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+/*
+ * Copyright (C) 2003-2013 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 "replay_gain_info.h"
+
+#ifndef NDEBUG
+#include "audio_format.h"
+#endif
+
+#include <stdint.h>
+#include <stddef.h>
+
+enum {
+ CHUNK_SIZE = 4096,
+};
+
+struct audio_format;
+
+/**
+ * A chunk of music data. Its format is defined by the
+ * music_pipe_append() caller.
+ */
+struct music_chunk {
+ /** the next chunk in a linked list */
+ struct music_chunk *next;
+
+ /**
+ * An optional chunk which should be mixed into this chunk.
+ * This is used for cross-fading.
+ */
+ struct music_chunk *other;
+
+ /**
+ * 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;
+
+ /** current bit rate of the source file */
+ uint16_t bit_rate;
+
+ /** the time stamp within the song */
+ float times;
+
+ /**
+ * 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 in music_chunk_free()
+ */
+ struct tag *tag;
+
+ /**
+ * Replay gain information associated with this chunk.
+ * Only valid if the serial is not 0.
+ */
+ struct replay_gain_info replay_gain_info;
+
+ /**
+ * 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) */
+ char data[CHUNK_SIZE];
+
+#ifndef NDEBUG
+ struct audio_format audio_format;
+#endif
+
+ music_chunk()
+ :other(nullptr),
+ length(0),
+ tag(nullptr),
+ replay_gain_serial(0) {}
+
+ ~music_chunk();
+
+ 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(const struct audio_format &audio_format) const;
+#endif
+
+ /**
+ * Prepares appending to the music chunk. Returns a buffer
+ * where you may write into. After you are finished, call
+ * music_chunk_expand().
+ *
+ * @param chunk the music_chunk object
+ * @param audio_format 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
+ * @param max_length_r the maximum write length is returned
+ * here
+ * @return a writable buffer, or NULL if the chunk is full
+ */
+ void *Write(const struct audio_format &af,
+ float data_time, uint16_t bit_rate,
+ size_t *max_length_r);
+
+ /**
+ * Increases the length of the chunk after the caller has written to
+ * the buffer returned by music_chunk_write().
+ *
+ * @param chunk the music_chunk object
+ * @param audio_format 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(const struct audio_format &af, size_t length);
+};
+
+void
+music_chunk_init(struct music_chunk *chunk);
+
+void
+music_chunk_free(struct music_chunk *chunk);
+
+#endif