Updated the documentation

Author: djthorpe

README.md

@@ -67,7 +67,11 @@ import (
 )
 
 func main() {
-  manager := media NewManager()
+  manager := media.NewManager()
+
+  // Open a media file for reading. The format of the file is guessed.
+  // Alteratively, you can pass a format as the second argument. Further optional
+  // arguments can be used to set the format options.
   file, err := manager.Open(os.Args[1], nil)
   if err != nil {
     log.Fatal(err)
@@ -77,7 +81,7 @@ func main() {
   // Choose which streams to demultiplex - pass the stream parameters
   // to the decoder. If you don't want to resample or reformat the streams,
   // then you can pass nil as the function and all streams will be demultiplexed.
-  decoder, err := file.Decoder(func (stream media.Stream) (Parameters, error) {
+  decoder, err := file.Decoder(func (stream media.Stream) (media.Parameters, error) {
     return stream.Parameters(), nil
   }
   if err != nil {
@@ -86,9 +90,11 @@ func main() {
 
   // Demuliplex the stream and receive the packets. If you don't want to
   // process the packets yourself, then you can pass nil as the function
-  if err := decoder.Demux(context.Background(), func(Packet) error {
-    // TODO: Each packet is specific to a stream. It can be processed here
-    // to receive audio or video frames, etc.
+  if err := decoder.Demux(context.Background(), func(_ media.Packet) error {
+    // Each packet is specific to a stream. It can be processed here
+    // to receive audio or video frames, then resize or resample them,
+    // for example. Alternatively, you can pass the packet to an encoder
+    // to remultiplex the streams without processing them.
     return nil
   }); err != nil {
     log.Fatal(err)