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1da177e4 LT |
1 | /* |
2 | * Linear conversion Plug-In | |
c1017a4c | 3 | * Copyright (c) 1999 by Jaroslav Kysela <perex@perex.cz>, |
1da177e4 LT |
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 | ||
1da177e4 LT |
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 | ||
6ac77bc1 | 32 | struct linear_priv { |
9390ec85 TI |
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 */ | |
6ac77bc1 | 40 | }; |
1da177e4 | 41 | |
9390ec85 TI |
42 | static 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 | ||
6ac77bc1 TI |
55 | static void convert(struct snd_pcm_plugin *plugin, |
56 | const struct snd_pcm_plugin_channel *src_channels, | |
57 | struct snd_pcm_plugin_channel *dst_channels, | |
1da177e4 LT |
58 | snd_pcm_uframes_t frames) |
59 | { | |
6ac77bc1 | 60 | struct linear_priv *data = (struct linear_priv *)plugin->extra_data; |
1da177e4 LT |
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) { | |
9390ec85 | 81 | do_convert(data, dst, src); |
1da177e4 LT |
82 | src += src_step; |
83 | dst += dst_step; | |
84 | } | |
85 | } | |
86 | } | |
87 | ||
6ac77bc1 TI |
88 | static 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, | |
1da177e4 LT |
91 | snd_pcm_uframes_t frames) |
92 | { | |
6ac77bc1 | 93 | struct linear_priv *data; |
1da177e4 | 94 | |
7eaa943c TI |
95 | if (snd_BUG_ON(!plugin || !src_channels || !dst_channels)) |
96 | return -ENXIO; | |
6ac77bc1 | 97 | data = (struct linear_priv *)plugin->extra_data; |
1da177e4 LT |
98 | if (frames == 0) |
99 | return 0; | |
100 | #ifdef CONFIG_SND_DEBUG | |
101 | { | |
102 | unsigned int channel; | |
103 | for (channel = 0; channel < plugin->src_format.channels; channel++) { | |
7eaa943c TI |
104 | if (snd_BUG_ON(src_channels[channel].area.first % 8 || |
105 | src_channels[channel].area.step % 8)) | |
106 | return -ENXIO; | |
107 | if (snd_BUG_ON(dst_channels[channel].area.first % 8 || | |
108 | dst_channels[channel].area.step % 8)) | |
109 | return -ENXIO; | |
1da177e4 LT |
110 | } |
111 | } | |
112 | #endif | |
113 | convert(plugin, src_channels, dst_channels, frames); | |
114 | return frames; | |
115 | } | |
116 | ||
9390ec85 | 117 | static void init_data(struct linear_priv *data, int src_format, int dst_format) |
1da177e4 | 118 | { |
9390ec85 | 119 | int src_le, dst_le, src_bytes, dst_bytes; |
1da177e4 | 120 | |
9390ec85 TI |
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; | |
1da177e4 | 125 | |
9390ec85 TI |
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 = cpu_to_le32(0x80000000); | |
144 | else | |
145 | data->flip = cpu_to_be32(0x80000000); | |
146 | } | |
1da177e4 LT |
147 | } |
148 | ||
6ac77bc1 TI |
149 | int 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) | |
1da177e4 LT |
153 | { |
154 | int err; | |
6ac77bc1 TI |
155 | struct linear_priv *data; |
156 | struct snd_pcm_plugin *plugin; | |
1da177e4 | 157 | |
7eaa943c TI |
158 | if (snd_BUG_ON(!r_plugin)) |
159 | return -ENXIO; | |
1da177e4 LT |
160 | *r_plugin = NULL; |
161 | ||
7eaa943c TI |
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; | |
1da177e4 LT |
169 | |
170 | err = snd_pcm_plugin_build(plug, "linear format conversion", | |
171 | src_format, dst_format, | |
6ac77bc1 | 172 | sizeof(struct linear_priv), &plugin); |
1da177e4 LT |
173 | if (err < 0) |
174 | return err; | |
6ac77bc1 | 175 | data = (struct linear_priv *)plugin->extra_data; |
9390ec85 | 176 | init_data(data, src_format->format, dst_format->format); |
1da177e4 LT |
177 | plugin->transfer = linear_transfer; |
178 | *r_plugin = plugin; | |
179 | return 0; | |
180 | } |