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Diffstat (limited to '')
-rw-r--r-- | src/filter/plugins/ReplayGainFilterPlugin.cxx | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/src/filter/plugins/ReplayGainFilterPlugin.cxx b/src/filter/plugins/ReplayGainFilterPlugin.cxx new file mode 100644 index 000000000..651352ac9 --- /dev/null +++ b/src/filter/plugins/ReplayGainFilterPlugin.cxx @@ -0,0 +1,207 @@ +/* + * 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 "mixer/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 ConstBuffer<void> FilterPCM(ConstBuffer<void> src, + Error &error) override; +}; + +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 ¶m, + 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(); +} + +ConstBuffer<void> +ReplayGainFilter::FilterPCM(ConstBuffer<void> src, gcc_unused Error &error) +{ + return pv.Apply(src); +} + +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); +} |