func decomp(decomp_buf, block *Block, in, out DuplexPipe, wg *sync.WaitGroup) {

	defer wg.Done()

	nBlocks := (in.FileSize / int64(in.BlockSize)) + 1

	if block.BlockID < int(nBlocks)-1 {
		snappy.Decode(decomp_buf.Buf, block.Buf[:block.NBytes])
		decomp_buf.BlockID = block.BlockID

	} else {
		decomp_buf.NBytes = block.NBytes
		decomp_buf.BlockID = block.BlockID
		copy(decomp_buf.Buf[:decomp_buf.NBytes], block.Buf)
	}

	in.Upstream <- block
	out.Downstream <- decomp_buf
}
func main() {
	// open input file
	dataFile, err := os.Open(os.Args[1])
	if err != nil {
		panic(err)
	}

	defer func() {
		if err := dataFile.Close(); err != nil {
			panic(err)
		}
	}()

	// open uncompressed file
	outFile, err := os.Create(os.Args[1] + ".ini")
	if err != nil {
		panic(err)
	}

	defer func() {
		if err := outFile.Close(); err != nil {
			panic(err)
		}
	}()

	f32s := make([]byte, 4)
	bytes := make([]byte, 1)

	dataFile.Seek(3, 0)
	dataFile.Read(bytes)
	type_size := int(bytes[0])

	dataFile.Seek(8, 0)
	dataFile.Read(f32s)
	file_size := binary.LittleEndian.Uint32(f32s)

	dataFile.Seek(12, 0)
	dataFile.Read(f32s)
	block_size := binary.LittleEndian.Uint32(f32s) * kB

	nBlocks := (file_size / (block_size)) + 1

	offsets := make([]byte, nBlocks*8)
	dataFile.Seek(20, 0)
	dataFile.Read(offsets)

	dbuf := make([]byte, block_size)

	for i := uint32(0); i < nBlocks-1; i++ {
		start := binary.LittleEndian.Uint32(offsets[i*8 : (i*8)+4])
		size := binary.LittleEndian.Uint32(offsets[i*8+4 : (i*8)+8])

		block := make([]byte, size)
		dataFile.Seek(int64(start), 0)
		dataFile.Read(block)
		d, _ := snappy.Decode(dbuf, block[:])

		bufo := make([]byte, len(d))

		for j := 0; j < type_size; j++ {
			for k := 0; k < int(block_size)/64; k++ {
				bufo[k*type_size+j] = d[k+(j*int(block_size)/type_size)]
			}
		}

		outFile.Write(bufo)
	}

	start := binary.LittleEndian.Uint32(offsets[(nBlocks-1)*8 : ((nBlocks-1)*8)+4])
	size := binary.LittleEndian.Uint32(offsets[(nBlocks-1)*8+4 : ((nBlocks-1)*8)+8])

	block := make([]byte, size)
	dataFile.Seek(int64(start), 0)
	dataFile.Read(block)
	outFile.Write(block)
}