1 files changed, 92 insertions, 0 deletions
diff --git a/sound/core/oss/copy.c b/sound/core/oss/copy.c
new file mode 100644
index 000000000..05b58d4fc
--- /dev/null
+++ b/sound/core/oss/copy.c
@@ -0,0 +1,92 @@
+/*
+ *  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 <linux/time.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include "pcm_plugin.h"
+
+static snd_pcm_sframes_t copy_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)
+{
+	unsigned int channel;
+	unsigned int nchannels;
+
+	if (snd_BUG_ON(!plugin || !src_channels || !dst_channels))
+		return -ENXIO;
+	if (frames == 0)
+		return 0;
+	nchannels = plugin->src_format.channels;
+	for (channel = 0; channel < nchannels; channel++) {
+		if (snd_BUG_ON(src_channels->area.first % 8 ||
+			       src_channels->area.step % 8))
+			return -ENXIO;
+		if (snd_BUG_ON(dst_channels->area.first % 8 ||
+			       dst_channels->area.step % 8))
+			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(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 snd_pcm_plugin *plugin;
+	int width;
+
+	if (snd_BUG_ON(!r_plugin))
+		return -ENXIO;
+	*r_plugin = NULL;
+
+	if (snd_BUG_ON(src_format->format != dst_format->format))
+		return -ENXIO;
+	if (snd_BUG_ON(src_format->rate != dst_format->rate))
+		return -ENXIO;
+	if (snd_BUG_ON(src_format->channels != dst_format->channels))
+		return -ENXIO;
+
+	width = snd_pcm_format_physical_width(src_format->format);
+	if (snd_BUG_ON(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;
+}