Updated README

README.md

@@ -1,24 +1,87 @@
-[![godoc](https://godoc.org/github.com/pierrec/lz4?status.png)](https://godoc.org/github.com/pierrec/lz4)
+# lz4 : LZ4 compression in pure Go
 
-# lz4
-LZ4 compression and decompression in pure Go.
+## Overview [![GoDoc](https://godoc.org/github.com/pierrec/lz4?status.svg)](https://godoc.org/github.com/pierrec/lz4) [![Build Status](https://travis-ci.org/pierrec/lz4.svg?branch=master)](https://travis-ci.org/pierrec/lz4) [![Go Report Card](https://goreportcard.com/badge/github.com/pierrec/lz4)](https://goreportcard.com/report/github.com/pierrec/lz4)
 
-## Usage
+This package provides a streaming interface to [LZ4 data streams](http://fastcompression.blogspot.fr/2013/04/lz4-streaming-format-final.html) as well as low level compress and uncompress functions for LZ4 data blocks.
+The implementation is based on the reference C [one](https://github.com/lz4/lz4).
+
+## Install
+
+Assuming you have the go toolchain installed:
+
+```
+go get github.com/pierrec/lz4
+```
+
+There is a command line interface tool to compress and decompress LZ4 files.
+
+```
+go install github.com/pierrec/lz4/cmd/lz4c
+```
+
+Usage
+
+```
+Usage of lz4c:
+  -version
+        print the program version
+
+Subcommands:
+Compress the given files or from stdin to stdout.
+compress [arguments] [<file name> ...]
+  -bc
+        enable block checksum
+  -l int
+        compression level (0=fastest)
+  -sc
+        disable stream checksum
+  -size string
+        block max size [64K,256K,1M,4M] (default "4M")
+
+Uncompress the given files or from stdin to stdout.
+uncompress [arguments] [<file name> ...]
 
-```go
-import "github.com/pierrec/lz4"
 ```
 
-## Description
-Package lz4 implements reading and writing lz4 compressed data (a frame),
-as specified in http://fastcompression.blogspot.fr/2013/04/lz4-streaming-format-final.html.
 
-This package is **compatible with the LZ4 frame format** although the block level compression 
-and decompression functions are exposed and are fully compatible with the lz4 block format 
-definition, they are low level and should not be used directly.
+## Example
+
+```
+// Compress and uncompress an input string.
+s := "hello world"
+r := bytes.NewReader([]byte(s))
+
+// The pipe will uncompress the data from the writer.
+pr, pw := io.Pipe()
+zw := lz4.NewWriter(pw)
+zr := lz4.NewReader(pr)
+
+go func() {
+	// Compress the input string.
+	_, _ = io.Copy(zw, r)
+	_ = zw.Close() // Make sure the writer is closed
+	_ = pw.Close() // Terminate the pipe
+}()
+
+_, _ = io.Copy(os.Stdout, zr)
+
+// Output:
+// hello world
+```
+
+## Contributing
+
+Contributions are very welcome for bug fixing, performance improvements...!
+
+- Open an issue with a proper description
+- Send a pull request with appropriate test case(s)
+
+## Contributors
+
+Thanks to all contributors so far.
 
-For a complete description of an lz4 compressed block, see:
-http://fastcompression.blogspot.fr/2011/05/lz4-explained.html
+Special thanks to [@Zariel](https://github.com/Zariel) for his asm implementation of the decoder
 
-See https://github.com/Cyan4973/lz4 for the reference C implementation.
+## License
 
+MIT.