alsa-lib/src/pcm/pcm.c

/*
 *  PCM Interface - main file
 *  Copyright (c) 1998 by Jaroslav Kysela <perex@suse.cz>
 *  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 <stdio.h>
#include <string.h>
#include <malloc.h>
#include <errno.h>
#include <stdarg.h>
#include <sys/ioctl.h>
#include <sys/poll.h>
#include <sys/shm.h>
#include <sys/mman.h>
#include <limits.h>
#include <dlfcn.h>
#include "pcm_local.h"
#include "list.h"

snd_pcm_type_t snd_pcm_type(snd_pcm_t *pcm)
{
	assert(pcm);
	return pcm->type;
}

snd_pcm_type_t snd_pcm_stream(snd_pcm_t *pcm)
{
	assert(pcm);
	return pcm->stream;
}

int snd_pcm_close(snd_pcm_t *pcm)
{
	int ret = 0;
	int err;
	assert(pcm);
	if (pcm->setup) {
		if (pcm->mode & SND_PCM_NONBLOCK)
			snd_pcm_drop(pcm);
		else
			snd_pcm_drain(pcm);
	}
	if (pcm->mmap_channels) {
		if ((err = snd_pcm_munmap(pcm)) < 0)
			ret = err;
	}
	if ((err = pcm->ops->close(pcm->op_arg)) < 0)
		ret = err;
	pcm->setup = 0;
	if (pcm->name)
		free(pcm->name);
	free(pcm);
	return 0;
}	

int snd_pcm_nonblock(snd_pcm_t *pcm, int nonblock)
{
	int err;
	assert(pcm);
	if ((err = pcm->ops->nonblock(pcm->op_arg, nonblock)) < 0)
		return err;
	if (nonblock)
		pcm->mode |= SND_PCM_NONBLOCK;
	else
		pcm->mode &= ~SND_PCM_NONBLOCK;
	return 0;
}

int snd_pcm_async(snd_pcm_t *pcm, int sig, pid_t pid)
{
	assert(pcm);
	return pcm->ops->async(pcm->op_arg, sig, pid);
}

int snd_pcm_info(snd_pcm_t *pcm, snd_pcm_info_t *info)
{
	assert(pcm && info);
	return pcm->ops->info(pcm->op_arg, info);
}

int snd_pcm_hw_info(snd_pcm_t *pcm, snd_pcm_hw_info_t *info)
{
	int err;
	assert(pcm && info);
#if 0
	fprintf(stderr, "hw_info entered:\n");
	snd_pcm_dump_hw_info(info, stderr);
	fprintf(stderr, "\n");
#endif
	err = pcm->ops->hw_info(pcm->op_arg, info);
#if 0
	fprintf(stderr, "hw_info return %d:\n", err);
	snd_pcm_dump_hw_info(info, stderr);
	fprintf(stderr, "\n");
#endif
	return err;
}

void snd_pcm_hw_info_any(snd_pcm_hw_info_t *info)
{
	assert(info);
	info->access_mask = ~0;
	info->format_mask = ~0;
	info->subformat_mask = ~0;
	info->channels_min = 1;
	info->channels_max = UINT_MAX;
	info->rate_min = 1;
	info->rate_max = UINT_MAX;
	info->fragment_length_min = 0;
	info->fragment_length_max = UINT_MAX;
	info->fragments_min = 1;
	info->fragments_max = UINT_MAX;
	info->buffer_length_min = 1;
	info->buffer_length_max = UINT_MAX;
}

void snd_pcm_hw_params_to_info(snd_pcm_hw_params_t *params, snd_pcm_hw_info_t *info)
{
	assert(info && params);
	info->access_mask = 1U << params->access;
	info->format_mask = 1U << params->format;
	info->subformat_mask = 1U << params->subformat;
	info->channels_min = info->channels_max = params->channels;
	info->rate_min = info->rate_max = params->rate;
	info->fragment_length_min = info->fragment_length_max = muldiv_down(params->fragment_size, 1000000, params->rate);
	info->fragments_min = info->fragments_max = params->fragments;
	info->buffer_length_min = info->buffer_length_max = muldiv_down(params->fragment_size * params->fragments, 1000000, params->rate);
}

int snd_pcm_hw_info_to_params(snd_pcm_t *pcm, snd_pcm_hw_info_t *info, snd_pcm_hw_params_t *params)
{
	snd_pcm_hw_info_t i = *info;
	int err;

	err = snd_pcm_hw_info(pcm, &i);
	if (err < 0)
		return err;

	assert(i.access_mask);
	if (i.access_mask & (i.access_mask - 1)) {
		i.access_mask = 1 << (ffs(i.access_mask - 1));
		err = snd_pcm_hw_info(pcm, info);
		assert(err >= 0);
	}
	assert(i.format_mask);
	if (i.format_mask & (i.format_mask - 1)) {
		i.format_mask = 1 << (ffs(i.format_mask - 1));
		err = snd_pcm_hw_info(pcm, info);
		assert(err >= 0);
	}
	assert(i.subformat_mask);
	if (i.subformat_mask & (i.subformat_mask - 1)) {
		i.subformat_mask = 1 << (ffs(i.subformat_mask - 1));
		err = snd_pcm_hw_info(pcm, info);
		assert(err >= 0);
	}
	assert(i.channels_min <= i.channels_max);
	if (i.channels_min < i.channels_max) {
		i.channels_max = i.channels_min;
		err = snd_pcm_hw_info(pcm, info);
		assert(err >= 0);
	}
	assert(i.rate_min <= i.rate_max);
	if (i.rate_min < i.rate_max) {
		i.rate_max = i.rate_min;
		err = snd_pcm_hw_info(pcm, info);
		assert(err >= 0);
	}
	assert(i.fragment_length_min <= i.fragment_length_max);
	if (i.fragment_length_min < i.fragment_length_max) {
		i.fragment_length_max = i.fragment_length_min;
		err = snd_pcm_hw_info(pcm, info);
		assert(err >= 0);
	}
	assert(i.fragments_min <= i.fragments_max);
	if (i.fragments_min < i.fragments_max) {
		i.fragments_max = i.fragments_min;
		err = snd_pcm_hw_info(pcm, info);
		assert(err >= 0);
	}
	params->access = ffs(i.access_mask) - 1;
	params->format = ffs(i.format_mask) - 1;
	params->subformat = ffs(i.subformat_mask) - 1;
	params->channels = i.channels_min;
	params->rate = i.rate_min;
	params->fragment_size = muldiv_near(i.fragment_length_min, i.rate_min, 1000000);
	params->fragments = i.fragments_min;
	return 0;
}

int snd_pcm_sw_params(snd_pcm_t *pcm, snd_pcm_sw_params_t *params)
{
	int err;
	assert(pcm && params);
	assert(pcm->setup);
	if ((err = pcm->ops->sw_params(pcm->op_arg, params)) < 0)
		return err;
	pcm->start_mode = params->start_mode;
	pcm->ready_mode = params->ready_mode;
	pcm->xrun_mode = params->xrun_mode;
	pcm->avail_min = params->avail_min;
	pcm->xfer_min = params->xfer_min;
	pcm->xfer_align = params->xfer_align;
	pcm->time = params->time;
	pcm->boundary = params->boundary;
	return 0;
}

int snd_pcm_dig_params(snd_pcm_t *pcm, snd_pcm_dig_params_t *params)
{
	assert(pcm && params);
	return pcm->ops->dig_params(pcm->op_arg, params);
}

int snd_pcm_dig_info(snd_pcm_t *pcm, snd_pcm_dig_info_t *info)
{
	assert(pcm && info);
	return pcm->ops->dig_info(pcm->op_arg, info);
}

int snd_pcm_status(snd_pcm_t *pcm, snd_pcm_status_t *status)
{
	assert(pcm && status);
	return pcm->fast_ops->status(pcm->fast_op_arg, status);
}

int snd_pcm_state(snd_pcm_t *pcm)
{
	assert(pcm);
	return pcm->fast_ops->state(pcm->fast_op_arg);
}

int snd_pcm_delay(snd_pcm_t *pcm, ssize_t *delayp)
{
	assert(pcm);
	assert(pcm->setup);
	return pcm->fast_ops->delay(pcm->fast_op_arg, delayp);
}

int snd_pcm_prepare(snd_pcm_t *pcm)
{
	assert(pcm);
	assert(pcm->setup);
	return pcm->fast_ops->prepare(pcm->fast_op_arg);
}

int snd_pcm_reset(snd_pcm_t *pcm)
{
	assert(pcm);
	assert(pcm->setup);
	return pcm->fast_ops->reset(pcm->fast_op_arg);
}

int snd_pcm_start(snd_pcm_t *pcm)
{
	assert(pcm);
	assert(pcm->setup);
	return pcm->fast_ops->start(pcm->fast_op_arg);
}

int snd_pcm_drop(snd_pcm_t *pcm)
{
	assert(pcm);
	assert(pcm->setup);
	return pcm->fast_ops->drop(pcm->fast_op_arg);
}

int snd_pcm_drain(snd_pcm_t *pcm)
{
	assert(pcm);
	assert(pcm->setup);
	return pcm->fast_ops->drain(pcm->fast_op_arg);
}

int snd_pcm_pause(snd_pcm_t *pcm, int enable)
{
	assert(pcm);
	assert(pcm->setup);
	return pcm->fast_ops->pause(pcm->fast_op_arg, enable);
}


ssize_t snd_pcm_rewind(snd_pcm_t *pcm, size_t frames)
{
	assert(pcm);
	assert(pcm->setup);
	assert(frames > 0);
	return pcm->fast_ops->rewind(pcm->fast_op_arg, frames);
}

int snd_pcm_set_avail_min(snd_pcm_t *pcm, size_t frames)
{
	int err;
	assert(pcm);
	assert(pcm->setup);
	assert(frames > 0);
	err = pcm->fast_ops->set_avail_min(pcm->fast_op_arg, frames);
	if (err < 0)
		return err;
	pcm->avail_min = frames;
	return 0;
}

ssize_t snd_pcm_writei(snd_pcm_t *pcm, const void *buffer, size_t size)
{
	assert(pcm);
	assert(size == 0 || buffer);
	assert(pcm->setup);
	assert(pcm->access == SND_PCM_ACCESS_RW_INTERLEAVED);
	return _snd_pcm_writei(pcm, buffer, size);
}

ssize_t snd_pcm_writen(snd_pcm_t *pcm, void **bufs, size_t size)
{
	assert(pcm);
	assert(size == 0 || bufs);
	assert(pcm->setup);
	assert(pcm->access == SND_PCM_ACCESS_RW_NONINTERLEAVED);
	return _snd_pcm_writen(pcm, bufs, size);
}

ssize_t snd_pcm_readi(snd_pcm_t *pcm, void *buffer, size_t size)
{
	assert(pcm);
	assert(size == 0 || buffer);
	assert(pcm->setup);
	assert(pcm->access == SND_PCM_ACCESS_RW_INTERLEAVED);
	return _snd_pcm_readi(pcm, buffer, size);
}

ssize_t snd_pcm_readn(snd_pcm_t *pcm, void **bufs, size_t size)
{
	assert(pcm);
	assert(size == 0 || bufs);
	assert(pcm->setup);
	assert(pcm->access == SND_PCM_ACCESS_RW_NONINTERLEAVED);
	return _snd_pcm_readn(pcm, bufs, size);
}

ssize_t snd_pcm_writev(snd_pcm_t *pcm, const struct iovec *vector, int count)
{
	void **bufs;
	int k;
	assert(pcm);
	assert(pcm->setup);
	assert((int)pcm->channels == count);
	bufs = alloca(sizeof(*bufs) * count);
	for (k = 0; k < count; ++k) {
		bufs[k] = vector[k].iov_base;
		assert(vector[k].iov_len == vector[0].iov_len);
	}
	return snd_pcm_writen(pcm, bufs, vector[0].iov_len);
}

ssize_t snd_pcm_readv(snd_pcm_t *pcm, const struct iovec *vector, int count)
{
	void **bufs;
	int k;
	assert(pcm);
	assert(pcm->setup);
	assert((int)pcm->channels == count);
	bufs = alloca(sizeof(*bufs) * count);
	for (k = 0; k < count; ++k) {
		bufs[k] = vector[k].iov_base;
		assert(vector[k].iov_len == vector[0].iov_len);
	}
	return snd_pcm_readn(pcm, bufs, vector[0].iov_len);
}

/* FIXME */
#define snd_pcm_link_descriptor snd_pcm_poll_descriptor

int snd_pcm_link(snd_pcm_t *pcm1, snd_pcm_t *pcm2)
{
	int fd1 = snd_pcm_link_descriptor(pcm1);
	int fd2 = snd_pcm_link_descriptor(pcm2);
	if (fd1 < 0 || fd2 < 0)
		return -ENOSYS;
	if (ioctl(fd1, SND_PCM_IOCTL_LINK, fd2) < 0) {
		SYSERR("SND_PCM_IOCTL_LINK failed");
		return -errno;
	}
	return 0;
}

int snd_pcm_unlink(snd_pcm_t *pcm)
{
	int fd;
	switch (pcm->type) {
	case SND_PCM_TYPE_HW:
	case SND_PCM_TYPE_MULTI:
		fd = snd_pcm_poll_descriptor(pcm);
		break;
	default:
		return -ENOSYS;
	}
	if (ioctl(fd, SND_PCM_IOCTL_UNLINK) < 0) {
		SYSERR("SND_PCM_IOCTL_UNLINK failed");
		return -errno;
	}
	return 0;
}

int snd_pcm_poll_descriptor(snd_pcm_t *pcm)
{
	assert(pcm);
	return pcm->poll_fd;
}

#define STATE(v) [SND_PCM_STATE_##v] = #v
#define STREAM(v) [SND_PCM_STREAM_##v] = #v
#define READY(v) [SND_PCM_READY_##v] = #v
#define XRUN(v) [SND_PCM_XRUN_##v] = #v
#define ACCESS(v) [SND_PCM_ACCESS_##v] = #v
#define START(v) [SND_PCM_START_##v] = #v
#define HW_INFO(v) [SND_PCM_HW_INFO_##v] = #v
#define HW_PARAM(v) [SND_PCM_HW_PARAM_##v] = #v
#define SW_PARAM(v) [SND_PCM_SW_PARAM_##v] = #v
#define FORMAT(v) [SND_PCM_FORMAT_##v] = #v
#define SUBFORMAT(v) [SND_PCM_SUBFORMAT_##v] = #v 

#define FORMATD(v, d) [SND_PCM_FORMAT_##v] = d
#define SUBFORMATD(v, d) [SND_PCM_SUBFORMAT_##v] = d 

char *snd_pcm_stream_names[] = {
	STREAM(PLAYBACK),
	STREAM(CAPTURE),
};

char *snd_pcm_state_names[] = {
	STATE(OPEN),
	STATE(SETUP),
	STATE(PREPARED),
	STATE(RUNNING),
	STATE(XRUN),
	STATE(PAUSED),
};

char *snd_pcm_hw_info_names[] = {
	HW_INFO(ACCESS),
	HW_INFO(FORMAT),
	HW_INFO(SUBFORMAT),
	HW_INFO(CHANNELS),
	HW_INFO(RATE),
	HW_INFO(FRAGMENT_LENGTH),
	HW_INFO(FRAGMENTS),
	HW_INFO(BUFFER_LENGTH),
};

char *snd_pcm_hw_param_names[] = {
	HW_PARAM(ACCESS),
	HW_PARAM(FORMAT),
	HW_PARAM(SUBFORMAT),
	HW_PARAM(CHANNELS),
	HW_PARAM(RATE),
	HW_PARAM(FRAGMENT_SIZE),
	HW_PARAM(FRAGMENTS),
};

char *snd_pcm_sw_param_names[] = {
	SW_PARAM(START_MODE),
	SW_PARAM(READY_MODE),
	SW_PARAM(AVAIL_MIN),
	SW_PARAM(XFER_MIN),
	SW_PARAM(XFER_ALIGN),
	SW_PARAM(XRUN_MODE),
	SW_PARAM(TIME),
};

char *snd_pcm_access_names[] = {
	ACCESS(MMAP_INTERLEAVED), 
	ACCESS(MMAP_NONINTERLEAVED),
	ACCESS(MMAP_COMPLEX),
	ACCESS(RW_INTERLEAVED),
	ACCESS(RW_NONINTERLEAVED),
};

char *snd_pcm_format_names[] = {
	FORMAT(S8),
	FORMAT(U8),
	FORMAT(S16_LE),
	FORMAT(S16_BE),
	FORMAT(U16_LE),
	FORMAT(U16_BE),
	FORMAT(S24_LE),
	FORMAT(S24_BE),
	FORMAT(U24_LE),
	FORMAT(U24_BE),
	FORMAT(S32_LE),
	FORMAT(S32_BE),
	FORMAT(U32_LE),
	FORMAT(U32_BE),
	FORMAT(FLOAT_LE),
	FORMAT(FLOAT_BE),
	FORMAT(FLOAT64_LE),
	FORMAT(FLOAT64_BE),
	FORMAT(IEC958_SUBFRAME_LE),
	FORMAT(IEC958_SUBFRAME_BE),
	FORMAT(MU_LAW),
	FORMAT(A_LAW),
	FORMAT(IMA_ADPCM),
	FORMAT(MPEG),
	FORMAT(GSM),
	FORMAT(SPECIAL),
};

char *snd_pcm_format_descriptions[] = {
	FORMATD(S8, "Signed 8-bit"), 
	FORMATD(U8, "Unsigned 8-bit"),
	FORMATD(S16_LE, "Signed 16-bit Little Endian"),
	FORMATD(S16_BE, "Signed 16-bit Big Endian"),
	FORMATD(U16_LE, "Unsigned 16-bit Little Endian"),
	FORMATD(U16_BE, "Unsigned 16-bit Big Endian"),
	FORMATD(S24_LE, "Signed 24-bit Little Endian"),
	FORMATD(S24_BE, "Signed 24-bit Big Endian"),
	FORMATD(U24_LE, "Unsigned 24-bit Little Endian"),
	FORMATD(U24_BE, "Unsigned 24-bit Big Endian"),
	FORMATD(S32_LE, "Signed 32-bit Little Endian"),
	FORMATD(S32_BE, "Signed 32-bit Big Endian"),
	FORMATD(U32_LE, "Unsigned 32-bit Little Endian"),
	FORMATD(U32_BE, "Unsigned 32-bit Big Endian"),
	FORMATD(FLOAT_LE, "Float Little Endian"),
	FORMATD(FLOAT_BE, "Float Big Endian"),
	FORMATD(FLOAT64_LE, "Float64 Little Endian"),
	FORMATD(FLOAT64_BE, "Float64 Big Endian"),
	FORMATD(IEC958_SUBFRAME_LE, "IEC-958 Little Endian"),
	FORMATD(IEC958_SUBFRAME_BE, "IEC-958 Big Endian"),
	FORMATD(MU_LAW, "Mu-Law"),
	FORMATD(A_LAW, "A-Law"),
	FORMATD(IMA_ADPCM, "Ima-ADPCM"),
	FORMATD(MPEG, "MPEG"),
	FORMATD(GSM, "GSM"),
	FORMATD(SPECIAL, "Special"),
};

char *snd_pcm_subformat_names[] = {
	SUBFORMAT(STD), 
};

char *snd_pcm_subformat_descriptions[] = {
	SUBFORMATD(STD, "Standard"), 
};

char *snd_pcm_start_mode_names[] = {
	START(EXPLICIT),
	START(DATA),
};

char *snd_pcm_ready_mode_names[] = {
	READY(FRAGMENT),
	READY(ASAP),
};

char *snd_pcm_xrun_mode_names[] = {
	XRUN(ASAP),
	XRUN(FRAGMENT),
	XRUN(NONE),
};

static char *onoff[] = {
	[0] = "OFF",
	[1] = "ON",
};

#define assoc(value, names) ({ \
	unsigned int __v = value; \
	assert(__v < sizeof(names) / sizeof(names[0])); \
	names[__v]; \
})


int snd_pcm_dump_hw_setup(snd_pcm_t *pcm, FILE *fp)
{
	assert(pcm);
	assert(fp);
	assert(pcm->setup);
        fprintf(fp, "stream       : %s\n", assoc(pcm->stream, snd_pcm_stream_names));
	fprintf(fp, "access       : %s\n", assoc(pcm->access, snd_pcm_access_names));
	fprintf(fp, "format       : %s\n", assoc(pcm->format, snd_pcm_format_names));
	fprintf(fp, "subformat    : %s\n", assoc(pcm->subformat, snd_pcm_subformat_names));
	fprintf(fp, "channels     : %d\n", pcm->channels);
	fprintf(fp, "rate         : %d\n", pcm->rate);
	fprintf(fp, "exact rate   : %g (%d/%d)\n", (double) pcm->rate_num / pcm->rate_den, pcm->rate_num, pcm->rate_den);
	fprintf(fp, "msbits       : %d\n", pcm->msbits);
	fprintf(fp, "fragment_size: %ld\n", (long)pcm->fragment_size);
	fprintf(fp, "fragments    : %d\n", pcm->fragments);
	return 0;
}

int snd_pcm_dump_sw_setup(snd_pcm_t *pcm, FILE *fp)
{
	assert(pcm);
	assert(fp);
	assert(pcm->setup);
	fprintf(fp, "start_mode   : %s\n", assoc(pcm->start_mode, snd_pcm_start_mode_names));
	fprintf(fp, "ready_mode   : %s\n", assoc(pcm->ready_mode, snd_pcm_ready_mode_names));
	fprintf(fp, "xrun_mode    : %s\n", assoc(pcm->xrun_mode, snd_pcm_xrun_mode_names));
	fprintf(fp, "avail_min    : %ld\n", (long)pcm->avail_min);
	fprintf(fp, "xfer_min     : %ld\n", (long)pcm->xfer_min);
	fprintf(fp, "xfer_align   : %ld\n", (long)pcm->xfer_align);
	fprintf(fp, "time         : %s\n", assoc(pcm->time, onoff));
	fprintf(fp, "boundary     : %ld\n", (long)pcm->boundary);
	return 0;
}

int snd_pcm_dump_setup(snd_pcm_t *pcm, FILE *fp)
{
	snd_pcm_dump_hw_setup(pcm, fp);
	snd_pcm_dump_sw_setup(pcm, fp);
	return 0;
}

int snd_pcm_dump_hw_params_fail(snd_pcm_hw_params_t *params, FILE *fp)
{
	int k;
	if (params->fail_mask == 0) {
		fprintf(fp, "unknown hw_params failure reason\n");
		return 0;
	}
	fprintf(fp, "hw_params failed on the following field value(s):\n");
	for (k = 0; k <= SND_PCM_HW_PARAM_LAST; ++k) {
		if (!(params->fail_mask & (1U << k)))
			continue;
		switch (k) {
		case SND_PCM_HW_PARAM_ACCESS:
			fprintf(fp, "access: %s\n", assoc(params->access, snd_pcm_access_names));
			break;
		case SND_PCM_HW_PARAM_FORMAT:
			fprintf(fp, "format: %s\n", assoc(params->format, snd_pcm_format_names));
			break;
		case SND_PCM_HW_PARAM_SUBFORMAT:
			fprintf(fp, "subformat: %s\n", assoc(params->subformat, snd_pcm_subformat_names));
			break;
		case SND_PCM_HW_PARAM_CHANNELS:
			fprintf(fp, "channels: %d\n", params->channels);
			break;
		case SND_PCM_HW_PARAM_RATE:
			fprintf(fp, "rate: %d\n", params->rate);
			break;
		case SND_PCM_HW_PARAM_FRAGMENT_SIZE:
			fprintf(fp, "fragment_size: %ld\n", (long)params->fragment_size);
			break;
		case SND_PCM_HW_PARAM_FRAGMENTS:
			fprintf(fp, "fragments: %d\n", params->fragments);
			break;
		default:
			assert(0);
			break;
		}
	}
	return 0;
}

int snd_pcm_dump_sw_params_fail(snd_pcm_sw_params_t *params, FILE *fp)
{
	int k;
	if (params->fail_mask == 0) {
		fprintf(fp, "unknown sw_params failure reason\n");
		return 0;
	}
	fprintf(fp, "sw_params failed on the following field value(s):\n");
	for (k = 0; k <= SND_PCM_SW_PARAM_LAST; ++k) {
		if (!(params->fail_mask & (1U << k)))
			continue;
		switch (k) {
		case SND_PCM_SW_PARAM_START_MODE:
			fprintf(fp, "start_mode: %s\n", assoc(params->start_mode, snd_pcm_start_mode_names));
			break;
		case SND_PCM_SW_PARAM_READY_MODE:
			fprintf(fp, "ready_mode: %s\n", assoc(params->ready_mode, snd_pcm_ready_mode_names));
			break;
		case SND_PCM_SW_PARAM_XRUN_MODE:
			fprintf(fp, "xrun_mode: %s\n", assoc(params->xrun_mode, snd_pcm_xrun_mode_names));
			break;
		case SND_PCM_SW_PARAM_AVAIL_MIN:
			fprintf(fp, "avail_min: %ld\n", (long)params->avail_min);
			break;
		case SND_PCM_SW_PARAM_XFER_MIN:
			fprintf(fp, "xfer_min: %ld\n", (long)params->xfer_min);
			break;
		case SND_PCM_SW_PARAM_XFER_ALIGN:
			fprintf(fp, "xfer_align: %ld\n", (long)params->xfer_align);
			break;
		case SND_PCM_SW_PARAM_TIME:
			fprintf(fp, "time: %d\n", params->time);
			break;
		default:
			assert(0);
			break;
		}
	}
	return 0;
}

int snd_pcm_dump_status(snd_pcm_status_t *status, FILE *fp)
{
	assert(status);
	fprintf(fp, "state       : %s\n", assoc(status->state, snd_pcm_state_names));
	fprintf(fp, "trigger_time: %ld.%06ld\n",
		status->trigger_time.tv_sec, status->trigger_time.tv_usec);
	fprintf(fp, "tstamp      : %ld.%06ld\n",
		status->tstamp.tv_sec, status->tstamp.tv_usec);
	fprintf(fp, "delay       : %ld\n", (long)status->delay);
	fprintf(fp, "avail       : %ld\n", (long)status->avail);
	fprintf(fp, "avail_max   : %ld\n", (long)status->avail_max);
	return 0;
}

int snd_pcm_dump(snd_pcm_t *pcm, FILE *fp)
{
	assert(pcm);
	assert(fp);
	pcm->ops->dump(pcm->op_arg, fp);
	return 0;
}

const char *snd_pcm_format_name(unsigned int format)
{
	assert(format <= SND_PCM_FORMAT_LAST);
	return snd_pcm_format_names[format];
}

const char *snd_pcm_format_description(unsigned int format)
{
	assert(format <= SND_PCM_FORMAT_LAST);
	return snd_pcm_format_descriptions[format];
}

int snd_pcm_format_value(const char* name)
{
	unsigned int format;
	for (format = 0; format <= SND_PCM_FORMAT_LAST; format++)
		if (snd_pcm_format_names[format] &&
		    strcasecmp(name, snd_pcm_format_names[format]) == 0)
			return format;
	return -1;
}

ssize_t snd_pcm_bytes_to_frames(snd_pcm_t *pcm, ssize_t bytes)
{
	assert(pcm);
	assert(pcm->setup);
	return bytes * 8 / pcm->bits_per_frame;
}

ssize_t snd_pcm_frames_to_bytes(snd_pcm_t *pcm, ssize_t frames)
{
	assert(pcm);
	assert(pcm->setup);
	return frames * pcm->bits_per_frame / 8;
}

ssize_t snd_pcm_bytes_to_samples(snd_pcm_t *pcm, ssize_t bytes)
{
	assert(pcm);
	assert(pcm->setup);
	return bytes * 8 / pcm->bits_per_sample;
}

ssize_t snd_pcm_samples_to_bytes(snd_pcm_t *pcm, ssize_t samples)
{
	assert(pcm);
	assert(pcm->setup);
	return samples * pcm->bits_per_sample / 8;
}

int snd_pcm_open(snd_pcm_t **pcmp, char *name, 
		 int stream, int mode)
{
	char *str;
	int err;
	snd_config_t *pcm_conf, *conf, *type_conf;
	snd_config_iterator_t i;
	char *lib = NULL, *open = NULL;
	int (*open_func)(snd_pcm_t **pcmp, char *name, snd_config_t *conf, 
			 int stream, int mode);
	void *h;
	assert(pcmp && name);
	err = snd_config_update();
	if (err < 0)
		return err;
	err = snd_config_searchv(snd_config, &pcm_conf, "pcm", name, 0);
	if (err < 0) {
		int card, dev, subdev;
		char socket[256], sname[256];
		char format[16], file[256];
		err = sscanf(name, "hw:%d,%d,%d", &card, &dev, &subdev);
		if (err == 3)
			return snd_pcm_hw_open(pcmp, name, card, dev, subdev, stream, mode);
		err = sscanf(name, "hw:%d,%d", &card, &dev);
		if (err == 2)
			return snd_pcm_hw_open(pcmp, name, card, dev, -1, stream, mode);
		err = sscanf(name, "plug:%d,%d,%d", &card, &dev, &subdev);
		if (err == 3)
			return snd_pcm_plug_open_hw(pcmp, name, card, dev, subdev, stream, mode);
		err = sscanf(name, "plug:%d,%d", &card, &dev);
		if (err == 2)
			return snd_pcm_plug_open_hw(pcmp, name, card, dev, -1, stream, mode);
		err = sscanf(name, "shm:%256s,%256s", socket, sname);
		if (err == 2)
			return snd_pcm_shm_open(pcmp, NULL, socket, sname, stream, mode);
		err = sscanf(name, "file:%256s,%16s", file, format);
		if (err == 2) {
			snd_pcm_t *slave;
			err = snd_pcm_null_open(&slave, NULL, stream, mode);
			if (err < 0)
				return err;
			return snd_pcm_file_open(pcmp, NULL, file, -1, format, slave, 1);
		}
		err = sscanf(name, "file:%256s", file);
		if (err == 1) {
			snd_pcm_t *slave;
			err = snd_pcm_null_open(&slave, NULL, stream, mode);
			if (err < 0)
				return err;
			return snd_pcm_file_open(pcmp, NULL, file, -1, "raw", slave, 1);
		}
		if (strcmp(name, "null") == 0)
			return snd_pcm_null_open(pcmp, NULL, stream, mode);
		ERR("Unknown PCM %s", name);
		return -ENOENT;
	}
	if (snd_config_type(pcm_conf) != SND_CONFIG_TYPE_COMPOUND) {
		ERR("Invalid type for PCM %s definition", name);
		return -EINVAL;
	}
	err = snd_config_search(pcm_conf, "stream", &conf);
	if (err >= 0) {
		err = snd_config_string_get(conf, &str);
		if (err < 0) {
			ERR("Invalid type for %s", conf->id);
			return err;
		}
		if (strcmp(str, "playback") == 0) {
			if (stream != SND_PCM_STREAM_PLAYBACK)
				return -EINVAL;
		} else if (strcmp(str, "capture") == 0) {
			if (stream != SND_PCM_STREAM_CAPTURE)
				return -EINVAL;
		} else {
			ERR("Invalid value for %s", conf->id);
			return -EINVAL;
		}
	}
	err = snd_config_search(pcm_conf, "type", &conf);
	if (err < 0) {
		ERR("type is not defined");
		return err;
	}
	err = snd_config_string_get(conf, &str);
	if (err < 0) {
		ERR("Invalid type for %s", conf->id);
		return err;
	}
	err = snd_config_searchv(snd_config, &type_conf, "pcmtype", str, 0);
	if (err < 0) {
		ERR("Unknown PCM type %s", str);
		return err;
	}
	snd_config_foreach(i, type_conf) {
		snd_config_t *n = snd_config_entry(i);
		if (strcmp(n->id, "comment") == 0)
			continue;
		if (strcmp(n->id, "lib") == 0) {
			err = snd_config_string_get(n, &lib);
			if (err < 0) {
				ERR("Invalid type for %s", n->id);
				return -EINVAL;
			}
			continue;
		}
		if (strcmp(n->id, "open") == 0) {
			err = snd_config_string_get(n, &open);
			if (err < 0) {
				ERR("Invalid type for %s", n->id);
				return -EINVAL;
			}
			continue;
			ERR("Unknown field %s", n->id);
			return -EINVAL;
		}
	}
	if (!open) {
		ERR("open is not defined");
		return -EINVAL;
	}
	if (!lib)
		lib = "libasound.so";
	h = dlopen(lib, RTLD_NOW);
	if (!h) {
		ERR("Cannot open shared library %s", lib);
		return -ENOENT;
	}
	open_func = dlsym(h, open);
	dlclose(h);
	if (!open_func) {
		ERR("symbol %s is not defined inside %s", open, lib);
		return -ENXIO;
	}
	return open_func(pcmp, name, pcm_conf, stream, mode);
}

void snd_pcm_areas_from_buf(snd_pcm_t *pcm, snd_pcm_channel_area_t *areas, 
			    void *buf)
{
	unsigned int channel;
	unsigned int channels = pcm->channels;
	for (channel = 0; channel < channels; ++channel, ++areas) {
		areas->addr = buf;
		areas->first = channel * pcm->bits_per_sample;
		areas->step = pcm->bits_per_frame;
	}
}

void snd_pcm_areas_from_bufs(snd_pcm_t *pcm, snd_pcm_channel_area_t *areas, 
			     void **bufs)
{
	unsigned int channel;
	unsigned int channels = pcm->channels;
	for (channel = 0; channel < channels; ++channel, ++areas, ++bufs) {
		areas->addr = *bufs;
		areas->first = 0;
		areas->step = pcm->bits_per_sample;
	}
}

int snd_pcm_wait(snd_pcm_t *pcm, int timeout)
{
	struct pollfd pfd;
	int err;
	pfd.fd = snd_pcm_poll_descriptor(pcm);
	pfd.events = pcm->stream == SND_PCM_STREAM_PLAYBACK ? POLLOUT : POLLIN;
	err = poll(&pfd, 1, timeout);
	if (err < 0)
		return err;
	return 0;
}

ssize_t snd_pcm_avail_update(snd_pcm_t *pcm)
{
	return pcm->fast_ops->avail_update(pcm->fast_op_arg);
}

ssize_t snd_pcm_mmap_forward(snd_pcm_t *pcm, size_t size)
{
	assert(size > 0);
	assert(size <= snd_pcm_mmap_avail(pcm));
	return pcm->fast_ops->mmap_forward(pcm->fast_op_arg, size);
}

int snd_pcm_area_silence(const snd_pcm_channel_area_t *dst_area, size_t dst_offset,
			 size_t samples, int format)
{
	/* FIXME: sub byte resolution and odd dst_offset */
	char *dst;
	unsigned int dst_step;
	int width;
	u_int64_t silence;
	if (!dst_area->addr)
		return 0;
	dst = snd_pcm_channel_area_addr(dst_area, dst_offset);
	width = snd_pcm_format_physical_width(format);
	silence = snd_pcm_format_silence_64(format);
	if (dst_area->step == (unsigned int) width) {
		size_t dwords = samples * width / 64;
		samples -= dwords * 64 / width;
		while (dwords-- > 0)
			*((u_int64_t*)dst)++ = silence;
		if (samples == 0)
			return 0;
	}
	dst_step = dst_area->step / 8;
	switch (width) {
	case 4: {
		u_int8_t s0 = silence & 0xf0;
		u_int8_t s1 = silence & 0x0f;
		int dstbit = dst_area->first % 8;
		int dstbit_step = dst_area->step % 8;
		while (samples-- > 0) {
			if (dstbit) {
				*dst &= 0xf0;
				*dst |= s1;
			} else {
				*dst &= 0x0f;
				*dst |= s0;
			}
			dst += dst_step;
			dstbit += dstbit_step;
			if (dstbit == 8) {
				dst++;
				dstbit = 0;
			}
		}
		break;
	}
	case 8: {
		u_int8_t sil = silence;
		while (samples-- > 0) {
			*dst = sil;
			dst += dst_step;
		}
		break;
	}
	case 16: {
		u_int16_t sil = silence;
		while (samples-- > 0) {
			*(u_int16_t*)dst = sil;
			dst += dst_step;
		}
		break;
	}
	case 32: {
		u_int32_t sil = silence;
		while (samples-- > 0) {
			*(u_int32_t*)dst = sil;
			dst += dst_step;
		}
		break;
	}
	case 64: {
		while (samples-- > 0) {
			*(u_int64_t*)dst = silence;
			dst += dst_step;
		}
		break;
	}
	default:
		assert(0);
	}
	return 0;
}

int snd_pcm_areas_silence(const snd_pcm_channel_area_t *dst_areas, size_t dst_offset,
			  size_t channels, size_t frames, int format)
{
	int width = snd_pcm_format_physical_width(format);
	while (channels > 0) {
		void *addr = dst_areas->addr;
		unsigned int step = dst_areas->step;
		const snd_pcm_channel_area_t *begin = dst_areas;
		int channels1 = channels;
		unsigned int chns = 0;
		int err;
		while (1) {
			channels1--;
			chns++;
			dst_areas++;
			if (channels1 == 0 ||
			    dst_areas->addr != addr ||
			    dst_areas->step != step ||
			    dst_areas->first != dst_areas[-1].first + width)
				break;
		}
		if (chns > 1 && chns * width == step) {
			/* Collapse the areas */
			snd_pcm_channel_area_t d;
			d.addr = begin->addr;
			d.first = begin->first;
			d.step = width;
			err = snd_pcm_area_silence(&d, dst_offset * chns, frames * chns, format);
			channels -= chns;
		} else {
			err = snd_pcm_area_silence(begin, dst_offset, frames, format);
			dst_areas = begin + 1;
			channels--;
		}
		if (err < 0)
			return err;
	}
	return 0;
}


int snd_pcm_area_copy(const snd_pcm_channel_area_t *src_area, size_t src_offset,
		      const snd_pcm_channel_area_t *dst_area, size_t dst_offset,
		      size_t samples, int format)
{
	/* FIXME: sub byte resolution and odd dst_offset */
	char *src, *dst;
	int width;
	int src_step, dst_step;
	if (!src_area->addr)
		return snd_pcm_area_silence(dst_area, dst_offset, samples, format);
	src = snd_pcm_channel_area_addr(src_area, src_offset);
	if (!dst_area->addr)
		return 0;
	dst = snd_pcm_channel_area_addr(dst_area, dst_offset);
	width = snd_pcm_format_physical_width(format);
	if (src_area->step == (unsigned int) width &&
	    dst_area->step == (unsigned int) width) {
		size_t bytes = samples * width / 8;
		samples -= bytes * 8 / width;
		memcpy(dst, src, bytes);
		if (samples == 0)
			return 0;
	}
	src_step = src_area->step / 8;
	dst_step = dst_area->step / 8;
	switch (width) {
	case 4: {
		int srcbit = src_area->first % 8;
		int srcbit_step = src_area->step % 8;
		int dstbit = dst_area->first % 8;
		int dstbit_step = dst_area->step % 8;
		while (samples-- > 0) {
			unsigned char srcval;
			if (srcbit)
				srcval = *src & 0x0f;
			else
				srcval = *src & 0xf0;
			if (dstbit)
				*dst &= 0xf0;
			else
				*dst &= 0x0f;
			*dst |= srcval;
			src += src_step;
			srcbit += srcbit_step;
			if (srcbit == 8) {
				src++;
				srcbit = 0;
			}
			dst += dst_step;
			dstbit += dstbit_step;
			if (dstbit == 8) {
				dst++;
				dstbit = 0;
			}
		}
		break;
	}
	case 8: {
		while (samples-- > 0) {
			*dst = *src;
			src += src_step;
			dst += dst_step;
		}
		break;
	}
	case 16: {
		while (samples-- > 0) {
			*(u_int16_t*)dst = *(u_int16_t*)src;
			src += src_step;
			dst += dst_step;
		}
		break;
	}
	case 32: {
		while (samples-- > 0) {
			*(u_int32_t*)dst = *(u_int32_t*)src;
			src += src_step;
			dst += dst_step;
		}
		break;
	}
	case 64: {
		while (samples-- > 0) {
			*(u_int64_t*)dst = *(u_int64_t*)src;
			src += src_step;
			dst += dst_step;
		}
		break;
	}
	default:
		assert(0);
	}
	return 0;
}

int snd_pcm_areas_copy(const snd_pcm_channel_area_t *src_areas, size_t src_offset,
		       const snd_pcm_channel_area_t *dst_areas, size_t dst_offset,
		       size_t channels, size_t frames, int format)
{
	int width = snd_pcm_format_physical_width(format);
	while (channels > 0) {
		unsigned int step = src_areas->step;
		void *src_addr = src_areas->addr;
		const snd_pcm_channel_area_t *src_start = src_areas;
		void *dst_addr = dst_areas->addr;
		const snd_pcm_channel_area_t *dst_start = dst_areas;
		int channels1 = channels;
		unsigned int chns = 0;
		while (dst_areas->step == step) {
			channels1--;
			chns++;
			src_areas++;
			dst_areas++;
			if (channels1 == 0 ||
			    src_areas->step != step ||
			    src_areas->addr != src_addr ||
			    dst_areas->addr != dst_addr ||
			    src_areas->first != src_areas[-1].first + width ||
			    dst_areas->first != dst_areas[-1].first + width)
				break;
		}
		if (chns > 1 && chns * width == step) {
			/* Collapse the areas */
			snd_pcm_channel_area_t s, d;
			s.addr = src_start->addr;
			s.first = src_start->first;
			s.step = width;
			d.addr = dst_start->addr;
			d.first = dst_start->first;
			d.step = width;
			snd_pcm_area_copy(&s, src_offset * chns, &d, dst_offset * chns, frames * chns, format);
			channels -= chns;
		} else {
			snd_pcm_area_copy(src_start, src_offset, dst_start, dst_offset, frames, format);
			src_areas = src_start + 1;
			dst_areas = dst_start + 1;
			channels--;
		}
	}
	return 0;
}

ssize_t snd_pcm_read_areas(snd_pcm_t *pcm, const snd_pcm_channel_area_t *areas,
			   size_t offset, size_t size,
			   snd_pcm_xfer_areas_func_t func)
{
	size_t xfer = 0;
	ssize_t err = 0;
	int state = snd_pcm_state(pcm);
	assert(size > 0);
	assert(state >= SND_PCM_STATE_PREPARED);
	if (state == SND_PCM_STATE_PREPARED &&
	    pcm->start_mode != SND_PCM_START_EXPLICIT) {
		err = snd_pcm_start(pcm);
		if (err < 0)
			return err;
		state = SND_PCM_STATE_RUNNING;
	}
	while (xfer < size) {
		ssize_t avail;
		size_t frames;
	again:
		avail = snd_pcm_avail_update(pcm);
		if (avail < 0) {
			err = avail;
			break;
		}
		if ((size_t)avail < pcm->avail_min) {
			if (state != SND_PCM_STATE_RUNNING) {
				err = -EPIPE;
				break;
			}
			if (pcm->mode & SND_PCM_NONBLOCK) {
				err = -EAGAIN;
				break;
			}
			err = snd_pcm_wait(pcm, -1);
			if (err < 0)
				break;
			state = snd_pcm_state(pcm);
			goto again;
		}
		frames = size - xfer;
		if (frames > (size_t)avail)
			frames = avail;
		err = func(pcm, areas, offset, frames, 0);
		if (err < 0)
			break;
		assert((size_t)err == frames);
		xfer += err;
		offset += err;
	}
	if (xfer > 0)
		return xfer;
	return err;
}

ssize_t snd_pcm_write_areas(snd_pcm_t *pcm, const snd_pcm_channel_area_t *areas,
			    size_t offset, size_t size,
			    snd_pcm_xfer_areas_func_t func)
{
	size_t xfer = 0;
	ssize_t err = 0;
	int state = snd_pcm_state(pcm);
	assert(size > 0);
	assert(state >= SND_PCM_STATE_PREPARED);
	while (xfer < size) {
		ssize_t avail;
		size_t frames;
	again:
		if (state == SND_PCM_STATE_XRUN) {
			err = -EPIPE;
			break;
		}
		avail = snd_pcm_avail_update(pcm);
		if (avail < 0) {
			err = avail;
			break;
		}
		if ((size_t)avail < pcm->avail_min) {
			if (state != SND_PCM_STATE_RUNNING) {
				err = -EPIPE;
				break;
			}
			if (pcm->mode & SND_PCM_NONBLOCK) {
				err = -EAGAIN;
				break;
			}
			err = snd_pcm_wait(pcm, -1);
			if (err < 0)
				break;
			state = snd_pcm_state(pcm);
			goto again;
		}
		frames = size - xfer;
		if (frames > (size_t)avail)
			frames = avail;
		err = func(pcm, areas, offset, frames, 0);
		if (err < 0)
			break;
		assert((size_t)err == frames);
		xfer += err;
		offset += err;
		if (state == SND_PCM_STATE_PREPARED &&
		    pcm->start_mode != SND_PCM_START_EXPLICIT) {
			err = snd_pcm_start(pcm);
			if (err < 0)
				break;
			state = SND_PCM_STATE_RUNNING;
		}
	}
	if (xfer > 0)
		return xfer;
	return err;
}

#if 0
int snd_pcm_alloc_user_mmap(snd_pcm_t *pcm, snd_pcm_mmap_info_t *i)
{
	i->type = SND_PCM_MMAP_USER;
	i->size = snd_pcm_frames_to_bytes(pcm, pcm->buffer_size);
	i->u.user.shmid = shmget(IPC_PRIVATE, i->size, 0666);
	if (i->u.user.shmid < 0) {
		SYSERR("shmget failed");
		return -errno;
	}
	i->addr = shmat(i->u.user.shmid, 0, 0);
	if (i->addr == (void*) -1) {
		SYSERR("shmat failed");
		return -errno;
	}
	return 0;
}

int snd_pcm_alloc_kernel_mmap(snd_pcm_t *pcm, snd_pcm_mmap_info_t *i, int fd)
{
	i->type = SND_PCM_MMAP_KERNEL;
	/* FIXME */
	i->size = PAGE_ALIGN(snd_pcm_frames_to_bytes(pcm, pcm->buffer_size));
	i->addr = mmap(NULL, i->size,
		       PROT_WRITE | PROT_READ,
		       MAP_FILE|MAP_SHARED, 
		       fd, SND_PCM_MMAP_OFFSET_DATA);
	if (i->addr == MAP_FAILED ||
	    i->addr == NULL) {
		SYSERR("data mmap failed");
		return -errno;
	}
	i->u.kernel.fd = fd;
	return 0;
}

int snd_pcm_free_mmap(snd_pcm_t *pcm, snd_pcm_mmap_info_t *i)
{
	if (i->type == SND_PCM_MMAP_USER) {
		if (shmdt(i->addr) < 0) {
			SYSERR("shmdt failed");
			return -errno;
		}
		if (shmctl(i->u.user.shmid, IPC_RMID, 0) < 0) {
			SYSERR("shmctl IPC_RMID failed");
			return -errno;
		}
	} else {
		if (munmap(pcm->mmap_info->addr, pcm->mmap_info->size) < 0) {
			SYSERR("data munmap failed");
			return -errno;
		}
	}
	return 0;
}
#endif

int snd_pcm_hw_info_bits_per_sample(snd_pcm_hw_info_t *info,
				    unsigned int *min, unsigned int *max)
{
	int k;
	unsigned int bits_min = UINT_MAX, bits_max = 0;
	int changed = 0;
	for (k = 0; k <= SND_PCM_FORMAT_LAST; ++k) {
		int bits;
		if (!(info->format_mask & (1U << k)))
			continue;
		bits = snd_pcm_format_physical_width(k);
		assert(bits > 0);
		if ((unsigned) bits < *min || (unsigned)bits > *max) {
			info->format_mask &= ~(1U << k);
			changed++;
			continue;
		}
		if ((unsigned)bits < bits_min)
			bits_min = bits;
		if ((unsigned)bits > bits_max)
			bits_max = bits;
	}
	*min = bits_min;
	*max = bits_max;
	if (info->format_mask == 0)
		return -EINVAL;
	return changed;
}


int snd_pcm_hw_info_complete(snd_pcm_hw_info_t *info)
{
	if (info->msbits == 0) {
		unsigned int bits_min = 0, bits_max = UINT_MAX;
		snd_pcm_hw_info_bits_per_sample(info, &bits_min, &bits_max);
		if (bits_min == bits_max)
			info->msbits = bits_min;
	}
	if (info->rate_den == 0 &&
	    info->rate_min == info->rate_max) {
		info->rate_num = info->rate_min;
		info->rate_den = 1;
	}
	return 0;
}

int snd_pcm_hw_params_info(snd_pcm_t *pcm, snd_pcm_hw_params_t *params,
			   snd_pcm_hw_info_t *info)
{
	int err = snd_pcm_hw_info_to_params(pcm, info, params);
	assert(err >= 0);
	return snd_pcm_hw_params(pcm, params);
}

struct _snd_pcm_strategy {
	unsigned int badness_min, badness_max;
	int (*choose_param)(const snd_pcm_hw_info_t *info,
			    snd_pcm_t *pcm,
			    const snd_pcm_strategy_t *strategy);
	int (*next_value)(const snd_pcm_hw_info_t *info,
			   unsigned int param,
			   int value,
			   snd_pcm_t *pcm,
			   const snd_pcm_strategy_t *strategy);
	int (*min_badness)(const snd_pcm_hw_info_t *info,
			   unsigned int max_badness,
			   snd_pcm_t *pcm,
			   const snd_pcm_strategy_t *strategy);
	void *private;
	void (*free)(snd_pcm_strategy_t *strategy);
};

/* Independent badness */
typedef struct _snd_pcm_strategy_simple snd_pcm_strategy_simple_t;

struct _snd_pcm_strategy_simple {
	int valid;
	unsigned int order;
	int (*next_value)(const snd_pcm_hw_info_t *info,
			   unsigned int param,
			   int value,
			   snd_pcm_t *pcm,
			   const snd_pcm_strategy_simple_t *par);
	unsigned int (*min_badness)(const snd_pcm_hw_info_t *info,
				    unsigned int param,
				    snd_pcm_t *pcm,
				    const snd_pcm_strategy_simple_t *par);
	void *private;
	void (*free)(snd_pcm_strategy_simple_t *strategy);
};

typedef struct _snd_pcm_strategy_simple_near {
	int best;
	unsigned int mul;
} snd_pcm_strategy_simple_near_t;

typedef struct _snd_pcm_strategy_simple_choices {
	unsigned int count;
	/* choices need to be sorted on ascending badness */
	snd_pcm_strategy_simple_choices_list_t *choices;
} snd_pcm_strategy_simple_choices_t;

static inline unsigned int hweight32(u_int32_t v)
{
        v = (v & 0x55555555) + ((v >> 1) & 0x55555555);
        v = (v & 0x33333333) + ((v >> 2) & 0x33333333);
        v = (v & 0x0F0F0F0F) + ((v >> 4) & 0x0F0F0F0F);
        v = (v & 0x00FF00FF) + ((v >> 8) & 0x00FF00FF);
        return (v & 0x0000FFFF) + ((v >> 16) & 0x0000FFFF);
}

static inline unsigned int ld2(u_int32_t v)
{
        unsigned r = 0;

        if (v >= 0x10000) {
                v >>= 16;
                r += 16;
        }
        if (v >= 0x100) {
                v >>= 8;
                r += 8;
        }
        if (v >= 0x10) {
                v >>= 4;
                r += 4;
        }
        if (v >= 4) {
                v >>= 2;
                r += 2;
        }
        if (v >= 2)
                r++;
        return r;
}

typedef struct {
	enum { MASK, MINMAX } type;
	char **names;
	unsigned int last;
} par_desc_t;

par_desc_t hw_infos[SND_PCM_HW_INFO_LAST + 1] = {
	[SND_PCM_HW_INFO_ACCESS] = {
		type: MASK,
		names: snd_pcm_access_names,
		last: SND_PCM_ACCESS_LAST,
	},
	[SND_PCM_HW_INFO_FORMAT] = {
		type: MASK,
		names: snd_pcm_format_names,
		last: SND_PCM_FORMAT_LAST,
	},
	[SND_PCM_HW_INFO_SUBFORMAT] = {
		type: MASK,
		names: snd_pcm_subformat_names,
		last: SND_PCM_SUBFORMAT_LAST,
	},
	[SND_PCM_HW_INFO_CHANNELS] = {
		type: MINMAX,
		names: 0,
		last: 0,
	},
	[SND_PCM_HW_INFO_RATE] = {
		type: MINMAX,
		names: 0,
		last: 0,
	},
	[SND_PCM_HW_INFO_FRAGMENT_LENGTH] = {
		type: MINMAX,
		names: 0,
		last: 0,
	},
	[SND_PCM_HW_INFO_FRAGMENTS] = {
		type: MINMAX,
		names: 0,
		last: 0,
	},
	[SND_PCM_HW_INFO_BUFFER_LENGTH] = {
		type: MINMAX,
		names: 0,
		last: 0,
	},
};

unsigned int snd_pcm_hw_info_par_get_mask(const snd_pcm_hw_info_t *info,
					  unsigned int param)
{
	switch (param) {
	case SND_PCM_HW_INFO_ACCESS:
		return info->access_mask;
	case SND_PCM_HW_INFO_FORMAT:
		return info->format_mask;
	case SND_PCM_HW_INFO_SUBFORMAT:
		return info->subformat_mask;
	default:
		assert(0);
		return 0;
	}
}
	
void snd_pcm_hw_info_par_get_minmax(const snd_pcm_hw_info_t *info,
				    unsigned int param,
				    unsigned int *min, unsigned int *max)
{
	switch (param) {
	case SND_PCM_HW_INFO_ACCESS:
	case SND_PCM_HW_INFO_FORMAT:
	case SND_PCM_HW_INFO_SUBFORMAT:
	{
		unsigned int mask = snd_pcm_hw_info_par_get_mask(info, param);
		if (!mask) {
			*min = 32;
			*max = 0;
		} else {
			*min = ffs(mask) - 1;
			*max = ld2(mask);
		}
		break;
	}
	case SND_PCM_HW_INFO_CHANNELS:
		*min = info->channels_min;
		*max = info->channels_max;
		break;
	case SND_PCM_HW_INFO_RATE:
		*min = info->rate_min;
		*max = info->rate_max;
		break;
	case SND_PCM_HW_INFO_FRAGMENT_LENGTH:
		*min = info->fragment_length_min;
		*max = info->fragment_length_max;
		break;
	case SND_PCM_HW_INFO_FRAGMENTS:
		*min = info->fragments_min;
		*max = info->fragments_max;
		break;
	case SND_PCM_HW_INFO_BUFFER_LENGTH:
		*min = info->buffer_length_min;
		*max = info->buffer_length_max;
		break;
	default:
		assert(0);
	}
}

void snd_pcm_hw_info_par_set_mask(snd_pcm_hw_info_t *info, unsigned int param,
				  unsigned int v)
{
	switch (param) {
	case SND_PCM_HW_INFO_ACCESS:
		info->access_mask = v;
		break;
	case SND_PCM_HW_INFO_FORMAT:
		info->format_mask = v;
		break;
	case SND_PCM_HW_INFO_SUBFORMAT:
		info->subformat_mask = v;
		break;
	default:
		assert(0);
	}
}

void snd_pcm_hw_info_par_set_minmax(snd_pcm_hw_info_t *info,
				    unsigned int param,
				    unsigned int min, unsigned int max)
{
	switch (param) {
	case SND_PCM_HW_INFO_ACCESS:
	case SND_PCM_HW_INFO_FORMAT:
	case SND_PCM_HW_INFO_SUBFORMAT:
	{
		unsigned int mask;
		if (min >= 32 || max <= 0 || min > max) {
			snd_pcm_hw_info_par_set_mask(info, param, 0);
			break;
		}
		if (max >= 31) {
			max = 31;
			if (min <= 0)
				break;
		}
		mask = snd_pcm_hw_info_par_get_mask(info, param);
		mask &= ((1U << (max - min + 1)) - 1) << min;
		snd_pcm_hw_info_par_set_mask(info, param, mask);
		break;
	}
	case SND_PCM_HW_INFO_CHANNELS:
		info->channels_min = min;
		info->channels_max = max;
		break;
	case SND_PCM_HW_INFO_RATE:
		info->rate_min = min;
		info->rate_max = max;
		break;
	case SND_PCM_HW_INFO_FRAGMENT_LENGTH:
		info->fragment_length_min = min;
		info->fragment_length_max = max;
		break;
	case SND_PCM_HW_INFO_FRAGMENTS:
		info->fragments_min = min;
		info->fragments_max = max;
		break;
	case SND_PCM_HW_INFO_BUFFER_LENGTH:
		info->buffer_length_min = min;
		info->buffer_length_max = max;
		break;
	default:
		assert(0);
	}
}

void snd_pcm_hw_info_par_copy(snd_pcm_hw_info_t *info, unsigned int param,
			      snd_pcm_hw_info_t *src)
{
	switch (param) {
	case SND_PCM_HW_INFO_ACCESS:
		info->access_mask = src->access_mask;
		break;
	case SND_PCM_HW_INFO_FORMAT:
		info->format_mask = src->format_mask;
		break;
	case SND_PCM_HW_INFO_SUBFORMAT:
		info->subformat_mask = src->subformat_mask;
		break;
	case SND_PCM_HW_INFO_CHANNELS:
		info->channels_min = src->channels_min;
		info->channels_max = src->channels_max;
		break;
	case SND_PCM_HW_INFO_RATE:
		info->rate_min = src->rate_min;
		info->rate_max = src->rate_max;
		break;
	case SND_PCM_HW_INFO_FRAGMENT_LENGTH:
		info->fragment_length_min = src->fragment_length_min;
		info->fragment_length_max = src->fragment_length_max;
		break;
	case SND_PCM_HW_INFO_FRAGMENTS:
		info->fragments_min = src->fragments_min;
		info->fragments_max = src->fragments_max;
		break;
	case SND_PCM_HW_INFO_BUFFER_LENGTH:
		info->buffer_length_min = src->buffer_length_min;
		info->buffer_length_max = src->buffer_length_max;
		break;
	default:
		assert(0);
		break;
	}
}

unsigned int snd_pcm_hw_info_par_choices(const snd_pcm_hw_info_t *info,
					  unsigned int param)
{
	par_desc_t *p;
	assert(param <= SND_PCM_HW_INFO_LAST);
	p = &hw_infos[param];
	switch (p->type) {
	case MASK:
		return hweight32(snd_pcm_hw_info_par_get_mask(info, param));
	case MINMAX:
	{
		unsigned int min, max;
		snd_pcm_hw_info_par_get_minmax(info, param, &min, &max);
		return max - min + 1;
	}
	default:
		assert(0);
		return 0;
	}
}

unsigned int snd_pcm_hw_info_par_refine_min(snd_pcm_hw_info_t *info,
					     unsigned int param,
					     unsigned int value)
{
	unsigned int min, max;
	snd_pcm_hw_info_par_get_minmax(info, param, &min, &max);
	if (min < value) {
		min = value;
		snd_pcm_hw_info_par_set_minmax(info, param, min, max);
	}
	return min;
}

unsigned int snd_pcm_hw_info_par_refine_max(snd_pcm_hw_info_t *info,
					     unsigned int param,
					     unsigned int value)
{
	unsigned int min, max;
	snd_pcm_hw_info_par_get_minmax(info, param, &min, &max);
	if (max > value) {
		max = value;
		snd_pcm_hw_info_par_set_minmax(info, param, min, max);
	}
	return max;
}

int snd_pcm_hw_info_par_check(const snd_pcm_hw_info_t *info, 
			      unsigned int param,
			      unsigned int value)
{
	par_desc_t *p;
	assert(param <= SND_PCM_HW_INFO_LAST);
	p = &hw_infos[param];
	switch (p->type) {
	case MASK:
		return snd_pcm_hw_info_par_get_mask(info, param) & (1 << value);
	case MINMAX:
	{
		unsigned int min, max;
		snd_pcm_hw_info_par_get_minmax(info, param, &min, &max);
		return value >= min && value <= max;
	}
	default:
		assert(0);
		return 0;
	}
}

int snd_pcm_hw_info_par_nearest_next(const snd_pcm_hw_info_t *info,
				      unsigned int param,
				      unsigned int best, int value,
				      snd_pcm_t *pcm)
{
	unsigned int min, max;
	unsigned int max1, min2;
	snd_pcm_hw_info_t i1, i2;
	int err1 = -EINVAL;
	int err2 = -EINVAL;
	
	snd_pcm_hw_info_par_get_minmax(info, param, &min, &max);
	i1 = *info;
	i2 = *info;
	if (value < 0) {
		max1 = best;
		min2 = best + 1;
	} else {
		int diff = value - best;
		if (diff < 0) {
			if (value > 1)
				max1 = value - 1;
			else
				max1 = 0;
			min2 = best - diff;
		} else {
			if (best > (unsigned int) diff)
				max1 = best - diff - 1;
			else
				max1 = 0;
			min2 = value + 1;
		}
	}
	max1 = snd_pcm_hw_info_par_refine_max(&i1, param, max1);
	min2 = snd_pcm_hw_info_par_refine_min(&i2, param, min2);
	if (min <= max1) {
		err1 = snd_pcm_hw_info(pcm, &i1);
		if (err1 >= 0)
			max1 = snd_pcm_hw_info_par_refine_max(&i1, param, max1);
	}
	if (min2 <= max && (err1 < 0 || best - max1 > min2 - best)) {
		err2 = snd_pcm_hw_info(pcm, &i2);
		if (err2 >= 0)
			min2 = snd_pcm_hw_info_par_refine_min(&i2, param, min2);
	}
	if (err1 < 0) {
		if (err2 < 0)
			return -1;
		return min2;
	} else if (err2 < 0)
		return max1;
	if (best - max1 <= min2 - best)
		return max1;
	return min2;
}

void snd_pcm_hw_info_par_dump(snd_pcm_hw_info_t *info, unsigned int param, FILE *fp)
{
	par_desc_t *p;
	assert(param <= SND_PCM_HW_INFO_LAST);
	p = &hw_infos[param];
	switch (p->type) {
	case MASK:
	{
		unsigned int mask = snd_pcm_hw_info_par_get_mask(info, param);
		if (mask == ~0U)
			fputs(" ALL", fp);
		else if (mask) {
			unsigned int k;
			for (k = 0; k <= p->last; ++k)
				if (mask & (1U << k)) {
					putc(' ', fp);
					fputs(p->names[k], fp);
				}
		} else
			fputs(" NONE", fp);
		break;
	}
	case MINMAX:
	{
		unsigned int min, max;
		snd_pcm_hw_info_par_get_minmax(info, param, &min, &max);
		printf("%d - %d", min, max);
		break;
	}
	default:
		assert(0);
		break;
	}
}

int snd_pcm_hw_info_par_empty(snd_pcm_hw_info_t *info, unsigned int param)
{
	par_desc_t *p;
	assert(param <= SND_PCM_HW_INFO_LAST);
	p = &hw_infos[param];
	switch (p->type) {
	case MASK:
		return !snd_pcm_hw_info_par_get_mask(info, param);
	case MINMAX:
	{
		unsigned int min, max;
		snd_pcm_hw_info_par_get_minmax(info, param, &min, &max);
		return min > max;
	}
	default:
		assert(0);
		return 0;;
	}
}

unsigned int snd_pcm_hw_info_fail_mask(snd_pcm_hw_info_t *info)
{
	unsigned int k, mask = 0;
	for (k = 0; k <= SND_PCM_HW_INFO_LAST; ++k) {
		if (snd_pcm_hw_info_par_empty(info, k))
			mask |= 1 << k;
	}
	return mask;
}

int _snd_pcm_hw_params(snd_pcm_t *pcm, snd_pcm_hw_params_t *params)
{
	int err;
	snd_pcm_hw_info_t info;

	snd_pcm_hw_params_to_info(params, &info);
	err = snd_pcm_hw_info(pcm, &info);
	if (err < 0) {
		params->fail_mask = snd_pcm_hw_info_fail_mask(&info);
		return err;
	}
	params->fail_mask = 0;
	
	if ((err = pcm->ops->hw_params(pcm->op_arg, params)) < 0)
		return err;
	pcm->setup = 1;
	pcm->access = params->access;
	pcm->format = params->format;
	pcm->subformat = params->subformat;
	pcm->rate = params->rate;
	pcm->channels = params->channels;
	pcm->fragment_size = params->fragment_size;
	pcm->fragments = params->fragments;
	pcm->bits_per_sample = snd_pcm_format_physical_width(params->format);
        pcm->bits_per_frame = pcm->bits_per_sample * params->channels;
	pcm->buffer_size = params->fragment_size * params->fragments;

	pcm->info = info.info;
	pcm->msbits = info.msbits;
	pcm->rate_num = info.rate_num;
	pcm->rate_den = info.rate_den;
	pcm->fifo_size = info.fifo_size;

	/* Default sw params */
	pcm->start_mode = SND_PCM_START_DATA;
	pcm->ready_mode = SND_PCM_READY_FRAGMENT;
	pcm->xrun_mode = SND_PCM_XRUN_FRAGMENT;
	pcm->avail_min = pcm->fragment_size;
	pcm->xfer_min = pcm->fragment_size;
	pcm->xfer_align = pcm->fragment_size;
	pcm->time = 0;
	pcm->boundary = LONG_MAX - pcm->buffer_size * 2 - LONG_MAX % pcm->buffer_size;
	return 0;
}

int snd_pcm_hw_params(snd_pcm_t *pcm, snd_pcm_hw_params_t *params)
{
	int err;
	assert(pcm && params);
	if (pcm->setup && pcm->mmap_channels && 
	    (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_munmap(pcm);
		if (err < 0)
			return err;
	}
	err = _snd_pcm_hw_params(pcm, params);
	if (pcm->setup &&
	    (pcm->mmap_rw || 
	     (pcm->access == SND_PCM_ACCESS_MMAP_INTERLEAVED ||
	      pcm->access == SND_PCM_ACCESS_MMAP_NONINTERLEAVED ||
	      pcm->access == SND_PCM_ACCESS_MMAP_COMPLEX))) {
		int err;
		err = snd_pcm_mmap(pcm);
		if (err < 0)
			return err;
	}
	return err;
}

int snd_pcm_hw_info_strategy1(snd_pcm_t *pcm, snd_pcm_hw_info_t *info,
			      const snd_pcm_strategy_t *strategy,
			      unsigned int badness_min, unsigned int badness_max)
{
	snd_pcm_hw_info_t best_info;
	int param;
	int value;
	unsigned int best_badness;
	unsigned int mask = ~0;
	int badness = strategy->min_badness(info, badness_max, pcm, strategy);
	snd_pcm_hw_info_t info1;
#if 0
	printf("\nBadness: %d\n", badness);
	snd_pcm_dump_hw_info(info, stdout);
#endif
	if (badness < 0)
		return badness;
	if ((unsigned int)badness > badness_min)
		badness_min = badness_min;
	param = strategy->choose_param(info, pcm, strategy);
	if (param < 0)
		return badness;
	best_badness = UINT_MAX;
	value = -1;
	while (1) {
		int err;
		value = strategy->next_value(info, param, value, pcm, strategy);
		if (value < 0)
			break;
		info1 = *info;
		snd_pcm_hw_info_par_set_minmax(&info1, param, value, value);
		err = snd_pcm_hw_info(pcm, &info1);
		if (err >= 0) {
			badness = snd_pcm_hw_info_strategy1(pcm, &info1, strategy, badness_min, badness_max);
			if (badness >= 0) {
				
				if ((unsigned int) badness <= badness_min) {
					*info = info1;
					return badness;
				}
				best_badness = badness;
				best_info = info1;
				badness_max = badness - 1;
				continue;
			}
			if (badness != -EINVAL)
				continue;
		}
		mask &= snd_pcm_hw_info_fail_mask(&info1);
	}
	if (best_badness == UINT_MAX) {
		for (param = 0; param <= SND_PCM_HW_INFO_LAST; param++) {
			if (!(mask & (1 << param)))
				continue;
			snd_pcm_hw_info_par_copy(info, param, &info1);
		}
		return -EINVAL;
	}
	*info = best_info;
	return best_badness;
}

int snd_pcm_hw_info_strategy(snd_pcm_t *pcm, snd_pcm_hw_info_t *info,
			     const snd_pcm_strategy_t *strategy)
{
	int err;
	err = snd_pcm_hw_info(pcm, info);
	if (err < 0)
		return err;
	return snd_pcm_hw_info_strategy1(pcm, info, strategy,
					 strategy->badness_min,
					 strategy->badness_max);
}


void snd_pcm_strategy_simple_free(snd_pcm_strategy_t *strategy)
{
	snd_pcm_strategy_simple_t *pars = strategy->private;
	int k;
	for (k = 0; k <= SND_PCM_HW_INFO_LAST; ++k) {
		if (pars[k].valid && pars[k].free)
			pars[k].free(&pars[k]);
	}
	free(pars);
}

int snd_pcm_strategy_simple_choose_param(const snd_pcm_hw_info_t *info,
					 snd_pcm_t *pcm ATTRIBUTE_UNUSED,
					 const snd_pcm_strategy_t *strategy)
{
	unsigned int param;
	int best_param = -1;
	const snd_pcm_strategy_simple_t *pars = strategy->private;
	unsigned int min_choices = UINT_MAX;
	unsigned int min_order = UINT_MAX;
	for (param = 0; param <= SND_PCM_HW_INFO_LAST; ++param) {
		const snd_pcm_strategy_simple_t *p = &pars[param];
		unsigned int choices;
		if (!p->valid)
			continue;
		choices = snd_pcm_hw_info_par_choices(info, param);
		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_param = param;
		}
	}
	return best_param;
}

int snd_pcm_strategy_simple_next_value(const snd_pcm_hw_info_t *info,
					unsigned int param,
					int value,
					snd_pcm_t *pcm,
					const snd_pcm_strategy_t *strategy)
{
	const snd_pcm_strategy_simple_t *pars = strategy->private;
	assert(pars[param].valid);
	return pars[param].next_value(info, param, value, pcm, &pars[param]);
}


int snd_pcm_strategy_simple_min_badness(const snd_pcm_hw_info_t *info,
					unsigned int max_badness,
					snd_pcm_t *pcm,
					const snd_pcm_strategy_t *strategy)
{
	unsigned int param;
	unsigned int badness = 0;
	const snd_pcm_strategy_simple_t *pars = strategy->private;
	for (param = 0; param <= SND_PCM_HW_INFO_LAST; ++param) {
		unsigned int b;
		if (!pars[param].valid)
			continue;
		b = pars[param].min_badness(info, param, pcm, &pars[param]);
		if (b > max_badness || max_badness - b < badness)
			return -E2BIG;
		badness += b;
	}
	return badness;
}


void snd_pcm_strategy_simple_near_free(snd_pcm_strategy_simple_t *par)
{
	snd_pcm_strategy_simple_near_t *p = par->private;
	free(p);
}

unsigned int snd_pcm_strategy_simple_near_min_badness(const snd_pcm_hw_info_t *info,
						      unsigned int param,
						      snd_pcm_t *pcm,
						      const snd_pcm_strategy_simple_t *par)
{
	const snd_pcm_strategy_simple_near_t *p = par->private;
	int value = snd_pcm_hw_info_par_nearest_next(info, param, p->best, -1, pcm);
	int diff;
	assert(value >= 0);
	diff = p->best - value;
	if (diff < 0)
		diff = -diff;
	return diff * p->mul;
}
	
int snd_pcm_strategy_simple_near_next_value(const snd_pcm_hw_info_t *info,
					     unsigned int param,
					     int value,
					     snd_pcm_t *pcm,
					     const snd_pcm_strategy_simple_t *par)
{
	const snd_pcm_strategy_simple_near_t *p = par->private;
	return snd_pcm_hw_info_par_nearest_next(info, param, p->best, value, pcm);
}

void snd_pcm_strategy_simple_choices_free(snd_pcm_strategy_simple_t *par)
{
	snd_pcm_strategy_simple_choices_t *p = par->private;
//	free(p->choices);
	free(p);
}

unsigned int snd_pcm_strategy_simple_choices_min_badness(const snd_pcm_hw_info_t *info,
							 unsigned int param,
							 snd_pcm_t *pcm ATTRIBUTE_UNUSED,
							 const snd_pcm_strategy_simple_t *par)
{
	const snd_pcm_strategy_simple_choices_t *p = par->private;
	unsigned int k;
	for (k = 0; k < p->count; ++k) {
		if (snd_pcm_hw_info_par_check(info, param, p->choices[k].value))
			return p->choices[k].badness;
	}
	assert(0);
	return UINT_MAX;
}
	
int snd_pcm_strategy_simple_choices_next_value(const snd_pcm_hw_info_t *info,
						unsigned int param,
						int value,
						snd_pcm_t *pcm ATTRIBUTE_UNUSED,
						const snd_pcm_strategy_simple_t *par)
{
	const snd_pcm_strategy_simple_choices_t *p = par->private;
	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;
		if (snd_pcm_hw_info_par_check(info, param, v))
			return v;
	}
	return -1;
}

int snd_pcm_strategy_free(snd_pcm_strategy_t *strategy)
{
	if (strategy->free)
		strategy->free(strategy);
	free(strategy);
	return 0;
}

int snd_pcm_strategy_simple(snd_pcm_strategy_t **strategyp,
			    unsigned int badness_min,
			    unsigned int badness_max)
{
	snd_pcm_strategy_simple_t *data;
	snd_pcm_strategy_t *s;
	assert(strategyp);
	data = calloc(SND_PCM_HW_INFO_LAST + 1, sizeof(*data));
	if (!data)
		return -ENOMEM;
	s = calloc(1, sizeof(*s));
	if (!s) {
		free(data);
		return -ENOMEM;
	}
	s->choose_param = snd_pcm_strategy_simple_choose_param;
	s->next_value = snd_pcm_strategy_simple_next_value;
	s->min_badness = snd_pcm_strategy_simple_min_badness;
	s->badness_min = badness_min;
	s->badness_max = badness_max;
	s->private = data;
	s->free = snd_pcm_strategy_simple_free;
	*strategyp = s;
	return 0;
}

int snd_pcm_strategy_simple_near(snd_pcm_strategy_t *strategy,
				 int order,
				 unsigned int param,
				 unsigned int best,
				 unsigned int mul)
{
	snd_pcm_strategy_simple_t *s = strategy->private;
	snd_pcm_strategy_simple_near_t *data;
	assert(strategy);
	assert(param <= SND_PCM_HW_INFO_LAST);
	assert(!s->valid);
	data = calloc(1, sizeof(*data));
	if (!data)
		return -ENOMEM;
	data->best = best;
	data->mul = mul;
	s += param;
	s->order = order;
	s->valid = 1;
	s->next_value = snd_pcm_strategy_simple_near_next_value;
	s->min_badness = snd_pcm_strategy_simple_near_min_badness;
	s->private = data;
	s->free = snd_pcm_strategy_simple_near_free;
	return 0;
}

int snd_pcm_strategy_simple_choices(snd_pcm_strategy_t *strategy,
				    int order,
				    unsigned int param,
				    unsigned int count,
				    snd_pcm_strategy_simple_choices_list_t *choices)
{
	snd_pcm_strategy_simple_t *s = strategy->private;
	snd_pcm_strategy_simple_choices_t *data;
	assert(strategy);
	assert(param <= SND_PCM_HW_INFO_LAST);
	assert(!s->valid);
	data = calloc(1, sizeof(*data));
	if (!data)
		return -ENOMEM;
	data->count = count;
	data->choices = choices;
	s += param;
	s->valid = 1;
	s->order = order;
	s->next_value = snd_pcm_strategy_simple_choices_next_value;
	s->min_badness = snd_pcm_strategy_simple_choices_min_badness;
	s->private = data;
	s->free = snd_pcm_strategy_simple_choices_free;
	return 0;
}

int snd_pcm_dump_hw_info(snd_pcm_hw_info_t *info, FILE *fp)
{
	unsigned int param;
	for (param = 0; param <= SND_PCM_HW_INFO_LAST; param++) {
		fprintf(fp, "%s: ", snd_pcm_hw_info_names[param]);
		snd_pcm_hw_info_par_dump(info, param, fp);
		putc('\n', fp);
	}
	return 0;
}

int snd_pcm_hw_info_try_explain_failure1(snd_pcm_t *pcm,
					 snd_pcm_hw_info_t *fail,
					 snd_pcm_hw_info_t *success,
					 unsigned int depth,
					 FILE *fp)
{
	unsigned int param;
	snd_pcm_hw_info_t i;
	if (depth < 1)
		return -ENOENT;
	for (param = 0; param <= SND_PCM_HW_INFO_LAST; param++) {
		int err;
		i = *success;
		snd_pcm_hw_info_par_copy(&i, param, fail);
		err = snd_pcm_hw_info(pcm, &i);
		if (err == 0 && 
		    snd_pcm_hw_info_try_explain_failure1(pcm, fail, &i, depth - 1, fp) < 0)
			continue;
		fprintf(fp, "%s: ", snd_pcm_hw_info_names[param]);
		snd_pcm_hw_info_par_dump(fail, param, fp);
		putc('\n', fp);
		return 0;
	}
	return -ENOENT;
}

int snd_pcm_hw_info_try_explain_failure(snd_pcm_t *pcm,
					snd_pcm_hw_info_t *fail,
					snd_pcm_hw_info_t *success,
					unsigned int depth,
					FILE *fp)
{
	snd_pcm_hw_info_t i, any;
	int err;
	unsigned int fail_mask;
	assert(pcm && fail);
        fail_mask = snd_pcm_hw_info_fail_mask(fail);
	if (fail_mask) {
		unsigned int param;
		for (param = 0; param <= SND_PCM_HW_INFO_LAST; param++) {
			if (!(fail_mask & (1 << param)))
				continue;
			fprintf(fp, "%s: ", snd_pcm_hw_info_names[param]);
			snd_pcm_hw_info_par_dump(fail, param, fp);
			putc('\n', fp);
		}
		return 0;
	}
	i = *fail;
	err = snd_pcm_hw_info(pcm, &i);
	if (err == 0) {
		fprintf(fp, "Too low max badness or configuration temporarily unavailable\n");
		return 0;
	}
	if (!success) {
		snd_pcm_hw_info_any(&any);
		success = &any;
	}
	return snd_pcm_hw_info_try_explain_failure1(pcm, fail, success, depth, fp);
}

size_t _snd_pcm_mmap_hw_ptr(snd_pcm_t *pcm)
{
	return *pcm->hw_ptr;
}