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
|
/***************************************************************************
SampleReader.h - stream for reading samples from a track
-------------------
begin : Apr 25 2001
copyright : (C) 2001 by Thomas Eschenbacher
email : Thomas Eschenbacher <thomas.eschenbacher@gmx.de>
***************************************************************************/
/***************************************************************************
* *
* 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. *
* *
***************************************************************************/
#ifndef SAMPLE_READER_H
#define SAMPLE_READER_H
#include "config.h"
#include "libkwave_export.h"
#include <QtGlobal>
#include <QElapsedTimer>
#include <QList>
#include <QObject>
#include "libkwave/InsertMode.h"
#include "libkwave/ReaderMode.h"
#include "libkwave/Sample.h"
#include "libkwave/SampleArray.h"
#include "libkwave/SampleSource.h"
#include "libkwave/Stripe.h"
namespace Kwave
{
class LIBKWAVE_EXPORT SampleReader: public Kwave::SampleSource
{
Q_OBJECT
public:
/**
* Constructor. Creates a stream for reading samples from a track.
* @param mode the reader mode, see Kwave::ReaderMode
* @param stripes list of stripes which contains the desired range
* @see InsertMode
*/
SampleReader(Kwave::ReaderMode mode, Kwave::Stripe::List stripes);
/** Destructor */
~SampleReader() override;
/** Resets the stream to it's start */
void reset();
/**
* Each KwaveSampleSource has to derive this method for producing
* sample data. It then should emit a signal like this:
* "output(SampleArray &data)"
*/
void goOn() override;
/** Checks if the last read operation has reached the end of input */
inline bool eof() const {
return (pos() > m_last);
}
/**
* Returns true if the end of the source has been reached,
* e.g. at EOF of an input stream.
*
* @return true if it can produce more sample data, otherwise false
* @see eof()
*/
bool done() const override { return eof(); }
/**
* Reads samples into a buffer.
* @param buffer the destination buffer to receive the samples
* @param dstoff offset within the destination buffer
* @param length number of samples to read
* @return number of read samples
*/
unsigned int read(Kwave::SampleArray &buffer, unsigned int dstoff,
unsigned int length);
/**
* Returns the minimum and maximum sample value within a range
* of samples.
* @param first index of the first sample
* @param last index of the last sample
* @param min receives the lowest value or 0 if no samples are in range
* @param max receives the highest value or 0 if no samples are in range
*
* @note min and max do not need to be initialized
*/
void minMax(sample_index_t first, sample_index_t last,
sample_t &min, sample_t &max);
/** Skips a number of samples. */
void skip(sample_index_t count);
/** Seeks to a given position */
void seek(sample_index_t pos);
/**
* Returns the current read position.
*/
inline sample_index_t pos() const {
return (m_src_position + m_buffer_position - m_buffer_used);
}
/** Returns the position of the first sample */
inline sample_index_t first() const {
return m_first;
}
/** Returns the position of the last sample */
inline sample_index_t last() const {
return m_last;
}
/**
* Reads one single sample.
*/
SampleReader& operator >> (sample_t &sample);
/**
* Reads a full buffer of samples. If the buffer cannot be filled,
* it will be shrinked to the number of samples that were really
* read.
*/
SampleReader& operator >> (Kwave::SampleArray &sample);
signals:
/**
* Emitted when the internal buffer is filled or the reader is closed
*/
void proceeded();
/**
* Interface for the signal/slot based streaming API.
* @param data sample data that has been read
*/
void output(Kwave::SampleArray data);
protected:
/** Fills the sample buffer */
void fillBuffer();
/**
* Read a block of samples, with padding if necessary.
*
* @param offset position where to start the read operation
* @param buffer receives the samples
* @param buf_offset offset within the buffer
* @param length number of samples to read
* @return number of read samples
*/
unsigned int readSamples(sample_index_t offset,
Kwave::SampleArray &buffer,
unsigned int buf_offset,
unsigned int length);
private:
/** operation mode of the reader, see Kwave::ReaderMode */
Kwave::ReaderMode m_mode;
/** list of stipes in range */
QList<Kwave::Stripe> m_stripes;
/**
* Current sample position, related to the source of the samples. Does
* not reflect the position of the next sample to be read out due to
* internal buffering.
* @see pos() for the output position
*/
sample_index_t m_src_position;
/** first sample index */
sample_index_t m_first;
/** last sample index */
sample_index_t m_last;
/** intermediate buffer for the input data */
Kwave::SampleArray m_buffer;
/** number of used elements in the buffer */
unsigned int m_buffer_used;
/** read position within the buffer */
unsigned int m_buffer_position;
/** timer for limiting the number of progress signals per second */
QElapsedTimer m_progress_time;
/** last seek position, needed in SinglePassReverse mode */
sample_index_t m_last_seek_pos;
};
}
#endif /* SAMPLE_READER_H */
//***************************************************************************
//***************************************************************************
|
