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1/*
2 * Linear conversion Plug-In
3 * Copyright (c) 1999 by Jaroslav Kysela <perex@perex.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 <linux/time.h>
24#include <sound/core.h>
25#include <sound/pcm.h>
26#include "pcm_plugin.h"
27
28/*
29 * Basic linear conversion plugin
30 */
31
32struct linear_priv {
33 int cvt_endian; /* need endian conversion? */
34 unsigned int src_ofs; /* byte offset in source format */
35 unsigned int dst_ofs; /* byte soffset in destination format */
36 unsigned int copy_ofs; /* byte offset in temporary u32 data */
37 unsigned int dst_bytes; /* byte size of destination format */
38 unsigned int copy_bytes; /* bytes to copy per conversion */
39 unsigned int flip; /* MSB flip for signeness, done after endian conv */
40};
41
42static inline void do_convert(struct linear_priv *data,
43 unsigned char *dst, unsigned char *src)
44{
45 unsigned int tmp = 0;
46 unsigned char *p = (unsigned char *)&tmp;
47
48 memcpy(p + data->copy_ofs, src + data->src_ofs, data->copy_bytes);
49 if (data->cvt_endian)
50 tmp = swab32(tmp);
51 tmp ^= data->flip;
52 memcpy(dst, p + data->dst_ofs, data->dst_bytes);
53}
54
55static void convert(struct snd_pcm_plugin *plugin,
56 const struct snd_pcm_plugin_channel *src_channels,
57 struct snd_pcm_plugin_channel *dst_channels,
58 snd_pcm_uframes_t frames)
59{
60 struct linear_priv *data = (struct linear_priv *)plugin->extra_data;
61 int channel;
62 int nchannels = plugin->src_format.channels;
63 for (channel = 0; channel < nchannels; ++channel) {
64 char *src;
65 char *dst;
66 int src_step, dst_step;
67 snd_pcm_uframes_t frames1;
68 if (!src_channels[channel].enabled) {
69 if (dst_channels[channel].wanted)
70 snd_pcm_area_silence(&dst_channels[channel].area, 0, frames, plugin->dst_format.format);
71 dst_channels[channel].enabled = 0;
72 continue;
73 }
74 dst_channels[channel].enabled = 1;
75 src = src_channels[channel].area.addr + src_channels[channel].area.first / 8;
76 dst = dst_channels[channel].area.addr + dst_channels[channel].area.first / 8;
77 src_step = src_channels[channel].area.step / 8;
78 dst_step = dst_channels[channel].area.step / 8;
79 frames1 = frames;
80 while (frames1-- > 0) {
81 do_convert(data, dst, src);
82 src += src_step;
83 dst += dst_step;
84 }
85 }
86}
87
88static snd_pcm_sframes_t linear_transfer(struct snd_pcm_plugin *plugin,
89 const struct snd_pcm_plugin_channel *src_channels,
90 struct snd_pcm_plugin_channel *dst_channels,
91 snd_pcm_uframes_t frames)
92{
93 if (snd_BUG_ON(!plugin || !src_channels || !dst_channels))
94 return -ENXIO;
95 if (frames == 0)
96 return 0;
97#ifdef CONFIG_SND_DEBUG
98 {
99 unsigned int channel;
100 for (channel = 0; channel < plugin->src_format.channels; channel++) {
101 if (snd_BUG_ON(src_channels[channel].area.first % 8 ||
102 src_channels[channel].area.step % 8))
103 return -ENXIO;
104 if (snd_BUG_ON(dst_channels[channel].area.first % 8 ||
105 dst_channels[channel].area.step % 8))
106 return -ENXIO;
107 }
108 }
109#endif
110 convert(plugin, src_channels, dst_channels, frames);
111 return frames;
112}
113
114static void init_data(struct linear_priv *data,
115 snd_pcm_format_t src_format, snd_pcm_format_t dst_format)
116{
117 int src_le, dst_le, src_bytes, dst_bytes;
118
119 src_bytes = snd_pcm_format_width(src_format) / 8;
120 dst_bytes = snd_pcm_format_width(dst_format) / 8;
121 src_le = snd_pcm_format_little_endian(src_format) > 0;
122 dst_le = snd_pcm_format_little_endian(dst_format) > 0;
123
124 data->dst_bytes = dst_bytes;
125 data->cvt_endian = src_le != dst_le;
126 data->copy_bytes = src_bytes < dst_bytes ? src_bytes : dst_bytes;
127 if (src_le) {
128 data->copy_ofs = 4 - data->copy_bytes;
129 data->src_ofs = src_bytes - data->copy_bytes;
130 } else
131 data->src_ofs = snd_pcm_format_physical_width(src_format) / 8 -
132 src_bytes;
133 if (dst_le)
134 data->dst_ofs = 4 - data->dst_bytes;
135 else
136 data->dst_ofs = snd_pcm_format_physical_width(dst_format) / 8 -
137 dst_bytes;
138 if (snd_pcm_format_signed(src_format) !=
139 snd_pcm_format_signed(dst_format)) {
140 if (dst_le)
141 data->flip = (__force u32)cpu_to_le32(0x80000000);
142 else
143 data->flip = (__force u32)cpu_to_be32(0x80000000);
144 }
145}
146
147int snd_pcm_plugin_build_linear(struct snd_pcm_substream *plug,
148 struct snd_pcm_plugin_format *src_format,
149 struct snd_pcm_plugin_format *dst_format,
150 struct snd_pcm_plugin **r_plugin)
151{
152 int err;
153 struct linear_priv *data;
154 struct snd_pcm_plugin *plugin;
155
156 if (snd_BUG_ON(!r_plugin))
157 return -ENXIO;
158 *r_plugin = NULL;
159
160 if (snd_BUG_ON(src_format->rate != dst_format->rate))
161 return -ENXIO;
162 if (snd_BUG_ON(src_format->channels != dst_format->channels))
163 return -ENXIO;
164 if (snd_BUG_ON(!snd_pcm_format_linear(src_format->format) ||
165 !snd_pcm_format_linear(dst_format->format)))
166 return -ENXIO;
167
168 err = snd_pcm_plugin_build(plug, "linear format conversion",
169 src_format, dst_format,
170 sizeof(struct linear_priv), &plugin);
171 if (err < 0)
172 return err;
173 data = (struct linear_priv *)plugin->extra_data;
174 init_data(data, src_format->format, dst_format->format);
175 plugin->transfer = linear_transfer;
176 *r_plugin = plugin;
177 return 0;
178}
1/*
2 * Linear conversion Plug-In
3 * Copyright (c) 1999 by Jaroslav Kysela <perex@perex.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 <linux/time.h>
24#include <sound/core.h>
25#include <sound/pcm.h>
26#include "pcm_plugin.h"
27
28/*
29 * Basic linear conversion plugin
30 */
31
32struct linear_priv {
33 int cvt_endian; /* need endian conversion? */
34 unsigned int src_ofs; /* byte offset in source format */
35 unsigned int dst_ofs; /* byte soffset in destination format */
36 unsigned int copy_ofs; /* byte offset in temporary u32 data */
37 unsigned int dst_bytes; /* byte size of destination format */
38 unsigned int copy_bytes; /* bytes to copy per conversion */
39 unsigned int flip; /* MSB flip for signeness, done after endian conv */
40};
41
42static inline void do_convert(struct linear_priv *data,
43 unsigned char *dst, unsigned char *src)
44{
45 unsigned int tmp = 0;
46 unsigned char *p = (unsigned char *)&tmp;
47
48 memcpy(p + data->copy_ofs, src + data->src_ofs, data->copy_bytes);
49 if (data->cvt_endian)
50 tmp = swab32(tmp);
51 tmp ^= data->flip;
52 memcpy(dst, p + data->dst_ofs, data->dst_bytes);
53}
54
55static void convert(struct snd_pcm_plugin *plugin,
56 const struct snd_pcm_plugin_channel *src_channels,
57 struct snd_pcm_plugin_channel *dst_channels,
58 snd_pcm_uframes_t frames)
59{
60 struct linear_priv *data = (struct linear_priv *)plugin->extra_data;
61 int channel;
62 int nchannels = plugin->src_format.channels;
63 for (channel = 0; channel < nchannels; ++channel) {
64 char *src;
65 char *dst;
66 int src_step, dst_step;
67 snd_pcm_uframes_t frames1;
68 if (!src_channels[channel].enabled) {
69 if (dst_channels[channel].wanted)
70 snd_pcm_area_silence(&dst_channels[channel].area, 0, frames, plugin->dst_format.format);
71 dst_channels[channel].enabled = 0;
72 continue;
73 }
74 dst_channels[channel].enabled = 1;
75 src = src_channels[channel].area.addr + src_channels[channel].area.first / 8;
76 dst = dst_channels[channel].area.addr + dst_channels[channel].area.first / 8;
77 src_step = src_channels[channel].area.step / 8;
78 dst_step = dst_channels[channel].area.step / 8;
79 frames1 = frames;
80 while (frames1-- > 0) {
81 do_convert(data, dst, src);
82 src += src_step;
83 dst += dst_step;
84 }
85 }
86}
87
88static snd_pcm_sframes_t linear_transfer(struct snd_pcm_plugin *plugin,
89 const struct snd_pcm_plugin_channel *src_channels,
90 struct snd_pcm_plugin_channel *dst_channels,
91 snd_pcm_uframes_t frames)
92{
93 if (snd_BUG_ON(!plugin || !src_channels || !dst_channels))
94 return -ENXIO;
95 if (frames == 0)
96 return 0;
97#ifdef CONFIG_SND_DEBUG
98 {
99 unsigned int channel;
100 for (channel = 0; channel < plugin->src_format.channels; channel++) {
101 if (snd_BUG_ON(src_channels[channel].area.first % 8 ||
102 src_channels[channel].area.step % 8))
103 return -ENXIO;
104 if (snd_BUG_ON(dst_channels[channel].area.first % 8 ||
105 dst_channels[channel].area.step % 8))
106 return -ENXIO;
107 }
108 }
109#endif
110 if (frames > dst_channels[0].frames)
111 frames = dst_channels[0].frames;
112 convert(plugin, src_channels, dst_channels, frames);
113 return frames;
114}
115
116static void init_data(struct linear_priv *data,
117 snd_pcm_format_t src_format, snd_pcm_format_t dst_format)
118{
119 int src_le, dst_le, src_bytes, dst_bytes;
120
121 src_bytes = snd_pcm_format_width(src_format) / 8;
122 dst_bytes = snd_pcm_format_width(dst_format) / 8;
123 src_le = snd_pcm_format_little_endian(src_format) > 0;
124 dst_le = snd_pcm_format_little_endian(dst_format) > 0;
125
126 data->dst_bytes = dst_bytes;
127 data->cvt_endian = src_le != dst_le;
128 data->copy_bytes = src_bytes < dst_bytes ? src_bytes : dst_bytes;
129 if (src_le) {
130 data->copy_ofs = 4 - data->copy_bytes;
131 data->src_ofs = src_bytes - data->copy_bytes;
132 } else
133 data->src_ofs = snd_pcm_format_physical_width(src_format) / 8 -
134 src_bytes;
135 if (dst_le)
136 data->dst_ofs = 4 - data->dst_bytes;
137 else
138 data->dst_ofs = snd_pcm_format_physical_width(dst_format) / 8 -
139 dst_bytes;
140 if (snd_pcm_format_signed(src_format) !=
141 snd_pcm_format_signed(dst_format)) {
142 if (dst_le)
143 data->flip = (__force u32)cpu_to_le32(0x80000000);
144 else
145 data->flip = (__force u32)cpu_to_be32(0x80000000);
146 }
147}
148
149int snd_pcm_plugin_build_linear(struct snd_pcm_substream *plug,
150 struct snd_pcm_plugin_format *src_format,
151 struct snd_pcm_plugin_format *dst_format,
152 struct snd_pcm_plugin **r_plugin)
153{
154 int err;
155 struct linear_priv *data;
156 struct snd_pcm_plugin *plugin;
157
158 if (snd_BUG_ON(!r_plugin))
159 return -ENXIO;
160 *r_plugin = NULL;
161
162 if (snd_BUG_ON(src_format->rate != dst_format->rate))
163 return -ENXIO;
164 if (snd_BUG_ON(src_format->channels != dst_format->channels))
165 return -ENXIO;
166 if (snd_BUG_ON(!snd_pcm_format_linear(src_format->format) ||
167 !snd_pcm_format_linear(dst_format->format)))
168 return -ENXIO;
169
170 err = snd_pcm_plugin_build(plug, "linear format conversion",
171 src_format, dst_format,
172 sizeof(struct linear_priv), &plugin);
173 if (err < 0)
174 return err;
175 data = (struct linear_priv *)plugin->extra_data;
176 init_data(data, src_format->format, dst_format->format);
177 plugin->transfer = linear_transfer;
178 *r_plugin = plugin;
179 return 0;
180}