psemek/libs/audio/source/stereo.cpp

69 lines
1.3 KiB
C++

#include <psemek/audio/stereo.hpp>
#include <vector>
namespace psemek::audio
{
namespace
{
struct stereo_impl
: stream
{
stereo_impl(stream_ptr left, stream_ptr right)
: left_(std::move(left))
, right_(std::move(right))
{}
std::optional<std::size_t> length() const override
{
auto left = left_->length();
auto right = right_->length();
if (left && right)
return std::min(*left, *right);
else if (left)
return left;
else
return right;
}
std::size_t played() const override
{
return std::min(left_->played(), right_->played());
}
std::size_t read(util::span<float> samples) override
{
if (buffer_.size() < samples.size())
buffer_.resize(samples.size());
auto right_result = right_->read(samples);
auto left_result = left_->read({buffer_.data(), samples.size()});
auto result = std::min(right_result, left_result);
{
auto begin = buffer_.data();
auto end = buffer_.data() + result;
auto dst = samples.data();
for (; begin < end; begin += 2, dst += 2)
*dst = *begin;
}
return result;
}
private:
stream_ptr left_, right_;
std::vector<float> buffer_;
};
}
stream_ptr stereo(stream_ptr left, stream_ptr right)
{
return std::make_shared<stereo_impl>(std::move(left), std::move(right));
}
}