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

81 lines
2.2 KiB
C++

// SPDX-License-Identifier: GPL-2.0-or-later
// Copyright The Music Player Daemon Project
#ifndef MPD_CROSSFADE_HXX
#define MPD_CROSSFADE_HXX
#include "Chrono.hxx"
struct AudioFormat;
class SignedSongTime;
struct CrossFadeSettings {
/**
* Songs shorter than this will never cross-fade.
*/
static constexpr SignedSongTime MIN_TOTAL_TIME{std::chrono::seconds{20}};
/**
* The configured cross fade duration [s].
*/
FloatDuration duration{0};
float mixramp_db{0};
/**
* The configured MixRapm delay [s]. A non-positive value
* disables MixRamp.
*/
FloatDuration mixramp_delay{-1};
constexpr bool IsEnabled() const noexcept {
return duration.count() > 0;
}
constexpr bool IsMixRampEnabled() const noexcept {
return mixramp_delay > FloatDuration::zero();
}
/**
* Determine whether cross-fading the two songs is possible.
*
* @param current_total_time the duration of the current song
* @param next_total_time the duration of the new song
* @param af the audio format of the new song
* @param old_format the audio format of the current song
* @return true if cross-fading is possible
*/
[[gnu::pure]]
bool CanCrossFade(SignedSongTime current_total_time,
SignedSongTime next_total_time,
AudioFormat af, AudioFormat old_format) const noexcept;
/**
* Calculate how many music pipe chunks should be used for crossfading.
*
* @param replay_gain_db the ReplayGain adjustment used for this song
* @param replay_gain_prev_db the ReplayGain adjustment used on the last song
* @param mixramp_start the next songs mixramp_start tag
* @param mixramp_prev_end the last songs mixramp_end setting
* @param af the audio format of the new song
* @param max_chunks the maximum number of chunks
* @return the number of chunks for crossfading, or 0 if cross fading
* should be disabled for this song change
*/
[[gnu::pure]]
unsigned Calculate(float replay_gain_db, float replay_gain_prev_db,
const char *mixramp_start,
const char *mixramp_prev_end,
AudioFormat af,
unsigned max_chunks) const noexcept;
private:
/**
* Can the described song be cross-faded?
*/
[[gnu::pure]]
bool CanCrossFadeSong(SignedSongTime total_time) const noexcept;
};
#endif