Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 346 insertions, 0 deletions

diff --git a/sound/core/oss/mulaw.c b/sound/core/oss/mulaw.c
new file mode 100644
index 000000000..fe27034f2
--- /dev/null
+++ b/sound/core/oss/mulaw.c
@@ -0,0 +1,346 @@
+/*
+ *  Mu-Law conversion Plug-In Interface
+ *  Copyright (c) 1999 by Jaroslav Kysela <perex@perex.cz>
+ *                        Uros Bizjak <uros@kss-loka.si>
+ *
+ *  Based on reference implementation by Sun Microsystems, Inc.
+ *
+ *   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 <linux/time.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include "pcm_plugin.h"
+
+#define	SIGN_BIT	(0x80)		/* Sign bit for a u-law byte. */
+#define	QUANT_MASK	(0xf)		/* Quantization field mask. */
+#define	NSEGS		(8)		/* Number of u-law segments. */
+#define	SEG_SHIFT	(4)		/* Left shift for segment number. */
+#define	SEG_MASK	(0x70)		/* Segment field mask. */
+
+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;
+}
+
+#define	BIAS		(0x84)		/* Bias for linear code. */
+
+/*
+ * linear2ulaw() - 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 linear2ulaw(int pcm_val)	/* 2's complement (16-bit range) */
+{
+	int mask;
+	int seg;
+	unsigned char uval;
+
+	/* Get the sign and the magnitude of the value. */
+	if (pcm_val < 0) {
+		pcm_val = BIAS - pcm_val;
+		mask = 0x7F;
+	} else {
+		pcm_val += BIAS;
+		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)) & 0xF);
+	return uval ^ mask;
+}
+
+/*
+ * ulaw2linear() - 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 ulaw2linear(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 & QUANT_MASK) << 3) + BIAS;
+	t <<= ((unsigned)u_val & SEG_MASK) >> SEG_SHIFT;
+
+	return ((u_val & SIGN_BIT) ? (BIAS - t) : (t - BIAS));
+}
+
+/*
+ *  Basic Mu-Law plugin
+ */
+
+typedef void (*mulaw_f)(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);
+
+struct mulaw_priv {
+	mulaw_f func;
+	int cvt_endian;			/* need endian conversion? */
+	unsigned int native_ofs;	/* byte offset in native format */
+	unsigned int copy_ofs;		/* byte offset in s16 format */
+	unsigned int native_bytes;	/* byte size of the native format */
+	unsigned int copy_bytes;	/* bytes to copy per conversion */
+	u16 flip; /* MSB flip for signedness, done after endian conversion */
+};
+
+static inline void cvt_s16_to_native(struct mulaw_priv *data,
+				     unsigned char *dst, u16 sample)
+{
+	sample ^= data->flip;
+	if (data->cvt_endian)
+		sample = swab16(sample);
+	if (data->native_bytes > data->copy_bytes)
+		memset(dst, 0, data->native_bytes);
+	memcpy(dst + data->native_ofs, (char *)&sample + data->copy_ofs,
+	       data->copy_bytes);
+}
+
+static void mulaw_decode(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)
+{
+	struct mulaw_priv *data = (struct mulaw_priv *)plugin->extra_data;
+	int channel;
+	int nchannels = plugin->src_format.channels;
+	for (channel = 0; channel < nchannels; ++channel) {
+		char *src;
+		char *dst;
+		int src_step, dst_step;
+		snd_pcm_uframes_t frames1;
+		if (!src_channels[channel].enabled) {
+			if (dst_channels[channel].wanted)
+				snd_pcm_area_silence(&dst_channels[channel].area, 0, frames, plugin->dst_format.format);
+			dst_channels[channel].enabled = 0;
+			continue;
+		}
+		dst_channels[channel].enabled = 1;
+		src = src_channels[channel].area.addr + src_channels[channel].area.first / 8;
+		dst = 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;
+		frames1 = frames;
+		while (frames1-- > 0) {
+			signed short sample = ulaw2linear(*src);
+			cvt_s16_to_native(data, dst, sample);
+			src += src_step;
+			dst += dst_step;
+		}
+	}
+}
+
+static inline signed short cvt_native_to_s16(struct mulaw_priv *data,
+					     unsigned char *src)
+{
+	u16 sample = 0;
+	memcpy((char *)&sample + data->copy_ofs, src + data->native_ofs,
+	       data->copy_bytes);
+	if (data->cvt_endian)
+		sample = swab16(sample);
+	sample ^= data->flip;
+	return (signed short)sample;
+}
+
+static void mulaw_encode(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)
+{
+	struct mulaw_priv *data = (struct mulaw_priv *)plugin->extra_data;
+	int channel;
+	int nchannels = plugin->src_format.channels;
+	for (channel = 0; channel < nchannels; ++channel) {
+		char *src;
+		char *dst;
+		int src_step, dst_step;
+		snd_pcm_uframes_t frames1;
+		if (!src_channels[channel].enabled) {
+			if (dst_channels[channel].wanted)
+				snd_pcm_area_silence(&dst_channels[channel].area, 0, frames, plugin->dst_format.format);
+			dst_channels[channel].enabled = 0;
+			continue;
+		}
+		dst_channels[channel].enabled = 1;
+		src = src_channels[channel].area.addr + src_channels[channel].area.first / 8;
+		dst = 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;
+		frames1 = frames;
+		while (frames1-- > 0) {
+			signed short sample = cvt_native_to_s16(data, src);
+			*dst = linear2ulaw(sample);
+			src += src_step;
+			dst += dst_step;
+		}
+	}
+}
+
+static snd_pcm_sframes_t mulaw_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)
+{
+	struct mulaw_priv *data;
+
+	if (snd_BUG_ON(!plugin || !src_channels || !dst_channels))
+		return -ENXIO;
+	if (frames == 0)
+		return 0;
+#ifdef CONFIG_SND_DEBUG
+	{
+		unsigned int channel;
+		for (channel = 0; channel < plugin->src_format.channels; channel++) {
+			if (snd_BUG_ON(src_channels[channel].area.first % 8 ||
+				       src_channels[channel].area.step % 8))
+				return -ENXIO;
+			if (snd_BUG_ON(dst_channels[channel].area.first % 8 ||
+				       dst_channels[channel].area.step % 8))
+				return -ENXIO;
+		}
+	}
+#endif
+	if (frames > dst_channels[0].frames)
+		frames = dst_channels[0].frames;
+	data = (struct mulaw_priv *)plugin->extra_data;
+	data->func(plugin, src_channels, dst_channels, frames);
+	return frames;
+}
+
+static void init_data(struct mulaw_priv *data, snd_pcm_format_t format)
+{
+#ifdef SNDRV_LITTLE_ENDIAN
+	data->cvt_endian = snd_pcm_format_big_endian(format) > 0;
+#else
+	data->cvt_endian = snd_pcm_format_little_endian(format) > 0;
+#endif
+	if (!snd_pcm_format_signed(format))
+		data->flip = 0x8000;
+	data->native_bytes = snd_pcm_format_physical_width(format) / 8;
+	data->copy_bytes = data->native_bytes < 2 ? 1 : 2;
+	if (snd_pcm_format_little_endian(format)) {
+		data->native_ofs = data->native_bytes - data->copy_bytes;
+		data->copy_ofs = 2 - data->copy_bytes;
+	} else {
+		/* S24 in 4bytes need an 1 byte offset */
+		data->native_ofs = data->native_bytes -
+			snd_pcm_format_width(format) / 8;
+	}
+}
+
+int snd_pcm_plugin_build_mulaw(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 mulaw_priv *data;
+	struct snd_pcm_plugin *plugin;
+	struct snd_pcm_plugin_format *format;
+	mulaw_f func;
+
+	if (snd_BUG_ON(!r_plugin))
+		return -ENXIO;
+	*r_plugin = NULL;
+
+	if (snd_BUG_ON(src_format->rate != dst_format->rate))
+		return -ENXIO;
+	if (snd_BUG_ON(src_format->channels != dst_format->channels))
+		return -ENXIO;
+
+	if (dst_format->format == SNDRV_PCM_FORMAT_MU_LAW) {
+		format = src_format;
+		func = mulaw_encode;
+	}
+	else if (src_format->format == SNDRV_PCM_FORMAT_MU_LAW) {
+		format = dst_format;
+		func = mulaw_decode;
+	}
+	else {
+		snd_BUG();
+		return -EINVAL;
+	}
+	if (!snd_pcm_format_linear(format->format))
+		return -EINVAL;
+
+	err = snd_pcm_plugin_build(plug, "Mu-Law<->linear conversion",
+				   src_format, dst_format,
+				   sizeof(struct mulaw_priv), &plugin);
+	if (err < 0)
+		return err;
+	data = (struct mulaw_priv *)plugin->extra_data;
+	data->func = func;
+	init_data(data, format->format);
+	plugin->transfer = mulaw_transfer;
+	*r_plugin = plugin;
+	return 0;
+}