1 /*******************************************************************************
2 * Copyright 2009-2016 Jörg Müller
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 ******************************************************************************/
16
17 #include "fx/DelayReader.h"
18
19 #include <cstring>
20
21 AUD_NAMESPACE_BEGIN
22
DelayReader(std::shared_ptr<IReader> reader,double delay)23 DelayReader::DelayReader(std::shared_ptr<IReader> reader, double delay) :
24 EffectReader(reader),
25 m_delay(int((SampleRate)delay * reader->getSpecs().rate)),
26 m_remdelay(int((SampleRate)delay * reader->getSpecs().rate))
27 {
28 }
29
seek(int position)30 void DelayReader::seek(int position)
31 {
32 if(position < m_delay)
33 {
34 m_remdelay = m_delay - position;
35 m_reader->seek(0);
36 }
37 else
38 {
39 m_remdelay = 0;
40 m_reader->seek(position - m_delay);
41 }
42 }
43
getLength() const44 int DelayReader::getLength() const
45 {
46 int len = m_reader->getLength();
47 if(len < 0)
48 return len;
49 return len + m_delay;
50 }
51
getPosition() const52 int DelayReader::getPosition() const
53 {
54 if(m_remdelay > 0)
55 return m_delay - m_remdelay;
56 return m_reader->getPosition() + m_delay;
57 }
58
read(int & length,bool & eos,sample_t * buffer)59 void DelayReader::read(int& length, bool& eos, sample_t* buffer)
60 {
61 if(m_remdelay > 0)
62 {
63 Specs specs = m_reader->getSpecs();
64 int samplesize = AUD_SAMPLE_SIZE(specs);
65
66 if(length > m_remdelay)
67 {
68 std::memset(buffer, 0, m_remdelay * samplesize);
69
70 int len = length - m_remdelay;
71 m_reader->read(len, eos, buffer + m_remdelay * specs.channels);
72
73 length = m_remdelay + len;
74
75 m_remdelay = 0;
76 }
77 else
78 {
79 std::memset(buffer, 0, length * samplesize);
80 m_remdelay -= length;
81 }
82 }
83 else
84 m_reader->read(length, eos, buffer);
85 }
86
87 AUD_NAMESPACE_END
88