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Diffstat (limited to '')
-rw-r--r-- | src/filter/VolumeFilterPlugin.cxx | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/src/filter/VolumeFilterPlugin.cxx b/src/filter/VolumeFilterPlugin.cxx new file mode 100644 index 000000000..0689f5da5 --- /dev/null +++ b/src/filter/VolumeFilterPlugin.cxx @@ -0,0 +1,148 @@ +/* + * Copyright (C) 2003-2013 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 "VolumeFilterPlugin.hxx" +#include "FilterPlugin.hxx" +#include "FilterInternal.hxx" +#include "FilterRegistry.hxx" +#include "conf.h" +#include "pcm_buffer.h" +#include "PcmVolume.hxx" +#include "audio_format.h" + +#include <assert.h> +#include <string.h> + +class VolumeFilter final : public Filter { + /** + * The current volume, from 0 to #PCM_VOLUME_1. + */ + unsigned volume; + + struct audio_format format; + + struct pcm_buffer buffer; + +public: + VolumeFilter() + :volume(PCM_VOLUME_1) {} + + unsigned GetVolume() const { + assert(volume <= PCM_VOLUME_1); + + return volume; + } + + void SetVolume(unsigned _volume) { + assert(_volume <= PCM_VOLUME_1); + + volume = _volume; + } + + virtual const audio_format *Open(audio_format &af, GError **error_r); + virtual void Close(); + virtual const void *FilterPCM(const void *src, size_t src_size, + size_t *dest_size_r, GError **error_r); +}; + +static inline GQuark +volume_quark(void) +{ + return g_quark_from_static_string("pcm_volume"); +} + +static Filter * +volume_filter_init(gcc_unused const struct config_param *param, + gcc_unused GError **error_r) +{ + return new VolumeFilter(); +} + +const struct audio_format * +VolumeFilter::Open(audio_format &audio_format, gcc_unused GError **error_r) +{ + format = audio_format; + pcm_buffer_init(&buffer); + + return &format; +} + +void +VolumeFilter::Close() +{ + pcm_buffer_deinit(&buffer); +} + +const void * +VolumeFilter::FilterPCM(const void *src, size_t src_size, + size_t *dest_size_r, GError **error_r) +{ + *dest_size_r = src_size; + + if (volume >= PCM_VOLUME_1) + /* optimized special case: 100% volume = no-op */ + return src; + + void *dest = pcm_buffer_get(&buffer, src_size); + + if (volume <= 0) { + /* optimized special case: 0% volume = memset(0) */ + /* XXX is this valid for all sample formats? What + about floating point? */ + memset(dest, 0, src_size); + return dest; + } + + memcpy(dest, src, src_size); + + bool success = pcm_volume(dest, src_size, + sample_format(format.format), + volume); + if (!success) { + g_set_error(error_r, volume_quark(), 0, + "pcm_volume() has failed"); + return NULL; + } + + return dest; +} + +const struct filter_plugin volume_filter_plugin = { + "volume", + volume_filter_init, +}; + +unsigned +volume_filter_get(const Filter *_filter) +{ + const VolumeFilter *filter = + (const VolumeFilter *)_filter; + + return filter->GetVolume(); +} + +void +volume_filter_set(Filter *_filter, unsigned volume) +{ + VolumeFilter *filter = (VolumeFilter *)_filter; + + filter->SetVolume(volume); +} + |