1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
|
/*
* 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
*/
struct linear_priv {
int cvt_endian; /* need endian conversion? */
unsigned int src_ofs; /* byte offset in source format */
unsigned int dst_ofs; /* byte soffset in destination format */
unsigned int copy_ofs; /* byte offset in temporary u32 data */
unsigned int dst_bytes; /* byte size of destination format */
unsigned int copy_bytes; /* bytes to copy per conversion */
unsigned int flip; /* MSB flip for signeness, done after endian conv */
};
static inline void do_convert(struct linear_priv *data,
unsigned char *dst, unsigned char *src)
{
unsigned int tmp = 0;
unsigned char *p = (unsigned char *)&tmp;
memcpy(p + data->copy_ofs, src + data->src_ofs, data->copy_bytes);
if (data->cvt_endian)
tmp = swab32(tmp);
tmp ^= data->flip;
memcpy(dst, p + data->dst_ofs, data->dst_bytes);
}
static void convert(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)
{
struct linear_priv *data = (struct linear_priv *)plugin->extra_data;
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) {
do_convert(data, dst, src);
src += src_step;
dst += dst_step;
}
}
}
static snd_pcm_sframes_t linear_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)
{
struct linear_priv *data;
snd_assert(plugin != NULL && src_channels != NULL && dst_channels != NULL, return -ENXIO);
data = (struct linear_priv *)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;
}
static void init_data(struct linear_priv *data, int src_format, int dst_format)
{
int src_le, dst_le, src_bytes, dst_bytes;
src_bytes = snd_pcm_format_width(src_format) / 8;
dst_bytes = snd_pcm_format_width(dst_format) / 8;
src_le = snd_pcm_format_little_endian(src_format) > 0;
dst_le = snd_pcm_format_little_endian(dst_format) > 0;
data->dst_bytes = dst_bytes;
data->cvt_endian = src_le != dst_le;
data->copy_bytes = src_bytes < dst_bytes ? src_bytes : dst_bytes;
if (src_le) {
data->copy_ofs = 4 - data->copy_bytes;
data->src_ofs = src_bytes - data->copy_bytes;
} else
data->src_ofs = snd_pcm_format_physical_width(src_format) / 8 -
src_bytes;
if (dst_le)
data->dst_ofs = 4 - data->dst_bytes;
else
data->dst_ofs = snd_pcm_format_physical_width(dst_format) / 8 -
dst_bytes;
if (snd_pcm_format_signed(src_format) !=
snd_pcm_format_signed(dst_format)) {
if (dst_le)
data->flip = cpu_to_le32(0x80000000);
else
data->flip = cpu_to_be32(0x80000000);
}
}
int snd_pcm_plugin_build_linear(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)
{
int err;
struct linear_priv *data;
struct snd_pcm_plugin *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(struct linear_priv), &plugin);
if (err < 0)
return err;
data = (struct linear_priv *)plugin->extra_data;
init_data(data, src_format->format, dst_format->format);
plugin->transfer = linear_transfer;
*r_plugin = plugin;
return 0;
}
|
