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1da177e4 LT |
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 | ||
6ac77bc1 | 33 | struct linear_priv { |
1da177e4 | 34 | int conv; |
6ac77bc1 | 35 | }; |
1da177e4 | 36 | |
6ac77bc1 TI |
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, | |
1da177e4 LT |
40 | snd_pcm_uframes_t frames) |
41 | { | |
42 | #define CONV_LABELS | |
43 | #include "plugin_ops.h" | |
44 | #undef CONV_LABELS | |
6ac77bc1 | 45 | struct linear_priv *data = (struct linear_priv *)plugin->extra_data; |
1da177e4 LT |
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 | ||
6ac77bc1 TI |
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, | |
1da177e4 LT |
81 | snd_pcm_uframes_t frames) |
82 | { | |
6ac77bc1 | 83 | struct linear_priv *data; |
1da177e4 LT |
84 | |
85 | snd_assert(plugin != NULL && src_channels != NULL && dst_channels != NULL, return -ENXIO); | |
6ac77bc1 | 86 | data = (struct linear_priv *)plugin->extra_data; |
1da177e4 LT |
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 | ||
6ac77bc1 TI |
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) | |
1da177e4 LT |
135 | { |
136 | int err; | |
6ac77bc1 TI |
137 | struct linear_priv *data; |
138 | struct snd_pcm_plugin *plugin; | |
1da177e4 LT |
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, | |
6ac77bc1 | 150 | sizeof(struct linear_priv), &plugin); |
1da177e4 LT |
151 | if (err < 0) |
152 | return err; | |
6ac77bc1 | 153 | data = (struct linear_priv *)plugin->extra_data; |
1da177e4 LT |
154 | data->conv = conv_index(src_format->format, dst_format->format); |
155 | plugin->transfer = linear_transfer; | |
156 | *r_plugin = plugin; | |
157 | return 0; | |
158 | } |