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/*
* 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;
}
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