Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 308 insertions, 0 deletions

diff --git a/sound/core/oss/mulaw.c b/sound/core/oss/mulaw.c
new file mode 100644
index 000000000000..44ec4c66eb19
--- /dev/null
+++ b/sound/core/oss/mulaw.c
@@ -0,0 +1,308 @@
+/*
+ *  Mu-Law conversion Plug-In Interface
+ *  Copyright (c) 1999 by Jaroslav Kysela <perex@suse.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 <sound/driver.h>
+#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)(snd_pcm_plugin_t *plugin,
+			const snd_pcm_plugin_channel_t *src_channels,
+			snd_pcm_plugin_channel_t *dst_channels,
+			snd_pcm_uframes_t frames);
+
+typedef struct mulaw_private_data {
+	mulaw_f func;
+	int conv;
+} mulaw_t;
+
+static void mulaw_decode(snd_pcm_plugin_t *plugin,
+			const snd_pcm_plugin_channel_t *src_channels,
+			snd_pcm_plugin_channel_t *dst_channels,
+			snd_pcm_uframes_t frames)
+{
+#define PUT_S16_LABELS
+#include "plugin_ops.h"
+#undef PUT_S16_LABELS
+	mulaw_t *data = (mulaw_t *)plugin->extra_data;
+	void *put = put_s16_labels[data->conv];
+	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);
+			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_plugin_t *plugin,
+			const snd_pcm_plugin_channel_t *src_channels,
+			snd_pcm_plugin_channel_t *dst_channels,
+			snd_pcm_uframes_t frames)
+{
+#define GET_S16_LABELS
+#include "plugin_ops.h"
+#undef GET_S16_LABELS
+	mulaw_t *data = (mulaw_t *)plugin->extra_data;
+	void *get = get_s16_labels[data->conv];
+	int channel;
+	int nchannels = plugin->src_format.channels;
+	signed short sample = 0;
+	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) {
+			goto *get;
+#define GET_S16_END after
+#include "plugin_ops.h"
+#undef GET_S16_END
+		after:
+			*dst = linear2ulaw(sample);
+			src += src_step;
+			dst += dst_step;
+		}
+	}
+}
+
+static snd_pcm_sframes_t mulaw_transfer(snd_pcm_plugin_t *plugin,
+			      const snd_pcm_plugin_channel_t *src_channels,
+			      snd_pcm_plugin_channel_t *dst_channels,
+			      snd_pcm_uframes_t frames)
+{
+	mulaw_t *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
+	data = (mulaw_t *)plugin->extra_data;
+	data->func(plugin, src_channels, dst_channels, frames);
+	return frames;
+}
+
+int snd_pcm_plugin_build_mulaw(snd_pcm_plug_t *plug,
+			       snd_pcm_plugin_format_t *src_format,
+			       snd_pcm_plugin_format_t *dst_format,
+			       snd_pcm_plugin_t **r_plugin)
+{
+	int err;
+	mulaw_t *data;
+	snd_pcm_plugin_t *plugin;
+	snd_pcm_plugin_format_t *format;
+	mulaw_f func;
+
+	snd_assert(r_plugin != NULL, return -ENXIO);
+	*r_plugin = NULL;
+
+	snd_assert(src_format->rate == dst_format->rate, return -ENXIO);
+	snd_assert(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;
+	}
+	snd_assert(snd_pcm_format_linear(format->format) != 0, return -ENXIO);
+
+	err = snd_pcm_plugin_build(plug, "Mu-Law<->linear conversion",
+				   src_format, dst_format,
+				   sizeof(mulaw_t), &plugin);
+	if (err < 0)
+		return err;
+	data = (mulaw_t*)plugin->extra_data;
+	data->func = func;
+	data->conv = getput_index(format->format);
+	snd_assert(data->conv >= 0 && data->conv < 4*2*2, return -EINVAL);
+	plugin->transfer = mulaw_transfer;
+	*r_plugin = plugin;
+	return 0;
+}