1 files changed, 87 insertions, 0 deletions
diff --git a/sound/core/oss/copy.c b/sound/core/oss/copy.c
new file mode 100644
index 000000000000..edecbe7417bd
--- /dev/null
+++ b/sound/core/oss/copy.c
@@ -0,0 +1,87 @@
+/*
+ *  Linear conversion Plug-In
+ *  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., 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"
+
+static snd_pcm_sframes_t copy_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)
+{
+	unsigned int channel;
+	unsigned int nchannels;
+
+	snd_assert(plugin != NULL && src_channels != NULL && dst_channels != NULL, return -ENXIO);
+	if (frames == 0)
+		return 0;
+	nchannels = plugin->src_format.channels;
+	for (channel = 0; channel < nchannels; channel++) {
+		snd_assert(src_channels->area.first % 8 == 0 &&
+			   src_channels->area.step % 8 == 0,
+			   return -ENXIO);
+		snd_assert(dst_channels->area.first % 8 == 0 &&
+			   dst_channels->area.step % 8 == 0,
+			   return -ENXIO);
+		if (!src_channels->enabled) {
+			if (dst_channels->wanted)
+				snd_pcm_area_silence(&dst_channels->area, 0, frames, plugin->dst_format.format);
+			dst_channels->enabled = 0;
+			continue;
+		}
+		dst_channels->enabled = 1;
+		snd_pcm_area_copy(&src_channels->area, 0, &dst_channels->area, 0, frames, plugin->src_format.format);
+		src_channels++;
+		dst_channels++;
+	}
+	return frames;
+}
+
+int snd_pcm_plugin_build_copy(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;
+	snd_pcm_plugin_t *plugin;
+	int width;
+
+	snd_assert(r_plugin != NULL, return -ENXIO);
+	*r_plugin = NULL;
+
+	snd_assert(src_format->format == dst_format->format, return -ENXIO);
+	snd_assert(src_format->rate == dst_format->rate, return -ENXIO);
+	snd_assert(src_format->channels == dst_format->channels, return -ENXIO);
+
+	width = snd_pcm_format_physical_width(src_format->format);
+	snd_assert(width > 0, return -ENXIO);
+
+	err = snd_pcm_plugin_build(plug, "copy", src_format, dst_format,
+				   0, &plugin);
+	if (err < 0)
+		return err;
+	plugin->transfer = copy_transfer;
+	*r_plugin = plugin;
+	return 0;
+}