mirror of
https://github.com/alsa-project/alsa-lib.git
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299 lines
6.5 KiB
C
299 lines
6.5 KiB
C
/*
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* Mixer Interface - main file
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* Copyright (c) 1998 by Jaroslav Kysela <perex@suse.cz>
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*
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*
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* This library is free software; you can redistribute it and/or modify
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* it under the terms of the GNU Library General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Library General Public License for more details.
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*
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* You should have received a copy of the GNU Library General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <string.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <sys/ioctl.h>
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#include "asoundlib.h"
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#define SND_FILE_MIXER "/dev/snd/mixerC%iD%i"
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#define SND_MIXER_VERSION_MAX SND_PROTOCOL_VERSION(1, 0, 0)
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struct snd_mixer {
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int card;
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int device;
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int fd;
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} ;
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int snd_mixer_open(snd_mixer_t **handle, int card, int device)
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{
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int fd, ver;
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char filename[32];
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snd_mixer_t *mixer;
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*handle = NULL;
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if (card < 0 || card >= SND_CARDS)
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return -EINVAL;
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sprintf(filename, SND_FILE_MIXER, card, device);
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if ((fd = open(filename, O_RDWR)) < 0) {
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snd_card_load(card);
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if ((fd = open(filename, O_RDWR)) < 0)
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return -errno;
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}
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if (ioctl(fd, SND_MIXER_IOCTL_PVERSION, &ver) < 0) {
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close(fd);
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return -errno;
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}
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if (SND_PROTOCOL_INCOMPATIBLE(ver, SND_MIXER_VERSION_MAX)) {
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close(fd);
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return -SND_ERROR_INCOMPATIBLE_VERSION;
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}
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mixer = (snd_mixer_t *) calloc(1, sizeof(snd_mixer_t));
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if (mixer == NULL) {
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close(fd);
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return -ENOMEM;
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}
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mixer->card = card;
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mixer->device = device;
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mixer->fd = fd;
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*handle = mixer;
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return 0;
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}
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int snd_mixer_close(snd_mixer_t *handle)
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{
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snd_mixer_t *mixer;
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int res;
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mixer = handle;
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if (!mixer)
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return -EINVAL;
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res = close(mixer->fd) < 0 ? -errno : 0;
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free(mixer);
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return res;
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}
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int snd_mixer_file_descriptor(snd_mixer_t *handle)
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{
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snd_mixer_t *mixer;
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mixer = handle;
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if (!mixer)
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return -EINVAL;
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return mixer->fd;
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}
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int snd_mixer_info(snd_mixer_t *handle, snd_mixer_info_t * info)
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{
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snd_mixer_t *mixer;
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mixer = handle;
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if (!mixer || !info)
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return -EINVAL;
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if (ioctl(mixer->fd, SND_MIXER_IOCTL_INFO, info) < 0)
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return -errno;
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return 0;
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}
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int snd_mixer_elements(snd_mixer_t *handle, snd_mixer_elements_t * elements)
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{
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snd_mixer_t *mixer;
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mixer = handle;
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if (!mixer || !elements)
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return -EINVAL;
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if (ioctl(mixer->fd, SND_MIXER_IOCTL_ELEMENTS, elements) < 0)
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return -errno;
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return 0;
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}
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int snd_mixer_routes(snd_mixer_t *handle, snd_mixer_routes_t * routes)
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{
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snd_mixer_t *mixer;
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mixer = handle;
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if (!mixer || !routes)
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return -EINVAL;
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if (ioctl(mixer->fd, SND_MIXER_IOCTL_ROUTES, routes) < 0)
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return -errno;
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return 0;
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}
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int snd_mixer_groups(snd_mixer_t *handle, snd_mixer_groups_t * groups)
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{
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snd_mixer_t *mixer;
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mixer = handle;
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if (!mixer || !groups)
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return -EINVAL;
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if (ioctl(mixer->fd, SND_MIXER_IOCTL_GROUPS, groups) < 0)
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return -errno;
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return 0;
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}
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int snd_mixer_group_read(snd_mixer_t *handle, snd_mixer_group_t * group)
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{
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snd_mixer_t *mixer;
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mixer = handle;
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if (!mixer || !group)
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return -EINVAL;
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if (ioctl(mixer->fd, SND_MIXER_IOCTL_GROUP_READ, group) < 0)
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return -errno;
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return 0;
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}
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int snd_mixer_group_write(snd_mixer_t *handle, snd_mixer_group_t * group)
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{
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snd_mixer_t *mixer;
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mixer = handle;
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if (!mixer || !group)
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return -EINVAL;
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if (ioctl(mixer->fd, SND_MIXER_IOCTL_GROUP_WRITE, group) < 0)
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return -errno;
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return 0;
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}
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int snd_mixer_element_info(snd_mixer_t *handle, snd_mixer_element_info_t * info)
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{
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snd_mixer_t *mixer;
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mixer = handle;
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if (!mixer || !info)
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return -EINVAL;
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if (ioctl(mixer->fd, SND_MIXER_IOCTL_ELEMENT_INFO, info) < 0)
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return -errno;
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return 0;
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}
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int snd_mixer_element_read(snd_mixer_t *handle, snd_mixer_element_t * element)
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{
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snd_mixer_t *mixer;
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mixer = handle;
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if (!mixer || !element)
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return -EINVAL;
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if (ioctl(mixer->fd, SND_MIXER_IOCTL_ELEMENT_READ, element) < 0)
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return -errno;
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return 0;
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}
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int snd_mixer_element_write(snd_mixer_t *handle, snd_mixer_element_t * element)
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{
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snd_mixer_t *mixer;
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mixer = handle;
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if (!mixer || !element)
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return -EINVAL;
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if (ioctl(mixer->fd, SND_MIXER_IOCTL_ELEMENT_WRITE, element) < 0)
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return -errno;
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return 0;
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}
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int snd_mixer_get_filter(snd_mixer_t *handle, snd_mixer_filter_t * filter)
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{
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snd_mixer_t *mixer;
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mixer = handle;
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if (!mixer || !filter)
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return -EINVAL;
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if (ioctl(mixer->fd, SND_MIXER_IOCTL_GET_FILTER, filter) < 0)
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return -errno;
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return 0;
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}
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int snd_mixer_put_filter(snd_mixer_t *handle, snd_mixer_filter_t * filter)
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{
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snd_mixer_t *mixer;
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mixer = handle;
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if (!mixer || !filter)
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return -EINVAL;
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if (ioctl(mixer->fd, SND_MIXER_IOCTL_PUT_FILTER, filter) < 0)
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return -errno;
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return 0;
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}
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int snd_mixer_read(snd_mixer_t *handle, snd_mixer_callbacks_t * callbacks)
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{
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snd_mixer_t *mixer;
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int result, count;
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snd_mixer_read_t r;
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mixer = handle;
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if (!mixer)
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return -EINVAL;
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count = 0;
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while ((result = read(mixer->fd, &r, sizeof(r))) > 0) {
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if (result != sizeof(r))
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return -EIO;
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if (!callbacks)
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continue;
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switch (r.cmd) {
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case SND_MIXER_READ_REBUILD:
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if (callbacks->rebuild)
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callbacks->rebuild(callbacks->private_data);
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break;
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case SND_MIXER_READ_ELEMENT_VALUE:
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case SND_MIXER_READ_ELEMENT_CHANGE:
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case SND_MIXER_READ_ELEMENT_ROUTE:
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case SND_MIXER_READ_ELEMENT_ADD:
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case SND_MIXER_READ_ELEMENT_REMOVE:
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if (callbacks->element)
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callbacks->element(callbacks->private_data, r.cmd, &r.data.eid);
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break;
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case SND_MIXER_READ_GROUP_CHANGE:
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case SND_MIXER_READ_GROUP_ADD:
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case SND_MIXER_READ_GROUP_REMOVE:
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if (callbacks->group)
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callbacks->group(callbacks->private_data, r.cmd, &r.data.gid);
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break;
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}
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count++;
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}
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return result >= 0 ? count : -errno;
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}
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void snd_mixer_set_bit(unsigned int *bitmap, int bit, int val)
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{
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if (val) {
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bitmap[bit >> 5] |= 1 << (bit & 31);
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} else {
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bitmap[bit >> 5] &= ~(1 << (bit & 31));
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}
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}
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int snd_mixer_get_bit(unsigned int *bitmap, int bit)
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{
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return (bitmap[bit >> 5] & (1 << (bit & 31))) ? 1 : 0;
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}
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const char *snd_mixer_channel_name(int channel)
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{
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static char *array[6] = {
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"Front-Left",
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"Front-Right",
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"Front-Center",
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"Rear-Left",
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"Rear-Right",
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"Woofer"
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};
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if (channel < 0 || channel > 5)
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return "?";
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return array[channel];
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}
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