/**

 * \file pcm/pcm_mulaw.c

 * \ingroup PCM_Plugins

 * \brief PCM Mu-Law Conversion Plugin Interface

 * \author Abramo Bagnara <abramo@alsa-project.org>

 * \date 2000-2001

 */

/*

 *  PCM - Mu-Law conversion

 *  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 Lesser General Public License as

 *   published by the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.

 *

 *   You should have received a copy of the GNU Lesser General Public

 *   License along with this library; if not, write to the Free Software

 *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

 *

 */

#include "bswap.h"

#include "pcm_local.h"

#include "pcm_plugin.h"

#include "plugin_ops.h"

#ifndef PIC

/* entry for static linking */

const char *_snd_module_pcm_mulaw = "";

#endif

#ifndef DOC_HIDDEN

typedef void (*mulaw_f)(const snd_pcm_channel_area_t *src_areas,

			snd_pcm_uframes_t src_offset,

			const snd_pcm_channel_area_t *dst_areas,

			snd_pcm_uframes_t dst_offset,

			unsigned int channels, snd_pcm_uframes_t frames,

			unsigned int getputidx);

typedef struct {

	/* This field need to be the first */

	snd_pcm_plugin_t plug;

	unsigned int getput_idx;

	mulaw_f func;

	snd_pcm_format_t sformat;

} snd_pcm_mulaw_t;

#endif

static inline int val_seg(int val)

{

	int r = 0;

	val >>= 7;

	if (val & 0xf0) {

		val >>= 4;

		r += 4;

	}

	if (val & 0x0c) {

		val >>= 2;

		r += 2;

	}

	if (val & 0x02)

		r += 1;

	return r;

}

/*

 * s16_to_ulaw() - Convert a linear PCM value to u-law

 *

 * In order to simplify the encoding process, the original linear magnitude

 * is biased by adding 33 which shifts the encoding range from (0 - 8158) to

 * (33 - 8191). The result can be seen in the following encoding table:

 *

 *	Biased Linear Input Code	Compressed Code

 *	------------------------	---------------

 *	00000001wxyza			000wxyz

 *	0000001wxyzab			001wxyz

 *	000001wxyzabc			010wxyz

 *	00001wxyzabcd			011wxyz

 *	0001wxyzabcde			100wxyz

 *	001wxyzabcdef			101wxyz

 *	01wxyzabcdefg			110wxyz

 *	1wxyzabcdefgh			111wxyz

 *

 * Each biased linear code has a leading 1 which identifies the segment

 * number. The value of the segment number is equal to 7 minus the number

 * of leading 0's. The quantization interval is directly available as the

 * four bits wxyz.  * The trailing bits (a - h) are ignored.

 *

 * Ordinarily the complement of the resulting code word is used for

 * transmission, and so the code word is complemented before it is returned.

 *

 * For further information see John C. Bellamy's Digital Telephony, 1982,

 * John Wiley & Sons, pps 98-111 and 472-476.

 */

static unsigned char s16_to_ulaw(int pcm_val)	/* 2's complement (16-bit range) */

{

	int mask;

	int seg;

	unsigned char uval;

	if (pcm_val < 0) {

		pcm_val = 0x84 - pcm_val;

		mask = 0x7f;

	} else {

		pcm_val += 0x84;

		mask = 0xff;

	}

	if (pcm_val > 0x7fff)

		pcm_val = 0x7fff;

	/* Convert the scaled magnitude to segment number. */

	seg = val_seg(pcm_val);

	/*

	 * Combine the sign, segment, quantization bits;

	 * and complement the code word.

	 */

	uval = (seg << 4) | ((pcm_val >> (seg + 3)) & 0x0f);

	return uval ^ mask;

}

/*

 * ulaw_to_s16() - Convert a u-law value to 16-bit linear PCM

 *

 * First, a biased linear code is derived from the code word. An unbiased

 * output can then be obtained by subtracting 33 from the biased code.

 *

 * Note that this function expects to be passed the complement of the

 * original code word. This is in keeping with ISDN conventions.

 */

static int ulaw_to_s16(unsigned char u_val)

{

	int t;

	/* Complement to obtain normal u-law value. */

	u_val = ~u_val;

	/*

	 * Extract and bias the quantization bits. Then

	 * shift up by the segment number and subtract out the bias.

	 */

	t = ((u_val & 0x0f) << 3) + 0x84;

	t <<= (u_val & 0x70) >> 4;

	return ((u_val & 0x80) ? (0x84 - t) : (t - 0x84));

}

#ifndef DOC_HIDDEN

void snd_pcm_mulaw_decode(const snd_pcm_channel_area_t *dst_areas,

			  snd_pcm_uframes_t dst_offset,

			  const snd_pcm_channel_area_t *src_areas,

			  snd_pcm_uframes_t src_offset,

			  unsigned int channels, snd_pcm_uframes_t frames,

			  unsigned int putidx)

{

#define PUT16_LABELS

#include "plugin_ops.h"

#undef PUT16_LABELS

	void *put = put16_labels[putidx];

	unsigned int channel;

	for (channel = 0; channel < channels; ++channel) {

		const unsigned char *src;

		char *dst;

		int src_step, dst_step;

		snd_pcm_uframes_t frames1;

		const snd_pcm_channel_area_t *src_area = &src_areas[channel];

		const snd_pcm_channel_area_t *dst_area = &dst_areas[channel];

		src = snd_pcm_channel_area_addr(src_area, src_offset);

		dst = snd_pcm_channel_area_addr(dst_area, dst_offset);

		src_step = snd_pcm_channel_area_step(src_area);

		dst_step = snd_pcm_channel_area_step(dst_area);

		frames1 = frames;

		while (frames1-- > 0) {

			int16_t sample = ulaw_to_s16(*src);

			goto *put;

#define PUT16_END after

#include "plugin_ops.h"

#undef PUT16_END

		after:

			src += src_step;

			dst += dst_step;

		}

	}

}

void snd_pcm_mulaw_encode(const snd_pcm_channel_area_t *dst_areas,

			  snd_pcm_uframes_t dst_offset,

			  const snd_pcm_channel_area_t *src_areas,

			  snd_pcm_uframes_t src_offset,

			  unsigned int channels, snd_pcm_uframes_t frames,

			  unsigned int getidx)

{

#define GET16_LABELS

#include "plugin_ops.h"

#undef GET16_LABELS

	void *get = get16_labels[getidx];

	unsigned int channel;

	int16_t sample = 0;

	for (channel = 0; channel < channels; ++channel) {

		const char *src;

		char *dst;

		int src_step, dst_step;

		snd_pcm_uframes_t frames1;

		const snd_pcm_channel_area_t *src_area = &src_areas[channel];

		const snd_pcm_channel_area_t *dst_area = &dst_areas[channel];

		src = snd_pcm_channel_area_addr(src_area, src_offset);

		dst = snd_pcm_channel_area_addr(dst_area, dst_offset);

		src_step = snd_pcm_channel_area_step(src_area);

		dst_step = snd_pcm_channel_area_step(dst_area);

		frames1 = frames;

		while (frames1-- > 0) {

			goto *get;

#define GET16_END after

#include "plugin_ops.h"

#undef GET16_END

		after:

			*dst = s16_to_ulaw(sample);

			src += src_step;

			dst += dst_step;

		}

	}

}

#endif /* DOC_HIDDEN */

static int snd_pcm_mulaw_hw_refine_cprepare(snd_pcm_t *pcm, snd_pcm_hw_params_t *params)

{

	snd_pcm_mulaw_t *mulaw = pcm->private_data;

	int err;

	snd_pcm_access_mask_t access_mask = { SND_PCM_ACCBIT_SHM };

	err = _snd_pcm_hw_param_set_mask(params, SND_PCM_HW_PARAM_ACCESS,

					 &access_mask);

	if (err < 0)

		return err;

	if (mulaw->sformat == SND_PCM_FORMAT_MU_LAW) {

		snd_pcm_format_mask_t format_mask= { SND_PCM_FMTBIT_LINEAR };

		err = _snd_pcm_hw_param_set_mask(params, SND_PCM_HW_PARAM_FORMAT,

						 &format_mask);

	} else {

		err = _snd_pcm_hw_params_set_format(params,

						   SND_PCM_FORMAT_MU_LAW);

	}

	err = _snd_pcm_hw_params_set_subformat(params, SND_PCM_SUBFORMAT_STD);

	if (err < 0)

		return err;

	params->info &= ~(SND_PCM_INFO_MMAP | SND_PCM_INFO_MMAP_VALID);

	return 0;

}

static int snd_pcm_mulaw_hw_refine_sprepare(snd_pcm_t *pcm, snd_pcm_hw_params_t *sparams)

{

	snd_pcm_mulaw_t *mulaw = pcm->private_data;

	snd_pcm_access_mask_t saccess_mask = { SND_PCM_ACCBIT_MMAP };

	_snd_pcm_hw_params_any(sparams);

	_snd_pcm_hw_param_set_mask(sparams, SND_PCM_HW_PARAM_ACCESS,

				   &saccess_mask);

	_snd_pcm_hw_params_set_format(sparams, mulaw->sformat);

	_snd_pcm_hw_params_set_subformat(sparams, SND_PCM_SUBFORMAT_STD);

	return 0;

}

static int snd_pcm_mulaw_hw_refine_schange(snd_pcm_t *pcm ATTRIBUTE_UNUSED, snd_pcm_hw_params_t *params,

					    snd_pcm_hw_params_t *sparams)

{

	int err;

	unsigned int links = (SND_PCM_HW_PARBIT_CHANNELS |

			      SND_PCM_HW_PARBIT_RATE |

			      SND_PCM_HW_PARBIT_PERIOD_SIZE |

			      SND_PCM_HW_PARBIT_BUFFER_SIZE |

			      SND_PCM_HW_PARBIT_PERIODS |

			      SND_PCM_HW_PARBIT_PERIOD_TIME |

			      SND_PCM_HW_PARBIT_BUFFER_TIME |

			      SND_PCM_HW_PARBIT_TICK_TIME);

	err = _snd_pcm_hw_params_refine(sparams, links, params);

	if (err < 0)

		return err;

	return 0;

}

static int snd_pcm_mulaw_hw_refine_cchange(snd_pcm_t *pcm ATTRIBUTE_UNUSED, snd_pcm_hw_params_t *params,

					    snd_pcm_hw_params_t *sparams)

{

	int err;

	unsigned int links = (SND_PCM_HW_PARBIT_CHANNELS |

			      SND_PCM_HW_PARBIT_RATE |

			      SND_PCM_HW_PARBIT_PERIOD_SIZE |

			      SND_PCM_HW_PARBIT_BUFFER_SIZE |

			      SND_PCM_HW_PARBIT_PERIODS |

			      SND_PCM_HW_PARBIT_PERIOD_TIME |

			      SND_PCM_HW_PARBIT_BUFFER_TIME |

			      SND_PCM_HW_PARBIT_TICK_TIME);

	err = _snd_pcm_hw_params_refine(params, links, sparams);

	if (err < 0)

		return err;

	return 0;

}

static int snd_pcm_mulaw_hw_refine(snd_pcm_t *pcm, snd_pcm_hw_params_t *params)

{

	return snd_pcm_hw_refine_slave(pcm, params,

				       snd_pcm_mulaw_hw_refine_cprepare,

				       snd_pcm_mulaw_hw_refine_cchange,

				       snd_pcm_mulaw_hw_refine_sprepare,

				       snd_pcm_mulaw_hw_refine_schange,

				       snd_pcm_generic_hw_refine);

}

static int snd_pcm_mulaw_hw_params(snd_pcm_t *pcm, snd_pcm_hw_params_t * params)

{

	snd_pcm_mulaw_t *mulaw = pcm->private_data;

	snd_pcm_format_t format;

	int err = snd_pcm_hw_params_slave(pcm, params,

					  snd_pcm_mulaw_hw_refine_cchange,

					  snd_pcm_mulaw_hw_refine_sprepare,

					  snd_pcm_mulaw_hw_refine_schange,

					  snd_pcm_generic_hw_params);

	if (err < 0)

		return err;

	err = INTERNAL(snd_pcm_hw_params_get_format)(params, &format);

	if (err < 0)

		return err;

	if (pcm->stream == SND_PCM_STREAM_PLAYBACK) {

		if (mulaw->sformat == SND_PCM_FORMAT_MU_LAW) {

			mulaw->getput_idx = snd_pcm_linear_get_index(format, SND_PCM_FORMAT_S16);

			mulaw->func = snd_pcm_mulaw_encode;

		} else {

			mulaw->getput_idx = snd_pcm_linear_put_index(SND_PCM_FORMAT_S16, mulaw->sformat);

			mulaw->func = snd_pcm_mulaw_decode;

		}

	} else {

		if (mulaw->sformat == SND_PCM_FORMAT_MU_LAW) {

			mulaw->getput_idx = snd_pcm_linear_put_index(SND_PCM_FORMAT_S16, format);

			mulaw->func = snd_pcm_mulaw_decode;

		} else {

			mulaw->getput_idx = snd_pcm_linear_get_index(mulaw->sformat, SND_PCM_FORMAT_S16);

			mulaw->func = snd_pcm_mulaw_encode;

		}

	}

	return 0;

}

static snd_pcm_uframes_t

snd_pcm_mulaw_write_areas(snd_pcm_t *pcm,

			  const snd_pcm_channel_area_t *areas,

			  snd_pcm_uframes_t offset,

			  snd_pcm_uframes_t size,

			  const snd_pcm_channel_area_t *slave_areas,

			  snd_pcm_uframes_t slave_offset,

			  snd_pcm_uframes_t *slave_sizep)

{

	snd_pcm_mulaw_t *mulaw = pcm->private_data;

	if (size > *slave_sizep)

		size = *slave_sizep;

	mulaw->func(slave_areas, slave_offset,

		    areas, offset, 

		    pcm->channels, size,

		    mulaw->getput_idx);

	*slave_sizep = size;

	return size;

}

static snd_pcm_uframes_t

snd_pcm_mulaw_read_areas(snd_pcm_t *pcm,

			 const snd_pcm_channel_area_t *areas,

			 snd_pcm_uframes_t offset,

			 snd_pcm_uframes_t size,

			 const snd_pcm_channel_area_t *slave_areas,

			 snd_pcm_uframes_t slave_offset,

			 snd_pcm_uframes_t *slave_sizep)

{

	snd_pcm_mulaw_t *mulaw = pcm->private_data;

	if (size > *slave_sizep)

		size = *slave_sizep;

	mulaw->func(areas, offset, 

		    slave_areas, slave_offset,

		    pcm->channels, size,

		    mulaw->getput_idx);

	*slave_sizep = size;

	return size;

}

static void snd_pcm_mulaw_dump(snd_pcm_t *pcm, snd_output_t *out)

{

	snd_pcm_mulaw_t *mulaw = pcm->private_data;

	snd_output_printf(out, "Mu-Law conversion PCM (%s)\n", 

		snd_pcm_format_name(mulaw->sformat));

	if (pcm->setup) {

		snd_output_printf(out, "Its setup is:\n");

		snd_pcm_dump_setup(pcm, out);

	}

	snd_output_printf(out, "Slave: ");

	snd_pcm_dump(mulaw->plug.gen.slave, out);

}

static const snd_pcm_ops_t snd_pcm_mulaw_ops = {

	.close = snd_pcm_generic_close,

	.info = snd_pcm_generic_info,

	.hw_refine = snd_pcm_mulaw_hw_refine,

	.hw_params = snd_pcm_mulaw_hw_params,

	.hw_free = snd_pcm_generic_hw_free,

	.sw_params = snd_pcm_generic_sw_params,

	.channel_info = snd_pcm_generic_channel_info,

	.dump = snd_pcm_mulaw_dump,

	.nonblock = snd_pcm_generic_nonblock,

	.async = snd_pcm_generic_async,

	.mmap = snd_pcm_generic_mmap,

	.munmap = snd_pcm_generic_munmap,

	.get_chmap = snd_pcm_generic_get_chmap,

	.set_chmap = snd_pcm_generic_set_chmap,

};

/**

 * \brief Creates a new Mu-Law conversion PCM

 * \param pcmp Returns created PCM handle

 * \param name Name of PCM

 * \param sformat Slave (destination) format

 * \param slave Slave PCM handle

 * \param close_slave When set, the slave PCM handle is closed with copy PCM

 * \retval zero on success otherwise a negative error code

 * \warning Using of this function might be dangerous in the sense

 *          of compatibility reasons. The prototype might be freely

 *          changed in future.

 */

int snd_pcm_mulaw_open(snd_pcm_t **pcmp, const char *name, snd_pcm_format_t sformat, snd_pcm_t *slave, int close_slave)

{

	snd_pcm_t *pcm;

	snd_pcm_mulaw_t *mulaw;

	int err;

	assert(pcmp && slave);

	if (snd_pcm_format_linear(sformat) != 1 &&

	    sformat != SND_PCM_FORMAT_MU_LAW)

		return -EINVAL;

	mulaw = calloc(1, sizeof(snd_pcm_mulaw_t));

	if (!mulaw) {

		return -ENOMEM;

	}

	snd_pcm_plugin_init(&mulaw->plug);

	mulaw->sformat = sformat;

	mulaw->plug.read = snd_pcm_mulaw_read_areas;

	mulaw->plug.write = snd_pcm_mulaw_write_areas;

	mulaw->plug.undo_read = snd_pcm_plugin_undo_read_generic;

	mulaw->plug.undo_write = snd_pcm_plugin_undo_write_generic;

	mulaw->plug.gen.slave = slave;

	mulaw->plug.gen.close_slave = close_slave;

	err = snd_pcm_new(&pcm, SND_PCM_TYPE_MULAW, name, slave->stream, slave->mode);

	if (err < 0) {

		free(mulaw);

		return err;

	}

	pcm->ops = &snd_pcm_mulaw_ops;

	pcm->fast_ops = &snd_pcm_plugin_fast_ops;

	pcm->private_data = mulaw;

	pcm->poll_fd = slave->poll_fd;

	pcm->poll_events = slave->poll_events;

	pcm->tstamp_type = slave->tstamp_type;

	snd_pcm_set_hw_ptr(pcm, &mulaw->plug.hw_ptr, -1, 0);

	snd_pcm_set_appl_ptr(pcm, &mulaw->plug.appl_ptr, -1, 0);

	*pcmp = pcm;

	return 0;

}

/*! \page pcm_plugins

\section pcm_plugins_mulaw Plugin: Mu-Law

This plugin converts Mu-Law samples to linear or linear to Mu-Law samples

from master Mu-Law conversion PCM to given slave PCM. The channel count,

format and rate must match for both of them.

\code

pcm.name {

        type mulaw              # Mu-Law conversion PCM

        slave STR               # Slave name

        # or

        slave {                 # Slave definition

                pcm STR         # Slave PCM name

                # or

                pcm { }         # Slave PCM definition

                format STR      # Slave format

        }

}

\endcode

\subsection pcm_plugins_mulaw_funcref Function reference

  
snd_pcm_mulaw_open()

  
_snd_pcm_mulaw_open()

*/

/**

 * \brief Creates a new Mu-Law conversion PCM

 * \param pcmp Returns created PCM handle

 * \param name Name of PCM

 * \param root Root configuration node

 * \param conf Configuration node with copy PCM description

 * \param stream Stream type

 * \param mode Stream mode

 * \retval zero on success otherwise a negative error code

 * \warning Using of this function might be dangerous in the sense

 *          of compatibility reasons. The prototype might be freely

 *          changed in future.

 */

int _snd_pcm_mulaw_open(snd_pcm_t **pcmp, const char *name,

			snd_config_t *root, snd_config_t *conf, 

			snd_pcm_stream_t stream, int mode)

{

	snd_config_iterator_t i, next;

	int err;

	snd_pcm_t *spcm;

	snd_config_t *slave = NULL, *sconf;

	snd_pcm_format_t sformat;

	snd_config_for_each(i, next, conf) {

		snd_config_t *n = snd_config_iterator_entry(i);

		const char *id;

		if (snd_config_get_id(n, &id) < 0)

			continue;

		if (snd_pcm_conf_generic_id(id))

			continue;

		if (strcmp(id, "slave") == 0) {

			slave = n;

			continue;

		}

		SNDERR("Unknown field %s", id);

		return -EINVAL;

	}

	if (!slave) {

		SNDERR("slave is not defined");

		return -EINVAL;

	}

	err = snd_pcm_slave_conf(root, slave, &sconf, 1,

				 SND_PCM_HW_PARAM_FORMAT, SCONF_MANDATORY, &sformat);

	if (err < 0)

		return err;

	if (snd_pcm_format_linear(sformat) != 1 &&

	    sformat != SND_PCM_FORMAT_MU_LAW) {

		snd_config_delete(sconf);

		SNDERR("invalid slave format");

		return -EINVAL;

	}

	err = snd_pcm_open_slave(&spcm, root, sconf, stream, mode, conf);

	snd_config_delete(sconf);

	if (err < 0)

		return err;

	err = snd_pcm_mulaw_open(pcmp, name, sformat, spcm, 1);

	if (err < 0)

		snd_pcm_close(spcm);

	return err;

}

#ifndef DOC_HIDDEN

SND_DLSYM_BUILD_VERSION(_snd_pcm_mulaw_open, SND_PCM_DLSYM_VERSION);

#endif