vorbis-tools/ogg123/buffer.h

   1 /********************************************************************
   2  *                                                                  *
   3  * THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE.   *
   4  * USE, DISTRIBUTION AND REPRODUCTION OF THIS SOURCE IS GOVERNED BY *
   5  * THE GNU PUBLIC LICENSE 2, WHICH IS INCLUDED WITH THIS SOURCE.    *
   6  * PLEASE READ THESE TERMS BEFORE DISTRIBUTING.                     *
   7  *                                                                  *
   8  * THE Ogg123 SOURCE CODE IS (C) COPYRIGHT 2000-2001                *
   9  * by Stan Seibert <volsung@xiph.org> AND OTHER CONTRIBUTORS        *
  10  * http://www.xiph.org/                                             *
  11  *                                                                  *
  12  ********************************************************************
  13
  14  last mod: $Id: buffer.h,v 1.6 2002/06/02 03:07:10 volsung Exp $
  15
  16 ********************************************************************/
  17
  18 /* A generic circular buffer interface with the ability to buffer
  19    actions (conceptually) between bytes in the buffer.*/
  20
  21 #ifndef __BUFFER_H__
  22 #define __BUFFER_H__
  23
  24 #include <stdlib.h>
  25 #include <pthread.h>
  26 #include <ogg/os_types.h>
  27
  28
  29 struct action_t; /* forward declaration */
  30
  31 /* buffer_write_func(void *data, int nbytes, int eos, void *arg) */
  32 typedef int (*buffer_write_func_t) (void *, int, int, void *);
  33
  34 typedef struct buf_t
  35 {
  36   /* generic buffer interface */
  37   void *write_arg;
  38   buffer_write_func_t write_func;
  39
  40   /* pthread variables */
  41   pthread_t thread;
  42
  43   pthread_mutex_t mutex;
  44
  45   pthread_cond_t playback_cond; /* signalled when playback can continue */
  46   pthread_cond_t write_cond;    /* signalled when more data can be written
  47                                    to the buffer */
  48
  49   /* buffer info (constant) */
  50   int  audio_chunk_size;  /* write data to audio device in this chunk size,
  51                              if possible */
  52   long prebuffer_size;    /* number of bytes to prebuffer */
  53   long size;              /* buffer size, for reference */
  54
  55   int cancel_flag;        /* When set, the playback thread should exit */
  56
  57   /* ----- Everything after this point is protected by mutex ----- */
  58
  59   /* buffering state variables */
  60   int prebuffering;
  61   int paused;
  62   int eos;
  63   int abort_write;
  64
  65   /* buffer data */
  66   long curfill;     /* how much the buffer is currently filled */
  67   long start;       /* offset in buffer of start of available data */
  68   ogg_int64_t position; /* How many bytes have we output so far */
  69   ogg_int64_t position_end; /* Position right after end of data */
  70
  71   struct action_t *actions; /* Queue actions to perform */
  72   char buffer[1];   /* The buffer itself. It's more than one byte. */
  73 } buf_t;
  74
  75
  76 /* action_func(buf_t *buf, void *arg) */
  77 typedef void (*action_func_t) (buf_t *, void *);
  78
  79 typedef struct action_t {
  80   ogg_int64_t position;
  81   action_func_t action_func;
  82   void *arg;
  83   struct action_t *next;
  84 } action_t;
  85
  86
  87 typedef struct buffer_stats_t {
  88   long size;
  89   double fill;
  90   double prebuffer_fill;
  91   int prebuffering;
  92   int paused;
  93   int eos;
  94 } buffer_stats_t;
  95
  96
  97 /* --- Buffer allocation --- */
  98
  99 buf_t *buffer_create (long size, long prebuffer,
 100                       buffer_write_func_t write_func, void *arg,
 101                       int audio_chunk_size);
 102
 103 void buffer_reset (buf_t *buf);
 104 void buffer_destroy (buf_t *buf);
 105
 106 /* --- Buffer thread control --- */
 107 int  buffer_thread_start   (buf_t *buf);
 108 void buffer_thread_pause   (buf_t *buf);
 109 void buffer_thread_unpause (buf_t *buf);
 110 void buffer_thread_kill    (buf_t *buf);
 111
 112 /* --- Data buffering functions --- */
 113 int buffer_submit_data (buf_t *buf, char *data, long nbytes);
 114 size_t buffer_get_data (buf_t *buf, char *data, long nbytes);
 115
 116 void buffer_mark_eos (buf_t *buf);
 117 void buffer_abort_write (buf_t *buf);
 118
 119 /* --- Action buffering functions --- */
 120 void buffer_action_now (buf_t *buf, action_func_t action_func,
 121                         void *action_arg);
 122 void buffer_insert_action_at_end (buf_t *buf, action_func_t action_func,
 123                                   void *action_arg);
 124 void buffer_append_action_at_end (buf_t *buf, action_func_t action_func,
 125                                   void *action_arg);
 126 void buffer_insert_action_at (buf_t *buf, action_func_t action_func,
 127                               void *action_arg, ogg_int64_t position);
 128 void buffer_append_action_at (buf_t *buf, action_func_t action_func,
 129                               void *action_arg, ogg_int64_t position);
 130
 131 /* --- Buffer status functions --- */
 132 void buffer_wait_for_empty (buf_t *buf);
 133 long buffer_full (buf_t *buf);
 134 buffer_stats_t *buffer_statistics (buf_t *buf);
 135
 136 #endif /* __BUFFER_H__ */