Commit | Line | Data |
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1da177e4 | 1 | /* |
0534ab42 | 2 | * Route Plug-In |
1da177e4 LT |
3 | * Copyright (c) 2000 by Abramo Bagnara <abramo@alsa-project.org> |
4 | * | |
5 | * | |
6 | * This library is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU Library General Public License as | |
8 | * published by the Free Software Foundation; either version 2 of | |
9 | * the License, or (at your option) any later version. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU Library General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU Library General Public | |
17 | * License along with this library; if not, write to the Free Software | |
18 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
19 | * | |
20 | */ | |
21 | ||
22 | #include <sound/driver.h> | |
21a3479a JK |
23 | |
24 | #ifdef CONFIG_SND_PCM_OSS_PLUGINS | |
25 | ||
1da177e4 LT |
26 | #include <linux/slab.h> |
27 | #include <linux/time.h> | |
28 | #include <sound/core.h> | |
29 | #include <sound/pcm.h> | |
30 | #include "pcm_plugin.h" | |
31 | ||
0534ab42 TI |
32 | static void zero_areas(struct snd_pcm_plugin_channel *dvp, int ndsts, |
33 | snd_pcm_uframes_t frames, int format) | |
1da177e4 | 34 | { |
0534ab42 TI |
35 | int dst = 0; |
36 | for (; dst < ndsts; ++dst) { | |
37 | if (dvp->wanted) | |
38 | snd_pcm_area_silence(&dvp->area, 0, frames, format); | |
39 | dvp->enabled = 0; | |
40 | dvp++; | |
1da177e4 LT |
41 | } |
42 | } | |
43 | ||
0534ab42 | 44 | static inline void copy_area(const struct snd_pcm_plugin_channel *src_channel, |
6ac77bc1 | 45 | struct snd_pcm_plugin_channel *dst_channel, |
0534ab42 | 46 | snd_pcm_uframes_t frames, int format) |
1da177e4 | 47 | { |
1da177e4 | 48 | dst_channel->enabled = 1; |
0534ab42 | 49 | snd_pcm_area_copy(&src_channel->area, 0, &dst_channel->area, 0, frames, format); |
1da177e4 LT |
50 | } |
51 | ||
6ac77bc1 | 52 | static snd_pcm_sframes_t route_transfer(struct snd_pcm_plugin *plugin, |
0534ab42 TI |
53 | const struct snd_pcm_plugin_channel *src_channels, |
54 | struct snd_pcm_plugin_channel *dst_channels, | |
55 | snd_pcm_uframes_t frames) | |
1da177e4 | 56 | { |
0534ab42 | 57 | int nsrcs, ndsts, dst; |
6ac77bc1 | 58 | struct snd_pcm_plugin_channel *dvp; |
0534ab42 | 59 | int format; |
1da177e4 LT |
60 | |
61 | snd_assert(plugin != NULL && src_channels != NULL && dst_channels != NULL, return -ENXIO); | |
62 | if (frames == 0) | |
63 | return 0; | |
1da177e4 | 64 | |
0534ab42 TI |
65 | nsrcs = plugin->src_format.channels; |
66 | ndsts = plugin->dst_format.channels; | |
1da177e4 | 67 | |
0534ab42 TI |
68 | format = plugin->dst_format.format; |
69 | dvp = dst_channels; | |
70 | if (nsrcs <= 1) { | |
71 | /* expand to all channels */ | |
72 | for (dst = 0; dst < ndsts; ++dst) { | |
73 | copy_area(src_channels, dvp, frames, format); | |
74 | dvp++; | |
1da177e4 | 75 | } |
0534ab42 | 76 | return frames; |
1da177e4 | 77 | } |
1da177e4 | 78 | |
0534ab42 TI |
79 | for (dst = 0; dst < ndsts && dst < nsrcs; ++dst) { |
80 | copy_area(src_channels, dvp, frames, format); | |
1da177e4 | 81 | dvp++; |
0534ab42 | 82 | src_channels++; |
1da177e4 | 83 | } |
0534ab42 TI |
84 | if (dst < ndsts) |
85 | zero_areas(dvp, ndsts - dst, frames, format); | |
1da177e4 LT |
86 | return frames; |
87 | } | |
88 | ||
6ac77bc1 TI |
89 | int snd_pcm_plugin_build_route(struct snd_pcm_substream *plug, |
90 | struct snd_pcm_plugin_format *src_format, | |
91 | struct snd_pcm_plugin_format *dst_format, | |
6ac77bc1 | 92 | struct snd_pcm_plugin **r_plugin) |
1da177e4 | 93 | { |
6ac77bc1 | 94 | struct snd_pcm_plugin *plugin; |
1da177e4 LT |
95 | int err; |
96 | ||
97 | snd_assert(r_plugin != NULL, return -ENXIO); | |
98 | *r_plugin = NULL; | |
99 | snd_assert(src_format->rate == dst_format->rate, return -ENXIO); | |
0534ab42 | 100 | snd_assert(src_format->format == dst_format->format, return -ENXIO); |
1da177e4 | 101 | |
0534ab42 TI |
102 | err = snd_pcm_plugin_build(plug, "route conversion", |
103 | src_format, dst_format, 0, &plugin); | |
1da177e4 LT |
104 | if (err < 0) |
105 | return err; | |
106 | ||
1da177e4 | 107 | plugin->transfer = route_transfer; |
1da177e4 LT |
108 | *r_plugin = plugin; |
109 | return 0; | |
110 | } | |
21a3479a JK |
111 | |
112 | #endif |