[ALSA] Remove xxx_t typedefs: PCM OSS-emulation
[linux-2.6.git] / sound / core / oss / linear.c
1 /*
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>
24 #include <linux/time.h>
25 #include <sound/core.h>
26 #include <sound/pcm.h>
27 #include "pcm_plugin.h"
28
29 /*
30  *  Basic linear conversion plugin
31  */
32  
33 struct linear_priv {
34         int conv;
35 };
36
37 static void convert(struct snd_pcm_plugin *plugin,
38                     const struct snd_pcm_plugin_channel *src_channels,
39                     struct snd_pcm_plugin_channel *dst_channels,
40                     snd_pcm_uframes_t frames)
41 {
42 #define CONV_LABELS
43 #include "plugin_ops.h"
44 #undef CONV_LABELS
45         struct linear_priv *data = (struct linear_priv *)plugin->extra_data;
46         void *conv = conv_labels[data->conv];
47         int channel;
48         int nchannels = plugin->src_format.channels;
49         for (channel = 0; channel < nchannels; ++channel) {
50                 char *src;
51                 char *dst;
52                 int src_step, dst_step;
53                 snd_pcm_uframes_t frames1;
54                 if (!src_channels[channel].enabled) {
55                         if (dst_channels[channel].wanted)
56                                 snd_pcm_area_silence(&dst_channels[channel].area, 0, frames, plugin->dst_format.format);
57                         dst_channels[channel].enabled = 0;
58                         continue;
59                 }
60                 dst_channels[channel].enabled = 1;
61                 src = src_channels[channel].area.addr + src_channels[channel].area.first / 8;
62                 dst = dst_channels[channel].area.addr + dst_channels[channel].area.first / 8;
63                 src_step = src_channels[channel].area.step / 8;
64                 dst_step = dst_channels[channel].area.step / 8;
65                 frames1 = frames;
66                 while (frames1-- > 0) {
67                         goto *conv;
68 #define CONV_END after
69 #include "plugin_ops.h"
70 #undef CONV_END
71                 after:
72                         src += src_step;
73                         dst += dst_step;
74                 }
75         }
76 }
77
78 static snd_pcm_sframes_t linear_transfer(struct snd_pcm_plugin *plugin,
79                                const struct snd_pcm_plugin_channel *src_channels,
80                                struct snd_pcm_plugin_channel *dst_channels,
81                                snd_pcm_uframes_t frames)
82 {
83         struct linear_priv *data;
84
85         snd_assert(plugin != NULL && src_channels != NULL && dst_channels != NULL, return -ENXIO);
86         data = (struct linear_priv *)plugin->extra_data;
87         if (frames == 0)
88                 return 0;
89 #ifdef CONFIG_SND_DEBUG
90         {
91                 unsigned int channel;
92                 for (channel = 0; channel < plugin->src_format.channels; channel++) {
93                         snd_assert(src_channels[channel].area.first % 8 == 0 &&
94                                    src_channels[channel].area.step % 8 == 0,
95                                    return -ENXIO);
96                         snd_assert(dst_channels[channel].area.first % 8 == 0 &&
97                                    dst_channels[channel].area.step % 8 == 0,
98                                    return -ENXIO);
99                 }
100         }
101 #endif
102         convert(plugin, src_channels, dst_channels, frames);
103         return frames;
104 }
105
106 int conv_index(int src_format, int dst_format)
107 {
108         int src_endian, dst_endian, sign, src_width, dst_width;
109
110         sign = (snd_pcm_format_signed(src_format) !=
111                 snd_pcm_format_signed(dst_format));
112 #ifdef SNDRV_LITTLE_ENDIAN
113         src_endian = snd_pcm_format_big_endian(src_format);
114         dst_endian = snd_pcm_format_big_endian(dst_format);
115 #else
116         src_endian = snd_pcm_format_little_endian(src_format);
117         dst_endian = snd_pcm_format_little_endian(dst_format);
118 #endif
119
120         if (src_endian < 0)
121                 src_endian = 0;
122         if (dst_endian < 0)
123                 dst_endian = 0;
124
125         src_width = snd_pcm_format_width(src_format) / 8 - 1;
126         dst_width = snd_pcm_format_width(dst_format) / 8 - 1;
127
128         return src_width * 32 + src_endian * 16 + sign * 8 + dst_width * 2 + dst_endian;
129 }
130
131 int snd_pcm_plugin_build_linear(struct snd_pcm_substream *plug,
132                                 struct snd_pcm_plugin_format *src_format,
133                                 struct snd_pcm_plugin_format *dst_format,
134                                 struct snd_pcm_plugin **r_plugin)
135 {
136         int err;
137         struct linear_priv *data;
138         struct snd_pcm_plugin *plugin;
139
140         snd_assert(r_plugin != NULL, return -ENXIO);
141         *r_plugin = NULL;
142
143         snd_assert(src_format->rate == dst_format->rate, return -ENXIO);
144         snd_assert(src_format->channels == dst_format->channels, return -ENXIO);
145         snd_assert(snd_pcm_format_linear(src_format->format) &&
146                    snd_pcm_format_linear(dst_format->format), return -ENXIO);
147
148         err = snd_pcm_plugin_build(plug, "linear format conversion",
149                                    src_format, dst_format,
150                                    sizeof(struct linear_priv), &plugin);
151         if (err < 0)
152                 return err;
153         data = (struct linear_priv *)plugin->extra_data;
154         data->conv = conv_index(src_format->format, dst_format->format);
155         plugin->transfer = linear_transfer;
156         *r_plugin = plugin;
157         return 0;
158 }