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/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/ByteBuffer.h>
#include <AK/MemoryStream.h>
#include <AK/Types.h>
#include <AK/Vector.h>
#include <LibCore/AnonymousBuffer.h>
#include <string.h>
namespace Audio {
// A single sample in an audio buffer.
// Values are floating point, and should range from -1.0 to +1.0
struct Frame {
Frame()
: left(0)
, right(0)
{
}
// For mono
Frame(double left)
: left(left)
, right(left)
{
}
// For stereo
Frame(double left, double 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)
{
double pct = (double)percent / 100.0;
left *= pct;
right *= pct;
}
Frame& operator+=(const Frame& other)
{
left += other.left;
right += other.right;
return *this;
}
double left;
double 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 ResampleHelper {
public:
ResampleHelper(double source, double target);
void process_sample(double sample_l, double sample_r);
bool read_sample(double& next_l, double& next_r);
private:
const double m_ratio;
double m_current_ratio { 0 };
double m_last_sample_l { 0 };
double m_last_sample_r { 0 };
};
// A buffer of audio samples, normalized to 44100hz.
class Buffer : public RefCounted<Buffer> {
public:
static RefPtr<Buffer> from_pcm_data(ReadonlyBytes data, ResampleHelper& resampler, int num_channels, int bits_per_sample);
static RefPtr<Buffer> from_pcm_stream(InputMemoryStream& stream, ResampleHelper& resampler, int num_channels, int bits_per_sample, int num_samples);
static NonnullRefPtr<Buffer> create_with_samples(Vector<Frame>&& samples)
{
return adopt(*new Buffer(move(samples)));
}
static NonnullRefPtr<Buffer> create_with_anonymous_buffer(Core::AnonymousBuffer buffer, i32 buffer_id, int sample_count)
{
return adopt(*new Buffer(move(buffer), buffer_id, sample_count));
}
const Frame* samples() const { return (const Frame*)data(); }
int sample_count() const { return m_sample_count; }
const void* data() const { return m_buffer.data<void>(); }
int size_in_bytes() const { return m_sample_count * (int)sizeof(Frame); }
int id() const { return m_id; }
const Core::AnonymousBuffer& anonymous_buffer() const { return m_buffer; }
private:
explicit Buffer(const Vector<Frame> samples)
: m_buffer(Core::AnonymousBuffer::create_with_size(samples.size() * sizeof(Frame)))
, m_id(allocate_id())
, m_sample_count(samples.size())
{
memcpy(m_buffer.data<void>(), samples.data(), samples.size() * sizeof(Frame));
}
explicit Buffer(Core::AnonymousBuffer buffer, i32 buffer_id, int sample_count)
: m_buffer(move(buffer))
, m_id(buffer_id)
, m_sample_count(sample_count)
{
}
static i32 allocate_id();
Core::AnonymousBuffer m_buffer;
const i32 m_id;
const int m_sample_count;
};
}
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