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v4.6
  1/*
  2 *  Route Plug-In
  3 *  Copyright (c) 2000 by Abramo Bagnara <abramo@alsa-project.org>
  4 *
  5 *
  6 *   This library is free software; you can redistribute it and/or modify
  7 *   it under the terms of the GNU Library General Public License as
  8 *   published by the Free Software Foundation; either version 2 of
  9 *   the License, or (at your option) any later version.
 10 *
 11 *   This program is distributed in the hope that it will be useful,
 12 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 13 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 14 *   GNU Library General Public License for more details.
 15 *
 16 *   You should have received a copy of the GNU Library General Public
 17 *   License along with this library; if not, write to the Free Software
 18 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 19 *
 20 */
 21
 22#include <linux/time.h>
 23#include <sound/core.h>
 24#include <sound/pcm.h>
 25#include "pcm_plugin.h"
 26
 27static void zero_areas(struct snd_pcm_plugin_channel *dvp, int ndsts,
 28		       snd_pcm_uframes_t frames, snd_pcm_format_t format)
 29{
 30	int dst = 0;
 31	for (; dst < ndsts; ++dst) {
 32		if (dvp->wanted)
 33			snd_pcm_area_silence(&dvp->area, 0, frames, format);
 34		dvp->enabled = 0;
 35		dvp++;
 36	}
 37}
 38
 39static inline void copy_area(const struct snd_pcm_plugin_channel *src_channel,
 40			     struct snd_pcm_plugin_channel *dst_channel,
 41			     snd_pcm_uframes_t frames, snd_pcm_format_t format)
 42{
 43	dst_channel->enabled = 1;
 44	snd_pcm_area_copy(&src_channel->area, 0, &dst_channel->area, 0, frames, format);
 45}
 46
 47static snd_pcm_sframes_t route_transfer(struct snd_pcm_plugin *plugin,
 48					const struct snd_pcm_plugin_channel *src_channels,
 49					struct snd_pcm_plugin_channel *dst_channels,
 50					snd_pcm_uframes_t frames)
 51{
 52	int nsrcs, ndsts, dst;
 53	struct snd_pcm_plugin_channel *dvp;
 54	snd_pcm_format_t format;
 55
 56	if (snd_BUG_ON(!plugin || !src_channels || !dst_channels))
 57		return -ENXIO;
 58	if (frames == 0)
 59		return 0;
 
 
 60
 61	nsrcs = plugin->src_format.channels;
 62	ndsts = plugin->dst_format.channels;
 63
 64	format = plugin->dst_format.format;
 65	dvp = dst_channels;
 66	if (nsrcs <= 1) {
 67		/* expand to all channels */
 68		for (dst = 0; dst < ndsts; ++dst) {
 69			copy_area(src_channels, dvp, frames, format);
 70			dvp++;
 71		}
 72		return frames;
 73	}
 74
 75	for (dst = 0; dst < ndsts && dst < nsrcs; ++dst) {
 76		copy_area(src_channels, dvp, frames, format);
 77		dvp++;
 78		src_channels++;
 79	}
 80	if (dst < ndsts)
 81		zero_areas(dvp, ndsts - dst, frames, format);
 82	return frames;
 83}
 84
 85int snd_pcm_plugin_build_route(struct snd_pcm_substream *plug,
 86			       struct snd_pcm_plugin_format *src_format,
 87			       struct snd_pcm_plugin_format *dst_format,
 88			       struct snd_pcm_plugin **r_plugin)
 89{
 90	struct snd_pcm_plugin *plugin;
 91	int err;
 92
 93	if (snd_BUG_ON(!r_plugin))
 94		return -ENXIO;
 95	*r_plugin = NULL;
 96	if (snd_BUG_ON(src_format->rate != dst_format->rate))
 97		return -ENXIO;
 98	if (snd_BUG_ON(src_format->format != dst_format->format))
 99		return -ENXIO;
100
101	err = snd_pcm_plugin_build(plug, "route conversion",
102				   src_format, dst_format, 0, &plugin);
103	if (err < 0)
104		return err;
105
106	plugin->transfer = route_transfer;
107	*r_plugin = plugin;
108	return 0;
109}
v6.2
  1/*
  2 *  Route Plug-In
  3 *  Copyright (c) 2000 by Abramo Bagnara <abramo@alsa-project.org>
  4 *
  5 *
  6 *   This library is free software; you can redistribute it and/or modify
  7 *   it under the terms of the GNU Library General Public License as
  8 *   published by the Free Software Foundation; either version 2 of
  9 *   the License, or (at your option) any later version.
 10 *
 11 *   This program is distributed in the hope that it will be useful,
 12 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 13 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 14 *   GNU Library General Public License for more details.
 15 *
 16 *   You should have received a copy of the GNU Library General Public
 17 *   License along with this library; if not, write to the Free Software
 18 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 19 *
 20 */
 21
 22#include <linux/time.h>
 23#include <sound/core.h>
 24#include <sound/pcm.h>
 25#include "pcm_plugin.h"
 26
 27static void zero_areas(struct snd_pcm_plugin_channel *dvp, int ndsts,
 28		       snd_pcm_uframes_t frames, snd_pcm_format_t format)
 29{
 30	int dst = 0;
 31	for (; dst < ndsts; ++dst) {
 32		if (dvp->wanted)
 33			snd_pcm_area_silence(&dvp->area, 0, frames, format);
 34		dvp->enabled = 0;
 35		dvp++;
 36	}
 37}
 38
 39static inline void copy_area(const struct snd_pcm_plugin_channel *src_channel,
 40			     struct snd_pcm_plugin_channel *dst_channel,
 41			     snd_pcm_uframes_t frames, snd_pcm_format_t format)
 42{
 43	dst_channel->enabled = 1;
 44	snd_pcm_area_copy(&src_channel->area, 0, &dst_channel->area, 0, frames, format);
 45}
 46
 47static snd_pcm_sframes_t route_transfer(struct snd_pcm_plugin *plugin,
 48					const struct snd_pcm_plugin_channel *src_channels,
 49					struct snd_pcm_plugin_channel *dst_channels,
 50					snd_pcm_uframes_t frames)
 51{
 52	int nsrcs, ndsts, dst;
 53	struct snd_pcm_plugin_channel *dvp;
 54	snd_pcm_format_t format;
 55
 56	if (snd_BUG_ON(!plugin || !src_channels || !dst_channels))
 57		return -ENXIO;
 58	if (frames == 0)
 59		return 0;
 60	if (frames > dst_channels[0].frames)
 61		frames = dst_channels[0].frames;
 62
 63	nsrcs = plugin->src_format.channels;
 64	ndsts = plugin->dst_format.channels;
 65
 66	format = plugin->dst_format.format;
 67	dvp = dst_channels;
 68	if (nsrcs <= 1) {
 69		/* expand to all channels */
 70		for (dst = 0; dst < ndsts; ++dst) {
 71			copy_area(src_channels, dvp, frames, format);
 72			dvp++;
 73		}
 74		return frames;
 75	}
 76
 77	for (dst = 0; dst < ndsts && dst < nsrcs; ++dst) {
 78		copy_area(src_channels, dvp, frames, format);
 79		dvp++;
 80		src_channels++;
 81	}
 82	if (dst < ndsts)
 83		zero_areas(dvp, ndsts - dst, frames, format);
 84	return frames;
 85}
 86
 87int snd_pcm_plugin_build_route(struct snd_pcm_substream *plug,
 88			       struct snd_pcm_plugin_format *src_format,
 89			       struct snd_pcm_plugin_format *dst_format,
 90			       struct snd_pcm_plugin **r_plugin)
 91{
 92	struct snd_pcm_plugin *plugin;
 93	int err;
 94
 95	if (snd_BUG_ON(!r_plugin))
 96		return -ENXIO;
 97	*r_plugin = NULL;
 98	if (snd_BUG_ON(src_format->rate != dst_format->rate))
 99		return -ENXIO;
100	if (snd_BUG_ON(src_format->format != dst_format->format))
101		return -ENXIO;
102
103	err = snd_pcm_plugin_build(plug, "route conversion",
104				   src_format, dst_format, 0, &plugin);
105	if (err < 0)
106		return err;
107
108	plugin->transfer = route_transfer;
109	*r_plugin = plugin;
110	return 0;
111}