1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
|
// SPDX-License-Identifier: LGPL-2.0+
/*
* Linear conversion Plug-In
* Copyright (c) 2000 by Abramo Bagnara <abramo@alsa-project.org>
*/
#include <linux/time.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include "pcm_plugin.h"
static snd_pcm_sframes_t copy_transfer(struct snd_pcm_plugin *plugin,
const struct snd_pcm_plugin_channel *src_channels,
struct snd_pcm_plugin_channel *dst_channels,
snd_pcm_uframes_t frames)
{
unsigned int channel;
unsigned int nchannels;
if (snd_BUG_ON(!plugin || !src_channels || !dst_channels))
return -ENXIO;
if (frames == 0)
return 0;
nchannels = plugin->src_format.channels;
for (channel = 0; channel < nchannels; channel++) {
if (snd_BUG_ON(src_channels->area.first % 8 ||
src_channels->area.step % 8))
return -ENXIO;
if (snd_BUG_ON(dst_channels->area.first % 8 ||
dst_channels->area.step % 8))
return -ENXIO;
if (!src_channels->enabled) {
if (dst_channels->wanted)
snd_pcm_area_silence(&dst_channels->area, 0, frames, plugin->dst_format.format);
dst_channels->enabled = 0;
continue;
}
dst_channels->enabled = 1;
snd_pcm_area_copy(&src_channels->area, 0, &dst_channels->area, 0, frames, plugin->src_format.format);
src_channels++;
dst_channels++;
}
return frames;
}
int snd_pcm_plugin_build_copy(struct snd_pcm_substream *plug,
struct snd_pcm_plugin_format *src_format,
struct snd_pcm_plugin_format *dst_format,
struct snd_pcm_plugin **r_plugin)
{
int err;
struct snd_pcm_plugin *plugin;
int width;
if (snd_BUG_ON(!r_plugin))
return -ENXIO;
*r_plugin = NULL;
if (snd_BUG_ON(src_format->format != dst_format->format))
return -ENXIO;
if (snd_BUG_ON(src_format->rate != dst_format->rate))
return -ENXIO;
if (snd_BUG_ON(src_format->channels != dst_format->channels))
return -ENXIO;
width = snd_pcm_format_physical_width(src_format->format);
if (snd_BUG_ON(width <= 0))
return -ENXIO;
err = snd_pcm_plugin_build(plug, "copy", src_format, dst_format,
0, &plugin);
if (err < 0)
return err;
plugin->transfer = copy_transfer;
*r_plugin = plugin;
return 0;
}
|
