[deliverable/linux.git] / sound / core / oss / rate.c

/*
 *  Rate conversion Plug-In
 *  Copyright (c) 1999 by Jaroslav Kysela <perex@suse.cz>
 *
 *
 *   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., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 */
  
#include <sound/driver.h>

#ifdef CONFIG_SND_PCM_OSS_PLUGINS

#include <linux/time.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include "pcm_plugin.h"

#define SHIFT	11
#define BITS	(1<<SHIFT)
#define R_MASK	(BITS-1)

/*
 *  Basic rate conversion plugin
 */

struct rate_channel {
	signed short last_S1;
	signed short last_S2;
};
 
typedef void (*rate_f)(struct snd_pcm_plugin *plugin,
		       const struct snd_pcm_plugin_channel *src_channels,
		       struct snd_pcm_plugin_channel *dst_channels,
		       int src_frames, int dst_frames);

struct rate_priv {
	unsigned int pitch;
	unsigned int pos;
	rate_f func;
	int get, put;
	snd_pcm_sframes_t old_src_frames, old_dst_frames;
	struct rate_channel channels[0];
};

static void rate_init(struct snd_pcm_plugin *plugin)
{
	unsigned int channel;
	struct rate_priv *data = (struct rate_priv *)plugin->extra_data;
	data->pos = 0;
	for (channel = 0; channel < plugin->src_format.channels; channel++) {
		data->channels[channel].last_S1 = 0;
		data->channels[channel].last_S2 = 0;
	}
}

static void resample_expand(struct snd_pcm_plugin *plugin,
			    const struct snd_pcm_plugin_channel *src_channels,
			    struct snd_pcm_plugin_channel *dst_channels,
			    int src_frames, int dst_frames)
{
	unsigned int pos = 0;
	signed int val;
	signed short S1, S2;
	char *src, *dst;
	unsigned int channel;
	int src_step, dst_step;
	int src_frames1, dst_frames1;
	struct rate_priv *data = (struct rate_priv *)plugin->extra_data;
	struct rate_channel *rchannels = data->channels;

#define GET_S16_LABELS
#define PUT_S16_LABELS
#include "plugin_ops.h"
#undef GET_S16_LABELS
#undef PUT_S16_LABELS
	void *get = get_s16_labels[data->get];
	void *put = put_s16_labels[data->put];
	signed short sample = 0;
	
	for (channel = 0; channel < plugin->src_format.channels; channel++) {
		pos = data->pos;
		S1 = rchannels->last_S1;
		S2 = rchannels->last_S2;
		if (!src_channels[channel].enabled) {
			if (dst_channels[channel].wanted)
				snd_pcm_area_silence(&dst_channels[channel].area, 0, dst_frames, plugin->dst_format.format);
			dst_channels[channel].enabled = 0;
			continue;
		}
		dst_channels[channel].enabled = 1;
		src = (char *)src_channels[channel].area.addr + src_channels[channel].area.first / 8;
		dst = (char *)dst_channels[channel].area.addr + dst_channels[channel].area.first / 8;
		src_step = src_channels[channel].area.step / 8;
		dst_step = dst_channels[channel].area.step / 8;
		src_frames1 = src_frames;
		dst_frames1 = dst_frames;
		while (dst_frames1-- > 0) {
			if (pos & ~R_MASK) {
				pos &= R_MASK;
				S1 = S2;
				if (src_frames1-- > 0) {
					goto *get;
#define GET_S16_END after_get
#include "plugin_ops.h"
#undef GET_S16_END
				after_get:
					S2 = sample;
					src += src_step;
				}
			}
			val = S1 + ((S2 - S1) * (signed int)pos) / BITS;
			if (val < -32768)
				val = -32768;
			else if (val > 32767)
				val = 32767;
			sample = val;
			goto *put;
#define PUT_S16_END after_put
#include "plugin_ops.h"
#undef PUT_S16_END
		after_put:
			dst += dst_step;
			pos += data->pitch;
		}
		rchannels->last_S1 = S1;
		rchannels->last_S2 = S2;
		rchannels++;
	}
	data->pos = pos;
}

static void resample_shrink(struct snd_pcm_plugin *plugin,
			    const struct snd_pcm_plugin_channel *src_channels,
			    struct snd_pcm_plugin_channel *dst_channels,
			    int src_frames, int dst_frames)
{
	unsigned int pos = 0;
	signed int val;
	signed short S1, S2;
	char *src, *dst;
	unsigned int channel;
	int src_step, dst_step;
	int src_frames1, dst_frames1;
	struct rate_priv *data = (struct rate_priv *)plugin->extra_data;
	struct rate_channel *rchannels = data->channels;
	
#define GET_S16_LABELS
#define PUT_S16_LABELS
#include "plugin_ops.h"
#undef GET_S16_LABELS
#undef PUT_S16_LABELS
	void *get = get_s16_labels[data->get];
	void *put = put_s16_labels[data->put];
	signed short sample = 0;

	for (channel = 0; channel < plugin->src_format.channels; ++channel) {
		pos = data->pos;
		S1 = rchannels->last_S1;
		S2 = rchannels->last_S2;
		if (!src_channels[channel].enabled) {
			if (dst_channels[channel].wanted)
				snd_pcm_area_silence(&dst_channels[channel].area, 0, dst_frames, plugin->dst_format.format);
			dst_channels[channel].enabled = 0;
			continue;
		}
		dst_channels[channel].enabled = 1;
		src = (char *)src_channels[channel].area.addr + src_channels[channel].area.first / 8;
		dst = (char *)dst_channels[channel].area.addr + dst_channels[channel].area.first / 8;
		src_step = src_channels[channel].area.step / 8;
		dst_step = dst_channels[channel].area.step / 8;
		src_frames1 = src_frames;
		dst_frames1 = dst_frames;
		while (dst_frames1 > 0) {
			S1 = S2;
			if (src_frames1-- > 0) {
				goto *get;
#define GET_S16_END after_get
#include "plugin_ops.h"
#undef GET_S16_END
			after_get:
				S2 = sample;
				src += src_step;
			}
			if (pos & ~R_MASK) {
				pos &= R_MASK;
				val = S1 + ((S2 - S1) * (signed int)pos) / BITS;
				if (val < -32768)
					val = -32768;
				else if (val > 32767)
					val = 32767;
				sample = val;
				goto *put;
#define PUT_S16_END after_put
#include "plugin_ops.h"
#undef PUT_S16_END
			after_put:
				dst += dst_step;
				dst_frames1--;
			}
			pos += data->pitch;
		}
		rchannels->last_S1 = S1;
		rchannels->last_S2 = S2;
		rchannels++;
	}
	data->pos = pos;
}

static snd_pcm_sframes_t rate_src_frames(struct snd_pcm_plugin *plugin, snd_pcm_uframes_t frames)
{
	struct rate_priv *data;
	snd_pcm_sframes_t res;

	snd_assert(plugin != NULL, return -ENXIO);
	if (frames == 0)
		return 0;
	data = (struct rate_priv *)plugin->extra_data;
	if (plugin->src_format.rate < plugin->dst_format.rate) {
		res = (((frames * data->pitch) + (BITS/2)) >> SHIFT);
	} else {
		res = (((frames << SHIFT) + (data->pitch / 2)) / data->pitch);		
	}
	if (data->old_src_frames > 0) {
		snd_pcm_sframes_t frames1 = frames, res1 = data->old_dst_frames;
		while (data->old_src_frames < frames1) {
			frames1 >>= 1;
			res1 <<= 1;
		}
		while (data->old_src_frames > frames1) {
			frames1 <<= 1;
			res1 >>= 1;
		}
		if (data->old_src_frames == frames1)
			return res1;
	}
	data->old_src_frames = frames;
	data->old_dst_frames = res;
	return res;
}

static snd_pcm_sframes_t rate_dst_frames(struct snd_pcm_plugin *plugin, snd_pcm_uframes_t frames)
{
	struct rate_priv *data;
	snd_pcm_sframes_t res;

	snd_assert(plugin != NULL, return -ENXIO);
	if (frames == 0)
		return 0;
	data = (struct rate_priv *)plugin->extra_data;
	if (plugin->src_format.rate < plugin->dst_format.rate) {
		res = (((frames << SHIFT) + (data->pitch / 2)) / data->pitch);
	} else {
		res = (((frames * data->pitch) + (BITS/2)) >> SHIFT);
	}
	if (data->old_dst_frames > 0) {
		snd_pcm_sframes_t frames1 = frames, res1 = data->old_src_frames;
		while (data->old_dst_frames < frames1) {
			frames1 >>= 1;
			res1 <<= 1;
		}
		while (data->old_dst_frames > frames1) {
			frames1 <<= 1;
			res1 >>= 1;
		}
		if (data->old_dst_frames == frames1)
			return res1;
	}
	data->old_dst_frames = frames;
	data->old_src_frames = res;
	return res;
}

static snd_pcm_sframes_t rate_transfer(struct snd_pcm_plugin *plugin,
			     const struct snd_pcm_plugin_channel *src_channels,
			     struct snd_pcm_plugin_channel *dst_channels,
			     snd_pcm_uframes_t frames)
{
	snd_pcm_uframes_t dst_frames;
	struct rate_priv *data;

	snd_assert(plugin != NULL && src_channels != NULL && dst_channels != NULL, return -ENXIO);
	if (frames == 0)
		return 0;
#ifdef CONFIG_SND_DEBUG
	{
		unsigned int channel;
		for (channel = 0; channel < plugin->src_format.channels; channel++) {
			snd_assert(src_channels[channel].area.first % 8 == 0 &&
				   src_channels[channel].area.step % 8 == 0,
				   return -ENXIO);
			snd_assert(dst_channels[channel].area.first % 8 == 0 &&
				   dst_channels[channel].area.step % 8 == 0,
				   return -ENXIO);
		}
	}
#endif

	dst_frames = rate_dst_frames(plugin, frames);
	if (dst_frames > dst_channels[0].frames)
		dst_frames = dst_channels[0].frames;
	data = (struct rate_priv *)plugin->extra_data;
	data->func(plugin, src_channels, dst_channels, frames, dst_frames);
	return dst_frames;
}

static int rate_action(struct snd_pcm_plugin *plugin,
		       enum snd_pcm_plugin_action action,
		       unsigned long udata)
{
	snd_assert(plugin != NULL, return -ENXIO);
	switch (action) {
	case INIT:
	case PREPARE:
		rate_init(plugin);
		break;
	default:
		break;
	}
	return 0;	/* silenty ignore other actions */
}

int snd_pcm_plugin_build_rate(struct snd_pcm_substream *plug,
			      struct snd_pcm_plugin_format *src_format,
			      struct snd_pcm_plugin_format *dst_format,
			      struct snd_pcm_plugin **r_plugin)
{
	int err;
	struct rate_priv *data;
	struct snd_pcm_plugin *plugin;

	snd_assert(r_plugin != NULL, return -ENXIO);
	*r_plugin = NULL;

	snd_assert(src_format->channels == dst_format->channels, return -ENXIO);
	snd_assert(src_format->channels > 0, return -ENXIO);
	snd_assert(snd_pcm_format_linear(src_format->format) != 0, return -ENXIO);
	snd_assert(snd_pcm_format_linear(dst_format->format) != 0, return -ENXIO);
	snd_assert(src_format->rate != dst_format->rate, return -ENXIO);

	err = snd_pcm_plugin_build(plug, "rate conversion",
				   src_format, dst_format,
				   sizeof(struct rate_priv) +
				   src_format->channels * sizeof(struct rate_channel),
				   &plugin);
	if (err < 0)
		return err;
	data = (struct rate_priv *)plugin->extra_data;
	data->get = getput_index(src_format->format);
	snd_assert(data->get >= 0 && data->get < 4*2*2, return -EINVAL);
	data->put = getput_index(dst_format->format);
	snd_assert(data->put >= 0 && data->put < 4*2*2, return -EINVAL);

	if (src_format->rate < dst_format->rate) {
		data->pitch = ((src_format->rate << SHIFT) + (dst_format->rate >> 1)) / dst_format->rate;
		data->func = resample_expand;
	} else {
		data->pitch = ((dst_format->rate << SHIFT) + (src_format->rate >> 1)) / src_format->rate;
		data->func = resample_shrink;
	}
	data->pos = 0;
	rate_init(plugin);
	data->old_src_frames = data->old_dst_frames = 0;
	plugin->transfer = rate_transfer;
	plugin->src_frames = rate_src_frames;
	plugin->dst_frames = rate_dst_frames;
	plugin->action = rate_action;
	*r_plugin = plugin;
	return 0;
}

#endif
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Rate conversion Plug-In
	3	* Copyright (c) 1999 by Jaroslav Kysela <perex@suse.cz>
	4	*
	5	*
	6	* This library is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU Library General Public License as
	8	* published by the Free Software Foundation; either version 2 of
	9	* the License, or (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU Library General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU Library General Public
	17	* License along with this library; if not, write to the Free Software
	18	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	19	*
	20	*/
	21
	22	#include <sound/driver.h>
21a3479a JK	23
	24	#ifdef CONFIG_SND_PCM_OSS_PLUGINS
	25
1da177e4 LT	26	#include <linux/time.h>
	27	#include <sound/core.h>
	28	#include <sound/pcm.h>
	29	#include "pcm_plugin.h"
	30
	31	#define SHIFT 11
	32	#define BITS (1<<SHIFT)
	33	#define R_MASK (BITS-1)
	34
	35	/*
	36	* Basic rate conversion plugin
	37	*/
	38
6ac77bc1	39	struct rate_channel {
1da177e4 LT	40	signed short last_S1;
1da177e4 LT	41	signed short last_S2;
6ac77bc1	42	};
1da177e4	43
6ac77bc1 TI	44	typedef void (rate_f)(struct snd_pcm_plugin plugin,
	45	const struct snd_pcm_plugin_channel *src_channels,
	46	struct snd_pcm_plugin_channel *dst_channels,
1da177e4 LT	47	int src_frames, int dst_frames);
1da177e4 LT	48
6ac77bc1	49	struct rate_priv {
1da177e4 LT	50	unsigned int pitch;
	51	unsigned int pos;
	52	rate_f func;
	53	int get, put;
	54	snd_pcm_sframes_t old_src_frames, old_dst_frames;
6ac77bc1 TI	55	struct rate_channel channels[0];
6ac77bc1 TI	56	};
1da177e4	57
6ac77bc1	58	static void rate_init(struct snd_pcm_plugin *plugin)
1da177e4 LT	59	{
1da177e4 LT	60	unsigned int channel;
6ac77bc1	61	struct rate_priv data = (struct rate_priv )plugin->extra_data;
1da177e4 LT	62	data->pos = 0;
	63	for (channel = 0; channel < plugin->src_format.channels; channel++) {
	64	data->channels[channel].last_S1 = 0;
	65	data->channels[channel].last_S2 = 0;
	66	}
	67	}
	68
6ac77bc1 TI	69	static void resample_expand(struct snd_pcm_plugin *plugin,
	70	const struct snd_pcm_plugin_channel *src_channels,
	71	struct snd_pcm_plugin_channel *dst_channels,
1da177e4 LT	72	int src_frames, int dst_frames)
	73	{
	74	unsigned int pos = 0;
	75	signed int val;
	76	signed short S1, S2;
	77	char src, dst;
	78	unsigned int channel;
	79	int src_step, dst_step;
	80	int src_frames1, dst_frames1;
6ac77bc1 TI	81	struct rate_priv data = (struct rate_priv )plugin->extra_data;
6ac77bc1 TI	82	struct rate_channel *rchannels = data->channels;
1da177e4 LT	83
	84	#define GET_S16_LABELS
	85	#define PUT_S16_LABELS
	86	#include "plugin_ops.h"
	87	#undef GET_S16_LABELS
	88	#undef PUT_S16_LABELS
	89	void *get = get_s16_labels[data->get];
	90	void *put = put_s16_labels[data->put];
	91	signed short sample = 0;
	92
	93	for (channel = 0; channel < plugin->src_format.channels; channel++) {
	94	pos = data->pos;
	95	S1 = rchannels->last_S1;
	96	S2 = rchannels->last_S2;
	97	if (!src_channels[channel].enabled) {
	98	if (dst_channels[channel].wanted)
	99	snd_pcm_area_silence(&dst_channels[channel].area, 0, dst_frames, plugin->dst_format.format);
	100	dst_channels[channel].enabled = 0;
	101	continue;
	102	}
	103	dst_channels[channel].enabled = 1;
	104	src = (char *)src_channels[channel].area.addr + src_channels[channel].area.first / 8;
	105	dst = (char *)dst_channels[channel].area.addr + dst_channels[channel].area.first / 8;
	106	src_step = src_channels[channel].area.step / 8;
	107	dst_step = dst_channels[channel].area.step / 8;
	108	src_frames1 = src_frames;
	109	dst_frames1 = dst_frames;
	110	while (dst_frames1-- > 0) {
	111	if (pos & ~R_MASK) {
	112	pos &= R_MASK;
	113	S1 = S2;
	114	if (src_frames1-- > 0) {
	115	goto *get;
	116	#define GET_S16_END after_get
	117	#include "plugin_ops.h"
	118	#undef GET_S16_END
	119	after_get:
	120	S2 = sample;
	121	src += src_step;
	122	}
	123	}
	124	val = S1 + ((S2 - S1) * (signed int)pos) / BITS;
	125	if (val < -32768)
	126	val = -32768;
	127	else if (val > 32767)
	128	val = 32767;
	129	sample = val;
	130	goto *put;
	131	#define PUT_S16_END after_put
	132	#include "plugin_ops.h"
	133	#undef PUT_S16_END
	134	after_put:
	135	dst += dst_step;
	136	pos += data->pitch;
	137	}
	138	rchannels->last_S1 = S1;
	139	rchannels->last_S2 = S2;
	140	rchannels++;
	141	}
	142	data->pos = pos;
	143	}
	144
6ac77bc1 TI	145	static void resample_shrink(struct snd_pcm_plugin *plugin,
	146	const struct snd_pcm_plugin_channel *src_channels,
	147	struct snd_pcm_plugin_channel *dst_channels,
1da177e4 LT	148	int src_frames, int dst_frames)
	149	{
	150	unsigned int pos = 0;
	151	signed int val;
	152	signed short S1, S2;
	153	char src, dst;
	154	unsigned int channel;
	155	int src_step, dst_step;
	156	int src_frames1, dst_frames1;
6ac77bc1 TI	157	struct rate_priv data = (struct rate_priv )plugin->extra_data;
6ac77bc1 TI	158	struct rate_channel *rchannels = data->channels;
1da177e4 LT	159
	160	#define GET_S16_LABELS
	161	#define PUT_S16_LABELS
	162	#include "plugin_ops.h"
	163	#undef GET_S16_LABELS
	164	#undef PUT_S16_LABELS
	165	void *get = get_s16_labels[data->get];
	166	void *put = put_s16_labels[data->put];
	167	signed short sample = 0;
	168
	169	for (channel = 0; channel < plugin->src_format.channels; ++channel) {
	170	pos = data->pos;
	171	S1 = rchannels->last_S1;
	172	S2 = rchannels->last_S2;
	173	if (!src_channels[channel].enabled) {
	174	if (dst_channels[channel].wanted)
	175	snd_pcm_area_silence(&dst_channels[channel].area, 0, dst_frames, plugin->dst_format.format);
	176	dst_channels[channel].enabled = 0;
	177	continue;
	178	}
	179	dst_channels[channel].enabled = 1;
	180	src = (char *)src_channels[channel].area.addr + src_channels[channel].area.first / 8;
	181	dst = (char *)dst_channels[channel].area.addr + dst_channels[channel].area.first / 8;
	182	src_step = src_channels[channel].area.step / 8;
	183	dst_step = dst_channels[channel].area.step / 8;
	184	src_frames1 = src_frames;
	185	dst_frames1 = dst_frames;
	186	while (dst_frames1 > 0) {
	187	S1 = S2;
	188	if (src_frames1-- > 0) {
	189	goto *get;
	190	#define GET_S16_END after_get
	191	#include "plugin_ops.h"
	192	#undef GET_S16_END
	193	after_get:
	194	S2 = sample;
	195	src += src_step;
	196	}
	197	if (pos & ~R_MASK) {
	198	pos &= R_MASK;
	199	val = S1 + ((S2 - S1) * (signed int)pos) / BITS;
	200	if (val < -32768)
	201	val = -32768;
	202	else if (val > 32767)
	203	val = 32767;
	204	sample = val;
	205	goto *put;
	206	#define PUT_S16_END after_put
	207	#include "plugin_ops.h"
	208	#undef PUT_S16_END
	209	after_put:
	210	dst += dst_step;
	211	dst_frames1--;
	212	}
	213	pos += data->pitch;
	214	}
	215	rchannels->last_S1 = S1;
	216	rchannels->last_S2 = S2;
	217	rchannels++;
	218	}
	219	data->pos = pos;
	220	}
	221
6ac77bc1	222	static snd_pcm_sframes_t rate_src_frames(struct snd_pcm_plugin *plugin, snd_pcm_uframes_t frames)
1da177e4	223	{
6ac77bc1	224	struct rate_priv *data;
1da177e4 LT	225	snd_pcm_sframes_t res;
	226
	227	snd_assert(plugin != NULL, return -ENXIO);
	228	if (frames == 0)
	229	return 0;
6ac77bc1	230	data = (struct rate_priv *)plugin->extra_data;
1da177e4 LT	231	if (plugin->src_format.rate < plugin->dst_format.rate) {
	232	res = (((frames * data->pitch) + (BITS/2)) >> SHIFT);
	233	} else {
	234	res = (((frames << SHIFT) + (data->pitch / 2)) / data->pitch);
	235	}
	236	if (data->old_src_frames > 0) {
	237	snd_pcm_sframes_t frames1 = frames, res1 = data->old_dst_frames;
	238	while (data->old_src_frames < frames1) {
	239	frames1 >>= 1;
	240	res1 <<= 1;
	241	}
	242	while (data->old_src_frames > frames1) {
	243	frames1 <<= 1;
	244	res1 >>= 1;
	245	}
	246	if (data->old_src_frames == frames1)
	247	return res1;
	248	}
	249	data->old_src_frames = frames;
	250	data->old_dst_frames = res;
	251	return res;
	252	}
	253
6ac77bc1	254	static snd_pcm_sframes_t rate_dst_frames(struct snd_pcm_plugin *plugin, snd_pcm_uframes_t frames)
1da177e4	255	{
6ac77bc1	256	struct rate_priv *data;
1da177e4 LT	257	snd_pcm_sframes_t res;
	258
	259	snd_assert(plugin != NULL, return -ENXIO);
	260	if (frames == 0)
	261	return 0;
6ac77bc1	262	data = (struct rate_priv *)plugin->extra_data;
1da177e4 LT	263	if (plugin->src_format.rate < plugin->dst_format.rate) {
	264	res = (((frames << SHIFT) + (data->pitch / 2)) / data->pitch);
	265	} else {
	266	res = (((frames * data->pitch) + (BITS/2)) >> SHIFT);
	267	}
	268	if (data->old_dst_frames > 0) {
	269	snd_pcm_sframes_t frames1 = frames, res1 = data->old_src_frames;
	270	while (data->old_dst_frames < frames1) {
	271	frames1 >>= 1;
	272	res1 <<= 1;
	273	}
	274	while (data->old_dst_frames > frames1) {
	275	frames1 <<= 1;
	276	res1 >>= 1;
	277	}
	278	if (data->old_dst_frames == frames1)
	279	return res1;
	280	}
	281	data->old_dst_frames = frames;
	282	data->old_src_frames = res;
	283	return res;
	284	}
	285
6ac77bc1 TI	286	static snd_pcm_sframes_t rate_transfer(struct snd_pcm_plugin *plugin,
	287	const struct snd_pcm_plugin_channel *src_channels,
	288	struct snd_pcm_plugin_channel *dst_channels,
1da177e4 LT	289	snd_pcm_uframes_t frames)
	290	{
	291	snd_pcm_uframes_t dst_frames;
6ac77bc1	292	struct rate_priv *data;
1da177e4 LT	293
	294	snd_assert(plugin != NULL && src_channels != NULL && dst_channels != NULL, return -ENXIO);
	295	if (frames == 0)
	296	return 0;
	297	#ifdef CONFIG_SND_DEBUG
	298	{
	299	unsigned int channel;
	300	for (channel = 0; channel < plugin->src_format.channels; channel++) {
	301	snd_assert(src_channels[channel].area.first % 8 == 0 &&
	302	src_channels[channel].area.step % 8 == 0,
	303	return -ENXIO);
	304	snd_assert(dst_channels[channel].area.first % 8 == 0 &&
	305	dst_channels[channel].area.step % 8 == 0,
	306	return -ENXIO);
	307	}
	308	}
	309	#endif
	310
	311	dst_frames = rate_dst_frames(plugin, frames);
	312	if (dst_frames > dst_channels[0].frames)
	313	dst_frames = dst_channels[0].frames;
6ac77bc1	314	data = (struct rate_priv *)plugin->extra_data;
1da177e4 LT	315	data->func(plugin, src_channels, dst_channels, frames, dst_frames);
	316	return dst_frames;
	317	}
	318
6ac77bc1 TI	319	static int rate_action(struct snd_pcm_plugin *plugin,
6ac77bc1 TI	320	enum snd_pcm_plugin_action action,
47eaebfd	321	unsigned long udata)
1da177e4 LT	322	{
	323	snd_assert(plugin != NULL, return -ENXIO);
	324	switch (action) {
	325	case INIT:
	326	case PREPARE:
	327	rate_init(plugin);
	328	break;
	329	default:
	330	break;
	331	}
	332	return 0; /* silenty ignore other actions */
	333	}
	334
6ac77bc1 TI	335	int snd_pcm_plugin_build_rate(struct snd_pcm_substream *plug,
	336	struct snd_pcm_plugin_format *src_format,
	337	struct snd_pcm_plugin_format *dst_format,
	338	struct snd_pcm_plugin **r_plugin)
1da177e4 LT	339	{
1da177e4 LT	340	int err;
6ac77bc1 TI	341	struct rate_priv *data;
6ac77bc1 TI	342	struct snd_pcm_plugin *plugin;
1da177e4 LT	343
	344	snd_assert(r_plugin != NULL, return -ENXIO);
	345	*r_plugin = NULL;
	346
	347	snd_assert(src_format->channels == dst_format->channels, return -ENXIO);
	348	snd_assert(src_format->channels > 0, return -ENXIO);
	349	snd_assert(snd_pcm_format_linear(src_format->format) != 0, return -ENXIO);
	350	snd_assert(snd_pcm_format_linear(dst_format->format) != 0, return -ENXIO);
	351	snd_assert(src_format->rate != dst_format->rate, return -ENXIO);
	352
	353	err = snd_pcm_plugin_build(plug, "rate conversion",
	354	src_format, dst_format,
6ac77bc1 TI	355	sizeof(struct rate_priv) +
6ac77bc1 TI	356	src_format->channels * sizeof(struct rate_channel),
1da177e4 LT	357	&plugin);
	358	if (err < 0)
	359	return err;
6ac77bc1	360	data = (struct rate_priv *)plugin->extra_data;
1da177e4 LT	361	data->get = getput_index(src_format->format);
	362	snd_assert(data->get >= 0 && data->get < 422, return -EINVAL);
	363	data->put = getput_index(dst_format->format);
	364	snd_assert(data->put >= 0 && data->put < 422, return -EINVAL);
	365
	366	if (src_format->rate < dst_format->rate) {
	367	data->pitch = ((src_format->rate << SHIFT) + (dst_format->rate >> 1)) / dst_format->rate;
	368	data->func = resample_expand;
	369	} else {
	370	data->pitch = ((dst_format->rate << SHIFT) + (src_format->rate >> 1)) / src_format->rate;
	371	data->func = resample_shrink;
	372	}
	373	data->pos = 0;
	374	rate_init(plugin);
	375	data->old_src_frames = data->old_dst_frames = 0;
	376	plugin->transfer = rate_transfer;
	377	plugin->src_frames = rate_src_frames;
	378	plugin->dst_frames = rate_dst_frames;
	379	plugin->action = rate_action;
	380	*r_plugin = plugin;
	381	return 0;
	382	}
21a3479a JK	383
21a3479a JK	384	#endif