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1da177e4 LT |
1 | /* |
2 | * Linear conversion Plug-In | |
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> | |
23 | #include <linux/time.h> | |
24 | #include <sound/core.h> | |
25 | #include <sound/pcm.h> | |
26 | #include "pcm_plugin.h" | |
27 | ||
6ac77bc1 TI |
28 | static snd_pcm_sframes_t copy_transfer(struct snd_pcm_plugin *plugin, |
29 | const struct snd_pcm_plugin_channel *src_channels, | |
30 | struct snd_pcm_plugin_channel *dst_channels, | |
1da177e4 LT |
31 | snd_pcm_uframes_t frames) |
32 | { | |
33 | unsigned int channel; | |
34 | unsigned int nchannels; | |
35 | ||
36 | snd_assert(plugin != NULL && src_channels != NULL && dst_channels != NULL, return -ENXIO); | |
37 | if (frames == 0) | |
38 | return 0; | |
39 | nchannels = plugin->src_format.channels; | |
40 | for (channel = 0; channel < nchannels; channel++) { | |
41 | snd_assert(src_channels->area.first % 8 == 0 && | |
42 | src_channels->area.step % 8 == 0, | |
43 | return -ENXIO); | |
44 | snd_assert(dst_channels->area.first % 8 == 0 && | |
45 | dst_channels->area.step % 8 == 0, | |
46 | return -ENXIO); | |
47 | if (!src_channels->enabled) { | |
48 | if (dst_channels->wanted) | |
49 | snd_pcm_area_silence(&dst_channels->area, 0, frames, plugin->dst_format.format); | |
50 | dst_channels->enabled = 0; | |
51 | continue; | |
52 | } | |
53 | dst_channels->enabled = 1; | |
54 | snd_pcm_area_copy(&src_channels->area, 0, &dst_channels->area, 0, frames, plugin->src_format.format); | |
55 | src_channels++; | |
56 | dst_channels++; | |
57 | } | |
58 | return frames; | |
59 | } | |
60 | ||
6ac77bc1 TI |
61 | int snd_pcm_plugin_build_copy(struct snd_pcm_substream *plug, |
62 | struct snd_pcm_plugin_format *src_format, | |
63 | struct snd_pcm_plugin_format *dst_format, | |
64 | struct snd_pcm_plugin **r_plugin) | |
1da177e4 LT |
65 | { |
66 | int err; | |
6ac77bc1 | 67 | struct snd_pcm_plugin *plugin; |
1da177e4 LT |
68 | int width; |
69 | ||
70 | snd_assert(r_plugin != NULL, return -ENXIO); | |
71 | *r_plugin = NULL; | |
72 | ||
73 | snd_assert(src_format->format == dst_format->format, return -ENXIO); | |
74 | snd_assert(src_format->rate == dst_format->rate, return -ENXIO); | |
75 | snd_assert(src_format->channels == dst_format->channels, return -ENXIO); | |
76 | ||
77 | width = snd_pcm_format_physical_width(src_format->format); | |
78 | snd_assert(width > 0, return -ENXIO); | |
79 | ||
80 | err = snd_pcm_plugin_build(plug, "copy", src_format, dst_format, | |
81 | 0, &plugin); | |
82 | if (err < 0) | |
83 | return err; | |
84 | plugin->transfer = copy_transfer; | |
85 | *r_plugin = plugin; | |
86 | return 0; | |
87 | } |