cb0e95c928
With the following change in how we send audio, the old Buffer type is not really needed anymore. However, moving WavLoader to the new system is a bit more involved and out of the scope of this PR. Therefore, we need to keep Buffer around, but to make it clear that it's the old buffer type which will be removed soon, we rename it to LegacyBuffer. Most of the users will be gone after the next commit anyways.
90 lines
2.4 KiB
C++
90 lines
2.4 KiB
C++
/*
|
|
* Copyright (c) 2022, kleines Filmröllchen <filmroellchen@serenityos.org>.
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include <AK/Concepts.h>
|
|
#include <AK/Types.h>
|
|
#include <AK/Vector.h>
|
|
|
|
namespace Audio {
|
|
|
|
// 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...
|
|
template<typename SampleType>
|
|
class ResampleHelper {
|
|
public:
|
|
ResampleHelper(u32 source, u32 target)
|
|
: m_source(source)
|
|
, m_target(target)
|
|
{
|
|
VERIFY(source > 0);
|
|
VERIFY(target > 0);
|
|
}
|
|
|
|
// To be used as follows:
|
|
// while the resampler doesn't need a new sample, read_sample(current) and store the resulting samples.
|
|
// as long as the resampler needs a new sample, process_sample(current)
|
|
|
|
// Stores a new sample
|
|
void process_sample(SampleType sample_l, SampleType sample_r)
|
|
{
|
|
m_last_sample_l = sample_l;
|
|
m_last_sample_r = sample_r;
|
|
m_current_ratio += m_target;
|
|
}
|
|
|
|
// Assigns the given sample to its correct value and returns false if there is a new sample required
|
|
bool read_sample(SampleType& next_l, SampleType& next_r)
|
|
{
|
|
if (m_current_ratio >= m_source) {
|
|
m_current_ratio -= m_source;
|
|
next_l = m_last_sample_l;
|
|
next_r = m_last_sample_r;
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
template<ArrayLike<SampleType> Samples>
|
|
Vector<SampleType> resample(Samples&& to_resample)
|
|
{
|
|
Vector<SampleType> resampled;
|
|
resampled.ensure_capacity(to_resample.size() * ceil_div(m_source, m_target));
|
|
for (auto sample : to_resample) {
|
|
process_sample(sample, sample);
|
|
|
|
while (read_sample(sample, sample))
|
|
resampled.unchecked_append(sample);
|
|
}
|
|
|
|
return resampled;
|
|
}
|
|
|
|
void reset()
|
|
{
|
|
m_current_ratio = 0;
|
|
m_last_sample_l = {};
|
|
m_last_sample_r = {};
|
|
}
|
|
|
|
u32 source() const { return m_source; }
|
|
u32 target() const { return m_target; }
|
|
|
|
private:
|
|
const u32 m_source;
|
|
const u32 m_target;
|
|
u32 m_current_ratio { 0 };
|
|
SampleType m_last_sample_l {};
|
|
SampleType m_last_sample_r {};
|
|
};
|
|
|
|
class LegacyBuffer;
|
|
ErrorOr<NonnullRefPtr<LegacyBuffer>> resample_buffer(ResampleHelper<double>& resampler, LegacyBuffer const& to_resample);
|
|
|
|
}
|