mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
111 lines
3.1 KiB
111 lines
3.1 KiB
/* |
|
* Route Plug-In |
|
* Copyright (c) 2000 by Abramo Bagnara <[email protected]> |
|
* |
|
* |
|
* 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 void zero_areas(struct snd_pcm_plugin_channel *dvp, int ndsts, |
|
snd_pcm_uframes_t frames, snd_pcm_format_t format) |
|
{ |
|
int dst = 0; |
|
for (; dst < ndsts; ++dst) { |
|
if (dvp->wanted) |
|
snd_pcm_area_silence(&dvp->area, 0, frames, format); |
|
dvp->enabled = 0; |
|
dvp++; |
|
} |
|
} |
|
|
|
static inline void copy_area(const struct snd_pcm_plugin_channel *src_channel, |
|
struct snd_pcm_plugin_channel *dst_channel, |
|
snd_pcm_uframes_t frames, snd_pcm_format_t format) |
|
{ |
|
dst_channel->enabled = 1; |
|
snd_pcm_area_copy(&src_channel->area, 0, &dst_channel->area, 0, frames, format); |
|
} |
|
|
|
static snd_pcm_sframes_t route_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) |
|
{ |
|
int nsrcs, ndsts, dst; |
|
struct snd_pcm_plugin_channel *dvp; |
|
snd_pcm_format_t format; |
|
|
|
if (snd_BUG_ON(!plugin || !src_channels || !dst_channels)) |
|
return -ENXIO; |
|
if (frames == 0) |
|
return 0; |
|
if (frames > dst_channels[0].frames) |
|
frames = dst_channels[0].frames; |
|
|
|
nsrcs = plugin->src_format.channels; |
|
ndsts = plugin->dst_format.channels; |
|
|
|
format = plugin->dst_format.format; |
|
dvp = dst_channels; |
|
if (nsrcs <= 1) { |
|
/* expand to all channels */ |
|
for (dst = 0; dst < ndsts; ++dst) { |
|
copy_area(src_channels, dvp, frames, format); |
|
dvp++; |
|
} |
|
return frames; |
|
} |
|
|
|
for (dst = 0; dst < ndsts && dst < nsrcs; ++dst) { |
|
copy_area(src_channels, dvp, frames, format); |
|
dvp++; |
|
src_channels++; |
|
} |
|
if (dst < ndsts) |
|
zero_areas(dvp, ndsts - dst, frames, format); |
|
return frames; |
|
} |
|
|
|
int snd_pcm_plugin_build_route(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) |
|
{ |
|
struct snd_pcm_plugin *plugin; |
|
int err; |
|
|
|
if (snd_BUG_ON(!r_plugin)) |
|
return -ENXIO; |
|
*r_plugin = NULL; |
|
if (snd_BUG_ON(src_format->rate != dst_format->rate)) |
|
return -ENXIO; |
|
if (snd_BUG_ON(src_format->format != dst_format->format)) |
|
return -ENXIO; |
|
|
|
err = snd_pcm_plugin_build(plug, "route conversion", |
|
src_format, dst_format, 0, &plugin); |
|
if (err < 0) |
|
return err; |
|
|
|
plugin->transfer = route_transfer; |
|
*r_plugin = plugin; |
|
return 0; |
|
}
|
|
|