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