MediaStreamer: Extend API to support DVD navigation

* This is a general review of the code and includes a rework
 of the sniffing API.

headers/os/codec/CodecRoster.h

@@ -44,7 +44,7 @@ public:
 	static void			ReleaseEncoder(BEncoder* encoder);
 
 	static status_t		InstantiateStreamer(BStreamer** streamer,
-							BUrl url, BDataIO** source);
+							BUrl url);
 	static void			ReleaseStreamer(BStreamer* streamer);
 
 	static status_t		GetDecoderInfo(BDecoder* decoder,

headers/os/codec/MediaExtractor.h

@@ -11,6 +11,7 @@
 
 
 #include <Decoder.h>
+#include <MediaStreamer.h>
 #include <Reader.h>
 
 
@@ -23,6 +24,8 @@ struct stream_info;
 class BMediaExtractor {
 public:
 								BMediaExtractor(BDataIO* source, int32 flags);
+								// TODO
+								//BMediaExtractor(BMediaStreamer* streamer);
 								~BMediaExtractor();
 
 			status_t			InitCheck();

headers/os/codec/MediaStreamer.h

@@ -6,6 +6,7 @@
 #define _MEDIA_STREAMER_H
 
 
+#include <MediaIO.h>
 #include <Streamer.h>
 #include <Url.h>
 
@@ -18,11 +19,34 @@ public:
 								BMediaStreamer(BUrl url);
 								~BMediaStreamer();
 
-			status_t			CreateAdapter(BDataIO** adapter);
+			status_t			InitCheck() const;
+
+			// TODO: So, it seems since this API was not public,
+			// the memory ownership is leaved to class users.
+			// See if this fits our plans, and eventually, move
+			// this memory management from BMediaFile to BMediaExtractor,
+			// BMediaWriter and BMediaStreamer.
+			BMediaIO*			Adapter() const;
+
+			// TODO: Don't we need an open in the extractor and writer?
+			status_t			Open();
+			void				Close();
+			bool				IsOpened() const;
+
+			//uint32			Capabilities() const;
+			//status_t			GetMetaData(BMetaData* data) const;
+			//status_t			SetHandler(BHandler* handler);
+			//BHandler*			Handler() const;
+
+			void				MouseMoved(uint32 x, uint32 y);
+			void				MouseDown(uint32 x, uint32 y);
 
 private:
 			BUrl				fUrl;
 			BStreamer*			fStreamer;
+			status_t			fInitCheck;
+
+			bool				fOpened;
 
 			// No virtual padding needed. Looks like a design decision.
 			// Let's respect that, for now.

headers/os/codec/Streamer.h

@@ -20,7 +20,12 @@ namespace BPrivate {
 
 class BStreamer {
 public:
-	virtual status_t			Sniff(const BUrl& url, BDataIO** source) = 0;
+	virtual status_t			Sniff(const BUrl& url) = 0;
+	virtual BMediaIO*			Adapter() const = 0;
+
+	// Base impl does nothing
+	virtual void				MouseMoved(uint32 x, uint32 y);
+	virtual void				MouseDown(uint32 x, uint32 y);
 
 protected:
 								BStreamer();