mpd/src/MusicChunk.hxx
Max Kellermann de90d401d2 MusicChunk: add magic value IGNORE_REPLAY_GAIN
This fixes spurious replay gain logs when the player inserts silence
chunks, because those silence chunks had no replay gain attached,
resetting the ReplayGainFilter state, flipping it forth and back.
2017-12-03 11:39:12 +01:00

153 lines
4.0 KiB
C++

/*
* Copyright 2003-2017 The Music Player Daemon Project
* http://www.musicpd.org
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef MPD_MUSIC_CHUNK_HXX
#define MPD_MUSIC_CHUNK_HXX
#include "Chrono.hxx"
#include "ReplayGainInfo.hxx"
#include "util/WritableBuffer.hxx"
#ifndef NDEBUG
#include "AudioFormat.hxx"
#endif
#include <stdint.h>
#include <stddef.h>
static constexpr size_t CHUNK_SIZE = 4096;
struct AudioFormat;
struct Tag;
/**
* A chunk of music data. Its format is defined by the
* MusicPipe::Push() caller.
*/
struct MusicChunk {
/** the next chunk in a linked list */
MusicChunk *next;
/**
* An optional chunk which should be mixed into this chunk.
* This is used for cross-fading.
*/
MusicChunk *other = nullptr;
/**
* The current mix ratio for cross-fading: 1.0 means play 100%
* of this chunk, 0.0 means play 100% of the "other" chunk.
*/
float mix_ratio;
/** number of bytes stored in this chunk */
uint16_t length = 0;
/** current bit rate of the source file */
uint16_t bit_rate;
/** the time stamp within the song */
SignedSongTime time;
/**
* An optional tag associated with this chunk (and the
* following chunks); appears at song boundaries. The tag
* object is owned by this chunk, and must be freed when this
* chunk is deinitialized.
*/
Tag *tag = nullptr;
/**
* Replay gain information associated with this chunk.
* Only valid if the serial is not 0.
*/
ReplayGainInfo replay_gain_info;
/**
* A magic value for #replay_gain_serial which omits updating
* the #ReplayGainFilter. This is used by "silence" chunks
* (see PlayerThread::SendSilence()) so they don't affect the
* replay gain.
*/
static constexpr unsigned IGNORE_REPLAY_GAIN = ~0u;
/**
* A serial number for checking if replay gain info has
* changed since the last chunk. The magic value 0 indicates
* that there is no replay gain info available.
*/
unsigned replay_gain_serial;
/** the data (probably PCM) */
uint8_t data[CHUNK_SIZE];
#ifndef NDEBUG
AudioFormat audio_format;
#endif
MusicChunk() = default;
MusicChunk(const MusicChunk &) = delete;
~MusicChunk();
MusicChunk &operator=(const MusicChunk &) = delete;
bool IsEmpty() const {
return length == 0 && tag == nullptr;
}
#ifndef NDEBUG
/**
* Checks if the audio format if the chunk is equal to the
* specified audio_format.
*/
gcc_pure
bool CheckFormat(AudioFormat audio_format) const noexcept;
#endif
/**
* Prepares appending to the music chunk. Returns a buffer
* where you may write into. After you are finished, call
* Expand().
*
* @param af the audio format for the appended data;
* must stay the same for the life cycle of this chunk
* @param data_time the time within the song
* @param bit_rate the current bit rate of the source file
* @return a writable buffer, or nullptr if the chunk is full
*/
WritableBuffer<void> Write(AudioFormat af,
SongTime data_time,
uint16_t bit_rate) noexcept;
/**
* Increases the length of the chunk after the caller has written to
* the buffer returned by Write().
*
* @param af the audio format for the appended data; must
* stay the same for the life cycle of this chunk
* @param length the number of bytes which were appended
* @return true if the chunk is full
*/
bool Expand(AudioFormat af, size_t length) noexcept;
};
#endif