annotate osx/include/vamp-hostsdk/PluginChannelAdapter.h @ 121:e678e95bc41b

Merge
author Chris Cannam <cannam@all-day-breakfast.com>
date Wed, 11 Mar 2015 13:32:44 +0000
parents 4c576e416934
children
rev   line source
cannam@110 1 /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */
cannam@110 2
cannam@110 3 /*
cannam@110 4 Vamp
cannam@110 5
cannam@110 6 An API for audio analysis and feature extraction plugins.
cannam@110 7
cannam@110 8 Centre for Digital Music, Queen Mary, University of London.
cannam@110 9 Copyright 2006-2009 Chris Cannam and QMUL.
cannam@110 10
cannam@110 11 Permission is hereby granted, free of charge, to any person
cannam@110 12 obtaining a copy of this software and associated documentation
cannam@110 13 files (the "Software"), to deal in the Software without
cannam@110 14 restriction, including without limitation the rights to use, copy,
cannam@110 15 modify, merge, publish, distribute, sublicense, and/or sell copies
cannam@110 16 of the Software, and to permit persons to whom the Software is
cannam@110 17 furnished to do so, subject to the following conditions:
cannam@110 18
cannam@110 19 The above copyright notice and this permission notice shall be
cannam@110 20 included in all copies or substantial portions of the Software.
cannam@110 21
cannam@110 22 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
cannam@110 23 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
cannam@110 24 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
cannam@110 25 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
cannam@110 26 ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
cannam@110 27 CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
cannam@110 28 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
cannam@110 29
cannam@110 30 Except as contained in this notice, the names of the Centre for
cannam@110 31 Digital Music; Queen Mary, University of London; and Chris Cannam
cannam@110 32 shall not be used in advertising or otherwise to promote the sale,
cannam@110 33 use or other dealings in this Software without prior written
cannam@110 34 authorization.
cannam@110 35 */
cannam@110 36
cannam@110 37 #ifndef _VAMP_PLUGIN_CHANNEL_ADAPTER_H_
cannam@110 38 #define _VAMP_PLUGIN_CHANNEL_ADAPTER_H_
cannam@110 39
cannam@110 40 #include "hostguard.h"
cannam@110 41 #include "PluginWrapper.h"
cannam@110 42
cannam@110 43 _VAMP_SDK_HOSTSPACE_BEGIN(PluginChannelAdapter.h)
cannam@110 44
cannam@110 45 namespace Vamp {
cannam@110 46
cannam@110 47 namespace HostExt {
cannam@110 48
cannam@110 49 /**
cannam@110 50 * \class PluginChannelAdapter PluginChannelAdapter.h <vamp-hostsdk/PluginChannelAdapter.h>
cannam@110 51 *
cannam@110 52 * PluginChannelAdapter is a Vamp plugin adapter that implements a
cannam@110 53 * policy for management of plugins that expect a different number of
cannam@110 54 * input channels from the number actually available in the source
cannam@110 55 * audio data.
cannam@110 56 *
cannam@110 57 * A host using PluginChannelAdapter may ignore the getMinChannelCount
cannam@110 58 * and getMaxChannelCount reported by the plugin, and still expect the
cannam@110 59 * plugin to run.
cannam@110 60 *
cannam@110 61 * PluginChannelAdapter implements the following policy:
cannam@110 62 *
cannam@110 63 * - If the plugin supports the provided number of channels directly,
cannam@110 64 * PluginChannelAdapter will just run the plugin as normal.
cannam@110 65 *
cannam@110 66 * - If the plugin only supports exactly one channel but more than
cannam@110 67 * one channel is provided, PluginChannelAdapter will use the mean of
cannam@110 68 * the channels. This ensures that the resulting values remain
cannam@110 69 * within the same magnitude range as expected for mono data.
cannam@110 70 *
cannam@110 71 * - If the plugin requires more than one channel but exactly one is
cannam@110 72 * provided, the provided channel will be duplicated across all the
cannam@110 73 * plugin input channels.
cannam@110 74 *
cannam@110 75 * If none of the above apply:
cannam@110 76 *
cannam@110 77 * - If the plugin requires more channels than are provided, the
cannam@110 78 * minimum acceptable number of channels will be produced by adding
cannam@110 79 * empty (zero valued) channels to those provided.
cannam@110 80 *
cannam@110 81 * - If the plugin requires fewer channels than are provided, the
cannam@110 82 * maximum acceptable number of channels will be produced by
cannam@110 83 * discarding the excess channels.
cannam@110 84 *
cannam@110 85 * Hosts requiring a different channel policy from the above will need
cannam@110 86 * to implement it themselves, instead of using PluginChannelAdapter.
cannam@110 87 *
cannam@110 88 * Note that PluginChannelAdapter does not override the minimum and
cannam@110 89 * maximum channel counts returned by the wrapped plugin. The host
cannam@110 90 * will need to be aware that it is using a PluginChannelAdapter, and
cannam@110 91 * be prepared to ignore these counts as necessary. (This contrasts
cannam@110 92 * with the approach used in PluginInputDomainAdapter, which aims to
cannam@110 93 * make the host completely unaware of which underlying input domain
cannam@110 94 * is in fact in use.)
cannam@110 95 *
cannam@110 96 * (The rationale for this is that a host may wish to use the
cannam@110 97 * PluginChannelAdapter but still discriminate in some way on the
cannam@110 98 * basis of the number of channels actually supported. For example, a
cannam@110 99 * simple stereo audio host may prefer to reject plugins that require
cannam@110 100 * more than two channels on the grounds that doesn't actually
cannam@110 101 * understand what they are for, rather than allow the channel adapter
cannam@110 102 * to make a potentially meaningless channel conversion for them.)
cannam@110 103 *
cannam@110 104 * In every respect other than its management of channels, the
cannam@110 105 * PluginChannelAdapter behaves identically to the plugin that it
cannam@110 106 * wraps. The wrapped plugin will be deleted when the wrapper is
cannam@110 107 * deleted.
cannam@110 108 *
cannam@110 109 * \note This class was introduced in version 1.1 of the Vamp plugin SDK.
cannam@110 110 */
cannam@110 111
cannam@110 112 class PluginChannelAdapter : public PluginWrapper
cannam@110 113 {
cannam@110 114 public:
cannam@110 115 /**
cannam@110 116 * Construct a PluginChannelAdapter wrapping the given plugin.
cannam@110 117 * The adapter takes ownership of the plugin, which will be
cannam@110 118 * deleted when the adapter is deleted.
cannam@110 119 */
cannam@110 120 PluginChannelAdapter(Plugin *plugin);
cannam@110 121 virtual ~PluginChannelAdapter();
cannam@110 122
cannam@110 123 bool initialise(size_t channels, size_t stepSize, size_t blockSize);
cannam@110 124
cannam@110 125 FeatureSet process(const float *const *inputBuffers, RealTime timestamp);
cannam@110 126
cannam@110 127 /**
cannam@110 128 * Call process(), providing interleaved audio data with the
cannam@110 129 * number of channels passed to initialise(). The adapter will
cannam@110 130 * de-interleave into temporary buffers as appropriate before
cannam@110 131 * calling process().
cannam@110 132 *
cannam@110 133 * \note This function was introduced in version 1.4 of the Vamp
cannam@110 134 * plugin SDK.
cannam@110 135 */
cannam@110 136 FeatureSet processInterleaved(const float *inputBuffer, RealTime timestamp);
cannam@110 137
cannam@110 138 protected:
cannam@110 139 class Impl;
cannam@110 140 Impl *m_impl;
cannam@110 141 };
cannam@110 142
cannam@110 143 }
cannam@110 144
cannam@110 145 }
cannam@110 146
cannam@110 147 _VAMP_SDK_HOSTSPACE_END(PluginChannelAdapter.h)
cannam@110 148
cannam@110 149 #endif