/* *  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;}