Filter*: move to filter/

1 files changed, 210 insertions, 0 deletions

diff --git a/src/filter/plugins/ReplayGainFilterPlugin.cxx b/src/filter/plugins/ReplayGainFilterPlugin.cxx
new file mode 100644
index 000000000..d89e79480
--- /dev/null
+++ b/src/filter/plugins/ReplayGainFilterPlugin.cxx
@@ -0,0 +1,210 @@
+/*
+ * Copyright (C) 2003-2014 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.
+ */
+
+#include "config.h"
+#include "ReplayGainFilterPlugin.hxx"
+#include "filter/FilterPlugin.hxx"
+#include "filter/FilterInternal.hxx"
+#include "filter/FilterRegistry.hxx"
+#include "AudioFormat.hxx"
+#include "ReplayGainInfo.hxx"
+#include "ReplayGainConfig.hxx"
+#include "MixerControl.hxx"
+#include "pcm/Volume.hxx"
+#include "pcm/PcmBuffer.hxx"
+#include "util/ConstBuffer.hxx"
+#include "util/Error.hxx"
+#include "util/Domain.hxx"
+#include "Log.hxx"
+
+#include <assert.h>
+#include <string.h>
+
+static constexpr Domain replay_gain_domain("replay_gain");
+
+class ReplayGainFilter final : public Filter {
+	/**
+	 * If set, then this hardware mixer is used for applying
+	 * replay gain, instead of the software volume library.
+	 */
+	Mixer *mixer;
+
+	/**
+	 * The base volume level for scale=1.0, between 1 and 100
+	 * (including).
+	 */
+	unsigned base;
+
+	ReplayGainMode mode;
+
+	ReplayGainInfo info;
+
+	/**
+	 * About the current volume: it is between 0 and a value that
+	 * may or may not exceed #PCM_VOLUME_1.
+	 *
+	 * If the default value of true is used for replaygain_limit, the
+	 * application of the volume to the signal will never cause clipping.
+	 *
+	 * On the other hand, if the user has set replaygain_limit to false,
+	 * the chance of clipping is explicitly preferred if that's required to
+	 * maintain a consistent audio level. Whether clipping will actually
+	 * occur depends on what value the user is using for replaygain_preamp.
+	 */
+	PcmVolume pv;
+
+public:
+	ReplayGainFilter()
+		:mixer(nullptr), mode(REPLAY_GAIN_OFF) {
+		info.Clear();
+	}
+
+	void SetMixer(Mixer *_mixer, unsigned _base) {
+		assert(_mixer == nullptr || (_base > 0 && _base <= 100));
+
+		mixer = _mixer;
+		base = _base;
+
+		Update();
+	}
+
+	void SetInfo(const ReplayGainInfo *_info) {
+		if (_info != nullptr) {
+			info = *_info;
+			info.Complete();
+		} else
+			info.Clear();
+
+		Update();
+	}
+
+	void SetMode(ReplayGainMode _mode) {
+		if (_mode == mode)
+			/* no change */
+			return;
+
+		FormatDebug(replay_gain_domain,
+			    "replay gain mode has changed %d->%d\n",
+			    mode, _mode);
+
+		mode = _mode;
+		Update();
+	}
+
+	/**
+	 * Recalculates the new volume after a property was changed.
+	 */
+	void Update();
+
+	virtual AudioFormat Open(AudioFormat &af, Error &error) override;
+	virtual void Close();
+	virtual const void *FilterPCM(const void *src, size_t src_size,
+				      size_t *dest_size_r, Error &error);
+};
+
+void
+ReplayGainFilter::Update()
+{
+	unsigned volume = PCM_VOLUME_1;
+	if (mode != REPLAY_GAIN_OFF) {
+		const auto &tuple = info.tuples[mode];
+		float scale = tuple.CalculateScale(replay_gain_preamp,
+						   replay_gain_missing_preamp,
+						   replay_gain_limit);
+		FormatDebug(replay_gain_domain,
+			    "scale=%f\n", (double)scale);
+
+		volume = pcm_float_to_volume(scale);
+	}
+
+	pv.SetVolume(volume);
+
+	if (mixer != nullptr) {
+		/* update the hardware mixer volume */
+
+		unsigned _volume = (volume * base) / PCM_VOLUME_1;
+		if (_volume > 100)
+			_volume = 100;
+
+		Error error;
+		if (!mixer_set_volume(mixer, _volume, error))
+			LogError(error, "Failed to update hardware mixer");
+	}
+}
+
+static Filter *
+replay_gain_filter_init(gcc_unused const config_param &param,
+			gcc_unused Error &error)
+{
+	return new ReplayGainFilter();
+}
+
+AudioFormat
+ReplayGainFilter::Open(AudioFormat &af, gcc_unused Error &error)
+{
+	if (!pv.Open(af.format, error))
+		return AudioFormat::Undefined();
+
+	return af;
+}
+
+void
+ReplayGainFilter::Close()
+{
+	pv.Close();
+}
+
+const void *
+ReplayGainFilter::FilterPCM(const void *src, size_t src_size,
+			    size_t *dest_size_r, gcc_unused Error &error)
+{
+	const auto dest = pv.Apply({src, src_size});
+	*dest_size_r = dest.size;
+	return dest.data;
+}
+
+const struct filter_plugin replay_gain_filter_plugin = {
+	"replay_gain",
+	replay_gain_filter_init,
+};
+
+void
+replay_gain_filter_set_mixer(Filter *_filter, Mixer *mixer,
+			     unsigned base)
+{
+	ReplayGainFilter *filter = (ReplayGainFilter *)_filter;
+
+	filter->SetMixer(mixer, base);
+}
+
+void
+replay_gain_filter_set_info(Filter *_filter, const ReplayGainInfo *info)
+{
+	ReplayGainFilter *filter = (ReplayGainFilter *)_filter;
+
+	filter->SetInfo(info);
+}
+
+void
+replay_gain_filter_set_mode(Filter *_filter, ReplayGainMode mode)
+{
+	ReplayGainFilter *filter = (ReplayGainFilter *)_filter;
+
+	filter->SetMode(mode);
+}