blob: 05b58d4fc2b72d6e2197171520567b9bf7dc16dc [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include <linux/time.h>
23#include <sound/core.h>
24#include <sound/pcm.h>
25#include "pcm_plugin.h"
26
Takashi Iwai6ac77bc2005-11-17 14:01:49 +010027static 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,
Linus Torvalds1da177e2005-04-16 15:20:36 -070030 snd_pcm_uframes_t frames)
31{
32 unsigned int channel;
33 unsigned int nchannels;
34
Takashi Iwai7eaa9432008-08-08 17:09:09 +020035 if (snd_BUG_ON(!plugin || !src_channels || !dst_channels))
36 return -ENXIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -070037 if (frames == 0)
38 return 0;
39 nchannels = plugin->src_format.channels;
40 for (channel = 0; channel < nchannels; channel++) {
Takashi Iwai7eaa9432008-08-08 17:09:09 +020041 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -070047 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
Takashi Iwai6ac77bc2005-11-17 14:01:49 +010061int 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)
Linus Torvalds1da177e2005-04-16 15:20:36 -070065{
66 int err;
Takashi Iwai6ac77bc2005-11-17 14:01:49 +010067 struct snd_pcm_plugin *plugin;
Linus Torvalds1da177e2005-04-16 15:20:36 -070068 int width;
69
Takashi Iwai7eaa9432008-08-08 17:09:09 +020070 if (snd_BUG_ON(!r_plugin))
71 return -ENXIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 *r_plugin = NULL;
73
Takashi Iwai7eaa9432008-08-08 17:09:09 +020074 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -070080
81 width = snd_pcm_format_physical_width(src_format->format);
Takashi Iwai7eaa9432008-08-08 17:09:09 +020082 if (snd_BUG_ON(width <= 0))
83 return -ENXIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -070084
85 err = snd_pcm_plugin_build(plug, "copy", src_format, dst_format,
86 0, &plugin);
87 if (err < 0)
88 return err;
89 plugin->transfer = copy_transfer;
90 *r_plugin = plugin;
91 return 0;
92}