Merged pcmplug branch.

src/pcm/pcm_mulaw.c

@@ -0,0 +1,536 @@
+/*
+ *  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 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 <byteswap.h>
+#include "pcm_local.h"
+#include "pcm_plugin.h"
+
+typedef void (*mulaw_f)(snd_pcm_channel_area_t *src_areas,
+			size_t src_offset,
+			snd_pcm_channel_area_t *dst_areas,
+			size_t dst_offset,
+			size_t frames, size_t channels, int getputidx);
+
+typedef struct {
+	/* This field need to be the first */
+	snd_pcm_plugin_t plug;
+	int getput_idx;
+	mulaw_f func;
+	int sformat;
+	int cformat;
+	int cxfer_mode, cmmap_shape;
+} snd_pcm_mulaw_t;
+
+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 = -pcm_val + 0x84;
+		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));
+}
+
+static void mulaw_decode(snd_pcm_channel_area_t *src_areas,
+			 size_t src_offset,
+			 snd_pcm_channel_area_t *dst_areas,
+			 size_t dst_offset,
+			 size_t frames, size_t channels, int putidx)
+{
+#define PUT_S16_LABELS
+#include "plugin_ops.h"
+#undef PUT_S16_LABELS
+	void *put = put_s16_labels[putidx];
+	size_t channel;
+	for (channel = 0; channel < channels; ++channel) {
+		char *src;
+		char *dst;
+		int src_step, dst_step;
+		size_t frames1;
+		snd_pcm_channel_area_t *src_area = &src_areas[channel];
+		snd_pcm_channel_area_t *dst_area = &dst_areas[channel];
+#if 0
+		if (!src_area->enabled) {
+			if (dst_area->wanted)
+				snd_pcm_area_silence(&dst_areas[channel], dst_offset, frames, dst_sfmt);
+			dst_area->enabled = 0;
+			continue;
+		}
+		dst_area->enabled = 1;
+#endif
+		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 PUT_S16_END after
+#include "plugin_ops.h"
+#undef PUT_S16_END
+		after:
+			src += src_step;
+			dst += dst_step;
+		}
+	}
+}
+
+static void mulaw_encode(snd_pcm_channel_area_t *src_areas,
+			 size_t src_offset,
+			 snd_pcm_channel_area_t *dst_areas,
+			 size_t dst_offset,
+			 size_t frames, size_t channels, int getidx)
+{
+#define GET_S16_LABELS
+#include "plugin_ops.h"
+#undef GET_S16_LABELS
+	void *get = get_s16_labels[getidx];
+	size_t channel;
+	int16_t sample = 0;
+	for (channel = 0; channel < channels; ++channel) {
+		char *src;
+		char *dst;
+		int src_step, dst_step;
+		size_t frames1;
+		snd_pcm_channel_area_t *src_area = &src_areas[channel];
+		snd_pcm_channel_area_t *dst_area = &dst_areas[channel];
+#if 0
+		if (!src_area->enabled) {
+			if (dst_area->wanted)
+				snd_pcm_area_silence(&dst_area->area, 0, frames, dst_sfmt);
+			dst_area->enabled = 0;
+			continue;
+		}
+		dst_area->enabled = 1;
+#endif
+		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 GET_S16_END after
+#include "plugin_ops.h"
+#undef GET_S16_END
+		after:
+			*dst = s16_to_ulaw(sample);
+			src += src_step;
+			dst += dst_step;
+		}
+	}
+}
+
+static int snd_pcm_mulaw_params_info(snd_pcm_t *pcm, snd_pcm_params_info_t * info)
+{
+	snd_pcm_mulaw_t *mulaw = pcm->private;
+	unsigned int req_mask = info->req_mask;
+	unsigned int sfmt = info->req.format.sfmt;
+	int err;
+	if (req_mask & SND_PCM_PARAMS_SFMT) {
+		if (mulaw->sformat == SND_PCM_SFMT_MU_LAW ?
+		    !snd_pcm_format_linear(sfmt) :
+		    sfmt != SND_PCM_SFMT_MU_LAW) {
+			info->req.fail_mask = SND_PCM_PARAMS_SFMT;
+			info->req.fail_reason = SND_PCM_PARAMS_FAIL_INVAL;
+			return -EINVAL;
+		}
+	}
+	info->req_mask |= SND_PCM_PARAMS_SFMT;
+	info->req_mask &= ~(SND_PCM_PARAMS_MMAP_SHAPE | 
+			    SND_PCM_PARAMS_XFER_MODE);
+	info->req.format.sfmt = mulaw->sformat;
+	err = snd_pcm_params_info(mulaw->plug.slave, info);
+	info->req_mask = req_mask;
+	info->req.format.sfmt = sfmt;
+	if (err < 0)
+		return err;
+	if (req_mask & SND_PCM_PARAMS_SFMT)
+		info->formats = 1 << sfmt;
+	else
+		info->formats = mulaw->sformat == SND_PCM_SFMT_MU_LAW ?
+			SND_PCM_LINEAR_FORMATS : 1 << SND_PCM_SFMT_MU_LAW;
+	info->flags &= ~(SND_PCM_INFO_MMAP | SND_PCM_INFO_MMAP_VALID);
+	info->flags |= SND_PCM_INFO_INTERLEAVED | SND_PCM_INFO_NONINTERLEAVED;
+	return err;
+}
+
+static int snd_pcm_mulaw_params(snd_pcm_t *pcm, snd_pcm_params_t * params)
+{
+	snd_pcm_mulaw_t *mulaw = pcm->private;
+	snd_pcm_t *slave = mulaw->plug.slave;
+	int err;
+	if (mulaw->sformat == SND_PCM_SFMT_MU_LAW ?
+	    !snd_pcm_format_linear(params->format.sfmt) :
+	    params->format.sfmt != SND_PCM_SFMT_MU_LAW) {
+		params->fail_mask = SND_PCM_PARAMS_SFMT;
+		params->fail_reason = SND_PCM_PARAMS_FAIL_INVAL;
+		return -EINVAL;
+	}
+	if (slave->mmap_data) {
+		err = snd_pcm_munmap_data(slave);
+		if (err < 0)
+			return err;
+	}
+	mulaw->cformat = params->format.sfmt;
+	mulaw->cxfer_mode = params->xfer_mode;
+	mulaw->cmmap_shape = params->mmap_shape;
+	params->format.sfmt = mulaw->sformat;
+	params->xfer_mode = SND_PCM_XFER_UNSPECIFIED;
+	params->mmap_shape = SND_PCM_MMAP_UNSPECIFIED;;
+	err = snd_pcm_params(slave, params);
+	params->format.sfmt = mulaw->cformat;
+	params->xfer_mode = mulaw->cxfer_mode;
+	params->mmap_shape = mulaw->cmmap_shape;
+ 	if (slave->valid_setup) {
+		int r = snd_pcm_mmap_data(slave, NULL);
+		assert(r >= 0);
+	}
+	return err;
+}
+
+static int snd_pcm_mulaw_setup(snd_pcm_t *pcm, snd_pcm_setup_t * setup)
+{
+	snd_pcm_mulaw_t *mulaw = pcm->private;
+	int err = snd_pcm_setup(mulaw->plug.slave, setup);
+	if (err < 0)
+		return err;
+	assert(mulaw->sformat == setup->format.sfmt);
+	if (mulaw->cxfer_mode == SND_PCM_XFER_UNSPECIFIED)
+		setup->xfer_mode = SND_PCM_XFER_NONINTERLEAVED;
+	else
+		setup->xfer_mode = mulaw->cxfer_mode;
+	if (mulaw->cmmap_shape == SND_PCM_MMAP_UNSPECIFIED)
+		setup->mmap_shape = SND_PCM_MMAP_NONINTERLEAVED;
+	else
+		setup->mmap_shape = mulaw->cmmap_shape;
+	setup->format.sfmt = mulaw->cformat;
+	setup->mmap_bytes = 0;
+	if (pcm->stream == SND_PCM_STREAM_PLAYBACK) {
+		if (mulaw->sformat == SND_PCM_SFMT_MU_LAW) {
+			mulaw->getput_idx = getput_index(mulaw->cformat);
+			mulaw->func = mulaw_encode;
+		} else {
+			mulaw->getput_idx = getput_index(mulaw->sformat);
+			mulaw->func = mulaw_decode;
+		}
+	} else {
+		if (mulaw->sformat == SND_PCM_SFMT_MU_LAW) {
+			mulaw->getput_idx = getput_index(mulaw->cformat);
+			mulaw->func = mulaw_decode;
+		} else {
+			mulaw->getput_idx = getput_index(mulaw->sformat);
+			mulaw->func = mulaw_encode;
+		}
+	}
+	return 0;
+}
+
+static ssize_t snd_pcm_mulaw_write_areas(snd_pcm_t *pcm,
+					 snd_pcm_channel_area_t *areas,
+					 size_t offset,
+					 size_t size,
+					 size_t *slave_sizep)
+{
+	snd_pcm_mulaw_t *mulaw = pcm->private;
+	snd_pcm_t *slave = mulaw->plug.slave;
+	size_t xfer = 0;
+	ssize_t err = 0;
+	if (slave_sizep && *slave_sizep < size)
+		size = *slave_sizep;
+	assert(size > 0);
+	while (xfer < size) {
+		size_t frames = snd_pcm_mmap_playback_xfer(slave, size - xfer);
+		mulaw->func(areas, offset, 
+			    slave->mmap_areas, snd_pcm_mmap_offset(slave),
+			    frames, pcm->setup.format.channels,
+			    mulaw->getput_idx);
+		err = snd_pcm_mmap_forward(slave, frames);
+		if (err < 0)
+			break;
+		assert((size_t)err == frames);
+		offset += err;
+		xfer += err;
+		snd_pcm_mmap_hw_forward(pcm, err);
+	}
+	if (xfer > 0) {
+		if (slave_sizep)
+			*slave_sizep = xfer;
+		return xfer;
+	}
+	return err;
+}
+
+static ssize_t snd_pcm_mulaw_read_areas(snd_pcm_t *pcm,
+					snd_pcm_channel_area_t *areas,
+					size_t offset,
+					size_t size,
+					size_t *slave_sizep)
+{
+	snd_pcm_mulaw_t *mulaw = pcm->private;
+	snd_pcm_t *slave = mulaw->plug.slave;
+	size_t xfer = 0;
+	ssize_t err = 0;
+	if (slave_sizep && *slave_sizep < size)
+		size = *slave_sizep;
+	assert(size > 0);
+	while (xfer < size) {
+		size_t frames = snd_pcm_mmap_capture_xfer(slave, size - xfer);
+		mulaw->func(slave->mmap_areas, snd_pcm_mmap_offset(slave),
+			    areas, offset, 
+			    frames, pcm->setup.format.channels,
+			    mulaw->getput_idx);
+		err = snd_pcm_mmap_forward(slave, frames);
+		if (err < 0)
+			break;
+		assert((size_t)err == frames);
+		offset += err;
+		xfer += err;
+		snd_pcm_mmap_hw_forward(pcm, err);
+	}
+	if (xfer > 0) {
+		if (slave_sizep)
+			*slave_sizep = xfer;
+		return xfer;
+	}
+	return err;
+}
+
+static void snd_pcm_mulaw_dump(snd_pcm_t *pcm, FILE *fp)
+{
+	snd_pcm_mulaw_t *mulaw = pcm->private;
+	fprintf(fp, "Mu-Law conversion PCM (%s)\n", 
+		snd_pcm_format_name(mulaw->sformat));
+	if (pcm->valid_setup) {
+		fprintf(fp, "Its setup is:\n");
+		snd_pcm_dump_setup(pcm, fp);
+	}
+	fprintf(fp, "Slave: ");
+	snd_pcm_dump(mulaw->plug.slave, fp);
+}
+
+struct snd_pcm_ops snd_pcm_mulaw_ops = {
+	close: snd_pcm_plugin_close,
+	info: snd_pcm_plugin_info,
+	params_info: snd_pcm_mulaw_params_info,
+	params: snd_pcm_mulaw_params,
+	setup: snd_pcm_mulaw_setup,
+	channel_info: snd_pcm_plugin_channel_info,
+	channel_params: snd_pcm_plugin_channel_params,
+	channel_setup: snd_pcm_plugin_channel_setup,
+	dump: snd_pcm_mulaw_dump,
+	nonblock: snd_pcm_plugin_nonblock,
+	mmap_status: snd_pcm_plugin_mmap_status,
+	mmap_control: snd_pcm_plugin_mmap_control,
+	mmap_data: snd_pcm_plugin_mmap_data,
+	munmap_status: snd_pcm_plugin_munmap_status,
+	munmap_control: snd_pcm_plugin_munmap_control,
+	munmap_data: snd_pcm_plugin_munmap_data,
+};
+
+int snd_pcm_mulaw_open(snd_pcm_t **handlep, int sformat, snd_pcm_t *slave, int close_slave)
+{
+	snd_pcm_t *handle;
+	snd_pcm_mulaw_t *mulaw;
+	int err;
+	assert(handlep && slave);
+	if (snd_pcm_format_linear(sformat) != 1 &&
+	    sformat != SND_PCM_SFMT_MU_LAW)
+		return -EINVAL;
+	mulaw = calloc(1, sizeof(snd_pcm_mulaw_t));
+	if (!mulaw) {
+		return -ENOMEM;
+	}
+	mulaw->sformat = sformat;
+	mulaw->plug.read = snd_pcm_mulaw_read_areas;
+	mulaw->plug.write = snd_pcm_mulaw_write_areas;
+	mulaw->plug.slave = slave;
+	mulaw->plug.close_slave = close_slave;
+
+	handle = calloc(1, sizeof(snd_pcm_t));
+	if (!handle) {
+		free(mulaw);
+		return -ENOMEM;
+	}
+	handle->type = SND_PCM_TYPE_MULAW;
+	handle->stream = slave->stream;
+	handle->ops = &snd_pcm_mulaw_ops;
+	handle->op_arg = handle;
+	handle->fast_ops = &snd_pcm_plugin_fast_ops;
+	handle->fast_op_arg = handle;
+	handle->mode = slave->mode;
+	handle->private = mulaw;
+	err = snd_pcm_init(handle);
+	if (err < 0) {
+		snd_pcm_close(handle);
+		return err;
+	}
+	*handlep = handle;
+
+	return 0;
+}
+
+int _snd_pcm_mulaw_open(snd_pcm_t **pcmp, char *name,
+			 snd_config_t *conf, 
+			 int stream, int mode)
+{
+	snd_config_iterator_t i;
+	char *sname = NULL;
+	int err;
+	snd_pcm_t *spcm;
+	int sformat = -1;
+	snd_config_foreach(i, conf) {
+		snd_config_t *n = snd_config_entry(i);
+		if (strcmp(n->id, "comment") == 0)
+			continue;
+		if (strcmp(n->id, "type") == 0)
+			continue;
+		if (strcmp(n->id, "stream") == 0)
+			continue;
+		if (strcmp(n->id, "sname") == 0) {
+			err = snd_config_string_get(n, &sname);
+			if (err < 0)
+				return -EINVAL;
+			continue;
+		}
+		if (strcmp(n->id, "sformat") == 0) {
+			char *f;
+			err = snd_config_string_get(n, &f);
+			if (err < 0)
+				return -EINVAL;
+			sformat = snd_pcm_format_value(f);
+			if (sformat < 0)
+				return -EINVAL;
+			if (snd_pcm_format_linear(sformat) != 1 &&
+			    sformat != SND_PCM_SFMT_MU_LAW)
+				return -EINVAL;
+			continue;
+		}
+		return -EINVAL;
+	}
+	if (!sname || !sformat)
+		return -EINVAL;
+	/* This is needed cause snd_config_update may destroy config */
+	sname = strdup(sname);
+	if (!sname)
+		return  -ENOMEM;
+	err = snd_pcm_open(&spcm, sname, stream, mode);
+	free(sname);
+	if (err < 0)
+		return err;
+	err = snd_pcm_mulaw_open(pcmp, sformat, spcm, 1);
+	if (err < 0)
+		snd_pcm_close(spcm);
+	return err;
+}
+				
+