comparison vamp-hostsdk/PluginChannelAdapter.h @ 233:521734d2b498 distinct-libraries

* Flatten directory tree a bit, update doxygen
author cannam
date Fri, 07 Nov 2008 15:28:33 +0000
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232:71ea10a3cbe7 233:521734d2b498
1 /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */
2
3 /*
4 Vamp
5
6 An API for audio analysis and feature extraction plugins.
7
8 Centre for Digital Music, Queen Mary, University of London.
9 Copyright 2006-2007 Chris Cannam and QMUL.
10
11 Permission is hereby granted, free of charge, to any person
12 obtaining a copy of this software and associated documentation
13 files (the "Software"), to deal in the Software without
14 restriction, including without limitation the rights to use, copy,
15 modify, merge, publish, distribute, sublicense, and/or sell copies
16 of the Software, and to permit persons to whom the Software is
17 furnished to do so, subject to the following conditions:
18
19 The above copyright notice and this permission notice shall be
20 included in all copies or substantial portions of the Software.
21
22 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
23 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
24 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
25 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
26 ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
27 CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
28 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
29
30 Except as contained in this notice, the names of the Centre for
31 Digital Music; Queen Mary, University of London; and Chris Cannam
32 shall not be used in advertising or otherwise to promote the sale,
33 use or other dealings in this Software without prior written
34 authorization.
35 */
36
37 #ifndef _VAMP_PLUGIN_CHANNEL_ADAPTER_H_
38 #define _VAMP_PLUGIN_CHANNEL_ADAPTER_H_
39
40 #include "PluginWrapper.h"
41
42 namespace Vamp {
43
44 namespace HostExt {
45
46 /**
47 * \class PluginChannelAdapter PluginChannelAdapter.h <vamp-hostsdk/PluginChannelAdapter.h>
48 *
49 * PluginChannelAdapter is a Vamp plugin adapter that implements a
50 * policy for management of plugins that expect a different number of
51 * input channels from the number actually available in the source
52 * audio data.
53 *
54 * A host using PluginChannelAdapter may ignore the getMinChannelCount
55 * and getMaxChannelCount reported by the plugin, and still expect the
56 * plugin to run.
57 *
58 * PluginChannelAdapter implements the following policy:
59 *
60 * - If the plugin supports the provided number of channels directly,
61 * PluginChannelAdapter will just run the plugin as normal.
62 *
63 * - If the plugin only supports exactly one channel but more than
64 * one channel is provided, PluginChannelAdapter will use the mean of
65 * the channels. This ensures that the resulting values remain
66 * within the same magnitude range as expected for mono data.
67 *
68 * - If the plugin requires more than one channel but exactly one is
69 * provided, the provided channel will be duplicated across all the
70 * plugin input channels.
71 *
72 * If none of the above apply:
73 *
74 * - If the plugin requires more channels than are provided, the
75 * minimum acceptable number of channels will be produced by adding
76 * empty (zero valued) channels to those provided.
77 *
78 * - If the plugin requires fewer channels than are provided, the
79 * maximum acceptable number of channels will be produced by
80 * discarding the excess channels.
81 *
82 * Hosts requiring a different channel policy from the above will need
83 * to implement it themselves, instead of using PluginChannelAdapter.
84 *
85 * Note that PluginChannelAdapter does not override the minimum and
86 * maximum channel counts returned by the wrapped plugin. The host
87 * will need to be aware that it is using a PluginChannelAdapter, and
88 * be prepared to ignore these counts as necessary. (This contrasts
89 * with the approach used in PluginInputDomainAdapter, which aims to
90 * make the host completely unaware of which underlying input domain
91 * is in fact in use.)
92 *
93 * (The rationale for this is that a host may wish to use the
94 * PluginChannelAdapter but still discriminate in some way on the
95 * basis of the number of channels actually supported. For example, a
96 * simple stereo audio host may prefer to reject plugins that require
97 * more than two channels on the grounds that doesn't actually
98 * understand what they are for, rather than allow the channel adapter
99 * to make a potentially meaningless channel conversion for them.)
100 *
101 * In every respect other than its management of channels, the
102 * PluginChannelAdapter behaves identically to the plugin that it
103 * wraps. The wrapped plugin will be deleted when the wrapper is
104 * deleted.
105 *
106 * \note This class was introduced in version 1.1 of the Vamp plugin SDK.
107 */
108
109 class PluginChannelAdapter : public PluginWrapper
110 {
111 public:
112 PluginChannelAdapter(Plugin *plugin); // I take ownership of plugin
113 virtual ~PluginChannelAdapter();
114
115 bool initialise(size_t channels, size_t stepSize, size_t blockSize);
116
117 FeatureSet process(const float *const *inputBuffers, RealTime timestamp);
118
119 /**
120 * Call process(), providing interleaved audio data with the
121 * number of channels passed to initialise(). The adapter will
122 * de-interleave into temporary buffers as appropriate before
123 * calling process().
124 *
125 * \note This function was introduced in version 1.4 of the Vamp
126 * plugin SDK.
127 */
128 FeatureSet processInterleaved(const float *inputBuffer, RealTime timestamp);
129
130 protected:
131 class Impl;
132 Impl *m_impl;
133 };
134
135 }
136
137 }
138
139 #endif