mpd/src/pcm/ChannelsConverter.hxx
2023-03-06 14:59:48 +01:00

65 lines
1.3 KiB
C++

// SPDX-License-Identifier: GPL-2.0-or-later
// Copyright The Music Player Daemon Project
#ifndef MPD_PCM_CHANNELS_CONVERTER_HXX
#define MPD_PCM_CHANNELS_CONVERTER_HXX
#include "SampleFormat.hxx"
#include "Buffer.hxx"
#include <span>
#ifndef NDEBUG
#include <cassert>
#endif
/**
* A class that converts samples from one format to another.
*/
class PcmChannelsConverter {
SampleFormat format;
unsigned src_channels, dest_channels;
PcmBuffer buffer;
public:
#ifndef NDEBUG
PcmChannelsConverter() noexcept
:format(SampleFormat::UNDEFINED) {}
~PcmChannelsConverter() noexcept {
assert(format == SampleFormat::UNDEFINED);
}
#endif
/**
* Opens the object, prepare for Convert().
*
* Throws std::runtime_error on error.
*
* @param format the sample format
* @param src_channels the number of source channels
* @param dest_channels the number of destination channels
*/
void Open(SampleFormat format,
unsigned src_channels, unsigned dest_channels);
/**
* Closes the object. After that, you may call Open() again.
*/
void Close() noexcept;
/**
* Convert a block of PCM data.
*
* Throws std::runtime_error on error.
*
* @param src the input buffer
* @return the destination buffer
*/
[[gnu::pure]]
std::span<const std::byte> Convert(std::span<const std::byte> src) noexcept;
};
#endif