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Commit	Line	Data
	1	/*
	2	* This file is part of DisOrder
	3	* Copyright (C) 2007 Richard Kettlewell
	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License as published by
	7	* the Free Software Foundation; either version 2 of the License, or
	8	* (at your option) any later version.
	9	*
	10	* This program is distributed in the hope that it will be useful, but
	11	* WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	13	* General Public License for more details.
	14	*
	15	* You should have received a copy of the GNU General Public License
	16	* along with this program; if not, write to the Free Software
	17	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
	18	* USA
	19	*/
	20	/** @file lib/mixer.c
	21	* @brief Mixer support
	22	*/
	23
	24	#include "common.h"
	25
	26	#include "configuration.h"
	27	#include "mixer.h"
	28	#include "log.h"
	29	#include "mem.h"
	30
	31	/** @brief Whether lack of volume support has been reported yet */
	32	static int none_reported;
	33
	34	/** @brief Get/set volume stub if volume control is not supported */
	35	static int none_get_set(int attribute((unused)) *left,
	36	int attribute((unused)) *right) {
	37	if(!none_reported) {
	38	error(0, "don't know how to get/set volume with this api");
	39	none_reported = 1;
	40	}
	41	return -1;
	42	}
	43
	44	/** @brief Stub mixer control */
	45	static const struct mixer mixer_none = {
	46	-1,
	47	none_get_set,
	48	none_get_set,
	49	"",
	50	""
	51	};
	52
	53	/** @brief Table of mixer definitions */
	54	static const struct mixer *mixers[] = {
	55	#if HAVE_SYS_SOUNDCARD_H
	56	&mixer_oss,
	57	#endif
	58	#if HAVE_ALSA_ASOUNDLIB_H
	59	&mixer_alsa,
	60	#endif
	61	&mixer_none /* make sure array is never empty */
	62	};
	63
	64	/** @brief Number of mixer definitions */
	65	#define NMIXERS (sizeof mixers / sizeof *mixers)
	66
	67	/** @brief Find the mixer definition */
	68	static const struct mixer *find_mixer(int api) {
	69	size_t n;
	70
	71	if(api == -1)
	72	api = config->api;
	73	for(n = 0; n < NMIXERS; ++n)
	74	if(mixers[n]->api == api)
	75	return mixers[n];
	76	return &mixer_none;
	77	}
	78
	79	/** @brief Return true if we know how to drive the mixer
	80	* @param api Sound api or -1 for default
	81	* @return true if suppored, false otherwise
	82	*/
	83	int mixer_supported(int api) {
	84	const struct mixer *const m = find_mixer(api);
	85	return m != &mixer_none;
	86	}
	87
	88	/** @brief Get/set volume
	89	* @param api Sound api or -1 for default
	90	* @param left Left channel level, 0-100
	91	* @param right Right channel level, 0-100
	92	* @param set Set volume if non-0
	93	* @return 0 on success, non-0 on error
	94	*
	95	* If getting the volume then @p left and @p right are filled in.
	96	*
	97	* If setting the volume then the target levels are read from @p left and
	98	* @p right, and the actual level set is stored in them.
	99	*/
	100	int mixer_control(int api, int left, int right, int set) {
	101	const struct mixer *const m = find_mixer(api);
	102
	103	/* We impose defaults bizarrely late, but this has the advantage of
	104	* not making everything depend on sound libraries */
	105	if(!config->mixer)
	106	config->mixer = xstrdup(m->device);
	107	if(!config->channel)
	108	config->channel = xstrdup(m->channel);
	109	if(set)
	110	return m->set(left, right);
	111	else
	112	return m->get(left, right);
	113	}
	114
	115	/*
	116	Local Variables:
	117	c-basic-offset:2
	118	comment-column:40
	119	End:
	120	*/