Decompress Zlib data

Question

I'm currently trying to decompress some bytes from .mat file compressed by Zlib. I read paragraph 3, page 1-12 from MAT-File Format, it told that the bytes in .mat file is compressed by Zlib.

So, my question is, does C# have some APIs or libraries that can decompress the bytes. If I got a group of bytes like

6236 20e6 0062 1606 0860 85f2 1981 980b
4cb3 30e4 25e6 a60a 40f9 2545 9989 39f1

Then I load them into an SByte array, how could I decompress them?

I also checked some libraries online. It seems that what they can do is to decompress the whole file, instead of some bytes....

I am quite new about this respect. Any help is appreciated.

Answer 1

You can use InflaterInputStream from SharpZipLib. .mat file has header with 0x88 length, so you have to skip it. I took sample file from here SampleMatlabMatDataFiles.zip.

byte[] data = File.ReadAllBytes("c.mat").Skip(0x88).ToArray();
byte[] decompressedData = new byte[10000];
int decompressedLength = 0;
using (MemoryStream memory = new MemoryStream(data))
using (InflaterInputStream inflater = new InflaterInputStream(memory))
    decompressedLength = inflater.Read(decompressedData, 0, decompressedData.Length);