summary refs log tree commit diff
path: root/sound/core/oss/rate.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /sound/core/oss/rate.c
downloadlinux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
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!
Diffstat (limited to 'sound/core/oss/rate.c')
-rw-r--r--sound/core/oss/rate.c378
1 files changed, 378 insertions, 0 deletions
diff --git a/sound/core/oss/rate.c b/sound/core/oss/rate.c
new file mode 100644
index 000000000000..1096ec186714
--- /dev/null
+++ b/sound/core/oss/rate.c
@@ -0,0 +1,378 @@
+/*
+ *  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>
+#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
+ */
+
+typedef struct {
+	signed short last_S1;
+	signed short last_S2;
+} rate_channel_t;
+ 
+typedef void (*rate_f)(snd_pcm_plugin_t *plugin,
+		       const snd_pcm_plugin_channel_t *src_channels,
+		       snd_pcm_plugin_channel_t *dst_channels,
+		       int src_frames, int dst_frames);
+
+typedef struct rate_private_data {
+	unsigned int pitch;
+	unsigned int pos;
+	rate_f func;
+	int get, put;
+	snd_pcm_sframes_t old_src_frames, old_dst_frames;
+	rate_channel_t channels[0];
+} rate_t;
+
+static void rate_init(snd_pcm_plugin_t *plugin)
+{
+	unsigned int channel;
+	rate_t *data = (rate_t *)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(snd_pcm_plugin_t *plugin,
+			    const snd_pcm_plugin_channel_t *src_channels,
+			    snd_pcm_plugin_channel_t *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;
+	rate_t *data = (rate_t *)plugin->extra_data;
+	rate_channel_t *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(snd_pcm_plugin_t *plugin,
+			    const snd_pcm_plugin_channel_t *src_channels,
+			    snd_pcm_plugin_channel_t *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;
+	rate_t *data = (rate_t *)plugin->extra_data;
+	rate_channel_t *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(snd_pcm_plugin_t *plugin, snd_pcm_uframes_t frames)
+{
+	rate_t *data;
+	snd_pcm_sframes_t res;
+
+	snd_assert(plugin != NULL, return -ENXIO);
+	if (frames == 0)
+		return 0;
+	data = (rate_t *)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(snd_pcm_plugin_t *plugin, snd_pcm_uframes_t frames)
+{
+	rate_t *data;
+	snd_pcm_sframes_t res;
+
+	snd_assert(plugin != NULL, return -ENXIO);
+	if (frames == 0)
+		return 0;
+	data = (rate_t *)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(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)
+{
+	snd_pcm_uframes_t dst_frames;
+	rate_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
+
+	dst_frames = rate_dst_frames(plugin, frames);
+	if (dst_frames > dst_channels[0].frames)
+		dst_frames = dst_channels[0].frames;
+	data = (rate_t *)plugin->extra_data;
+	data->func(plugin, src_channels, dst_channels, frames, dst_frames);
+	return dst_frames;
+}
+
+static int rate_action(snd_pcm_plugin_t *plugin,
+		       snd_pcm_plugin_action_t action,
+		       unsigned long udata ATTRIBUTE_UNUSED)
+{
+	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(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;
+	rate_t *data;
+	snd_pcm_plugin_t *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(rate_t) + src_format->channels * sizeof(rate_channel_t),
+				   &plugin);
+	if (err < 0)
+		return err;
+	data = (rate_t *)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;
+}