/*
|
* 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;
|
}
|
