/* 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