From 4e55719a0811275cd8d14ec4ff5cde7e0896f81d Mon Sep 17 00:00:00 2001 From: Taylor Holberton Date: Wed, 23 Nov 2016 11:48:06 -0800 Subject: finished mixer API documentation --- src/mixer.c | 88 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 88 insertions(+) (limited to 'src/mixer.c') diff --git a/src/mixer.c b/src/mixer.c index e6f50bb..1d2cd74 100644 --- a/src/mixer.c +++ b/src/mixer.c @@ -363,6 +363,13 @@ static int int_to_percent(struct snd_ctl_elem_info *ei, int value) return ((value - ei->value.integer.min) / range) * 100; } +/** Gets a percentage representation of a specified control value. + * @param ctl An initialized control handle. + * @param id The index of the value within the control. + * @returns On success, the percentage representation of the control value. + * On failure, -EINVAL is returned. + * @ingroup libtinyalsa-mixer + */ int mixer_ctl_get_percent(struct mixer_ctl *ctl, unsigned int id) { if (!ctl || (ctl->info.type != SNDRV_CTL_ELEM_TYPE_INTEGER)) @@ -371,6 +378,14 @@ int mixer_ctl_get_percent(struct mixer_ctl *ctl, unsigned int id) return int_to_percent(&ctl->info, mixer_ctl_get_value(ctl, id)); } +/** Sets the value of a control by percent, specified by the value index. + * @param ctl An initialized control handle. + * @param id The index of the value to set + * @param percent A percentage value between 0 and 100. + * @returns On success, zero is returned. + * On failure, non-zero is returned. + * @ingroup libtinyalsa-mixer + */ int mixer_ctl_set_percent(struct mixer_ctl *ctl, unsigned int id, int percent) { if (!ctl || (ctl->info.type != SNDRV_CTL_ELEM_TYPE_INTEGER)) @@ -379,6 +394,13 @@ int mixer_ctl_set_percent(struct mixer_ctl *ctl, unsigned int id, int percent) return mixer_ctl_set_value(ctl, id, percent_to_int(&ctl->info, percent)); } +/** Gets the value of a control. + * @param ctl An initialized control handle. + * @param id The index of the control value. + * @returns On success, the specified value is returned. + * On failure, -EINVAL is returned. + * @ingroup libtinyalsa-mixer + */ int mixer_ctl_get_value(struct mixer_ctl *ctl, unsigned int id) { struct snd_ctl_elem_value ev; @@ -413,6 +435,18 @@ int mixer_ctl_get_value(struct mixer_ctl *ctl, unsigned int id) return 0; } +/** Gets the contents of a control's value array. + * @param ctl An initialized control handle. + * @param array A pointer to write the array data to. + * The size of this array must be equal to the number of items in the array + * multiplied by the size of each item. + * @param count The number of items in the array. + * This parameter must match the number of items in the control. + * The number of items in the control may be accessed via @ref mixer_ctl_get_num_values + * @returns On success, zero. + * On failure, non-zero. + * @ingroup libtinyalsa-mixer + */ int mixer_ctl_get_array(struct mixer_ctl *ctl, void *array, size_t count) { struct snd_ctl_elem_value ev; @@ -475,6 +509,16 @@ int mixer_ctl_get_array(struct mixer_ctl *ctl, void *array, size_t count) return 0; } +/** Sets the value of a control, specified by the value index. + * @param ctl An initialized control handle. + * @param id The index of the value within the control. + * @param value The value to set. + * This must be in a range specified by @ref mixer_ctl_get_range_min + * and @ref mixer_ctl_get_range_max. + * @returns On success, zero is returned. + * On failure, non-zero is returned. + * @ingroup libtinyalsa-mixer + */ int mixer_ctl_set_value(struct mixer_ctl *ctl, unsigned int id, int value) { struct snd_ctl_elem_value ev; @@ -518,6 +562,16 @@ int mixer_ctl_set_value(struct mixer_ctl *ctl, unsigned int id, int value) return ioctl(ctl->mixer->fd, SNDRV_CTL_IOCTL_ELEM_WRITE, &ev); } +/** Sets the contents of a control's value array. + * @param ctl An initialized control handle. + * @param array The array containing control values. + * @param count The number of values in the array. + * This must match the number of values in the control. + * The number of values in a control may be accessed via @ref mixer_ctl_get_num_values + * @returns On success, zero. + * On failure, non-zero. + * @ingroup libtinyalsa-mixer + */ int mixer_ctl_set_array(struct mixer_ctl *ctl, const void *array, size_t count) { struct snd_ctl_elem_value ev; @@ -570,6 +624,14 @@ int mixer_ctl_set_array(struct mixer_ctl *ctl, const void *array, size_t count) return ioctl(ctl->mixer->fd, SNDRV_CTL_IOCTL_ELEM_WRITE, &ev); } +/** Gets the minimum value of an control. + * The control must have an integer type. + * The type of the control can be checked with @ref mixer_ctl_get_type. + * @param ctl An initialized control handle. + * @returns On success, the minimum value of the control. + * On failure, -EINVAL. + * @ingroup libtinyalsa-mixer + */ int mixer_ctl_get_range_min(struct mixer_ctl *ctl) { if (!ctl || (ctl->info.type != SNDRV_CTL_ELEM_TYPE_INTEGER)) @@ -578,6 +640,14 @@ int mixer_ctl_get_range_min(struct mixer_ctl *ctl) return ctl->info.value.integer.min; } +/** Gets the maximum value of an control. + * The control must have an integer type. + * The type of the control can be checked with @ref mixer_ctl_get_type. + * @param ctl An initialized control handle. + * @returns On success, the maximum value of the control. + * On failure, -EINVAL. + * @ingroup libtinyalsa-mixer + */ int mixer_ctl_get_range_max(struct mixer_ctl *ctl) { if (!ctl || (ctl->info.type != SNDRV_CTL_ELEM_TYPE_INTEGER)) @@ -586,6 +656,11 @@ int mixer_ctl_get_range_max(struct mixer_ctl *ctl) return ctl->info.value.integer.max; } +/** Get the number of enumerated items in the control. + * @param ctl An initialized control handle. + * @returns The number of enumerated items in the control. + * @ingroup libtinyalsa-mixer + */ unsigned int mixer_ctl_get_num_enums(struct mixer_ctl *ctl) { if (!ctl) @@ -632,6 +707,12 @@ fail: return -1; } +/** Gets the string representation of an enumerated item. + * @param ctl An initialized control handle. + * @param enum_id The index of the enumerated value. + * @returns A string representation of the enumerated item. + * @ingroup libtinyalsa-mixer + */ const char *mixer_ctl_get_enum_string(struct mixer_ctl *ctl, unsigned int enum_id) { @@ -643,6 +724,13 @@ const char *mixer_ctl_get_enum_string(struct mixer_ctl *ctl, return (const char *)ctl->ename[enum_id]; } +/** Set an enumeration value by string value. + * @param ctl An enumerated mixer control. + * @param string The string representation of an enumeration. + * @returns On success, zero. + * On failure, zero. + * @ingroup libtinyalsa-mixer + */ int mixer_ctl_set_enum_by_string(struct mixer_ctl *ctl, const char *string) { unsigned int i, num_enums; -- cgit v1.2.3