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
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
|
/*
* Copyright (C) 2003-2013 The Music Player Daemon Project
* http://www.musicpd.org
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "config.h"
#include "ChainFilterPlugin.hxx"
#include "FilterPlugin.hxx"
#include "FilterInternal.hxx"
#include "FilterRegistry.hxx"
#include "AudioFormat.hxx"
#include "util/Error.hxx"
#include "util/Domain.hxx"
#include <glib.h>
#include <list>
#include <assert.h>
class ChainFilter final : public Filter {
struct Child {
const char *name;
Filter *filter;
Child(const char *_name, Filter *_filter)
:name(_name), filter(_filter) {}
~Child() {
delete filter;
}
Child(const Child &) = delete;
Child &operator=(const Child &) = delete;
};
std::list<Child> children;
public:
void Append(const char *name, Filter *filter) {
children.emplace_back(name, filter);
}
virtual AudioFormat Open(AudioFormat &af, Error &error) override;
virtual void Close();
virtual const void *FilterPCM(const void *src, size_t src_size,
size_t *dest_size_r, Error &error);
private:
/**
* Close all filters in the chain until #until is reached.
* #until itself is not closed.
*/
void CloseUntil(const Filter *until);
};
static constexpr Domain chain_filter_domain("chain_filter");
static Filter *
chain_filter_init(gcc_unused const config_param ¶m,
gcc_unused Error &error)
{
return new ChainFilter();
}
void
ChainFilter::CloseUntil(const Filter *until)
{
for (auto &child : children) {
if (child.filter == until)
/* don't close this filter */
return;
/* close this filter */
child.filter->Close();
}
/* this assertion fails if #until does not exist (anymore) */
assert(false);
gcc_unreachable();
}
static AudioFormat
chain_open_child(const char *name, Filter *filter,
const AudioFormat &prev_audio_format,
Error &error)
{
AudioFormat conv_audio_format = prev_audio_format;
const AudioFormat next_audio_format =
filter->Open(conv_audio_format, error);
if (!next_audio_format.IsDefined())
return next_audio_format;
if (conv_audio_format != prev_audio_format) {
struct audio_format_string s;
filter->Close();
error.Format(chain_filter_domain,
"Audio format not supported by filter '%s': %s",
name,
audio_format_to_string(prev_audio_format, &s));
return AudioFormat::Undefined();
}
return next_audio_format;
}
AudioFormat
ChainFilter::Open(AudioFormat &in_audio_format, Error &error)
{
AudioFormat audio_format = in_audio_format;
for (auto &child : children) {
audio_format = chain_open_child(child.name, child.filter,
audio_format, error);
if (!audio_format.IsDefined()) {
/* rollback, close all children */
CloseUntil(child.filter);
break;
}
}
/* return the output format of the last filter */
return audio_format;
}
void
ChainFilter::Close()
{
for (auto &child : children)
child.filter->Close();
}
const void *
ChainFilter::FilterPCM(const void *src, size_t src_size,
size_t *dest_size_r, Error &error)
{
for (auto &child : children) {
/* feed the output of the previous filter as input
into the current one */
src = child.filter->FilterPCM(src, src_size, &src_size,
error);
if (src == NULL)
return NULL;
}
/* return the output of the last filter */
*dest_size_r = src_size;
return src;
}
const struct filter_plugin chain_filter_plugin = {
"chain",
chain_filter_init,
};
Filter *
filter_chain_new(void)
{
return new ChainFilter();
}
void
filter_chain_append(Filter &_chain, const char *name, Filter *filter)
{
ChainFilter &chain = (ChainFilter &)_chain;
chain.Append(name, filter);
}
|
