mixer.c

xmms-1.2.10.tar.gz学习使用的就下吧

/*  XMMS - Cross-platform multimedia player
 *  Copyright (C) 1998-2003  Peter Alm, Mikael Alm, Olle Hallnas,
 *                           Thomas Nilsson and 4Front Technologies
 *  Copyright (C) 1999       Galex Yen
 *  Copyright (C) 1999-2003  Haavard Kvaalen
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#include "config.h"
#include "esdout.h"

#include <sys/ioctl.h>
#ifdef HAVE_OSS
# include <Output/OSS/soundcard.h>
# define OSS_AVAILABLE TRUE
#else
# define OSS_AVAILABLE FALSE
#endif

static void esdout_get_oss_volume(int *l, int *r);
static void esdout_set_oss_volume(int l, int r);


static int player = -1;
static int lp = 100, rp = 100;

void esdout_reset_playerid(void)
{
	player = -1;
}

/*
 * Find the stream id, and set stream volume to 'persistent' value.
 */
void esdout_mixer_init(void)
{
	esdout_fetch_volume(NULL, NULL);
	if (!(OSS_AVAILABLE && esd_cfg.use_oss_mixer && !esd_cfg.use_remote))
		esdout_set_volume(lp, rp);
}

/*
 * Grab the stream volume from the server.  The problem here is that
 * ESD does not have a built-in function for finding the player ID of
 * a specific player - nor does it let us know what the player ID is
 * when the player is created! So, we grab 'allinfo' and scan the
 * returned player list for the string which we know is our player
 * name (esd_cfg.playername) This function seems to take a long time
 * to run... I'm not sure where to start optimizing, however...
 */
void esdout_fetch_volume(int *l, int *r)
{
	int fd;
	esd_info_t *all_info = NULL;
	esd_player_info_t *info;

	fd = esd_open_sound(esd_cfg.hostname);
	all_info = esd_get_all_info(fd);
		
	/* scan linked list for our playername */
	for (info = all_info->player_list; info != NULL; info = info->next)
		if (!strcmp(esd_cfg.playername, info->name))
			break;

	if (info)
	{
		player = info->source_id;
		if (l && r)
		{
			/*
			 * Sometimes we call with NULL
			 * args to fetch the player num
			 */
			*l = (info->left_vol_scale * 100) / 256;
			*r = (info->right_vol_scale * 100) / 256;
		}
	}
	else
		g_warning("xmms: Couldn't find our player "
			  "(was looking for %s) at the server",
			  esd_cfg.playername);

	if (all_info)
		esd_free_all_info(all_info);
	esd_close(fd);
}

void esdout_get_volume(int *l, int *r)
{
	if (OSS_AVAILABLE && esd_cfg.use_oss_mixer && !esd_cfg.use_remote)
	{
		esdout_get_oss_volume(l, r);
		lp = *l;
		rp = *r;
	}
	else
	{
		/*
		 * We assume that the volume hasn't changed from the
		 * 'persistant' value. Constantly polling takes too
		 * much time/resources.  Commenting this section out
		 * will consistently check the ESD server to see if
		 * someone else changed our stream volume.
		 */
		*l = lp;
		*r = rp;
/*  		esdout_fetch_volume(l, r); */
	}
}

void esdout_set_volume(int l, int r)
{
	lp = l;
	rp = r;

	if (OSS_AVAILABLE && esd_cfg.use_oss_mixer && !esd_cfg.use_remote)
	{
		esdout_set_oss_volume(l, r);
	}
	else if (player != -1 && esd_cfg.playername != NULL)
	{
		int fd = esd_open_sound(esd_cfg.hostname);
		if (fd >= 0)
		{
			esd_set_stream_pan(fd, player,
					   (l * 256) / 100, (r * 256) / 100);
			esd_close(fd);
		}
	}
}

#ifdef HAVE_OSS

static void esdout_get_oss_volume(int *l, int *r)
{
	int fd, v, cmd, devs;

	if (esd_cfg.use_remote)
		return;

	fd = open(DEV_MIXER, O_RDONLY);
	if (fd != -1)
	{
		ioctl(fd, SOUND_MIXER_READ_DEVMASK, &devs);
		if (devs & SOUND_MASK_PCM)
			cmd = SOUND_MIXER_READ_PCM;
		else if (devs & SOUND_MASK_VOLUME)
			cmd = SOUND_MIXER_READ_VOLUME;
		else
		{
			close(fd);
			return;
		}
		ioctl(fd, cmd, &v);
		*r = (v & 0xFF00) >> 8;
		*l = (v & 0x00FF);
		close(fd);
	}
}

static void esdout_set_oss_volume(int l, int r)
{
	int fd, v, cmd, devs;

	if (esd_cfg.use_remote)
		return;

	fd = open(DEV_MIXER, O_RDONLY);

	if (fd != -1)
	{
		ioctl(fd, SOUND_MIXER_READ_DEVMASK, &devs);
		if (devs & SOUND_MASK_PCM)
			cmd = SOUND_MIXER_WRITE_PCM;
		else if (devs & SOUND_MASK_VOLUME)
			cmd = SOUND_MIXER_WRITE_VOLUME;
		else
		{
			close(fd);
			return;
		}
		v = (r << 8) | l;
		ioctl(fd, cmd, &v);
		close(fd);
	}
}

#else

static void esdout_get_oss_volume(int *l, int *r) {}

static void esdout_set_oss_volume(int l, int r) {}

#endif