Construction of the sdr buffer

hello,
I’m new here.
I have a RTL2832SDR dongle. On Windows 11 64 Bit.
I a software developer and I do ADS-B with severals programs.
dump1090, sdrangel.
But I want to develop my own program in Pascal. (Lazarus)
Which read data from sdr direct by myself.
I have written a sample program and it works.
I got a buffer of 262144 Bytes from SDR.
But I need then construction of the buffer to read then ADS-B data.
Is there anyone how can help me?
kind regards
Jürgen