alsa-lib/src/pcm/pcm_params.c

/*
 *  PCM - Params functions
 *  Copyright (c) 2000 by Abramo Bagnara <abramo@alsa-project.org>
 *
 *
 *   This library is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Library 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 Library General Public License for more details.
 *
 *   You should have received a copy of the GNU Library General Public
 *   License along with this library; if not, write to the Free Software
 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */
  
#include "pcm_local.h"

static inline int hw_is_mask(snd_pcm_hw_param_t var)
{
	return var >= SND_PCM_HW_PARAM_FIRST_MASK &&
		var <= SND_PCM_HW_PARAM_LAST_MASK;
}

static inline int hw_is_interval(snd_pcm_hw_param_t var)
{
	return var >= SND_PCM_HW_PARAM_FIRST_INTERVAL &&
		var <= SND_PCM_HW_PARAM_LAST_INTERVAL;
}

static inline snd_mask_t *hw_param_mask(snd_pcm_hw_params_t *params,
					snd_pcm_hw_param_t var)
{
	assert(hw_is_mask(var));
	return (snd_mask_t*)&params->masks[var - SND_PCM_HW_PARAM_FIRST_MASK];
}

static inline snd_interval_t *hw_param_interval(snd_pcm_hw_params_t *params,
						snd_pcm_hw_param_t var)
{
	assert(hw_is_interval(var));
	return &params->intervals[var - SND_PCM_HW_PARAM_FIRST_INTERVAL];
}

static inline const snd_mask_t *hw_param_mask_c(const snd_pcm_hw_params_t *params,
						snd_pcm_hw_param_t var)
{
	return (const snd_mask_t *)hw_param_mask((snd_pcm_hw_params_t*) params, var);
}

static inline const snd_interval_t *hw_param_interval_c(const snd_pcm_hw_params_t *params,
							snd_pcm_hw_param_t var)
{
	return (const snd_interval_t *)hw_param_interval((snd_pcm_hw_params_t*) params, var);
}

static void _snd_pcm_hw_param_any(snd_pcm_hw_params_t *params, snd_pcm_hw_param_t var)
{
	if (hw_is_mask(var)) {
		snd_mask_any(hw_param_mask(params, var));
		params->cmask |= 1 << var;
		params->rmask |= 1 << var;
		return;
	}
	if (hw_is_interval(var)) {
		snd_interval_any(hw_param_interval(params, var));
		params->cmask |= 1 << var;
		params->rmask |= 1 << var;
		return;
	}
	assert(0);
}

int snd_pcm_hw_param_any(snd_pcm_t *pcm, snd_pcm_hw_params_t *params,
			 snd_pcm_hw_param_t var)
{
	_snd_pcm_hw_param_any(params, var);
	return snd_pcm_hw_refine(pcm, params);
}

void _snd_pcm_hw_params_any(snd_pcm_hw_params_t *params)
{
	unsigned int k;
	memset(params, 0, sizeof(*params));
	for (k = 0; k <= SND_PCM_HW_PARAM_LAST; k++)
		_snd_pcm_hw_param_any(params, k);
	params->info = ~0U;
}

/* Return the value for field PAR if it's fixed in configuration space 
   defined by PARAMS. Return -EINVAL otherwise
*/
int snd_pcm_hw_param_get(const snd_pcm_hw_params_t *params,
			 snd_pcm_hw_param_t var, int *dir)
{
	if (hw_is_mask(var)) {
		const snd_mask_t *mask = hw_param_mask_c(params, var);
		if (snd_mask_empty(mask) || !snd_mask_single(mask))
			return -EINVAL;
		if (dir)
			*dir = 0;
		return snd_mask_value(mask);
	}
	if (hw_is_interval(var)) {
		const snd_interval_t *i = hw_param_interval_c(params, var);
		if (snd_interval_empty(i) || !snd_interval_single(i))
			return -EINVAL;
		if (dir)
			*dir = i->openmin;
		return snd_interval_value(i);
	}
	assert(0);
	return -EINVAL;
}

/* Return the minimum value for field PAR. */
unsigned int snd_pcm_hw_param_get_min(const snd_pcm_hw_params_t *params,
				      snd_pcm_hw_param_t var, int *dir)
{
	if (hw_is_mask(var)) {
		if (dir)
			*dir = 0;
		return snd_mask_min(hw_param_mask_c(params, var));
	}
	if (hw_is_interval(var)) {
		const snd_interval_t *i = hw_param_interval_c(params, var);
		if (dir)
			*dir = i->openmin;
		return snd_interval_min(i);
	}
	assert(0);
	return 0;
}

/* Return the maximum value for field PAR. */
unsigned int snd_pcm_hw_param_get_max(const snd_pcm_hw_params_t *params,
				      snd_pcm_hw_param_t var, int *dir)
{
	if (hw_is_mask(var)) {
		if (dir)
			*dir = 0;
		return snd_mask_max(hw_param_mask_c(params, var));
	}
	if (hw_is_interval(var)) {
		const snd_interval_t *i = hw_param_interval_c(params, var);
		if (dir)
			*dir = - (int) i->openmax;
		return snd_interval_max(i);
	}
	assert(0);
	return 0;
}

/* Return the mask for field PAR.
   This function can be called only for SND_PCM_HW_PARAM_ACCESS,
   SND_PCM_HW_PARAM_FORMAT, SND_PCM_HW_PARAM_SUBFORMAT. */
const snd_mask_t *snd_pcm_hw_param_get_mask(const snd_pcm_hw_params_t *params,
					   snd_pcm_hw_param_t var)
{
	assert(hw_is_mask(var));
	return hw_param_mask_c(params, var);
}

/* Return the interval for field PAR.
   This function cannot be called for SND_PCM_HW_PARAM_ACCESS,
   SND_PCM_HW_PARAM_FORMAT, SND_PCM_HW_PARAM_SUBFORMAT. */
const snd_interval_t *snd_pcm_hw_param_get_interval(const snd_pcm_hw_params_t *params,
						  snd_pcm_hw_param_t var)
{
	assert(hw_is_interval(var));
	return hw_param_interval_c(params, var);
}

/* --- Refinement functions --- */

int _snd_pcm_hw_param_set_interval(snd_pcm_hw_params_t *params,
				   snd_pcm_hw_param_t var,
				   const snd_interval_t *val)
{
	int changed;
	assert(hw_is_interval(var));
	changed = snd_interval_refine(hw_param_interval(params, var), val);
	if (changed) {
		params->cmask |= 1 << var;
		params->rmask |= 1 << var;
	}
	return changed;
}

void _snd_pcm_hw_param_set_empty(snd_pcm_hw_params_t *params,
				 snd_pcm_hw_param_t var)
{
	if (hw_is_mask(var)) {
	snd_mask_none(hw_param_mask(params, var));
		params->cmask |= 1 << var;
		params->rmask |= 1 << var;
	} else if (hw_is_interval(var)) {
		snd_interval_none(hw_param_interval(params, var));
		params->cmask |= 1 << var;
		params->rmask |= 1 << var;
	} else {
		assert(0);
	}
}

static int _snd_pcm_hw_param_set_integer(snd_pcm_hw_params_t *params,
					 snd_pcm_hw_param_t var)
{
	int changed;
	assert(hw_is_interval(var));
	changed = snd_interval_setinteger(hw_param_interval(params, var));
	if (changed) {
		params->cmask |= 1 << var;
		params->rmask |= 1 << var;
	}
	return changed;
}
	
/* Inside configuration space defined by PARAMS remove from PAR all 
   non integer values. Reduce configuration space accordingly.
   Return -EINVAL if the configuration space is empty
*/
int snd_pcm_hw_param_set_integer(snd_pcm_t *pcm, 
				 snd_pcm_hw_params_t *params,
				 snd_set_mode_t mode,
				 snd_pcm_hw_param_t var)
{
	snd_pcm_hw_params_t save;
	int err;
	switch (snd_enum_to_int(mode)) {
	case SND_CHANGE:
		break;
	case SND_TRY:
		save = *params;
		break;
	case SND_TEST:
		save = *params;
		params = &save;
		break;
	default:
		assert(0);
		return -EINVAL;
	}
	err = _snd_pcm_hw_param_set_integer(params, var);
	if (err < 0)
		goto _fail;
	if (params->rmask) {
		err = snd_pcm_hw_refine(pcm, params);
		if (err < 0)
			goto _fail;
	}
	return 0;
 _fail:
	if (mode == SND_TRY)
		*params = save;
	return err;
}

static int _snd_pcm_hw_param_set_first(snd_pcm_hw_params_t *params,
				       snd_pcm_hw_param_t var)
{
	int changed;
	if (hw_is_mask(var))
		changed = snd_mask_refine_first(hw_param_mask(params, var));
	else if (hw_is_interval(var))
		changed = snd_interval_refine_first(hw_param_interval(params, var));
	else {
		assert(0);
		return -EINVAL;
	}
	if (changed) {
		params->cmask |= 1 << var;
		params->rmask |= 1 << var;
	}
	return changed;
}


/* Inside configuration space defined by PARAMS remove from PAR all 
   values > minimum. Reduce configuration space accordingly.
   Return the minimum.
*/
unsigned int snd_pcm_hw_param_set_first(snd_pcm_t *pcm, 
					snd_pcm_hw_params_t *params, 
					snd_pcm_hw_param_t var, int *dir)
{
	_snd_pcm_hw_param_set_first(params, var);
	if (params->rmask) {
		int err = snd_pcm_hw_refine(pcm, params);
		assert(err >= 0);
	}
	return snd_pcm_hw_param_get(params, var, dir);
}

static int _snd_pcm_hw_param_set_last(snd_pcm_hw_params_t *params,
				      snd_pcm_hw_param_t var)
{
	int changed;
	if (hw_is_mask(var))
		changed = snd_mask_refine_last(hw_param_mask(params, var));
	else if (hw_is_interval(var))
		changed = snd_interval_refine_last(hw_param_interval(params, var));
	else {
		assert(0);
		return -EINVAL;
	}
	if (changed) {
		params->cmask |= 1 << var;
		params->rmask |= 1 << var;
	}
	return changed;
}


/* Inside configuration space defined by PARAMS remove from PAR all 
   values < maximum. Reduce configuration space accordingly.
   Return the maximum.
*/
unsigned int snd_pcm_hw_param_set_last(snd_pcm_t *pcm, 
				       snd_pcm_hw_params_t *params,
				       snd_pcm_hw_param_t var, int *dir)
{
	_snd_pcm_hw_param_set_last(params, var);
	if (params->rmask) {
		int err = snd_pcm_hw_refine(pcm, params);
		assert(err >= 0);
	}
	return snd_pcm_hw_param_get(params, var, dir);
}

int _snd_pcm_hw_param_set_min(snd_pcm_hw_params_t *params,
			      snd_pcm_hw_param_t var, unsigned int val, int dir)
{
	int changed;
	int openmin = 0;
	if (dir) {
		if (dir > 0) {
			openmin = 1;
		} else if (dir < 0) {
			if (val > 0) {
				openmin = 1;
				val--;
			}
		}
	}
	if (hw_is_mask(var))
		changed = snd_mask_refine_min(hw_param_mask(params, var), val + !!openmin);
	else if (hw_is_interval(var))
		changed = snd_interval_refine_min(hw_param_interval(params, var), val, openmin);
	else {
		assert(0);
		return -EINVAL;
	}
	if (changed) {
		params->cmask |= 1 << var;
		params->rmask |= 1 << var;
	}
	return changed;
}

/* Inside configuration space defined by PARAMS remove from PAR all 
   values < VAL. Reduce configuration space accordingly.
   Return new minimum or -EINVAL if the configuration space is empty
*/
int snd_pcm_hw_param_set_min(snd_pcm_t *pcm, snd_pcm_hw_params_t *params,
			     snd_set_mode_t mode,
			     snd_pcm_hw_param_t var, unsigned int *val, int *dir)
{
	snd_pcm_hw_params_t save;
	int err;
	switch (snd_enum_to_int(mode)) {
	case SND_CHANGE:
		break;
	case SND_TRY:
		save = *params;
		break;
	case SND_TEST:
		save = *params;
		params = &save;
		break;
	default:
		assert(0);
		return -EINVAL;
	}
	err = _snd_pcm_hw_param_set_min(params, var, *val, dir ? *dir : 0);
	if (err < 0)
		goto _fail;
	if ((mode != SND_TEST || hw_is_interval(var)) && params->rmask) {
		err = snd_pcm_hw_refine(pcm, params);
		if (err < 0)
			goto _fail;
	}
	*val = snd_pcm_hw_param_get_min(params, var, dir);
	return 0;
 _fail:
	if (mode == SND_TRY)
		*params = save;
	return err;
}

int _snd_pcm_hw_param_set_max(snd_pcm_hw_params_t *params,
			      snd_pcm_hw_param_t var, unsigned int val, int dir)
{
	int changed;
	int openmax = 0;
	if (dir) {
		if (dir < 0) {
			openmax = 1;
		} else if (dir > 0) {
			openmax = 1;
			val++;
		}
	}
	if (hw_is_mask(var)) {
		if (val == 0 && openmax) {
		snd_mask_none(hw_param_mask(params, var));
			changed = -EINVAL;
		} else
			changed = snd_mask_refine_max(hw_param_mask(params, var), val - !!openmax);
	} else if (hw_is_interval(var))
		changed = snd_interval_refine_max(hw_param_interval(params, var), val, openmax);
	else {
		assert(0);
		return -EINVAL;
	}
	if (changed) {
		params->cmask |= 1 << var;
		params->rmask |= 1 << var;
	}
	return changed;
}

/* Inside configuration space defined by PARAMS remove from PAR all 
   values >= VAL + 1. Reduce configuration space accordingly.
   Return new maximum or -EINVAL if the configuration space is empty
*/
int snd_pcm_hw_param_set_max(snd_pcm_t *pcm, snd_pcm_hw_params_t *params,
			     snd_set_mode_t mode,
			     snd_pcm_hw_param_t var, unsigned int *val, int *dir)
{
	snd_pcm_hw_params_t save;
	int err;
	switch (snd_enum_to_int(mode)) {
	case SND_CHANGE:
		break;
	case SND_TRY:
		save = *params;
		break;
	case SND_TEST:
		save = *params;
		params = &save;
		break;
	default:
		assert(0);
		return -EINVAL;
	}
	err = _snd_pcm_hw_param_set_max(params, var, *val, dir ? *dir : 0);
	if (err < 0)
		goto _fail;
	if ((mode != SND_TEST || hw_is_interval(var)) && params->rmask) {
		err = snd_pcm_hw_refine(pcm, params);
		if (err < 0)
			goto _fail;
	}
	*val = snd_pcm_hw_param_get_max(params, var, dir);
	return 0;
 _fail:
	if (mode == SND_TRY)
		*params = save;
	return err;
}

int _snd_pcm_hw_param_set_minmax(snd_pcm_hw_params_t *params,
				 snd_pcm_hw_param_t var,
				 unsigned int min, int mindir,
				 unsigned int max, int maxdir)
{
	int changed, c1, c2;
	int openmin = 0, openmax = 0;
	if (mindir) {
		if (mindir > 0) {
			openmin = 1;
		} else if (mindir < 0) {
			if (min > 0) {
				openmin = 1;
				min--;
			}
		}
	}
	if (maxdir) {
		if (maxdir < 0) {
			openmax = 1;
		} else if (maxdir > 0) {
			openmax = 1;
			max++;
		}
	}
	if (hw_is_mask(var)) {
		snd_mask_t *mask = hw_param_mask(params, var);
		if (max == 0 && openmax) {
		snd_mask_none(mask);
			changed = -EINVAL;
		} else {
			c1 = snd_mask_refine_min(mask, min + !!openmin);
			if (c1 < 0)
				changed = c1;
			else {
				c2 = snd_mask_refine_max(mask, max - !!openmax);
				if (c2 < 0)
					changed = c2;
				else
					changed = (c1 || c2);
			}
		}
	}
	else if (hw_is_interval(var)) {
		snd_interval_t *i = hw_param_interval(params, var);
		c1 = snd_interval_refine_min(i, min, openmin);
		if (c1 < 0)
			changed = c1;
		else {
			c2 = snd_interval_refine_max(i, max, openmax);
			if (c2 < 0)
				changed = c2;
			else
				changed = (c1 || c2);
		}
	} else {
		assert(0);
		return -EINVAL;
	}
	if (changed) {
		params->cmask |= 1 << var;
		params->rmask |= 1 << var;
	}
	return changed;
}

/* Inside configuration space defined by PARAMS remove from PAR all 
   values < MIN and all values > MAX. Reduce configuration space accordingly.
   Return 0 or -EINVAL if the configuration space is empty
*/
int snd_pcm_hw_param_set_minmax(snd_pcm_t *pcm, snd_pcm_hw_params_t *params,
				snd_set_mode_t mode,
				snd_pcm_hw_param_t var,
				unsigned int *min, int *mindir,
				unsigned int *max, int *maxdir)
{
	snd_pcm_hw_params_t save;
	int err;
	switch (snd_enum_to_int(mode)) {
	case SND_CHANGE:
		break;
	case SND_TRY:
		save = *params;
		break;
	case SND_TEST:
		save = *params;
		params = &save;
		break;
	default:
		assert(0);
		return -EINVAL;
	}
	err = _snd_pcm_hw_param_set_minmax(params, var, 
					   *min, mindir ? *mindir : 0,
					   *max, maxdir ? *maxdir : 0);
	if (err < 0)
		goto _fail;
	if ((mode != SND_TEST || hw_is_interval(var)) && params->rmask) {
		err = snd_pcm_hw_refine(pcm, params);
		if (err < 0)
			goto _fail;
	}
	*min = snd_pcm_hw_param_get_min(params, var, mindir);
	*max = snd_pcm_hw_param_get_max(params, var, maxdir);
	return 0;
 _fail:
	if (mode == SND_TRY)
		*params = save;
	return err;
}

int _snd_pcm_hw_param_set(snd_pcm_hw_params_t *params,
			  snd_pcm_hw_param_t var, unsigned int val, int dir)
{
	int changed;
	if (hw_is_mask(var)) {
		snd_mask_t *m = hw_param_mask(params, var);
		if (val == 0 && dir < 0) {
			changed = -EINVAL;
		snd_mask_none(m);
		} else {
			if (dir > 0)
				val++;
			else if (dir < 0)
				val--;
			changed = snd_mask_refine_set(hw_param_mask(params, var), val);
		}
	} else if (hw_is_interval(var)) {
		snd_interval_t *i = hw_param_interval(params, var);
		if (val == 0 && dir < 0) {
			changed = -EINVAL;
			snd_interval_none(i);
		} else if (dir == 0)
			changed = snd_interval_refine_set(i, val);
		else {
			snd_interval_t t;
			t.openmin = 1;
			t.openmax = 1;
			t.empty = 0;
			t.integer = 0;
			if (dir < 0) {
				t.min = val - 1;
				t.max = val;
			} else {
				t.min = val;
				t.max = val+1;
			}
			changed = snd_interval_refine(i, &t);
		}
	} else {
		assert(0);
		return -EINVAL;
	}
	if (changed) {
		params->cmask |= 1 << var;
		params->rmask |= 1 << var;
	}
	return changed;
}

/* Inside configuration space defined by PARAMS remove from PAR all 
   values != VAL. Reduce configuration space accordingly.
   Return -EINVAL if the configuration space is empty
*/
int snd_pcm_hw_param_set(snd_pcm_t *pcm, snd_pcm_hw_params_t *params,
			 snd_set_mode_t mode,
			 snd_pcm_hw_param_t var, unsigned int val, int dir)
{
	snd_pcm_hw_params_t save;
	int err;
	switch (snd_enum_to_int(mode)) {
	case SND_CHANGE:
		break;
	case SND_TRY:
		save = *params;
		break;
	case SND_TEST:
		save = *params;
		params = &save;
		break;
	default:
		assert(0);
		return -EINVAL;
	}
	err = _snd_pcm_hw_param_set(params, var, val, dir);
	if (err < 0)
		goto _fail;
	if ((mode != SND_TEST || hw_is_interval(var)) && params->rmask) {
		err = snd_pcm_hw_refine(pcm, params);
		if (err < 0)
			goto _fail;
	}
	return 0;
 _fail:
	if (mode == SND_TRY)
		*params = save;
	return err;
}

int _snd_pcm_hw_param_set_mask(snd_pcm_hw_params_t *params,
			       snd_pcm_hw_param_t var, const snd_mask_t *val)
{
	int changed;
	assert(hw_is_mask(var));
	changed = snd_mask_refine(hw_param_mask(params, var), val);
	if (changed) {
		params->cmask |= 1 << var;
		params->rmask |= 1 << var;
	}
	return changed;
}

/* Inside configuration space defined by PARAMS remove from PAR all values
   not contained in MASK. Reduce configuration space accordingly.
   This function can be called only for SND_PCM_HW_PARAM_ACCESS,
   SND_PCM_HW_PARAM_FORMAT, SND_PCM_HW_PARAM_SUBFORMAT.
   Return 0 on success or -EINVAL
   if the configuration space is empty
*/
int snd_pcm_hw_param_set_mask(snd_pcm_t *pcm, snd_pcm_hw_params_t *params,
			      snd_set_mode_t mode,
			      snd_pcm_hw_param_t var, const snd_mask_t *val)
{
	snd_pcm_hw_params_t save;
	int err;
	switch (snd_enum_to_int(mode)) {
	case SND_CHANGE:
		break;
	case SND_TRY:
		save = *params;
		break;
	case SND_TEST:
		save = *params;
		params = &save;
		break;
	default:
		assert(0);
		return -EINVAL;
	}
	err = _snd_pcm_hw_param_set_mask(params, var, val);
	if (err < 0)
		goto _fail;
	if (mode != SND_TEST && params->rmask) {
		err = snd_pcm_hw_refine(pcm, params);
		if (err < 0)
			goto _fail;
	}
	return 0;
 _fail:
	if (mode == SND_TRY)
		*params = save;
	return err;
}

/* Inside configuration space defined by PARAMS set PAR to the available value
   nearest to VAL. Reduce configuration space accordingly.
   This function cannot be called for SND_PCM_HW_PARAM_ACCESS,
   SND_PCM_HW_PARAM_FORMAT, SND_PCM_HW_PARAM_SUBFORMAT.
   Return the value found.
 */
unsigned int snd_pcm_hw_param_set_near(snd_pcm_t *pcm, snd_pcm_hw_params_t *params,
				       snd_pcm_hw_param_t var, unsigned int best, int *dir)
{
	snd_pcm_hw_params_t save;
	int v, err;
	unsigned int saved_min;
	int last = 0;
	int min, max;
	int mindir, maxdir;
	int valdir = dir ? *dir : 0;
	/* FIXME */
	if (best > INT_MAX)
		best = INT_MAX;
	min = max = best;
	mindir = maxdir = valdir;
	if (maxdir > 0)
		maxdir = 0;
	else if (maxdir == 0)
		maxdir = -1;
	else {
		maxdir = 1;
		max--;
	}
	save = *params;
	saved_min = min;
	err = snd_pcm_hw_param_set_min(pcm, params, SND_CHANGE, var, &min, &mindir);
	if (err >= 0) {
		snd_pcm_hw_params_t params1;
		if (max < 0)
			goto _end;
		if ((unsigned int)min == saved_min && mindir == valdir)
			goto _end;
		params1 = save;
		err = snd_pcm_hw_param_set_max(pcm, &params1, SND_CHANGE, var, &max, &maxdir);
		if (err < 0)
			goto _end;
		if (boundary_nearer(max, maxdir, best, valdir, min, mindir)) {
			*params = params1;
			last = 1;
		}
	} else {
		*params = save;
		err = snd_pcm_hw_param_set_max(pcm, params, SND_CHANGE, var, &max, &maxdir);
		assert(err >= 0);
		last = 1;
	}
 _end:
	if (last)
		v = snd_pcm_hw_param_set_last(pcm, params, var, dir);
	else
		v = snd_pcm_hw_param_set_first(pcm, params, var, dir);
	assert(v >= 0);
	return v;
}

#if 0
/* Inside configuration space defined by PARAMS set PAR to the available value
   nearest to BEST after VAL (on equal difference values less than BEST are
   returned first).
   Reduce configuration space accordingly.
   This function cannot be called for SND_PCM_HW_PARAM_ACCESS,
   SND_PCM_HW_PARAM_FORMAT, SND_PCM_HW_PARAM_SUBFORMAT.
   Return the value found.
 */
int snd_pcm_hw_param_set_next(snd_pcm_t *pcm, snd_pcm_hw_params_t *params,
			      snd_pcm_hw_param_t var, 
			      unsigned int best, int bestdir,
			      unsigned int val, int *dir)
{
	snd_pcm_hw_params_t save;
	int v, err;
	int last = 0;
	int min, max;
	int mindir, maxdir;
	int diff, diffdir;
	int valdir = dir ? *dir : 0;
	/* FIXME */
	if (best > INT_MAX)
		best = INT_MAX;
	boundary_sub(val, valdir, best, bestdir, &diff, &diffdir);
	if (diff < 0 || (diff == 0 && diffdir < 0)) {
		min = best - diff;
		mindir = bestdir - diffdir;
		max = val;
		maxdir = bestdir - 1;
	} else {
		min = val;
		mindir = bestdir + 1;
		max = best + diff;
		maxdir = bestdir + diffdir + 1;
	}
	min += mindir / 2;
	mindir %= 2;
	max += maxdir / 2;
	maxdir %= 2;
	save = *params;
	if (min >= 0 &&
	    (err = snd_pcm_hw_param_set_min(pcm, params, SND_CHANGE, var, &min, &mindir)) >= 0) {
		snd_pcm_hw_params_t params1;
		if (max < 0)
			goto _end;
		params1 = save;
		err = snd_pcm_hw_param_set_max(pcm, &params1, SND_CHANGE, var, &max, &maxdir);
		if (err < 0)
			goto _end;
		if (boundary_nearer(max, maxdir, best, bestdir, min, mindir)) {
			*params = params1;
			last = 1;
		}
	} else {
		if (max < 0)
			return -EINVAL;
		*params = save;
		err = snd_pcm_hw_param_set_max(pcm, params, SND_CHANGE, var, &max, &maxdir);
		if (err < 0)
			return max;
		last = 1;
	}
 _end:
	if (last)
		v = snd_pcm_hw_param_set_last(pcm, params, var, dir);
	else
		v = snd_pcm_hw_param_set_first(pcm, params, var, dir);
	assert(v >= 0);
	return v;
}
#endif

static void snd_pcm_hw_param_set_near_minmax(snd_pcm_t *pcm,
					     snd_pcm_hw_params_t *params,
					     snd_pcm_hw_param_t var,
					     unsigned int min, int *mindir,
					     unsigned int max, int *maxdir)
{
	snd_pcm_hw_params_t tmp;
	int err;
	if (!boundary_lt(min, *mindir, max, *maxdir)) {
		snd_pcm_hw_param_set_near(pcm, params, var, min, mindir);
		return;
	}
	tmp = *params;
	min = snd_pcm_hw_param_set_near(pcm, &tmp, var, min, mindir);
	if (boundary_lt(min, *mindir, max, *maxdir)) {
		tmp = *params;
		max = snd_pcm_hw_param_set_near(pcm, &tmp, var, max, maxdir);
	} else {
		max = min;
		*maxdir = *mindir;
	}
	err = snd_pcm_hw_param_set_minmax(pcm, params, SND_CHANGE, var, &min, mindir,
					  &max, maxdir);
	assert(err >= 0);
}

void snd_pcm_hw_param_refine_near(snd_pcm_t *pcm,
				  snd_pcm_hw_params_t *params,
				  snd_pcm_hw_param_t var,
				  const snd_pcm_hw_params_t *src)
{
	unsigned int min, max;
	int mindir, maxdir;
	min = snd_pcm_hw_param_get_min(src, var, &mindir);
	max = snd_pcm_hw_param_get_max(src, var, &maxdir);
	snd_pcm_hw_param_set_near_minmax(pcm, params, var,
					 min, &mindir, max, &maxdir);
}

/* ---- end of refinement functions ---- */

#if 0
static int snd_pcm_hw_param_empty(const snd_pcm_hw_params_t *params,
				  snd_pcm_hw_param_t var)
{
	if (hw_is_mask(var))
		return snd_mask_empty(hw_param_mask_c(params, var));
	if (hw_is_interval(var))
		return snd_interval_empty(hw_param_interval_c(params, var));
	assert(0);
	return -EINVAL;
}
#endif

int snd_pcm_hw_param_always_eq(const snd_pcm_hw_params_t *params,
			       snd_pcm_hw_param_t var,
			       const snd_pcm_hw_params_t *params1)
{
	if (hw_is_mask(var))
		return snd_mask_always_eq(hw_param_mask_c(params, var),
				      hw_param_mask_c(params1, var));
	if (hw_is_interval(var))
		return snd_interval_always_eq(hw_param_interval_c(params, var),
					  hw_param_interval_c(params1, var));
	assert(0);
	return -EINVAL;
}

int snd_pcm_hw_param_never_eq(const snd_pcm_hw_params_t *params,
			      snd_pcm_hw_param_t var,
			      const snd_pcm_hw_params_t *params1)
{
	if (hw_is_mask(var))
		return snd_mask_never_eq(hw_param_mask_c(params, var),
				      hw_param_mask_c(params1, var));
	if (hw_is_interval(var))
		return snd_interval_never_eq(hw_param_interval_c(params, var),
					 hw_param_interval_c(params1, var));
	assert(0);
	return -EINVAL;
}


/* Choose one configuration from configuration space defined by PARAMS
   The configuration choosen is that obtained fixing in this order:
   first access
   first format
   first subformat
   min channels
   min rate
   min period time
   max buffer size
   min tick time
*/
static void snd_pcm_hw_params_choose(snd_pcm_t *pcm, snd_pcm_hw_params_t *params)
{
	snd_pcm_hw_param_set_first(pcm, params, SND_PCM_HW_PARAM_ACCESS, 0);
	snd_pcm_hw_param_set_first(pcm, params, SND_PCM_HW_PARAM_FORMAT, 0);
	snd_pcm_hw_param_set_first(pcm, params, SND_PCM_HW_PARAM_SUBFORMAT, 0);
	snd_pcm_hw_param_set_first(pcm, params, SND_PCM_HW_PARAM_CHANNELS, 0);
	snd_pcm_hw_param_set_first(pcm, params, SND_PCM_HW_PARAM_RATE, 0);
	snd_pcm_hw_param_set_first(pcm, params, SND_PCM_HW_PARAM_PERIOD_TIME, 0);
	snd_pcm_hw_param_set_first(pcm, params, SND_PCM_HW_PARAM_PERIOD_SIZE, 0);
	snd_pcm_hw_param_set_last(pcm, params, SND_PCM_HW_PARAM_BUFFER_SIZE, 0);
	snd_pcm_hw_param_set_first(pcm, params, SND_PCM_HW_PARAM_TICK_TIME, 0);
}

#if 0
static unsigned int snd_pcm_hw_param_count(const snd_pcm_hw_params_t *params,
					   snd_pcm_hw_param_t var)
{
	if (hw_is_mask(var)) {
		const snd_mask_t *mask = hw_param_mask_c(params, var);
		return snd_mask_count(mask);
	}
	if (hw_is_interval(var)) {
		const snd_interval_t *i = hw_param_interval_c(params, var);
		return snd_interval_max(i) - snd_interval_min(i) + 1;
	}
	assert(0);
	return 0;
}
#endif

int _snd_pcm_hw_param_refine(snd_pcm_hw_params_t *params,
			     snd_pcm_hw_param_t var,
			     const snd_pcm_hw_params_t *src)
{
	int changed = 0;
	if (hw_is_mask(var)) {
		snd_mask_t *d = hw_param_mask(params, var);
		const snd_mask_t *s = hw_param_mask_c(src, var);
		changed = snd_mask_refine(d, s);
	} else if (hw_is_interval(var)) {
		snd_interval_t *d = hw_param_interval(params, var);
		const snd_interval_t *s = hw_param_interval_c(src, var);
		changed = snd_interval_refine(d, s);
	} else
		assert(0);
	if (changed) {
		params->cmask |= 1 << var;
		params->rmask |= 1 << var;
	}
	return changed;
}
			     
#if 0
static void _snd_pcm_hw_param_copy(snd_pcm_hw_params_t *params, snd_pcm_hw_param_t var,
				   const snd_pcm_hw_params_t *src)
{
	if (hw_is_mask(var)) {
		snd_mask_t *d = hw_param_mask(params, var);
		const snd_mask_t *s = hw_param_mask_c(src, var);
		snd_mask_copy(d, s);
		params->cmask |= 1 << var;
		params->rmask |= 1 << var;
		return;
	}
	if (hw_is_interval(var)) {
		snd_interval_t *d = hw_param_interval(params, var);
		const snd_interval_t *s = hw_param_interval_c(src, var);
		snd_interval_copy(d, s);
		params->cmask |= 1 << var;
		params->rmask |= 1 << var;
		return;
	}
	assert(0);
}
#endif

void snd_pcm_hw_param_dump(const snd_pcm_hw_params_t *params,
			   snd_pcm_hw_param_t var, snd_output_t *out)
{
	if (hw_is_mask(var)) {
		const snd_mask_t *mask = hw_param_mask_c(params, var);
		if (snd_mask_empty(mask))
			snd_output_puts(out, " NONE");
		else if (snd_mask_full(mask))
			snd_output_puts(out, " ALL");
		else {
			unsigned int k;
			for (k = 0; k <= SND_MASK_MAX; ++k) {
				if (snd_mask_test(mask, k)) {
					const char *s;
					switch (var) {
					case SND_PCM_HW_PARAM_ACCESS:
						s = snd_pcm_access_name(snd_int_to_enum(k));
						break;
					case SND_PCM_HW_PARAM_FORMAT:
						s = snd_pcm_format_name(snd_int_to_enum(k));
						break;
					case SND_PCM_HW_PARAM_SUBFORMAT:
						s = snd_pcm_subformat_name(snd_int_to_enum(k));
						break;
					default:
						assert(0);
						s = NULL;
					}
					if (s) {
						snd_output_putc(out, ' ');
						snd_output_puts(out, s);
					}
				}
			}
		}
		return;
	}
	if (hw_is_interval(var)) {
		snd_interval_print(hw_param_interval_c(params, var), out);
		return;
	}
	assert(0);
}

#define HW_PARAM(v) [SND_PCM_HW_PARAM_##v] = #v

const char *snd_pcm_hw_param_names[] = {
	HW_PARAM(ACCESS),
	HW_PARAM(FORMAT),
	HW_PARAM(SUBFORMAT),
	HW_PARAM(SAMPLE_BITS),
	HW_PARAM(FRAME_BITS),
	HW_PARAM(CHANNELS),
	HW_PARAM(RATE),
	HW_PARAM(PERIOD_TIME),
	HW_PARAM(PERIOD_SIZE),
	HW_PARAM(PERIOD_BYTES),
	HW_PARAM(PERIODS),
	HW_PARAM(BUFFER_TIME),
	HW_PARAM(BUFFER_SIZE),
	HW_PARAM(BUFFER_BYTES),
	HW_PARAM(TICK_TIME),
};

const char *snd_pcm_hw_param_name(snd_pcm_hw_param_t param)
{
	assert(param <= SND_PCM_HW_PARAM_LAST);
	return snd_pcm_hw_param_names[snd_enum_to_int(param)];
}

#if 0
/* Strategies */

struct _snd_pcm_hw_strategy {
	unsigned int badness_min, badness_max;
	int (*choose_param)(const snd_pcm_hw_params_t *params,
			    snd_pcm_t *pcm,
			    const snd_pcm_hw_strategy_t *strategy);
	int (*next_value)(snd_pcm_hw_params_t *params,
			  unsigned int param,
			  int value, int *dir,
			  snd_pcm_t *pcm,
			  const snd_pcm_hw_strategy_t *strategy);
	int (*min_badness)(const snd_pcm_hw_params_t *params,
			   unsigned int max_badness,
			   snd_pcm_t *pcm,
			   const snd_pcm_hw_strategy_t *strategy);
	void *private_data;
	void (*free)(snd_pcm_hw_strategy_t *strategy);
};

/* Independent badness */
typedef struct _snd_pcm_hw_strategy_simple snd_pcm_hw_strategy_simple_t;

struct _snd_pcm_hw_strategy_simple {
	int valid;
	unsigned int order;
	int (*next_value)(snd_pcm_hw_params_t *params,
			  unsigned int param,
			  int value, int *dir,
			  snd_pcm_t *pcm,
			  const snd_pcm_hw_strategy_simple_t *par);
	unsigned int (*min_badness)(const snd_pcm_hw_params_t *params,
				    unsigned int param,
				    snd_pcm_t *pcm,
				    const snd_pcm_hw_strategy_simple_t *par);
	void *private_data;
	void (*free)(snd_pcm_hw_strategy_simple_t *strategy);
};

typedef struct _snd_pcm_hw_strategy_simple_near {
	int best;
	unsigned int mul;
} snd_pcm_hw_strategy_simple_near_t;

typedef struct _snd_pcm_hw_strategy_simple_choices {
	unsigned int count;
	/* choices need to be sorted on ascending badness */
	snd_pcm_hw_strategy_simple_choices_list_t *choices;
} snd_pcm_hw_strategy_simple_choices_t;

int snd_pcm_hw_params_strategy(snd_pcm_t *pcm, snd_pcm_hw_params_t *params,
			       const snd_pcm_hw_strategy_t *strategy,
			       unsigned int badness_min,
			       unsigned int badness_max)
{
	snd_pcm_hw_params_t best_params;
	int var;
	int value, dir;
	unsigned int best_badness;
	int badness = strategy->min_badness(params, badness_max, pcm, strategy);
	snd_pcm_hw_params_t params1;
#if 0
	printf("\nBadness: %d\n", badness);
	snd_pcm_hw_params_dump(params, stdout);
#endif
	if (badness < 0)
		return badness;
	if ((unsigned int)badness > badness_min)
		badness_min = badness_min;
	var = strategy->choose_param(params, pcm, strategy);
	if (var < 0)
		return badness;
	best_badness = UINT_MAX;
	value = -1;
	while (1) {
		params1 = *params;
		value = strategy->next_value(&params1, var, value, &dir, pcm, strategy);
		if (value < 0)
			break;
		badness = snd_pcm_hw_params_strategy(pcm, &params1, strategy, badness_min, badness_max);
		if (badness >= 0) {
			if ((unsigned int) badness <= badness_min) {
				*params = params1;
				return badness;
			}
			best_badness = badness;
			best_params = params1;
			badness_max = badness - 1;
		}
	}
	if (best_badness == UINT_MAX) {
		return -EINVAL;
	}
	*params = best_params;
	return best_badness;
}

void snd_pcm_hw_strategy_simple_free(snd_pcm_hw_strategy_t *strategy)
{
	snd_pcm_hw_strategy_simple_t *pars = strategy->private_data;
	int k;
	for (k = 0; k <= SND_PCM_HW_PARAM_LAST; ++k) {
		if (pars[k].valid && pars[k].free)
			pars[k].free(&pars[k]);
	}
	free(pars);
}

int snd_pcm_hw_strategy_simple_choose_param(const snd_pcm_hw_params_t *params,
					 snd_pcm_t *pcm ATTRIBUTE_UNUSED,
					 const snd_pcm_hw_strategy_t *strategy)
{
	snd_pcm_hw_param_t var;
	int best_var = -1;
	const snd_pcm_hw_strategy_simple_t *pars = strategy->private_data;
	unsigned int min_choices = UINT_MAX;
	unsigned int min_order = UINT_MAX;
	for (var = 0; var <= SND_PCM_HW_PARAM_LAST; ++var) {
		const snd_pcm_hw_strategy_simple_t *p = &pars[var];
		unsigned int choices;
		if (!p->valid)
			continue;
		choices = snd_pcm_hw_param_count(params, var);
		if (choices == 1)
			continue;
		assert(choices != 0);
		if (p->order < min_order ||
		    (p->order == min_order &&
		     choices < min_choices)) {
			min_order = p->order;
			min_choices = choices;
			best_var = var;
		}
	}
	return best_var;
}

int snd_pcm_hw_strategy_simple_next_value(snd_pcm_hw_params_t *params,
					  snd_pcm_hw_param_t var,
					  int value, int *dir,
					  snd_pcm_t *pcm,
					  const snd_pcm_hw_strategy_t *strategy)
{
	const snd_pcm_hw_strategy_simple_t *pars = strategy->private_data;
	assert(pars[var].valid);
	return pars[var].next_value(params, var, value, dir, pcm, &pars[var]);
}


int snd_pcm_hw_strategy_simple_min_badness(const snd_pcm_hw_params_t *params,
					unsigned int max_badness,
					snd_pcm_t *pcm,
					const snd_pcm_hw_strategy_t *strategy)
{
	snd_pcm_hw_param_t var;
	unsigned int badness = 0;
	const snd_pcm_hw_strategy_simple_t *pars = strategy->private_data;
	for (var = 0; var <= SND_PCM_HW_PARAM_LAST; ++var) {
		unsigned int b;
		if (!pars[var].valid)
			continue;
		b = pars[var].min_badness(params, var, pcm, &pars[var]);
		if (b > max_badness || max_badness - b < badness)
			return -E2BIG;
		badness += b;
	}
	return badness;
}


void snd_pcm_hw_strategy_simple_near_free(snd_pcm_hw_strategy_simple_t *par)
{
	snd_pcm_hw_strategy_simple_near_t *p = par->private_data;
	free(p);
}

unsigned int snd_pcm_hw_strategy_simple_near_min_badness(const snd_pcm_hw_params_t *params,
						      snd_pcm_hw_param_t var,
						      snd_pcm_t *pcm,
						      const snd_pcm_hw_strategy_simple_t *par)
{
	const snd_pcm_hw_strategy_simple_near_t *p = par->private_data;
	snd_pcm_hw_params_t params1 = *params;
	int value = snd_pcm_hw_param_set_near(pcm, &params1, var, p->best, 0);
	int diff;
	assert(value >= 0);
	diff = p->best - value;
	if (diff < 0)
		diff = -diff;
	return diff * p->mul;
}
	
int snd_pcm_hw_strategy_simple_near_next_value(snd_pcm_hw_params_t *params,
					       snd_pcm_hw_param_t var,
					       int value, int *dir,
					       snd_pcm_t *pcm,
					       const snd_pcm_hw_strategy_simple_t *par)
{
	const snd_pcm_hw_strategy_simple_near_t *p = par->private_data;
	if (value < 0) {
		*dir = 0;
		return snd_pcm_hw_param_set_near(pcm, params, var, p->best, dir);
	} else
		return snd_pcm_hw_param_set_next(pcm, params, var, p->best, 0, value, dir);
}

void snd_pcm_hw_strategy_simple_choices_free(snd_pcm_hw_strategy_simple_t *par)
{
	snd_pcm_hw_strategy_simple_choices_t *p = par->private_data;
//	free(p->choices);
	free(p);
}

unsigned int snd_pcm_hw_strategy_simple_choices_min_badness(const snd_pcm_hw_params_t *params,
							 snd_pcm_hw_param_t var,
							 snd_pcm_t *pcm,
							 const snd_pcm_hw_strategy_simple_t *par)
{
	const snd_pcm_hw_strategy_simple_choices_t *p = par->private_data;
	unsigned int k;
	for (k = 0; k < p->count; ++k) {
		if (snd_pcm_hw_param_set(pcm, (snd_pcm_hw_params_t *) params, SND_TEST, var, p->choices[k].value, 0))
			return p->choices[k].badness;
	}
	assert(0);
	return UINT_MAX;
}
	
int snd_pcm_hw_strategy_simple_choices_next_value(snd_pcm_hw_params_t *params,
						  snd_pcm_hw_param_t var,
						  int value, int *dir,
						  snd_pcm_t *pcm,
						  const snd_pcm_hw_strategy_simple_t *par)
{
	const snd_pcm_hw_strategy_simple_choices_t *p = par->private_data;
	unsigned int k = 0;
	if (value >= 0) {
		for (; k < p->count; ++k) {
			if (p->choices[k].value == (unsigned int) value) {
				k++;
				break;
			}
		}
	}
	for (; k < p->count; ++k) {
		unsigned int v = p->choices[k].value;
		int err = snd_pcm_hw_param_set(pcm, params, SND_TRY, var, v, 0);
		if (err < 0)
			continue;
		*dir = 0;
		return v;
	}
	return -1;
}

void snd_pcm_hw_strategy_free(snd_pcm_hw_strategy_t *strategy)
{
	if (strategy->free)
		strategy->free(strategy);
	free(strategy);
}

int snd_pcm_hw_strategy_simple(snd_pcm_hw_strategy_t **strategyp,
			    unsigned int badness_min,
			    unsigned int badness_max)
{
	snd_pcm_hw_strategy_simple_t *data;
	snd_pcm_hw_strategy_t *s;
	assert(strategyp);
	data = calloc(SND_PCM_HW_PARAM_LAST + 1, sizeof(*data));
	if (!data)
		return -ENOMEM;
	s = calloc(1, sizeof(*s));
	if (!s) {
		free(data);
		return -ENOMEM;
	}
	s->choose_param = snd_pcm_hw_strategy_simple_choose_param;
	s->next_value = snd_pcm_hw_strategy_simple_next_value;
	s->min_badness = snd_pcm_hw_strategy_simple_min_badness;
	s->badness_min = badness_min;
	s->badness_max = badness_max;
	s->private_data = data;
	s->free = snd_pcm_hw_strategy_simple_free;
	*strategyp = s;
	return 0;
}

int snd_pcm_hw_strategy_simple_near(snd_pcm_hw_strategy_t *strategy,
				 int order,
				 snd_pcm_hw_param_t var,
				 unsigned int best,
				 unsigned int mul)
{
	snd_pcm_hw_strategy_simple_t *s = strategy->private_data;
	snd_pcm_hw_strategy_simple_near_t *data;
	assert(strategy);
	assert(var <= SND_PCM_HW_PARAM_LAST);
	assert(!s->valid);
	data = calloc(1, sizeof(*data));
	if (!data)
		return -ENOMEM;
	data->best = best;
	data->mul = mul;
	s += var;
	s->order = order;
	s->valid = 1;
	s->next_value = snd_pcm_hw_strategy_simple_near_next_value;
	s->min_badness = snd_pcm_hw_strategy_simple_near_min_badness;
	s->private_data = data;
	s->free = snd_pcm_hw_strategy_simple_near_free;
	return 0;
}

int snd_pcm_hw_strategy_simple_choices(snd_pcm_hw_strategy_t *strategy,
				    int order,
				    snd_pcm_hw_param_t var,
				    unsigned int count,
				    snd_pcm_hw_strategy_simple_choices_list_t *choices)
{
	snd_pcm_hw_strategy_simple_t *s = strategy->private_data;
	snd_pcm_hw_strategy_simple_choices_t *data;
	assert(strategy);
	assert(var <= SND_PCM_HW_PARAM_LAST);
	assert(!s->valid);
	data = calloc(1, sizeof(*data));
	if (!data)
		return -ENOMEM;
	data->count = count;
	data->choices = choices;
	s += var;
	s->valid = 1;
	s->order = order;
	s->next_value = snd_pcm_hw_strategy_simple_choices_next_value;
	s->min_badness = snd_pcm_hw_strategy_simple_choices_min_badness;
	s->private_data = data;
	s->free = snd_pcm_hw_strategy_simple_choices_free;
	return 0;
}

int snd_pcm_hw_params_try_explain_failure1(snd_pcm_t *pcm,
					   snd_pcm_hw_params_t *fail,
					   snd_pcm_hw_params_t *success,
					   unsigned int depth,
					   snd_output_t *out)
{
	snd_pcm_hw_param_t var;
	snd_pcm_hw_params_t i;
	if (depth < 1)
		return -ENOENT;
	for (var = 0; var <= SND_PCM_HW_PARAM_LAST; var++) {
		int err;
		i = *success;
		_snd_pcm_hw_param_copy(&i, var, fail);
		err = snd_pcm_hw_refine(pcm, &i);
		if (err == 0 && 
		    snd_pcm_hw_params_try_explain_failure1(pcm, fail, &i, depth - 1, out) < 0)
			continue;
		snd_output_printf(out, "%s: ", snd_pcm_hw_param_name(var));
		snd_pcm_hw_param_dump(fail, var, out);
		snd_output_putc(out, '\n');
		return 0;
	}
	return -ENOENT;
}

int snd_pcm_hw_params_try_explain_failure(snd_pcm_t *pcm,
					  snd_pcm_hw_params_t *fail,
					  snd_pcm_hw_params_t *success,
					  unsigned int depth,
					  snd_output_t *out)
{
	snd_pcm_hw_params_t i, any;
	int err;
	snd_pcm_hw_param_t var;
	int done = 0;
	assert(pcm && fail);
	for (var = 0; var <= SND_PCM_HW_PARAM_LAST; var++) {
		if (!snd_pcm_hw_param_empty(fail, var))
			continue;
		snd_output_printf(out, "%s is empty\n", snd_pcm_hw_param_name(var));
		done = 1;
	}
	if (done)
		return 0;
	i = *fail;
	err = snd_pcm_hw_refine(pcm, &i);
	if (err == 0) {
		snd_output_printf(out, "Configuration is virtually correct\n");
		return 0;
	}
	if (!success) {
		snd_pcm_hw_params_any(pcm, &any);
		success = &any;
	}
	return snd_pcm_hw_params_try_explain_failure1(pcm, fail, success, depth, out);
}

#endif

typedef struct _snd_pcm_hw_rule snd_pcm_hw_rule_t;

typedef int (*snd_pcm_hw_rule_func_t)(snd_pcm_hw_params_t *params,
				      snd_pcm_hw_rule_t *rule);

struct _snd_pcm_hw_rule {
	int var;
	snd_pcm_hw_rule_func_t func;
	int deps[4];
	void *private_data;
};

static int snd_pcm_hw_rule_mul(snd_pcm_hw_params_t *params,
			       snd_pcm_hw_rule_t *rule)
{
	snd_interval_t t;
	snd_interval_mul(hw_param_interval_c(params, rule->deps[0]),
		     hw_param_interval_c(params, rule->deps[1]), &t);
	return snd_interval_refine(hw_param_interval(params, rule->var), &t);
}

static int snd_pcm_hw_rule_div(snd_pcm_hw_params_t *params,
			snd_pcm_hw_rule_t *rule)
{
	snd_interval_t t;
	snd_interval_div(hw_param_interval_c(params, rule->deps[0]),
		     hw_param_interval_c(params, rule->deps[1]), &t);
	return snd_interval_refine(hw_param_interval(params, rule->var), &t);
}

static int snd_pcm_hw_rule_muldivk(snd_pcm_hw_params_t *params,
				   snd_pcm_hw_rule_t *rule)
{
	snd_interval_t t;
	snd_interval_muldivk(hw_param_interval_c(params, rule->deps[0]),
			 hw_param_interval_c(params, rule->deps[1]),
			 (unsigned long) rule->private_data, &t);
	return snd_interval_refine(hw_param_interval(params, rule->var), &t);
}

static int snd_pcm_hw_rule_mulkdiv(snd_pcm_hw_params_t *params,
				   snd_pcm_hw_rule_t *rule)
{
	snd_interval_t t;
	snd_interval_mulkdiv(hw_param_interval_c(params, rule->deps[0]),
			 (unsigned long) rule->private_data,
			 hw_param_interval_c(params, rule->deps[1]), &t);
	return snd_interval_refine(hw_param_interval(params, rule->var), &t);
}

static int snd_pcm_hw_rule_format(snd_pcm_hw_params_t *params,
				  snd_pcm_hw_rule_t *rule)
{
	int changed = 0;
	snd_pcm_format_t k;
	snd_mask_t *mask = hw_param_mask(params, rule->var);
	snd_interval_t *i = hw_param_interval(params, rule->deps[0]);
	for (k = 0; k <= SND_PCM_FORMAT_LAST; snd_enum_incr(k)) {
		int bits;
		if (!snd_pcm_format_mask_test(mask, k))
			continue;
		bits = snd_pcm_format_physical_width(k);
		if (bits < 0)
			continue;
		if (!snd_interval_test(i, (unsigned int) bits)) {
			snd_pcm_format_mask_reset(mask, k);
			if (snd_mask_empty(mask))
				return -EINVAL;
			changed = 1;
		}
	}
	return changed;
}


static int snd_pcm_hw_rule_sample_bits(snd_pcm_hw_params_t *params,
				       snd_pcm_hw_rule_t *rule)
{
	unsigned int min, max;
	snd_pcm_format_t k;
	snd_interval_t *i = hw_param_interval(params, rule->var);
	snd_mask_t *mask = hw_param_mask(params, rule->deps[0]);
	int c, changed = 0;
	min = UINT_MAX;
	max = 0;
	for (k = 0; k <= SND_PCM_FORMAT_LAST; snd_enum_incr(k)) {
		int bits;
		if (!snd_pcm_format_mask_test(mask, k))
			continue;
		bits = snd_pcm_format_physical_width(k);
		if (bits < 0)
			continue;
		if (min > (unsigned)bits)
			min = bits;
		if (max < (unsigned)bits)
			max = bits;
	}
	c = snd_interval_refine_min(i, min, 0);
	if (c < 0)
		return c;
	if (c)
		changed = 1;
	c = snd_interval_refine_max(i, max, 0);
	if (c < 0)
		return c;
	if (c)
		changed = 1;
	return changed;
}

static snd_pcm_hw_rule_t refine_rules[] = {
	{
		var: SND_PCM_HW_PARAM_FORMAT,
		func: snd_pcm_hw_rule_format,
		deps: { SND_PCM_HW_PARAM_SAMPLE_BITS, -1 },
		private_data: 0,
	},
	{
		var: SND_PCM_HW_PARAM_SAMPLE_BITS, 
		func: snd_pcm_hw_rule_sample_bits,
		deps: { SND_PCM_HW_PARAM_FORMAT, 
			SND_PCM_HW_PARAM_SAMPLE_BITS, -1 },
		private_data: 0,
	},
	{
		var: SND_PCM_HW_PARAM_SAMPLE_BITS, 
		func: snd_pcm_hw_rule_div,
		deps: { SND_PCM_HW_PARAM_FRAME_BITS,
			SND_PCM_HW_PARAM_CHANNELS, -1 },
		private_data: 0,
	},
	{
		var: SND_PCM_HW_PARAM_FRAME_BITS, 
		func: snd_pcm_hw_rule_mul,
		deps: { SND_PCM_HW_PARAM_SAMPLE_BITS,
			SND_PCM_HW_PARAM_CHANNELS, -1 },
		private_data: 0,
	},
	{
		var: SND_PCM_HW_PARAM_FRAME_BITS, 
		func: snd_pcm_hw_rule_mulkdiv,
		deps: { SND_PCM_HW_PARAM_PERIOD_BYTES,
			SND_PCM_HW_PARAM_PERIOD_SIZE, -1 },
		private_data: (void*) 8,
	},
	{
		var: SND_PCM_HW_PARAM_FRAME_BITS, 
		func: snd_pcm_hw_rule_mulkdiv,
		deps: { SND_PCM_HW_PARAM_BUFFER_BYTES,
			SND_PCM_HW_PARAM_BUFFER_SIZE, -1 },
		private_data: (void*) 8,
	},
	{
		var: SND_PCM_HW_PARAM_CHANNELS, 
		func: snd_pcm_hw_rule_div,
		deps: { SND_PCM_HW_PARAM_FRAME_BITS,
			SND_PCM_HW_PARAM_SAMPLE_BITS, -1 },
		private_data: 0,
	},
	{
		var: SND_PCM_HW_PARAM_RATE, 
		func: snd_pcm_hw_rule_mulkdiv,
		deps: { SND_PCM_HW_PARAM_PERIOD_SIZE,
			SND_PCM_HW_PARAM_PERIOD_TIME, -1 },
		private_data: (void*) 1000000,
	},
	{
		var: SND_PCM_HW_PARAM_RATE, 
		func: snd_pcm_hw_rule_mulkdiv,
		deps: { SND_PCM_HW_PARAM_BUFFER_SIZE,
			SND_PCM_HW_PARAM_BUFFER_TIME, -1 },
		private_data: (void*) 1000000,
	},
	{
		var: SND_PCM_HW_PARAM_PERIODS, 
		func: snd_pcm_hw_rule_div,
		deps: { SND_PCM_HW_PARAM_BUFFER_SIZE,
			SND_PCM_HW_PARAM_PERIOD_SIZE, -1 },
		private_data: 0,
	},
	{
		var: SND_PCM_HW_PARAM_PERIOD_SIZE, 
		func: snd_pcm_hw_rule_div,
		deps: { SND_PCM_HW_PARAM_BUFFER_SIZE,
			SND_PCM_HW_PARAM_PERIODS, -1 },
		private_data: 0,
	},
	{
		var: SND_PCM_HW_PARAM_PERIOD_SIZE, 
		func: snd_pcm_hw_rule_mulkdiv,
		deps: { SND_PCM_HW_PARAM_PERIOD_BYTES,
			SND_PCM_HW_PARAM_FRAME_BITS, -1 },
		private_data: (void*) 8,
	},
	{
		var: SND_PCM_HW_PARAM_PERIOD_SIZE, 
		func: snd_pcm_hw_rule_muldivk,
		deps: { SND_PCM_HW_PARAM_PERIOD_TIME,
			SND_PCM_HW_PARAM_RATE, -1 },
		private_data: (void*) 1000000,
	},
	{
		var: SND_PCM_HW_PARAM_BUFFER_SIZE, 
		func: snd_pcm_hw_rule_mul,
		deps: { SND_PCM_HW_PARAM_PERIOD_SIZE,
			SND_PCM_HW_PARAM_PERIODS, -1 },
		private_data: 0,
	},
	{
		var: SND_PCM_HW_PARAM_BUFFER_SIZE, 
		func: snd_pcm_hw_rule_mulkdiv,
		deps: { SND_PCM_HW_PARAM_BUFFER_BYTES,
			SND_PCM_HW_PARAM_FRAME_BITS, -1 },
		private_data: (void*) 8,
	},
	{
		var: SND_PCM_HW_PARAM_BUFFER_SIZE, 
		func: snd_pcm_hw_rule_muldivk,
		deps: { SND_PCM_HW_PARAM_BUFFER_TIME,
			SND_PCM_HW_PARAM_RATE, -1 },
		private_data: (void*) 1000000,
	},
	{
		var: SND_PCM_HW_PARAM_PERIOD_BYTES, 
		func: snd_pcm_hw_rule_muldivk,
		deps: { SND_PCM_HW_PARAM_PERIOD_SIZE,
			SND_PCM_HW_PARAM_FRAME_BITS, -1 },
		private_data: (void*) 8,
	},
	{
		var: SND_PCM_HW_PARAM_BUFFER_BYTES, 
		func: snd_pcm_hw_rule_muldivk,
		deps: { SND_PCM_HW_PARAM_BUFFER_SIZE,
			SND_PCM_HW_PARAM_FRAME_BITS, -1 },
		private_data: (void*) 8,
	},
	{
		var: SND_PCM_HW_PARAM_PERIOD_TIME, 
		func: snd_pcm_hw_rule_mulkdiv,
		deps: { SND_PCM_HW_PARAM_PERIOD_SIZE,
			SND_PCM_HW_PARAM_RATE, -1 },
		private_data: (void*) 1000000,
	},
	{
		var: SND_PCM_HW_PARAM_BUFFER_TIME, 
		func: snd_pcm_hw_rule_mulkdiv,
		deps: { SND_PCM_HW_PARAM_BUFFER_SIZE,
			SND_PCM_HW_PARAM_RATE, -1 },
		private_data: (void*) 1000000,
	},
};

#define RULES (sizeof(refine_rules) / sizeof(refine_rules[0]))

static snd_mask_t refine_masks[SND_PCM_HW_PARAM_LAST_MASK - SND_PCM_HW_PARAM_FIRST_MASK + 1] = {
	[SND_PCM_HW_PARAM_ACCESS - SND_PCM_HW_PARAM_FIRST_MASK] = {
		bits: 0x1f,
	},
	[SND_PCM_HW_PARAM_FORMAT - SND_PCM_HW_PARAM_FIRST_MASK] = {
		bits: 0x81ffffff,
	},
	[SND_PCM_HW_PARAM_SUBFORMAT - SND_PCM_HW_PARAM_FIRST_MASK] = {
		bits: 0x1,
	},
};

static snd_interval_t refine_intervals[SND_PCM_HW_PARAM_LAST_INTERVAL - SND_PCM_HW_PARAM_FIRST_INTERVAL + 1] = {
	[SND_PCM_HW_PARAM_SAMPLE_BITS - SND_PCM_HW_PARAM_FIRST_INTERVAL] = {
		min: 1, max: UINT_MAX,
		openmin: 0, openmax: 0, integer: 1, empty: 0,
	},
	[SND_PCM_HW_PARAM_FRAME_BITS - SND_PCM_HW_PARAM_FIRST_INTERVAL] = {
		min: 1, max: UINT_MAX,
		openmin: 0, openmax: 0, integer: 1, empty: 0,
	},
	[SND_PCM_HW_PARAM_CHANNELS - SND_PCM_HW_PARAM_FIRST_INTERVAL] = {
		min: 1, max: UINT_MAX,
		openmin: 0, openmax: 0, integer: 1, empty: 0,
	},
	[SND_PCM_HW_PARAM_RATE - SND_PCM_HW_PARAM_FIRST_INTERVAL] = {
		min: 1, max: UINT_MAX,
		openmin: 0, openmax: 0, integer: 0, empty: 0,
	},
	[SND_PCM_HW_PARAM_PERIOD_TIME - SND_PCM_HW_PARAM_FIRST_INTERVAL] = {
		min: 0, max: UINT_MAX,
		openmin: 0, openmax: 0, integer: 0, empty: 0,
	},
	[SND_PCM_HW_PARAM_PERIOD_SIZE - SND_PCM_HW_PARAM_FIRST_INTERVAL] = {
		min: 0, max: UINT_MAX,
		openmin: 0, openmax: 0, integer: 0, empty: 0,
	},
	[SND_PCM_HW_PARAM_PERIOD_BYTES - SND_PCM_HW_PARAM_FIRST_INTERVAL] = {
		min: 0, max: UINT_MAX,
		openmin: 0, openmax: 0, integer: 0, empty: 0,
	},
	[SND_PCM_HW_PARAM_PERIODS - SND_PCM_HW_PARAM_FIRST_INTERVAL] = {
		min: 0, max: UINT_MAX,
		openmin: 0, openmax: 0, integer: 0, empty: 0,
	},
	[SND_PCM_HW_PARAM_BUFFER_TIME - SND_PCM_HW_PARAM_FIRST_INTERVAL] = {
		min: 1, max: UINT_MAX,
		openmin: 0, openmax: 0, integer: 0, empty: 0,
	},
	[SND_PCM_HW_PARAM_BUFFER_SIZE - SND_PCM_HW_PARAM_FIRST_INTERVAL] = {
		min: 1, max: UINT_MAX,
		openmin: 0, openmax: 0, integer: 1, empty: 0,
	},
	[SND_PCM_HW_PARAM_BUFFER_BYTES - SND_PCM_HW_PARAM_FIRST_INTERVAL] = {
		min: 1, max: UINT_MAX,
		openmin: 0, openmax: 0, integer: 1, empty: 0,
	},
	[SND_PCM_HW_PARAM_TICK_TIME - SND_PCM_HW_PARAM_FIRST_INTERVAL] = {
		min: 0, max: UINT_MAX,
		openmin: 0, openmax: 0, integer: 0, empty: 0,
	},
};

#undef RULES_DEBUG

int snd_pcm_hw_refine_soft(snd_pcm_t *pcm ATTRIBUTE_UNUSED, snd_pcm_hw_params_t *params)
{
	unsigned int k;
	snd_interval_t *i;
	unsigned int rstamps[RULES];
	unsigned int vstamps[SND_PCM_HW_PARAM_LAST + 1];
	unsigned int stamp = 2;
	int changed, again;
#ifdef RULES_DEBUG
	snd_output_t *log;
	snd_output_stdio_attach(&log, stderr, 0);
#endif

	for (k = SND_PCM_HW_PARAM_FIRST_MASK; k <= SND_PCM_HW_PARAM_LAST_MASK; k++) {
		if (!(params->rmask & (1 << k)))
			continue;
		changed = snd_mask_refine(hw_param_mask(params, k),
				  &refine_masks[k - SND_PCM_HW_PARAM_FIRST_MASK]);
		if (changed)
			params->cmask |= 1 << k;
		if (changed < 0)
			goto _err;
	}

	for (k = SND_PCM_HW_PARAM_FIRST_INTERVAL; k <= SND_PCM_HW_PARAM_LAST_INTERVAL; k++) {
		if (!(params->rmask & (1 << k)))
			continue;
		changed = snd_interval_refine(hw_param_interval(params, k),
				      &refine_intervals[k - SND_PCM_HW_PARAM_FIRST_INTERVAL]);
		if (changed)
			params->cmask |= 1 << k;
		if (changed < 0)
			goto _err;
	}

	for (k = 0; k < RULES; k++)
		rstamps[k] = 0;
	for (k = 0; k <= SND_PCM_HW_PARAM_LAST; k++)
		vstamps[k] = (params->rmask & (1 << k)) ? 1 : 0;
	do {
		again = 0;
		for (k = 0; k < RULES; k++) {
			snd_pcm_hw_rule_t *r = &refine_rules[k];
			unsigned int d;
			int doit = 0;
			for (d = 0; r->deps[d] >= 0; d++) {
				if (vstamps[r->deps[d]] > rstamps[k]) {
					doit = 1;
					break;
				}
			}
			if (!doit)
				continue;
#ifdef RULES_DEBUG
			snd_output_printf(log, "Rule %d: ", k);
			if (r->var >= 0) {
				snd_output_printf(log, "%s=", snd_pcm_hw_param_name(r->var));
				snd_pcm_hw_param_dump(params, r->var, log);
				snd_output_puts(log, " -> ");
			}
#endif
			changed = r->func(params, r);
#ifdef RULES_DEBUG
			if (r->var >= 0)
				snd_pcm_hw_param_dump(params, r->var, log);
			snd_output_putc(log, ' ');
			for (d = 0; r->deps[d] >= 0; d++) {
				snd_output_printf(log, "%s=", snd_pcm_hw_param_name(r->deps[d]));
				snd_pcm_hw_param_dump(params, r->deps[d], log);
			}
			snd_output_putc(log, '\n');
#endif
			rstamps[k] = stamp;
			if (changed && r->var >= 0) {
				params->cmask |= 1 << r->var;
				vstamps[r->var] = stamp;
				again = 1;
			}
			if (changed < 0)
				goto _err;
			stamp++;
		}
	} while (again);
	if (!params->msbits) {
		i = hw_param_interval(params, SND_PCM_HW_PARAM_SAMPLE_BITS);
		if (snd_interval_single(i))
			params->msbits = snd_interval_value(i);
	}

	if (!params->rate_den) {
		i = hw_param_interval(params, SND_PCM_HW_PARAM_RATE);
		if (snd_interval_single(i)) {
			params->rate_num = snd_interval_value(i);
			params->rate_den = 1;
		}
	}
	params->rmask = 0;
	return 0;
 _err:
#ifdef RULES_DEBUG
	snd_output_close(log);
#endif
	return changed;
}

int _snd_pcm_hw_params_refine(snd_pcm_hw_params_t *params,
			      unsigned int vars,
			      const snd_pcm_hw_params_t *src)
{
	int changed, err = 0;
	unsigned int k;
	for (k = 0; k <= SND_PCM_HW_PARAM_LAST; ++k) {
		if (!(vars & (1 << k)))
			continue;
		changed = _snd_pcm_hw_param_refine(params, k, src);
		if (changed < 0)
			err = changed;
	}
	return err;
}

int snd_pcm_hw_refine_slave(snd_pcm_t *pcm, snd_pcm_hw_params_t *params,
			    int (*cprepare)(snd_pcm_t *pcm,
					    snd_pcm_hw_params_t *params),
			    int (*cchange)(snd_pcm_t *pcm,
					   snd_pcm_hw_params_t *params,
					   snd_pcm_hw_params_t *sparams),
			    int (*sprepare)(snd_pcm_t *pcm,
					    snd_pcm_hw_params_t *params),
			    int (*schange)(snd_pcm_t *pcm,
					   snd_pcm_hw_params_t *params,
					   snd_pcm_hw_params_t *sparams),
			    int (*srefine)(snd_pcm_t *pcm,
					   snd_pcm_hw_params_t *sparams))

{
	snd_pcm_hw_params_t sparams;
	int err;
	unsigned int cmask, changed;
	err = cprepare(pcm, params);
	if (err < 0)
		return err;
	err = sprepare(pcm, &sparams);
	if (err < 0) {
		SNDERR("Slave PCM not useable");
		return err;
	}
	do {
		cmask = params->cmask;
		params->cmask = 0;
		err = schange(pcm, params, &sparams);
		if (err >= 0) {
			err = srefine(pcm, &sparams);
		}
		if (err < 0) {
			cchange(pcm, params, &sparams);
			return err;
		}
		err = cchange(pcm, params, &sparams);
		if (err < 0)
			return err;
		err = snd_pcm_hw_refine_soft(pcm, params);
		changed = params->cmask;
		params->cmask |= cmask;
		if (err < 0)
			return err;
	} while (changed);
	return 0;
}

int snd_pcm_hw_params_slave(snd_pcm_t *pcm, snd_pcm_hw_params_t *params,
			    int (*cchange)(snd_pcm_t *pcm,
					   snd_pcm_hw_params_t *params,
					   snd_pcm_hw_params_t *sparams),
			    int (*sprepare)(snd_pcm_t *pcm,
					    snd_pcm_hw_params_t *params),
			    int (*schange)(snd_pcm_t *pcm,
					   snd_pcm_hw_params_t *params,
					   snd_pcm_hw_params_t *sparams),
			    int (*sparams)(snd_pcm_t *pcm,
					   snd_pcm_hw_params_t *sparams))

{
	snd_pcm_hw_params_t slave_params;
	int err;
	err = sprepare(pcm, &slave_params);
	assert(err >= 0);
	err = schange(pcm, params, &slave_params);
	assert(err >= 0);
	err = sparams(pcm, &slave_params);
	if (err < 0)
		cchange(pcm, params, &slave_params);
	return err;
}

static int snd_pcm_sw_params_default(snd_pcm_t *pcm, snd_pcm_sw_params_t *params)
{
	assert(pcm && params);
	assert(pcm->setup);
	params->tstamp_mode = snd_enum_to_int(SND_PCM_TSTAMP_NONE);
	params->period_step = 1;
	params->sleep_min = 0;
	params->avail_min = pcm->period_size;
	params->xfer_align = pcm->period_size;
	params->start_threshold = 1;
	params->stop_threshold = pcm->buffer_size;
	params->silence_threshold = 0;
	params->silence_size = 0;
	params->boundary = pcm->buffer_size;
	while (params->boundary * 2 <= LONG_MAX - pcm->buffer_size)
		params->boundary *= 2;
	return 0;
}

int snd_pcm_hw_refine(snd_pcm_t *pcm, snd_pcm_hw_params_t *params)
{
	assert(pcm && params);
	return pcm->ops->hw_refine(pcm->op_arg, params);
}

/* Install one of the configurations present in configuration
   space defined by PARAMS.
   The configuration choosen is that obtained fixing in this order:
   first access
   first format
   first subformat
   min channels
   min rate
   min period_size
   max periods
   Return 0 on success otherwise a negative error code
*/
int _snd_pcm_hw_params(snd_pcm_t *pcm, snd_pcm_hw_params_t *params)
{
	int err;
	snd_pcm_sw_params_t sw;
	int fb, min_align;
	err = snd_pcm_hw_refine(pcm, params);
	if (err < 0)
		return err;
	snd_pcm_hw_params_choose(pcm, params);
	if (pcm->setup) {
		err = snd_pcm_hw_free(pcm);
		if (err < 0)
			return err;
	}
	err = pcm->ops->hw_params(pcm->op_arg, params);
	if (err < 0)
		return err;

	pcm->setup = 1;
	pcm->access = snd_pcm_hw_params_get_access(params);
	pcm->format = snd_pcm_hw_params_get_format(params);
	pcm->subformat = snd_pcm_hw_params_get_subformat(params);
	pcm->channels = snd_pcm_hw_params_get_channels(params);
	pcm->rate = snd_pcm_hw_params_get_rate(params, 0);
	pcm->period_time = snd_pcm_hw_params_get_period_time(params, 0);
	pcm->period_size = snd_pcm_hw_params_get_period_size(params, 0);
	pcm->buffer_size = snd_pcm_hw_params_get_buffer_size(params);
	pcm->tick_time = snd_pcm_hw_params_get_tick_time(params, 0);
	pcm->sample_bits = snd_pcm_format_physical_width(pcm->format);
	pcm->frame_bits = pcm->sample_bits * pcm->channels;
	fb = pcm->frame_bits;
	min_align = 1;
	while (fb % 8) {
		fb *= 2;
		min_align *= 2;
	}
	pcm->min_align = min_align;
	
	pcm->info = params->info;
	pcm->msbits = params->msbits;
	pcm->rate_num = params->rate_num;
	pcm->rate_den = params->rate_den;
	pcm->fifo_size = params->fifo_size;
	
	/* Default sw params */
	snd_pcm_sw_params_default(pcm, &sw);
	err = snd_pcm_sw_params(pcm, &sw);
	assert(err >= 0);

	if (pcm->mmap_rw || 
	    pcm->access == SND_PCM_ACCESS_MMAP_INTERLEAVED ||
	    pcm->access == SND_PCM_ACCESS_MMAP_NONINTERLEAVED ||
	    pcm->access == SND_PCM_ACCESS_MMAP_COMPLEX) {
		err = snd_pcm_mmap(pcm);
	}
	if (err < 0)
		return err;
	return 0;
}