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
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
|
/* This file is part of the KDE project
Copyright (C) 2007 Matthias Kretz <kretz@kde.org>
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) version 3, or any
later version accepted by the membership of KDE e.V. (or its
successor approved by the membership of KDE e.V.), Nokia Corporation
(or its successors, if any) and the KDE Free Qt Foundation, which shall
act as a proxy defined in Section 6 of version 3 of the license.
This library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef PHONON_ABSTRACTMEDIASTREAM_H
#define PHONON_ABSTRACTMEDIASTREAM_H
#include "phonon_export.h"
#include "phononnamespace.h"
#include <QtCore/QObject>
QT_BEGIN_HEADER
QT_BEGIN_NAMESPACE
class QByteArray;
#ifndef QT_NO_PHONON_ABSTRACTMEDIASTREAM
namespace Phonon
{
class MediaObject;
class AbstractMediaStreamPrivate;
/** \class AbstractMediaStream abstractmediastream.h Phonon/AbstractMediaStream
* \brief Base class for custom media data streams.
*
* Implement this class to provide a custom data stream to the backend. The class supports both, the
* push and the pull model.
*
* Push:
* \code
* PushStream::PushStream(QObject *parent)
* : AbstractMediaStream(parent), m_timer(new QTimer(this))
* {
* setStreamSize(getMediaStreamSize());
*
* connect(m_timer, SIGNAL(timeout()), SLOT(moreData()));
* m_timer->setInterval(0);
* }
*
* void PushStream::moreData()
* {
* const QByteArray data = getMediaData();
* if (data.isEmpty()) {
* endOfData();
* } else {
* writeData(data);
* }
* }
*
* void PushStream::needData()
* {
* m_timer->start();
* moreData();
* }
*
* void PushStream::enoughData()
* {
* m_timer->stop();
* }
* \endcode
*
* Pull:
* \code
* PullStream::PullStream(QObject *parent)
* : AbstractMediaStream(parent)
* {
* setStreamSize(getMediaStreamSize());
* }
*
* void PullStream::needData()
* {
* const QByteArray data = getMediaData();
* if (data.isEmpty()) {
* endOfData();
* } else {
* writeData(data);
* }
* }
* \endcode
*
* \ingroup Playback
* \author Matthias Kretz <kretz@kde.org>
*/
class PHONON_EXPORT AbstractMediaStream : public QObject
{
Q_OBJECT
Q_DECLARE_PRIVATE(AbstractMediaStream)
friend class MediaObject;
friend class MediaObjectPrivate;
friend class StreamInterface;
public:
virtual ~AbstractMediaStream();
protected:
/**
* Constructs an AbstractMediaStream object with a \p parent.
*/
explicit AbstractMediaStream(QObject *parent = 0);
/**
* Returns the stream size that was set with \ref setStreamSize.
*
* A negative value means that the length of the stream cannot be known.
*
* Defaults to \c 0.
*/
qint64 streamSize() const;
/**
* Sets the size of the stream in number of bytes.
*
* A negative value means that the length of the stream cannot be known.
*
* Defaults to 0.
*
* This function has to be called. A backend will not call \ref needData() until the
* stream size is set.
*/
void setStreamSize(qint64);
/**
* Returns whether your data stream is set as seekable.
*
* Defaults to \c false.
*/
bool streamSeekable() const;
/**
* Sets whether your data stream is seekable.
*
* Defaults to \c false.
*
* If you set this to \c true you have to implement the \ref seekStream function.
*/
void setStreamSeekable(bool);
/**
* Sends the media \p data to the backend for decoding.
*
* \warning Don't call this function before the first needData() is emitted.
*/
void writeData(const QByteArray &data);
/**
* Tells the backend that the media data stream is at its end.
*
* \warning Don't call this function before the first needData() is emitted.
*/
void endOfData();
/**
* If an I/O error occurs you should call this function to make MediaObject go into
* ErrorState.
*
* \see MediaObject::errorType()
* \see MediaObject::errorString()
*/
void error(Phonon::ErrorType errorType, const QString &errorString);
/**
* Reimplement this function to reset the stream. Subsequent calls to writeData should start
* from the first position of the data unless a seek is requested.
*
* The function is necessary for the case where a non-seekable MediaStream is
* played more than once. For a seekable stream the implementation can simply call
* \code
* seekStream(0);
* \endcode.
*/
virtual void reset() = 0;
/**
* Reimplement this function to be notified when the backend needs data.
*
* When this function is called you should try to call writeData or endOfData before
* returning.
*/
virtual void needData() = 0;
/**
* Reimplement this function to be notified when the backend has enough data and your stream
* object may take a break. This method is important for pushing data to the backend in
* order to not fill the backend buffer unnecessarily.
*/
virtual void enoughData();
/**
* Reimplement this function if your stream is seekable.
*
* When this function is called the next call to writeData has to be at the requested \p
* offset.
*
* \warning Do not call the parent implementation.
*/
virtual void seekStream(qint64 offset);
AbstractMediaStream(AbstractMediaStreamPrivate &dd, QObject *parent);
QScopedPointer<AbstractMediaStreamPrivate> d_ptr;
};
} // namespace Phonon
#endif //QT_NO_PHONON_ABSTRACTMEDIASTREAM
QT_END_NAMESPACE
QT_END_HEADER
#endif // PHONON_ABSTRACTMEDIASTREAM_H
|
