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22#include <linux/time.h>
23#include <sound/core.h>
24#include <sound/pcm.h>
25#include "pcm_plugin.h"
26
27static void zero_areas(struct snd_pcm_plugin_channel *dvp, int ndsts,
28 snd_pcm_uframes_t frames, snd_pcm_format_t format)
29{
30 int dst = 0;
31 for (; dst < ndsts; ++dst) {
32 if (dvp->wanted)
33 snd_pcm_area_silence(&dvp->area, 0, frames, format);
34 dvp->enabled = 0;
35 dvp++;
36 }
37}
38
39static inline void copy_area(const struct snd_pcm_plugin_channel *src_channel,
40 struct snd_pcm_plugin_channel *dst_channel,
41 snd_pcm_uframes_t frames, snd_pcm_format_t format)
42{
43 dst_channel->enabled = 1;
44 snd_pcm_area_copy(&src_channel->area, 0, &dst_channel->area, 0, frames, format);
45}
46
47static snd_pcm_sframes_t route_transfer(struct snd_pcm_plugin *plugin,
48 const struct snd_pcm_plugin_channel *src_channels,
49 struct snd_pcm_plugin_channel *dst_channels,
50 snd_pcm_uframes_t frames)
51{
52 int nsrcs, ndsts, dst;
53 struct snd_pcm_plugin_channel *dvp;
54 snd_pcm_format_t format;
55
56 if (snd_BUG_ON(!plugin || !src_channels || !dst_channels))
57 return -ENXIO;
58 if (frames == 0)
59 return 0;
60
61 nsrcs = plugin->src_format.channels;
62 ndsts = plugin->dst_format.channels;
63
64 format = plugin->dst_format.format;
65 dvp = dst_channels;
66 if (nsrcs <= 1) {
67
68 for (dst = 0; dst < ndsts; ++dst) {
69 copy_area(src_channels, dvp, frames, format);
70 dvp++;
71 }
72 return frames;
73 }
74
75 for (dst = 0; dst < ndsts && dst < nsrcs; ++dst) {
76 copy_area(src_channels, dvp, frames, format);
77 dvp++;
78 src_channels++;
79 }
80 if (dst < ndsts)
81 zero_areas(dvp, ndsts - dst, frames, format);
82 return frames;
83}
84
85int snd_pcm_plugin_build_route(struct snd_pcm_substream *plug,
86 struct snd_pcm_plugin_format *src_format,
87 struct snd_pcm_plugin_format *dst_format,
88 struct snd_pcm_plugin **r_plugin)
89{
90 struct snd_pcm_plugin *plugin;
91 int err;
92
93 if (snd_BUG_ON(!r_plugin))
94 return -ENXIO;
95 *r_plugin = NULL;
96 if (snd_BUG_ON(src_format->rate != dst_format->rate))
97 return -ENXIO;
98 if (snd_BUG_ON(src_format->format != dst_format->format))
99 return -ENXIO;
100
101 err = snd_pcm_plugin_build(plug, "route conversion",
102 src_format, dst_format, 0, &plugin);
103 if (err < 0)
104 return err;
105
106 plugin->transfer = route_transfer;
107 *r_plugin = plugin;
108 return 0;
109}
110