File Read and Byte Conversion Efficiency

Question

Im working on a program that needs to store WAV data.
2 unsigned bytes Little Endian -> signed Short
this is my code:
fis = new BufferedInputStream(new FileInputStream(file), 1764000);
for(int x = 0; x < wav.samples; x++){
fis.read(byte2);
wav.left[i] = (short)b2LEtoInt();
public int b2LEtoInt(){
i += (int)(byte2[1] & 0xff) << 8;
i += (int)(byte2[0] & 0xff);
if(i > 32767){ i -= 65536; }
return i;
}I set the buffer size to 1,764,000 bytes because that is fairly
large and it is 10 seconds of 44100 16bit stereo WAV data.
Reading 79,161,264 takes 8282 ms
Waiting 8 seconds for almost 8 mins of WAV data isnt horrible
but its markedly worse than WaveLAB or CoolEditPro etc that can
load the same data and graph it pretty much as quickly as i can
drag the file onto the screen.
Is this a Java vs Native code speed problem or a design problem?
Does anyone have any tips to speed up this loading process?
I dont know if thats the best 2 byte little endian to short conversion.
I dont know if im using the right reader / buffersize.
I dont know how programs like WaveLAB work with wavs.
Do they load them into memory completely? Are the graphs
images that are then zoomed into or are they redrawn every
time you move them?
Anyone have any expert advice?

Answer 1

is this right...
the buffered reader grabs 1,765,000 bytes from the
file automatically,
read(byte[]...) then reads [x] many bytes from the
reader?Yes but if your byte array has only 2 elements this read method will be called (1,765,000 /2) times and that was the problem. You can reduce by increasing the size of the array.
What the buffered reader does is it minimze the IO blocks which will occure when you actualy read file from the disk buy redusing the niumber of Disk IOs.
and also read method does not gurrantee that the exact number of bytes that you specify is read from the stream by read method
(Read the java documentation of InputStream.read(byte[],int,int))
it says that the maximum number of bytes that will be read is what you specified but the actual number read may be less than that and that depending on the implementation.
read method return an integer value which is the actuall number of bytes I think you should get it in to a variable and use when processing