Update README.md

README.md

@@ -1,7 +1,42 @@
-# Golang mp4 muxer/demuxer
+# A pure golang mp4 library
 
-Includes h264/aac track muxer, mp4 atoms reader/writer/dumper
+Provides mp4 reader/writer and mp4 atom manipulations functions.
 
-# Examples
+Open a mp4 file and read the first sample:
+```
+file, _ := os.Open("test.mp4")
+demuxer := &mp4.Demuxer{R: file}
+demuxer.ReadHeader()
+pts, dts, isKeyFrame, data, err := demuxer.TrackH264.ReadSample()
+```
+
+do some seeking:
+
+```
+demuxer.TrackH264.SeekToTime(2.0)
+```
+
+demuxer demo code [here](https://github.com/nareix/mp4/blob/master/example/example.go#L11)
+
+the library also provide atom struct decoding/encoding functions(
+learn more about mp4 atoms [here](https://developer.apple.com/library/mac/documentation/QuickTime/QTFF/QTFFChap2/qtff2.html)
+)
+
+you can access atom structs via `Demuxer.TrackH264.TrackAtom`. for example:
+
+```
+// Get the raw TimeScale field inside `mvhd` atom
+fmt.Println(demuxer.TrackH264.TrackAtom.Media.Header.TimeScale)
+```
+
+for more see Atom API Docs
+
+# Documentation
+
+[API Docs](https://godoc.org/github.com/nareix/mp4)
+
+[Atom API Docs](https://godoc.org/github.com/nareix/mp4/atom)
+
+
+## Atoms manipulation
 
-[Demuxer example](https://github.com/nareix/mp4/blob/master/example/example.go#L11)