c# - How can i convert bytes to shorts

Question

I am trying to convert a byte array to a array to shorts but it doesn't seem to work. The issue is, my for loop will stop when it gets to the bitconverter. Here is my code snippet:

byte[] input = File.ReadAllBytes("frame.jpg");
short[] output = new short[input.Length / 2];
Console.WriteLine("Converting bytes to shorts");
for (int i = 0; i == input.Length; i++)
{
    output[i/2] = BitConverter.ToInt16(input, i);
    Console.WriteLine(Convert.ToString(output[i/2]) + " ");
}

I appreciate any help you can give.

Answer 1

Yesterday I posted a hasty answer and deleted it, because well in all honesty the question could be a lot better... With some deduction I have come to the conclusion that what you actually want to do is load a bunch of bytes into their word representation. Meaning shift the first byte left by 8 bits and add the second byte.

byte[] bytes = File.ReadAllBytes("frame.jpg");
var output = new List<ushort>();
for (int i = 0; i < bytes.Length; i += 2)
{
    try
    {
        output.Add((ushort)((bytes[i] * 256) + bytes[i + 1]));
    }
    catch (IndexOutOfRangeException ex)
    {
        output.Add((ushort)(bytes[i] * 256));
    }
}
return output.ToArray();

Answer 2

It wasn't far off, just a few logic errors in the for loop:

public static void Main()
{
        byte[] input = File.ReadAllBytes("frame.jpg");
        short[] output = new short[input.Length / 2];
        Console.WriteLine("Converting bytes to shorts");
        for (int i = 0; i < input.Length-1; i+=2)
        {
            output[i/2] = BitConverter.ToInt16(input, i);
            Console.WriteLine(Convert.ToString(output[i/2]) + " ");
        }   
}

You should also probably check that the input image has an even number of bytes.

Answer 3

You used ToInt16(input, i) in your code. So I think this was wrong. I suggest you to use BitConverter.ToInt16(new byte[2] {(byte)input[i] , (byte)input[i+1] },i) to fix your issues.