Merge branch 'mv-merge'
[linux-2.6] / 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
25 #ifdef CONFIG_SND_PCM_OSS_PLUGINS
26
27 #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  
36 struct linear_priv {
37         int conv;
38 };
39
40 static void convert(struct snd_pcm_plugin *plugin,
41                     const struct snd_pcm_plugin_channel *src_channels,
42                     struct snd_pcm_plugin_channel *dst_channels,
43                     snd_pcm_uframes_t frames)
44 {
45 #define CONV_LABELS
46 #include "plugin_ops.h"
47 #undef CONV_LABELS
48         struct linear_priv *data = (struct linear_priv *)plugin->extra_data;
49         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
81 static 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,
84                                snd_pcm_uframes_t frames)
85 {
86         struct linear_priv *data;
87
88         snd_assert(plugin != NULL && src_channels != NULL && dst_channels != NULL, return -ENXIO);
89         data = (struct linear_priv *)plugin->extra_data;
90         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
109 static int conv_index(int src_format, int dst_format)
110 {
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
134 int 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)
138 {
139         int err;
140         struct linear_priv *data;
141         struct snd_pcm_plugin *plugin;
142
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,
153                                    sizeof(struct linear_priv), &plugin);
154         if (err < 0)
155                 return err;
156         data = (struct linear_priv *)plugin->extra_data;
157         data->conv = conv_index(src_format->format, dst_format->format);
158         plugin->transfer = linear_transfer;
159         *r_plugin = plugin;
160         return 0;
161 }
162
163 #endif