Saving short[] in java (android) with low cpu and space

Question

while streaming music i'm getting pcm data as type short[] and i want to save it to file in my android device so i can play it again later (using AudioTrack). i wan't the store of the music to be efficent in memory and cpu.

how to save short[] to file cause i dont see any function in.write(short[])?

how can i decrease the space\cpu for saving this file?

bezmax · Answer 1 · 2011-11-24T09:53:22.323

3

Wrap your FileOutputStream with DataOutputStream:

DataOutputStream doStream = new DataOutputStream(new BufferedOutputStream(fileOutputStream));
doStream.writeInt(numberArray.length); //Save size
for (int i=0;i<numberArray.length;i++) {
    doStream.writeShort(numberArray[i]); //Save each number
}

Same way for reading it back:

DataInputStream diStream = new DataInputStream(new BufferedInputStream(fileInputStream));
int size = diStream.readInt(); //Read size
short[] data = new short[size]; //Create new array with required length
for (int i=0;i<size;i++) {
    data[i] = diStream.readShort(); //Read each number
}

edited Nov 24 '11 at 09:53

answered Nov 24 '11 at 09:40

bezmax

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1

A `BufferedOutputStream` between the DOS and the FOS would do wonders for the efficiency of that. – user207421 Nov 24 '11 at 09:45
EJP, would you give an example? – Defuera Mar 11 '15 at 23:39
1

@Defuera I changed my answer according to EJP comment. – bezmax Mar 12 '15 at 15:18
@Max, please do so, I also appreciate if you show how to use in in a loop if necessary. – Defuera Mar 13 '15 at 06:56

score 0 · Answer 2 · answered Nov 24 '11 at 09:49

Without any encoding to MP3 or similar you can always do like this.

short[] sound = ...;
ByteBuffer byteMyShorts = ByteBuffer.allocate(sound.length * 2);
ShortBuffer shortBytes = byteMyShorts.asShortBuffer();
shortBytes.put(sound);
byteMyShorts.flip();

// byteMyShorts.array() now contains your short[] array as an
// array of bytes.

Saving short[] in java (android) with low cpu and space

2 Answers2