X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=source%2Fsounddecoder.h;h=20b9d0fb7f4e3d6afa4bd2d9a3dc8806e5477c5e;hb=HEAD;hp=ad56646b30dc149c9bfe48ef3fb243f3d811121f;hpb=6cc0f1735a00e8f9eb80ff0c9468fb67205f6d20;p=libs%2Fal.git

diff --git a/source/sounddecoder.h b/source/sounddecoder.h
index ad56646..20b9d0f 100644
--- a/source/sounddecoder.h
+++ b/source/sounddecoder.h
@@ -1,42 +1,61 @@
-#ifndef MSP_AL_SOUND_H_
-#define MSP_AL_SOUND_H_
+#ifndef MSP_AL_SOUNDDECODER_H_
+#define MSP_AL_SOUNDDECODER_H_
 
 #include <string>
-#include <vorbis/vorbisfile.h>
+#include <msp/io/seekable.h>
 #include "format.h"
 
 namespace Msp {
 namespace AL {
 
+class unsupported_sound: public std::runtime_error
+{
+public:
+	unsupported_sound(const std::string &);
+	virtual ~unsupported_sound() throw() { }
+};
+
+
 /**
-This class facilitates loading sound files.  Currently only Ogg Vorbis is
-supported.
+Base class for sound decoders.
 */
 class SoundDecoder
 {
 private:
-	OggVorbis_File ovfile;
+	IO::Seekable *source;
+protected:
 	unsigned freq;
 	unsigned size;
 	Format format;
 	bool eof_flag;
 
-public:
 	SoundDecoder();
-	~SoundDecoder();
-
-	void open_file(const std::string &);
-	void open_memory(const void *, unsigned);
-private:
-	void open_common();
 public:
-	void close();
-	void rewind();
-	unsigned read(char *, unsigned);
+	virtual ~SoundDecoder();
+
+	/** Opens a file and creates a decoder of an appropriate type for it. */
+	static SoundDecoder *open_file(const std::string &);
+
+	/** Creates a decoder for an already-opened audio file. */
+	static SoundDecoder *open_io(IO::Seekable &);
+
+	/** Restarts decoding from the beginning of the file. */
+	virtual void rewind() { seek(0); }
+
+	/** Sets decoding position expressed in PCM bytes.  This may involve seeking
+	to the beginning and skipping until the desired position is reached.*/
+	virtual void seek(unsigned) = 0;
+
+	/** Reads decoded sound data.  Length is specified in bytes. */
+	virtual unsigned read(char *, unsigned) = 0;
+
 	bool eof() const { return eof_flag; }
 
 	Format get_format() const { return format; }
 	unsigned get_frequency() const { return freq; }
+
+	/** Returns the total length of the sound data in bytes.  Some decoders may
+	not be able to provide this information. */
 	unsigned get_size() const { return size; }
 };