an audio data array object of type byte[] and a String object for a file name and uses that information to either play the data in the audio array immediately or write it into an audio output file oftype AU.

Normally the audio data array must be formatted in a specific way as partially defined by the contents of the AudioFormatParameters01 object. In the case of white noise, however, there is no order or organizationto the bytes of audio data. Therefore, our only requirement was to ascertain that the proper number of signed random byte values were used to populate the array.

That is not the case in this module. Our audio data is organized and we must meet the requiredformat for the audio array.

Given the values that we are using in the AudioFormatParameters01 object, the format requirements for monaural and stereo are shown below. (Note that in both cases, each audio value must be a signed 16-bit value decomposed into a pair of 8-bit bytes.)

Monaural, channels = 1

For mono, each successive pair of bytes in the array must contain one audio value. The element with the lower index must contain the most significanteight bits of the 16-bit audio value.

Stereo, channels = 2

For stereo, alternating pairs of bytes must each contain one audio value in the same byte order as for mono. One pair of bytes is routed to the left speaker and the other pair of bytes is routed to the right speaker (almost) simultaneously.

Questions & Answers

a perfect square v²+2v+_
Dearan Reply
kkk nice
Abdirahman Reply
algebra 2 Inequalities:If equation 2 = 0 it is an open set?
Kim Reply
or infinite solutions?
Kim
y=10×
Embra Reply
if |A| not equal to 0 and order of A is n prove that adj (adj A = |A|
Nancy Reply
rolling four fair dice and getting an even number an all four dice
ramon Reply
Kristine 2*2*2=8
Bridget Reply
Differences Between Laspeyres and Paasche Indices
Emedobi Reply
No. 7x -4y is simplified from 4x + (3y + 3x) -7y
Mary Reply
is it 3×y ?
Joan Reply
J, combine like terms 7x-4y
Bridget Reply
im not good at math so would this help me
Rachael Reply
how did I we'll learn this
Noor Reply
f(x)= 2|x+5| find f(-6)
Prince Reply
f(n)= 2n + 1
Samantha Reply
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
Crystal Reply
. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
Chris Reply
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
can nanotechnology change the direction of the face of the world
Prasenjit Reply
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
Ali Reply
the Beer law works very well for dilute solutions but fails for very high concentrations. why?
bamidele Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
Got questions? Join the online conversation and get instant answers!
QuizOver.com Reply

Get the best Algebra and trigonometry course in your pocket!





Source:  OpenStax, Accessible objected-oriented programming concepts for blind students using java. OpenStax CNX. Sep 01, 2014 Download for free at https://legacy.cnx.org/content/col11349/1.17
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Accessible objected-oriented programming concepts for blind students using java' conversation and receive update notifications?

Ask