lib/xiph/OggStreamState: new ogg_stream_state wrapper

Makefile.am

@@ -597,6 +597,7 @@ libxiph_a_SOURCES += \
 	src/lib/xiph/OggUtil.cxx src/lib/xiph/OggUtil.hxx \
 	src/lib/xiph/OggSyncState.hxx \
 	src/lib/xiph/OggPage.hxx \
+	src/lib/xiph/OggStreamState.hxx \
 	src/lib/xiph/OggStream.hxx
 endif
 

src/decoder/plugins/OpusDecoderPlugin.cxx

@@ -23,6 +23,7 @@
 #include "OpusHead.hxx"
 #include "OpusTags.hxx"
 #include "OggFind.hxx"
+#include "lib/xiph/OggStreamState.hxx"
 #include "lib/xiph/OggSyncState.hxx"
 #include "../DecoderAPI.hxx"
 #include "decoder/Reader.hxx"
@@ -209,11 +210,13 @@ LoadEOSPacket(InputStream &is, Decoder *decoder, int serialno,
 	   EOS packet */
 	DecoderReader reader(decoder, is);
 	OggSyncState oy(reader);
-	ogg_stream_state os;
-	ogg_stream_init(&os, serialno);
 
-	bool result = OggSeekFindEOS(oy, os, packet, is);
-	ogg_stream_clear(&os);
+	bool result;
+
+	{
+		OggStreamState os(serialno);
+		result = OggSeekFindEOS(oy, os, packet, is);
+	}
 
 	/* restore the previous file position */
 	is.LockSeek(old_offset, IgnoreError());

src/lib/xiph/OggStreamState.hxx

@@ -0,0 +1,73 @@
+/*
+ * Copyright 2003-2016 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_OGG_STREAM_STATE_HXX
+#define MPD_OGG_STREAM_STATE_HXX
+
+#include "check.h"
+
+#include <ogg/ogg.h>
+
+#include <assert.h>
+#include <string.h>
+#include <stdint.h>
+
+class OggStreamState {
+	ogg_stream_state state;
+
+public:
+	explicit OggStreamState(int serialno) {
+		ogg_stream_init(&state, serialno);
+	}
+
+	~OggStreamState() {
+		ogg_stream_clear(&state);
+	}
+
+	operator ogg_stream_state &() {
+		return state;
+	}
+
+	void Reinitialize(int serialno) {
+		ogg_stream_reset_serialno(&state, serialno);
+	}
+
+	/* encoding */
+
+	void PacketIn(const ogg_packet &packet) {
+		ogg_stream_packetin(&state,
+				    const_cast<ogg_packet *>(&packet));
+	}
+
+	bool PageOut(ogg_page &page) {
+		return ogg_stream_pageout(&state, &page) != 0;
+	}
+
+	bool Flush(ogg_page &page) {
+		return ogg_stream_flush(&state, &page) != 0;
+	}
+
+	/* decoding */
+
+	int PacketOut(ogg_packet &packet) {
+		return ogg_stream_packetout(&state, &packet);
+	}
+};
+
+#endif