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-rw-r--r--sound/core/oss/linear.c158
1 files changed, 158 insertions, 0 deletions
diff --git a/sound/core/oss/linear.c b/sound/core/oss/linear.c
new file mode 100644
index 00000000000..12ed27a57b2
--- /dev/null
+++ b/sound/core/oss/linear.c
@@ -0,0 +1,158 @@
+/*
+ * Linear conversion Plug-In
+ * Copyright (c) 1999 by Jaroslav Kysela <perex@suse.cz>,
+ * 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., 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"
+
+/*
+ * Basic linear conversion plugin
+ */
+
+typedef struct linear_private_data {
+ int conv;
+} linear_t;
+
+static void convert(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 CONV_LABELS
+#include "plugin_ops.h"
+#undef CONV_LABELS
+ linear_t *data = (linear_t *)plugin->extra_data;
+ void *conv = conv_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) {
+ goto *conv;
+#define CONV_END after
+#include "plugin_ops.h"
+#undef CONV_END
+ after:
+ src += src_step;
+ dst += dst_step;
+ }
+ }
+}
+
+static snd_pcm_sframes_t linear_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)
+{
+ linear_t *data;
+
+ snd_assert(plugin != NULL && src_channels != NULL && dst_channels != NULL, return -ENXIO);
+ data = (linear_t *)plugin->extra_data;
+ 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
+ convert(plugin, src_channels, dst_channels, frames);
+ return frames;
+}
+
+int conv_index(int src_format, int dst_format)
+{
+ int src_endian, dst_endian, sign, src_width, dst_width;
+
+ sign = (snd_pcm_format_signed(src_format) !=
+ snd_pcm_format_signed(dst_format));
+#ifdef SNDRV_LITTLE_ENDIAN
+ src_endian = snd_pcm_format_big_endian(src_format);
+ dst_endian = snd_pcm_format_big_endian(dst_format);
+#else
+ src_endian = snd_pcm_format_little_endian(src_format);
+ dst_endian = snd_pcm_format_little_endian(dst_format);
+#endif
+
+ if (src_endian < 0)
+ src_endian = 0;
+ if (dst_endian < 0)
+ dst_endian = 0;
+
+ src_width = snd_pcm_format_width(src_format) / 8 - 1;
+ dst_width = snd_pcm_format_width(dst_format) / 8 - 1;
+
+ return src_width * 32 + src_endian * 16 + sign * 8 + dst_width * 2 + dst_endian;
+}
+
+int snd_pcm_plugin_build_linear(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;
+ struct linear_private_data *data;
+ snd_pcm_plugin_t *plugin;
+
+ 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);
+ snd_assert(snd_pcm_format_linear(src_format->format) &&
+ snd_pcm_format_linear(dst_format->format), return -ENXIO);
+
+ err = snd_pcm_plugin_build(plug, "linear format conversion",
+ src_format, dst_format,
+ sizeof(linear_t), &plugin);
+ if (err < 0)
+ return err;
+ data = (linear_t *)plugin->extra_data;
+ data->conv = conv_index(src_format->format, dst_format->format);
+ plugin->transfer = linear_transfer;
+ *r_plugin = plugin;
+ return 0;
+}