436 lines
21 KiB
C++
436 lines
21 KiB
C++
#ifndef foovolumehfoo
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#define foovolumehfoo
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/***
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This file is part of PulseAudio.
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Copyright 2004-2006 Lennart Poettering
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Copyright 2006 Pierre Ossman <ossman@cendio.se> for Cendio AB
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PulseAudio is free software; you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as published
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by the Free Software Foundation; either version 2.1 of the License,
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or (at your option) any later version.
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PulseAudio is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
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***/
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#include <inttypes.h>
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#include <limits.h>
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#include <pulse/cdecl.h>
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#include <pulse/gccmacro.h>
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#include <pulse/sample.h>
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#include <pulse/channelmap.h>
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#include <pulse/version.h>
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/** \page volume Volume Control
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*
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* \section overv_sec Overview
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*
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* Sinks, sources, sink inputs and samples can all have their own volumes.
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* To deal with these, The PulseAudio library contains a number of functions
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* that ease handling.
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*
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* The basic volume type in PulseAudio is the \ref pa_volume_t type. Most of
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* the time, applications will use the aggregated pa_cvolume structure that
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* can store the volume of all channels at once.
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*
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* Volumes commonly span between muted (0%), and normal (100%). It is possible
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* to set volumes to higher than 100%, but clipping might occur.
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*
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* There is no single well-defined meaning attached to the 100% volume for a
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* sink input. In fact, it depends on the server configuration. With flat
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* volumes enabled (the default in most Linux distributions), it means the
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* maximum volume that the sound hardware is capable of, which is usually so
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* high that you absolutely must not set sink input volume to 100% unless the
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* the user explicitly requests that (note that usually you shouldn't set the
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* volume anyway if the user doesn't explicitly request it, instead, let
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* PulseAudio decide the volume for the sink input). With flat volumes disabled
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* (the default in Ubuntu), the sink input volume is relative to the sink
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* volume, so 100% sink input volume means that the sink input is played at the
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* current sink volume level. In this case 100% is often a good default volume
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* for a sink input, although you still should let PulseAudio decide the
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* default volume. It is possible to figure out whether flat volume mode is in
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* effect for a given sink by calling pa_context_get_sink_info_by_name().
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*
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* \section calc_sec Calculations
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*
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* The volumes in PulseAudio are logarithmic in nature and applications
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* shouldn't perform calculations with them directly. Instead, they should
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* be converted to and from either dB or a linear scale:
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*
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* \li dB - pa_sw_volume_from_dB() / pa_sw_volume_to_dB()
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* \li Linear - pa_sw_volume_from_linear() / pa_sw_volume_to_linear()
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*
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* For simple multiplication, pa_sw_volume_multiply() and
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* pa_sw_cvolume_multiply() can be used.
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*
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* Calculations can only be reliably performed on software volumes
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* as it is commonly unknown what scale hardware volumes relate to.
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*
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* The functions described above are only valid when used with
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* software volumes. Hence it is usually a better idea to treat all
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* volume values as opaque with a range from PA_VOLUME_MUTED (0%) to
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* PA_VOLUME_NORM (100%) and to refrain from any calculations with
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* them.
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*
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* \section conv_sec Convenience Functions
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*
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* To handle the pa_cvolume structure, the PulseAudio library provides a
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* number of convenience functions:
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*
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* \li pa_cvolume_valid() - Tests if a pa_cvolume structure is valid.
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* \li pa_cvolume_equal() - Tests if two pa_cvolume structures are identical.
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* \li pa_cvolume_channels_equal_to() - Tests if all channels of a pa_cvolume
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* structure have a given volume.
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* \li pa_cvolume_is_muted() - Tests if all channels of a pa_cvolume
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* structure are muted.
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* \li pa_cvolume_is_norm() - Tests if all channels of a pa_cvolume structure
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* are at a normal volume.
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* \li pa_cvolume_set() - Set the first n channels of a pa_cvolume structure to
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* a certain volume.
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* \li pa_cvolume_reset() - Set the first n channels of a pa_cvolume structure
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* to a normal volume.
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* \li pa_cvolume_mute() - Set the first n channels of a pa_cvolume structure
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* to a muted volume.
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* \li pa_cvolume_avg() - Return the average volume of all channels.
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* \li pa_cvolume_snprint() - Pretty print a pa_cvolume structure.
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*/
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/** \file
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* Constants and routines for volume handling
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*
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* See also \subpage volume
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*/
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PA_C_DECL_BEGIN
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/** Volume specification:
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* PA_VOLUME_MUTED: silence;
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* < PA_VOLUME_NORM: decreased volume;
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* PA_VOLUME_NORM: normal volume;
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* > PA_VOLUME_NORM: increased volume */
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typedef uint32_t pa_volume_t;
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/** Normal volume (100%, 0 dB) */
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#define PA_VOLUME_NORM ((pa_volume_t) 0x10000U)
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/** Muted (minimal valid) volume (0%, -inf dB) */
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#define PA_VOLUME_MUTED ((pa_volume_t) 0U)
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/** Maximum valid volume we can store. \since 0.9.15 */
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#define PA_VOLUME_MAX ((pa_volume_t) UINT32_MAX/2)
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/** Recommended maximum volume to show in user facing UIs.
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* Note: UIs should deal gracefully with volumes greater than this value
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* and not cause feedback loops etc. - i.e. if the volume is more than
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* this, the UI should not limit it and push the limited value back to
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* the server. \since 0.9.23 */
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#define PA_VOLUME_UI_MAX (pa_sw_volume_from_dB(+11.0))
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/** Special 'invalid' volume. \since 0.9.16 */
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#define PA_VOLUME_INVALID ((pa_volume_t) UINT32_MAX)
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/** Check if volume is valid. \since 1.0 */
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#define PA_VOLUME_IS_VALID(v) ((v) <= PA_VOLUME_MAX)
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/** Clamp volume to the permitted range. \since 1.0 */
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#define PA_CLAMP_VOLUME(v) (PA_CLAMP_UNLIKELY((v), PA_VOLUME_MUTED, PA_VOLUME_MAX))
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/** A structure encapsulating a per-channel volume */
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typedef struct pa_cvolume {
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uint8_t channels; /**< Number of channels */
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pa_volume_t values[PA_CHANNELS_MAX]; /**< Per-channel volume */
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} pa_cvolume;
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/** Return non-zero when *a == *b */
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int pa_cvolume_equal(const pa_cvolume *a, const pa_cvolume *b) PA_GCC_PURE;
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/** Initialize the specified volume and return a pointer to
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* it. The sample spec will have a defined state but
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* pa_cvolume_valid() will fail for it. \since 0.9.13 */
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pa_cvolume* pa_cvolume_init(pa_cvolume *a);
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/** Set the volume of the first n channels to PA_VOLUME_NORM */
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#define pa_cvolume_reset(a, n) pa_cvolume_set((a), (n), PA_VOLUME_NORM)
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/** Set the volume of the first n channels to PA_VOLUME_MUTED */
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#define pa_cvolume_mute(a, n) pa_cvolume_set((a), (n), PA_VOLUME_MUTED)
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/** Set the volume of the specified number of channels to the volume v */
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pa_cvolume* pa_cvolume_set(pa_cvolume *a, unsigned channels, pa_volume_t v);
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/** Maximum length of the strings returned by
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* pa_cvolume_snprint(). Please note that this value can change with
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* any release without warning and without being considered API or ABI
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* breakage. You should not use this definition anywhere where it
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* might become part of an ABI.*/
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#define PA_CVOLUME_SNPRINT_MAX 320
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/** Pretty print a volume structure */
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char *pa_cvolume_snprint(char *s, size_t l, const pa_cvolume *c);
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/** Maximum length of the strings returned by
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* pa_sw_cvolume_snprint_dB(). Please note that this value can change with
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* any release without warning and without being considered API or ABI
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* breakage. You should not use this definition anywhere where it
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* might become part of an ABI. \since 0.9.13 */
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#define PA_SW_CVOLUME_SNPRINT_DB_MAX 448
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/** Pretty print a volume structure but show dB values. \since 0.9.13 */
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char *pa_sw_cvolume_snprint_dB(char *s, size_t l, const pa_cvolume *c);
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/** Maximum length of the strings returned by pa_cvolume_snprint_verbose().
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* Please note that this value can change with any release without warning and
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* without being considered API or ABI breakage. You should not use this
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* definition anywhere where it might become part of an ABI. \since 5.0 */
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#define PA_CVOLUME_SNPRINT_VERBOSE_MAX 1984
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/** Pretty print a volume structure in a verbose way. The volume for each
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* channel is printed in several formats: the raw pa_volume_t value,
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* percentage, and if print_dB is non-zero, also the dB value. If map is not
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* NULL, the channel names will be printed. \since 5.0 */
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char *pa_cvolume_snprint_verbose(char *s, size_t l, const pa_cvolume *c, const pa_channel_map *map, int print_dB);
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/** Maximum length of the strings returned by
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* pa_volume_snprint(). Please note that this value can change with
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* any release without warning and without being considered API or ABI
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* breakage. You should not use this definition anywhere where it
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* might become part of an ABI. \since 0.9.15 */
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#define PA_VOLUME_SNPRINT_MAX 10
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/** Pretty print a volume \since 0.9.15 */
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char *pa_volume_snprint(char *s, size_t l, pa_volume_t v);
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/** Maximum length of the strings returned by
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* pa_sw_volume_snprint_dB(). Please note that this value can change with
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* any release without warning and without being considered API or ABI
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* breakage. You should not use this definition anywhere where it
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* might become part of an ABI. \since 0.9.15 */
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#define PA_SW_VOLUME_SNPRINT_DB_MAX 11
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/** Pretty print a volume but show dB values. \since 0.9.15 */
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char *pa_sw_volume_snprint_dB(char *s, size_t l, pa_volume_t v);
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/** Maximum length of the strings returned by pa_volume_snprint_verbose().
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* Please note that this value can change with any release without warning and
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* withou being considered API or ABI breakage. You should not use this
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* definition anywhere where it might become part of an ABI. \since 5.0 */
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#define PA_VOLUME_SNPRINT_VERBOSE_MAX 35
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/** Pretty print a volume in a verbose way. The volume is printed in several
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* formats: the raw pa_volume_t value, percentage, and if print_dB is non-zero,
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* also the dB value. \since 5.0 */
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char *pa_volume_snprint_verbose(char *s, size_t l, pa_volume_t v, int print_dB);
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/** Return the average volume of all channels */
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pa_volume_t pa_cvolume_avg(const pa_cvolume *a) PA_GCC_PURE;
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/** Return the average volume of all channels that are included in the
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* specified channel map with the specified channel position mask. If
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* cm is NULL this call is identical to pa_cvolume_avg(). If no
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* channel is selected the returned value will be
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* PA_VOLUME_MUTED. \since 0.9.16 */
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pa_volume_t pa_cvolume_avg_mask(const pa_cvolume *a, const pa_channel_map *cm, pa_channel_position_mask_t mask) PA_GCC_PURE;
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/** Return the maximum volume of all channels. \since 0.9.12 */
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pa_volume_t pa_cvolume_max(const pa_cvolume *a) PA_GCC_PURE;
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/** Return the maximum volume of all channels that are included in the
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* specified channel map with the specified channel position mask. If
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* cm is NULL this call is identical to pa_cvolume_max(). If no
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* channel is selected the returned value will be PA_VOLUME_MUTED.
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* \since 0.9.16 */
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pa_volume_t pa_cvolume_max_mask(const pa_cvolume *a, const pa_channel_map *cm, pa_channel_position_mask_t mask) PA_GCC_PURE;
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/** Return the minimum volume of all channels. \since 0.9.16 */
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pa_volume_t pa_cvolume_min(const pa_cvolume *a) PA_GCC_PURE;
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/** Return the minimum volume of all channels that are included in the
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* specified channel map with the specified channel position mask. If
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* cm is NULL this call is identical to pa_cvolume_min(). If no
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* channel is selected the returned value will be PA_VOLUME_MUTED.
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* \since 0.9.16 */
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pa_volume_t pa_cvolume_min_mask(const pa_cvolume *a, const pa_channel_map *cm, pa_channel_position_mask_t mask) PA_GCC_PURE;
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/** Return non-zero when the passed cvolume structure is valid */
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int pa_cvolume_valid(const pa_cvolume *v) PA_GCC_PURE;
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/** Return non-zero if the volume of all channels is equal to the specified value */
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int pa_cvolume_channels_equal_to(const pa_cvolume *a, pa_volume_t v) PA_GCC_PURE;
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/** Return 1 if the specified volume has all channels muted */
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#define pa_cvolume_is_muted(a) pa_cvolume_channels_equal_to((a), PA_VOLUME_MUTED)
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/** Return 1 if the specified volume has all channels on normal level */
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#define pa_cvolume_is_norm(a) pa_cvolume_channels_equal_to((a), PA_VOLUME_NORM)
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/** Multiply two volume specifications, return the result. This uses
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* PA_VOLUME_NORM as neutral element of multiplication. This is only
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* valid for software volumes! */
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pa_volume_t pa_sw_volume_multiply(pa_volume_t a, pa_volume_t b) PA_GCC_CONST;
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/** Multiply two per-channel volumes and return the result in
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* *dest. This is only valid for software volumes! a, b and dest may
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* point to the same structure. */
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pa_cvolume *pa_sw_cvolume_multiply(pa_cvolume *dest, const pa_cvolume *a, const pa_cvolume *b);
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/** Multiply a per-channel volume with a scalar volume and return the
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* result in *dest. This is only valid for software volumes! a
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* and dest may point to the same structure. \since
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* 0.9.16 */
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pa_cvolume *pa_sw_cvolume_multiply_scalar(pa_cvolume *dest, const pa_cvolume *a, pa_volume_t b);
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/** Divide two volume specifications, return the result. This uses
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* PA_VOLUME_NORM as neutral element of division. This is only valid
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* for software volumes! If a division by zero is tried the result
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* will be 0. \since 0.9.13 */
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pa_volume_t pa_sw_volume_divide(pa_volume_t a, pa_volume_t b) PA_GCC_CONST;
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/** Divide two per-channel volumes and return the result in
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* *dest. This is only valid for software volumes! a, b
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* and dest may point to the same structure. \since 0.9.13 */
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pa_cvolume *pa_sw_cvolume_divide(pa_cvolume *dest, const pa_cvolume *a, const pa_cvolume *b);
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/** Divide a per-channel volume by a scalar volume and return the
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* result in *dest. This is only valid for software volumes! a
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* and dest may point to the same structure. \since
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* 0.9.16 */
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pa_cvolume *pa_sw_cvolume_divide_scalar(pa_cvolume *dest, const pa_cvolume *a, pa_volume_t b);
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/** Convert a decibel value to a volume (amplitude, not power). This is only valid for software volumes! */
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pa_volume_t pa_sw_volume_from_dB(double f) PA_GCC_CONST;
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/** Convert a volume to a decibel value (amplitude, not power). This is only valid for software volumes! */
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double pa_sw_volume_to_dB(pa_volume_t v) PA_GCC_CONST;
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/** Convert a linear factor to a volume. 0.0 and less is muted while
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* 1.0 is PA_VOLUME_NORM. This is only valid for software volumes! */
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pa_volume_t pa_sw_volume_from_linear(double v) PA_GCC_CONST;
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/** Convert a volume to a linear factor. This is only valid for software volumes! */
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double pa_sw_volume_to_linear(pa_volume_t v) PA_GCC_CONST;
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#ifdef INFINITY
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#define PA_DECIBEL_MININFTY ((double) -INFINITY)
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#else
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/** This floor value is used as minus infinity when using pa_sw_volume_to_dB() / pa_sw_volume_from_dB(). */
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#define PA_DECIBEL_MININFTY ((double) -200.0)
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#endif
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/** Remap a volume from one channel mapping to a different channel mapping. \since 0.9.12 */
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pa_cvolume *pa_cvolume_remap(pa_cvolume *v, const pa_channel_map *from, const pa_channel_map *to);
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/** Return non-zero if the specified volume is compatible with the
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* specified sample spec. \since 0.9.13 */
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int pa_cvolume_compatible(const pa_cvolume *v, const pa_sample_spec *ss) PA_GCC_PURE;
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/** Return non-zero if the specified volume is compatible with the
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* specified sample spec. \since 0.9.15 */
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int pa_cvolume_compatible_with_channel_map(const pa_cvolume *v, const pa_channel_map *cm) PA_GCC_PURE;
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/** Calculate a 'balance' value for the specified volume with the
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* specified channel map. The return value will range from -1.0f
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* (left) to +1.0f (right). If no balance value is applicable to this
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* channel map the return value will always be 0.0f. See
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* pa_channel_map_can_balance(). \since 0.9.15 */
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float pa_cvolume_get_balance(const pa_cvolume *v, const pa_channel_map *map) PA_GCC_PURE;
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/** Adjust the 'balance' value for the specified volume with the
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* specified channel map. v will be modified in place and
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* returned. The balance is a value between -1.0f and +1.0f. This
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* operation might not be reversible! Also, after this call
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* pa_cvolume_get_balance() is not guaranteed to actually return the
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* requested balance value (e.g. when the input volume was zero anyway for
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* all channels). If no balance value is applicable to
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* this channel map the volume will not be modified. See
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* pa_channel_map_can_balance(). \since 0.9.15 */
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pa_cvolume* pa_cvolume_set_balance(pa_cvolume *v, const pa_channel_map *map, float new_balance);
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/** Calculate a 'fade' value (i.e.\ 'balance' between front and rear)
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* for the specified volume with the specified channel map. The return
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* value will range from -1.0f (rear) to +1.0f (left). If no fade
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* value is applicable to this channel map the return value will
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* always be 0.0f. See pa_channel_map_can_fade(). \since 0.9.15 */
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float pa_cvolume_get_fade(const pa_cvolume *v, const pa_channel_map *map) PA_GCC_PURE;
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/** Adjust the 'fade' value (i.e.\ 'balance' between front and rear)
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* for the specified volume with the specified channel map. v will be
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* modified in place and returned. The balance is a value between
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* -1.0f and +1.0f. This operation might not be reversible! Also,
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* after this call pa_cvolume_get_fade() is not guaranteed to actually
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* return the requested fade value (e.g. when the input volume was
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* zero anyway for all channels). If no fade value is applicable to
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* this channel map the volume will not be modified. See
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* pa_channel_map_can_fade(). \since 0.9.15 */
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pa_cvolume* pa_cvolume_set_fade(pa_cvolume *v, const pa_channel_map *map, float new_fade);
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/** Calculate a 'lfe balance' value for the specified volume with
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* the specified channel map. The return value will range from
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* -1.0f (no lfe) to +1.0f (only lfe), where 0.0f is balanced.
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* If no value is applicable to this channel map the return value
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* will always be 0.0f. See pa_channel_map_can_lfe_balance(). \since 8.0 */
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float pa_cvolume_get_lfe_balance(const pa_cvolume *v, const pa_channel_map *map) PA_GCC_PURE;
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/** Adjust the 'lfe balance' value for the specified volume with
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* the specified channel map. v will be modified in place and returned.
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* The balance is a value between -1.0f (no lfe) and +1.0f (only lfe).
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* This operation might not be reversible! Also, after this call
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* pa_cvolume_get_lfe_balance() is not guaranteed to actually
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* return the requested value (e.g. when the input volume was
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* zero anyway for all channels). If no lfe balance value is applicable to
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* this channel map the volume will not be modified. See
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* pa_channel_map_can_lfe_balance(). \since 8.0 */
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pa_cvolume* pa_cvolume_set_lfe_balance(pa_cvolume *v, const pa_channel_map *map, float new_balance);
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/** Scale the passed pa_cvolume structure so that the maximum volume
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* of all channels equals max. The proportions between the channel
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* volumes are kept. \since 0.9.15 */
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pa_cvolume* pa_cvolume_scale(pa_cvolume *v, pa_volume_t max);
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/** Scale the passed pa_cvolume structure so that the maximum volume
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* of all channels selected via cm/mask equals max. This also modifies
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* the volume of those channels that are unmasked. The proportions
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* between the channel volumes are kept. \since 0.9.16 */
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pa_cvolume* pa_cvolume_scale_mask(pa_cvolume *v, pa_volume_t max, pa_channel_map *cm, pa_channel_position_mask_t mask);
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/** Set the passed volume to all channels at the specified channel
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* position. Will return the updated volume struct, or NULL if there
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* is no channel at the position specified. You can check if a channel
|
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* map includes a specific position by calling
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* pa_channel_map_has_position(). \since 0.9.16 */
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pa_cvolume* pa_cvolume_set_position(pa_cvolume *cv, const pa_channel_map *map, pa_channel_position_t t, pa_volume_t v);
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/** Get the maximum volume of all channels at the specified channel
|
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* position. Will return 0 if there is no channel at the position
|
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* specified. You can check if a channel map includes a specific
|
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* position by calling pa_channel_map_has_position(). \since 0.9.16 */
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pa_volume_t pa_cvolume_get_position(pa_cvolume *cv, const pa_channel_map *map, pa_channel_position_t t) PA_GCC_PURE;
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/** This goes through all channels in a and b and sets the
|
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* corresponding channel in dest to the greater volume of both. a, b
|
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* and dest may point to the same structure. \since 0.9.16 */
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pa_cvolume* pa_cvolume_merge(pa_cvolume *dest, const pa_cvolume *a, const pa_cvolume *b);
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/** Increase the volume passed in by 'inc', but not exceeding 'limit'.
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* The proportions between the channels are kept. \since 0.9.19 */
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pa_cvolume* pa_cvolume_inc_clamp(pa_cvolume *v, pa_volume_t inc, pa_volume_t limit);
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/** Increase the volume passed in by 'inc'. The proportions between
|
|
* the channels are kept. \since 0.9.16 */
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pa_cvolume* pa_cvolume_inc(pa_cvolume *v, pa_volume_t inc);
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/** Decrease the volume passed in by 'dec'. The proportions between
|
|
* the channels are kept. \since 0.9.16 */
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pa_cvolume* pa_cvolume_dec(pa_cvolume *v, pa_volume_t dec);
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PA_C_DECL_END
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#endif
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