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
|
#pragma once
#include <AK/ByteBuffer.h>
#include <AK/Types.h>
#include <AK/Vector.h>
#include <AK/SharedBuffer.h>
// A single sample in an audio buffer.
// Values are floating point, and should range from -1.0 to +1.0
struct ASample {
ASample()
: left(0)
, right(0)
{
}
// For mono
ASample(float left)
: left(left)
, right(left)
{
}
// For stereo
ASample(float left, float right)
: left(left)
, right(right)
{
}
void clip()
{
if (left > 1)
left = 1;
else if (left < -1)
left = -1;
if (right > 1)
right = 1;
else if (right < -1)
right = -1;
}
void scale(int percent)
{
float pct = (float)percent / 100.0;
left *= pct;
right *= pct;
}
ASample& operator+=(const ASample& other)
{
left += other.left;
right += other.right;
return *this;
}
float left;
float right;
};
// Small helper to resample from one playback rate to another
// This isn't really "smart", in that we just insert (or drop) samples.
// Should do better...
class AResampleHelper {
public:
AResampleHelper(float source, float target);
void process_sample(float sample_l, float sample_r);
bool read_sample(float& next_l, float& next_r);
private:
const float m_ratio;
float m_current_ratio { 0 };
float m_last_sample_l { 0 };
float m_last_sample_r { 0 };
};
// A buffer of audio samples, normalized to 44100hz.
class ABuffer : public RefCounted<ABuffer> {
public:
static RefPtr<ABuffer> from_pcm_data(ByteBuffer& data, AResampleHelper& resampler, int num_channels, int bits_per_sample);
static NonnullRefPtr<ABuffer> create_with_samples(Vector<ASample>&& samples)
{
return adopt(*new ABuffer(move(samples)));
}
static NonnullRefPtr<ABuffer> create_with_shared_buffer(NonnullRefPtr<SharedBuffer>&& buffer, int sample_count)
{
return adopt(*new ABuffer(move(buffer), sample_count));
}
const ASample* samples() const { return (const ASample*)data(); }
int sample_count() const { return m_sample_count; }
const void* data() const { return m_buffer->data(); }
int size_in_bytes() const { return m_sample_count * (int)sizeof(ASample); }
int shared_buffer_id() const { return m_buffer->shared_buffer_id(); }
SharedBuffer& shared_buffer() { return *m_buffer; }
private:
explicit ABuffer(Vector<ASample>&& samples)
: m_buffer(*SharedBuffer::create_with_size(samples.size() * sizeof(ASample))),
m_sample_count(samples.size())
{
memcpy(m_buffer->data(), samples.data(), samples.size() * sizeof(ASample));
}
explicit ABuffer(NonnullRefPtr<SharedBuffer>&& buffer, int sample_count)
: m_buffer(move(buffer)),
m_sample_count(sample_count)
{
}
NonnullRefPtr<SharedBuffer> m_buffer;
const int m_sample_count;
};
|
