encoder/{vorbis,opus}: move common code to class OggEncoder

Makefile.am

@@ -1149,6 +1149,11 @@ libencoder_plugins_a_SOURCES += \
 	src/encoder/plugins/WaveEncoderPlugin.hxx
 endif
 
+if HAVE_OGG
+libencoder_plugins_a_SOURCES += \
+	src/encoder/plugins/OggEncoder.hxx
+endif
+
 if ENABLE_VORBISENC
 libencoder_plugins_a_SOURCES += \
 	src/encoder/plugins/VorbisEncoderPlugin.cxx \

src/encoder/plugins/OggEncoder.hxx

@@ -0,0 +1,59 @@
+/*
+ * 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_ENCODER_HXX
+#define MPD_OGG_ENCODER_HXX
+
+#include "config.h"
+#include "../EncoderAPI.hxx"
+#include "lib/xiph/OggStream.hxx"
+#include "lib/xiph/OggSerial.hxx"
+
+#include <ogg/ogg.h>
+
+/**
+ * An abstract base class which contains code common to all encoders
+ * with Ogg container output.
+ */
+class OggEncoder : public Encoder {
+protected:
+	OggStream stream;
+
+public:
+	OggEncoder(bool _implements_tag)
+		:Encoder(_implements_tag) {
+		stream.Initialize(GenerateOggSerial());
+	}
+
+	~OggEncoder() override {
+		stream.Deinitialize();
+	}
+
+	/* virtual methods from class Encoder */
+	bool Flush(Error &) override {
+		stream.Flush();
+		return true;
+	}
+
+	size_t Read(void *dest, size_t length) override {
+		return stream.PageOut(dest, length);
+	}
+};
+
+#endif

src/encoder/plugins/OpusEncoderPlugin.cxx

@@ -19,9 +19,7 @@
 
 #include "config.h"
 #include "OpusEncoderPlugin.hxx"
-#include "lib/xiph/OggStream.hxx"
+#include "OggEncoder.hxx"
-#include "lib/xiph/OggSerial.hxx"
-#include "../EncoderAPI.hxx"
 #include "AudioFormat.hxx"
 #include "config/ConfigError.hxx"
 #include "util/Alloc.hxx"
@@ -37,7 +35,7 @@
 
 namespace {
 
-class OpusEncoder final : public Encoder {
+class OpusEncoder final : public OggEncoder {
 	const AudioFormat audio_format;
 
 	const size_t frame_size;
@@ -50,8 +48,6 @@ class OpusEncoder final : public Encoder {
 
 	unsigned char buffer2[1275 * 3 + 7];
 
-	OggStream stream;
-
 	int lookahead;
 
 	ogg_int64_t packetno = 0;
@@ -64,7 +60,6 @@ public:
 
 	/* virtual methods from class Encoder */
 	bool End(Error &) override;
-	bool Flush(Error &) override;
 	bool Write(const void *data, size_t length, Error &) override;
 
 	size_t Read(void *dest, size_t length) override;
@@ -150,7 +145,7 @@ opus_encoder_init(const ConfigBlock &block, Error &error)
 }
 
 OpusEncoder::OpusEncoder(AudioFormat &_audio_format, ::OpusEncoder *_enc)
-	:Encoder(false),
+	:OggEncoder(false),
 	 audio_format(_audio_format),
 	 frame_size(_audio_format.GetFrameSize()),
 	 buffer_frames(_audio_format.sample_rate / 50),
@@ -159,8 +154,6 @@ OpusEncoder::OpusEncoder(AudioFormat &_audio_format, ::OpusEncoder *_enc)
 	 enc(_enc)
 {
 	opus_encoder_ctl(enc, OPUS_GET_LOOKAHEAD(&lookahead));
-
-	stream.Initialize(GenerateOggSerial());
 }
 
 Encoder *
@@ -206,7 +199,6 @@ PreparedOpusEncoder::Open(AudioFormat &audio_format, Error &error)
 
 OpusEncoder::~OpusEncoder()
 {
-	stream.Deinitialize();
 	free(buffer);
 	opus_encoder_destroy(enc);
 }
@@ -261,13 +253,6 @@ OpusEncoder::End(Error &error)
 	return DoEncode(true, error);
 }
 
-bool
-OpusEncoder::Flush(gcc_unused Error &error)
-{
-	stream.Flush();
-	return true;
-}
-
 bool
 OpusEncoder::WriteSilence(unsigned fill_frames, Error &error)
 {

src/encoder/plugins/VorbisEncoderPlugin.cxx

@@ -19,9 +19,7 @@
 
 #include "config.h"
 #include "VorbisEncoderPlugin.hxx"
-#include "lib/xiph/OggStream.hxx"
+#include "OggEncoder.hxx"
-#include "lib/xiph/OggSerial.hxx"
-#include "../EncoderAPI.hxx"
 #include "AudioFormat.hxx"
 #include "config/ConfigError.hxx"
 #include "util/StringUtil.hxx"
@@ -31,18 +29,16 @@
 
 #include <vorbis/vorbisenc.h>
 
-class VorbisEncoder final : public Encoder {
+class VorbisEncoder final : public OggEncoder {
 	AudioFormat audio_format;
 
 	vorbis_dsp_state vd;
 	vorbis_block vb;
 	vorbis_info vi;
 
-	OggStream stream;
-
 public:
 	VorbisEncoder()
-		:Encoder(true) {}
+		:OggEncoder(true) {}
 
 	virtual ~VorbisEncoder() {
 		Clear();
@@ -56,16 +52,11 @@ public:
 		return PreTag(error);
 	}
 
-	bool Flush(Error &error) override;
 	bool PreTag(Error &error) override;
 	bool SendTag(const Tag &tag, Error &error) override;
 
 	bool Write(const void *data, size_t length, Error &) override;
 
-	size_t Read(void *dest, size_t length) override {
-		return stream.PageOut(dest, length);
-	}
-
 private:
 	void HeaderOut(vorbis_comment &vc);
 	void SendHeader();
@@ -189,7 +180,6 @@ VorbisEncoder::Open(float quality, int bitrate, AudioFormat &_audio_format,
 
 	vorbis_analysis_init(&vd, &vi);
 	vorbis_block_init(&vd, &vb);
-	stream.Initialize(GenerateOggSerial());
 
 	SendHeader();
 
@@ -234,7 +224,6 @@ PreparedVorbisEncoder::Open(AudioFormat &audio_format, Error &error)
 void
 VorbisEncoder::Clear()
 {
-	stream.Deinitialize();
 	vorbis_block_clear(&vb);
 	vorbis_dsp_clear(&vd);
 	vorbis_info_clear(&vi);
@@ -253,13 +242,6 @@ VorbisEncoder::BlockOut()
 	}
 }
 
-bool
-VorbisEncoder::Flush(gcc_unused Error &error)
-{
-	stream.Flush();
-	return true;
-}
-
 bool
 VorbisEncoder::PreTag(gcc_unused Error &error)
 {