How to convert ByteBuffer into image in Android

Question

I am receiving jpg image through socket and it is sent as ByteBuffer what I am doing is:

        ByteBuffer receivedData ;
        // Image bytes
        byte[] imageBytes = new byte[0];
        // fill in received data buffer with data
        receivedData=  DecodeData.mReceivingBuffer;
        // Convert ByteByffer into bytes
        imageBytes = receivedData.array();
        //////////////
        // Show image
        //////////////
        final Bitmap bitmap = BitmapFactory.decodeByteArray(imageBytes,0,imageBytes.length);
        showImage(bitmap1);

But what is happening that it fails to decode the imageBytes and bitmap is null.

Also I got imagebytes as: imageBytes: {-1, -40, -1, -32, 0, 16, 74, 70, 73, 70, 0, 1, 1, 1, 0, 96, 0, 0, 0, 0, -1, -37, 0, 40, 28, 30, 35, +10,478 more}

What would be the problem? is it decoding problem? or conversion from ByteBuffer to Byte array?

Thanks in advance for help.

`it is sent as ByteBuffer`. Don't think so. It's sent as a stream of bytes. — greenapps, Jul 28 '16 at 15:12
`DecodeData.mReceivingBuffer`. You did not show how you received the data. Very incomplete code. Please show a hexadecimal notation of the received bytes. And also the sent bytes hexadecimal please. — greenapps, Jul 28 '16 at 15:14

score 15 · Answer 1 · answered Sep 28 '16 at 15:04

This one worked for me (for ARGB_8888 pixel buffer):

private Bitmap getBitmap(Buffer buffer, int width, int height) {
    buffer.rewind();
    Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
    bitmap.copyPixelsFromBuffer(buffer);
    return bitmap;
}

score 9 · Accepted Answer · edited Jan 12 '21 at 13:03

9

ByteBuffer buf = DecodeData.mReceivingBuffer;
byte[] imageBytes= new byte[buf.remaining()];
buf.get(imageBytes);
final Bitmap bmp=BitmapFactory.decodeByteArray(imageBytes,0,imageBytes.length);
    showImage(bmp);

OR

// Create a byte array
byte[] bytes = new byte[10];

// Wrap a byte array into a buffer
ByteBuffer buf = ByteBuffer.wrap(bytes);

// Retrieve bytes between the position and limit
// (see Putting Bytes into a ByteBuffer)
bytes = new byte[buf.remaining()];

// transfer bytes from this buffer into the given destination array
buf.get(bytes, 0, bytes.length);

// Retrieve all bytes in the buffer
buf.clear();
bytes = new byte[buf.capacity()];

// transfer bytes from this buffer into the given destination array
buf.get(bytes, 0, bytes.length);

final Bitmap bmp=BitmapFactory.decodeByteArray(bytes,0,bytes.length); showImage(bmp);

USE ANY ONE ABOVE TO CONVERT BYTEBUFFER TO BYTE ARRAY AND CONVERT IT TO BITMAP AND SET IT INTO YOUR IMAGEVIEW.

Hope this will help you.

edited Jan 12 '21 at 13:03

Andrii Omelchenko

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answered Jul 28 '16 at 14:50

Andolasoft Inc

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Just code without any further explanation isn't very helpful. – Robert Jul 28 '16 at 14:55
it is not working using buf.get(imageBytes); do not fill imagebytes with data I think imageBytes = receivedData.array(); is better and now it is decoding but also can not display, but thanks – zelf Jul 28 '16 at 15:01
@Andolasoft thanks for your help I think first solution with changing buf.get(imageBytes); to buf.array will work, as buf.get() writing nothing inside imageBytes in the two solutions. – zelf Jul 28 '16 at 15:15
Thanks! `BitmapFactory.decodeByteArray(buf, 0, buf.length)` was really useful! – Trake Vital Mar 29 '21 at 08:45

How to convert ByteBuffer into image in Android

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