include/wvdsp.h

   1 /* -*- Mode: C++ -*-
   2  * Worldvisions Weaver Software:
   3  *   Copyright (C) 1997-2002 Net Integration Technologies, Inc.
   4  *
   5  * One more attempt at making a decent stream for Linux /dev/dsp.  This is
   6  * apparently much trickier than it looks.
   7  */
   8 #ifndef __WVDSP_H
   9 #define __WVDSP_H
  10
  11 #include "wvmagiccircle.h"
  12 #include "wvloopback.h"
  13 #include "wvlog.h"
  14 #include "wvrateadjust.h"
  15
  16 /**
  17  * Class to access the /dev/dsp device in a way that's sane enough for
  18  * full-duplex access.
  19  *
  20  * This is still rather heavily under construction at this time, so
  21  * please don't count on any side-effects to make anything
  22  * built with this class to work.
  23  */
  24 class WvDsp : public WvStream
  25 {
  26 public:
  27
  28     /**
  29      * Construct a /dev/dsp accessor object
  30      * msec_latency = number of milliseconds of latency that are permissible
  31      * srate = sampling rate ( 44, 22, 11, or 8 Hz )
  32      * bits = bits per sample ( 8 or 16 )
  33      * stereo = should this be a stereo stream?
  34      * readable/writeable = should this stream be readable and/or writeable
  35      * realtime = should the stream give itself realtime priority (needs root)
  36      * oss = is this a real OSS driver (not ALSA's OSS emulation)?
  37      */
  38     WvDsp(int msec_latency, int srate, int bits, bool stereo,
  39           bool readable = true, bool writable = true,
  40           bool _realtime = false, bool _oss = false);
  41     virtual ~WvDsp();
  42
  43     size_t ispace();
  44     size_t ospace();
  45     void realtime();
  46
  47     /*** Overridden members ***/
  48
  49     virtual void pre_select(SelectInfo &si);
  50     virtual bool post_select(SelectInfo &si);
  51     virtual size_t uread(void *buf, size_t len);
  52     virtual size_t uwrite(const void *buf, size_t len);
  53     virtual bool isok() const;
  54     virtual void close();
  55
  56 private:
  57     bool setioctl(int ctl, int param);
  58     void subproc(bool reading, bool writing);
  59
  60     size_t do_uread(void *buf, size_t len);
  61     size_t do_uwrite(const void *buf, size_t len);
  62
  63     size_t frag_size, num_frags;
  64     WvLog log;
  65     WvMagicCircle rcircle, wcircle;
  66     WvDynBuf rbuf, wbuf;
  67     WvLoopback rloop, wloop;
  68     WvRateAdjust inrate, outrate;
  69     int fd;
  70     bool is_realtime;
  71
  72 public:
  73     const char *wstype() const { return "WvDsp"; }
  74 };
  75
  76
  77 #endif // __WVDSP_H