/* the Music Player Daemon (MPD)
* Copyright (C) 2003-2007 by Warren Dukes (warren.dukes@gmail.com)
* This project's homepage is: 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef OUTPUT_BUFFER_H
#define OUTPUT_BUFFER_H
#include "audio_format.h"
#include <stddef.h>
#include <stdbool.h>
/* pick 1020 since its devisible for 8,16,24, and 32-bit audio */
#define CHUNK_SIZE 1020
typedef struct _OutputBufferChunk {
uint16_t chunkSize;
uint16_t bitRate;
float times;
char data[CHUNK_SIZE];
} ob_chunk;
/**
* A ring set of buffers where the decoder appends data after the end,
* and the player consumes data from the beginning.
*/
struct output_buffer {
ob_chunk *chunks;
unsigned int size;
/** the index of the first decoded chunk */
unsigned int volatile begin;
/** the index after the last decoded chunk */
unsigned int volatile end;
/** non-zero if the player thread should only we woken up if
the buffer becomes non-empty */
bool lazy;
struct audio_format audioFormat;
struct notify *notify;
};
extern struct output_buffer ob;
void
ob_init(unsigned int size, struct notify *notify);
void ob_free(void);
void ob_clear(void);
void ob_flush(void);
/**
* When a chunk is decoded, we wake up the player thread to tell him
* about it. In "lazy" mode, we only wake him up when the buffer was
* previously empty, i.e. when the player thread has really been
* waiting for us.
*/
void ob_set_lazy(bool lazy);
/** is the buffer empty? */
static inline bool ob_is_empty(void)
{
return ob.begin == ob.end;
}
void ob_shift(void);
/**
* what is the position of the specified chunk number, relative to
* the first chunk in use?
*/
unsigned int ob_relative(const unsigned i);
/** determine the number of decoded chunks */
unsigned ob_available(void);
/**
* Get the absolute index of the nth used chunk after the first one.
* Returns -1 if there is no such chunk.
*/
int ob_absolute(const unsigned relative);
ob_chunk * ob_get_chunk(const unsigned i);
/**
* Append a data block to the buffer.
*
* @return the number of bytes actually written
*/
size_t ob_append(const void *data, size_t datalen,
float data_time, uint16_t bitRate);
void ob_skip(unsigned num);
#endif
