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 <linux/time.h> |
23 | #include <sound/core.h> |
24 | #include <sound/pcm.h> |
25 | #include "pcm_plugin.h" |
26 | |
27 | static snd_pcm_sframes_t copy_transfer(struct snd_pcm_plugin *plugin, |
28 | const struct snd_pcm_plugin_channel *src_channels, |
29 | struct snd_pcm_plugin_channel *dst_channels, |
30 | snd_pcm_uframes_t frames) |
31 | { |
32 | unsigned int channel; |
33 | unsigned int nchannels; |
34 | |
35 | if (snd_BUG_ON(!plugin || !src_channels || !dst_channels)) |
36 | return -ENXIO; |
37 | if (frames == 0) |
38 | return 0; |
39 | nchannels = plugin->src_format.channels; |
40 | for (channel = 0; channel < nchannels; channel++) { |
41 | if (snd_BUG_ON(src_channels->area.first % 8 || |
42 | src_channels->area.step % 8)) |
43 | return -ENXIO; |
44 | if (snd_BUG_ON(dst_channels->area.first % 8 || |
45 | dst_channels->area.step % 8)) |
46 | return -ENXIO; |
47 | if (!src_channels->enabled) { |
48 | if (dst_channels->wanted) |
49 | snd_pcm_area_silence(dst_channel: &dst_channels->area, dst_offset: 0, samples: frames, format: plugin->dst_format.format); |
50 | dst_channels->enabled = 0; |
51 | continue; |
52 | } |
53 | dst_channels->enabled = 1; |
54 | snd_pcm_area_copy(src_channel: &src_channels->area, src_offset: 0, dst_channel: &dst_channels->area, dst_offset: 0, samples: frames, format: plugin->src_format.format); |
55 | src_channels++; |
56 | dst_channels++; |
57 | } |
58 | return frames; |
59 | } |
60 | |
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) |
65 | { |
66 | int err; |
67 | struct snd_pcm_plugin *plugin; |
68 | int width; |
69 | |
70 | if (snd_BUG_ON(!r_plugin)) |
71 | return -ENXIO; |
72 | *r_plugin = NULL; |
73 | |
74 | if (snd_BUG_ON(src_format->format != dst_format->format)) |
75 | return -ENXIO; |
76 | if (snd_BUG_ON(src_format->rate != dst_format->rate)) |
77 | return -ENXIO; |
78 | if (snd_BUG_ON(src_format->channels != dst_format->channels)) |
79 | return -ENXIO; |
80 | |
81 | width = snd_pcm_format_physical_width(format: src_format->format); |
82 | if (snd_BUG_ON(width <= 0)) |
83 | return -ENXIO; |
84 | |
85 | err = snd_pcm_plugin_build(handle: plug, name: "copy" , src_format, dst_format, |
86 | extra: 0, ret: &plugin); |
87 | if (err < 0) |
88 | return err; |
89 | plugin->transfer = copy_transfer; |
90 | *r_plugin = plugin; |
91 | return 0; |
92 | } |
93 | |