Question

Here is my code:

              long max = pcmU16.Length;
              long index = 0;

              fixed (ushort* srcFix = pcmU16)
              {
                    ushort* src = srcFix;

                    next:

                    *src = 32768;
                    src++;
                    index++;

                    if (index != max)
                    {
                          goto next;
                    }
              }

Like you see, it is writing 2 bytes at once. How to use ulong type and write 8 bytes at once? pcmU16 is ushort[] array.

Answer 1

You just coerce it:

ulong* src = (ulong*)srcFix;

Things to watch, though:

• your max needs to be divided by 4, else you’re going out of range
• you need to handle any stray values – for example, say you have 10 ushort values (max was 10 initially); that is 2 sets of ulong (4 each), and a final 2 ushort; the usual divisor/remainder stuff

As a final note, you might find the index syntax more convenient, i.e.

for(int i = 0 ; i < max ; i++) {
    src[i] = ...
}