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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Linear conversion Plug-In
3 * Copyright (c) 1999 by Jaroslav Kysela <perex@suse.cz>,
4 * Abramo Bagnara <abramo@alsa-project.org>
5 *
6 *
7 * This library is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU Library General Public License as
9 * published by the Free Software Foundation; either version 2 of
10 * the License, or (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU Library General Public License for more details.
16 *
17 * You should have received a copy of the GNU Library General Public
18 * License along with this library; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 *
21 */
22
23#include <sound/driver.h>
Jaroslav Kysela21a34792006-01-13 09:12:11 +010024
25#ifdef CONFIG_SND_PCM_OSS_PLUGINS
26
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#include <linux/time.h>
28#include <sound/core.h>
29#include <sound/pcm.h>
30#include "pcm_plugin.h"
31
32/*
33 * Basic linear conversion plugin
34 */
35
Takashi Iwai6ac77bc2005-11-17 14:01:49 +010036struct linear_priv {
Linus Torvalds1da177e2005-04-16 15:20:36 -070037 int conv;
Takashi Iwai6ac77bc2005-11-17 14:01:49 +010038};
Linus Torvalds1da177e2005-04-16 15:20:36 -070039
Takashi Iwai6ac77bc2005-11-17 14:01:49 +010040static void convert(struct snd_pcm_plugin *plugin,
41 const struct snd_pcm_plugin_channel *src_channels,
42 struct snd_pcm_plugin_channel *dst_channels,
Linus Torvalds1da177e2005-04-16 15:20:36 -070043 snd_pcm_uframes_t frames)
44{
45#define CONV_LABELS
46#include "plugin_ops.h"
47#undef CONV_LABELS
Takashi Iwai6ac77bc2005-11-17 14:01:49 +010048 struct linear_priv *data = (struct linear_priv *)plugin->extra_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -070049 void *conv = conv_labels[data->conv];
50 int channel;
51 int nchannels = plugin->src_format.channels;
52 for (channel = 0; channel < nchannels; ++channel) {
53 char *src;
54 char *dst;
55 int src_step, dst_step;
56 snd_pcm_uframes_t frames1;
57 if (!src_channels[channel].enabled) {
58 if (dst_channels[channel].wanted)
59 snd_pcm_area_silence(&dst_channels[channel].area, 0, frames, plugin->dst_format.format);
60 dst_channels[channel].enabled = 0;
61 continue;
62 }
63 dst_channels[channel].enabled = 1;
64 src = src_channels[channel].area.addr + src_channels[channel].area.first / 8;
65 dst = dst_channels[channel].area.addr + dst_channels[channel].area.first / 8;
66 src_step = src_channels[channel].area.step / 8;
67 dst_step = dst_channels[channel].area.step / 8;
68 frames1 = frames;
69 while (frames1-- > 0) {
70 goto *conv;
71#define CONV_END after
72#include "plugin_ops.h"
73#undef CONV_END
74 after:
75 src += src_step;
76 dst += dst_step;
77 }
78 }
79}
80
Takashi Iwai6ac77bc2005-11-17 14:01:49 +010081static snd_pcm_sframes_t linear_transfer(struct snd_pcm_plugin *plugin,
82 const struct snd_pcm_plugin_channel *src_channels,
83 struct snd_pcm_plugin_channel *dst_channels,
Linus Torvalds1da177e2005-04-16 15:20:36 -070084 snd_pcm_uframes_t frames)
85{
Takashi Iwai6ac77bc2005-11-17 14:01:49 +010086 struct linear_priv *data;
Linus Torvalds1da177e2005-04-16 15:20:36 -070087
88 snd_assert(plugin != NULL && src_channels != NULL && dst_channels != NULL, return -ENXIO);
Takashi Iwai6ac77bc2005-11-17 14:01:49 +010089 data = (struct linear_priv *)plugin->extra_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -070090 if (frames == 0)
91 return 0;
92#ifdef CONFIG_SND_DEBUG
93 {
94 unsigned int channel;
95 for (channel = 0; channel < plugin->src_format.channels; channel++) {
96 snd_assert(src_channels[channel].area.first % 8 == 0 &&
97 src_channels[channel].area.step % 8 == 0,
98 return -ENXIO);
99 snd_assert(dst_channels[channel].area.first % 8 == 0 &&
100 dst_channels[channel].area.step % 8 == 0,
101 return -ENXIO);
102 }
103 }
104#endif
105 convert(plugin, src_channels, dst_channels, frames);
106 return frames;
107}
108
Takashi Iwai0534ab42006-01-13 12:09:12 +0100109static int conv_index(int src_format, int dst_format)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110{
111 int src_endian, dst_endian, sign, src_width, dst_width;
112
113 sign = (snd_pcm_format_signed(src_format) !=
114 snd_pcm_format_signed(dst_format));
115#ifdef SNDRV_LITTLE_ENDIAN
116 src_endian = snd_pcm_format_big_endian(src_format);
117 dst_endian = snd_pcm_format_big_endian(dst_format);
118#else
119 src_endian = snd_pcm_format_little_endian(src_format);
120 dst_endian = snd_pcm_format_little_endian(dst_format);
121#endif
122
123 if (src_endian < 0)
124 src_endian = 0;
125 if (dst_endian < 0)
126 dst_endian = 0;
127
128 src_width = snd_pcm_format_width(src_format) / 8 - 1;
129 dst_width = snd_pcm_format_width(dst_format) / 8 - 1;
130
131 return src_width * 32 + src_endian * 16 + sign * 8 + dst_width * 2 + dst_endian;
132}
133
Takashi Iwai6ac77bc2005-11-17 14:01:49 +0100134int snd_pcm_plugin_build_linear(struct snd_pcm_substream *plug,
135 struct snd_pcm_plugin_format *src_format,
136 struct snd_pcm_plugin_format *dst_format,
137 struct snd_pcm_plugin **r_plugin)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138{
139 int err;
Takashi Iwai6ac77bc2005-11-17 14:01:49 +0100140 struct linear_priv *data;
141 struct snd_pcm_plugin *plugin;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142
143 snd_assert(r_plugin != NULL, return -ENXIO);
144 *r_plugin = NULL;
145
146 snd_assert(src_format->rate == dst_format->rate, return -ENXIO);
147 snd_assert(src_format->channels == dst_format->channels, return -ENXIO);
148 snd_assert(snd_pcm_format_linear(src_format->format) &&
149 snd_pcm_format_linear(dst_format->format), return -ENXIO);
150
151 err = snd_pcm_plugin_build(plug, "linear format conversion",
152 src_format, dst_format,
Takashi Iwai6ac77bc2005-11-17 14:01:49 +0100153 sizeof(struct linear_priv), &plugin);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154 if (err < 0)
155 return err;
Takashi Iwai6ac77bc2005-11-17 14:01:49 +0100156 data = (struct linear_priv *)plugin->extra_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157 data->conv = conv_index(src_format->format, dst_format->format);
158 plugin->transfer = linear_transfer;
159 *r_plugin = plugin;
160 return 0;
161}
Jaroslav Kysela21a34792006-01-13 09:12:11 +0100162
163#endif