reorganized

svn path=/trunk/; revision=9400

1 files changed, 571 insertions, 0 deletions

diff --git a/desiredata/src/s_audio_mmio.c b/desiredata/src/s_audio_mmio.c
new file mode 100644
index 00000000..9165ee93
--- /dev/null
+++ b/desiredata/src/s_audio_mmio.c
@@ -0,0 +1,571 @@
+/* Copyright (c) 1997-1999 Miller Puckette.
+* For information on usage and redistribution, and for a DISCLAIMER OF ALL
+* WARRANTIES, see the file, "LICENSE.txt," in this distribution.  */
+
+/* modified 2/98 by Winfried Ritsch to deal with up to 4 synchronized
+"wave" devices, which is how ADAT boards appear to the WAVE API. */
+
+#include "m_pd.h"
+#include "s_stuff.h"
+#include <stdio.h>
+#include <windows.h>
+#include <MMSYSTEM.H>
+
+/* ------------------------- audio -------------------------- */
+
+static void nt_close_midiin();
+static void nt_noresync();
+static void postflags();
+
+#define NAPORTS 16   /* wini hack for multiple ADDA devices  */
+#define CHANNELS_PER_DEVICE 2
+#define DEFAULTCHANS 2
+#define DEFAULTSRATE 44100
+#define SAMPSIZE 2
+
+int nt_realdacblksize;
+#define DEFREALDACBLKSIZE (4 * sys_dacblocksize) /* larger underlying bufsize */
+
+#define MAXBUFFER 100   /* number of buffers in use at maximum advance */
+#define DEFBUFFER 30    /* default is about 30x6 = 180 msec! */
+static int nt_naudiobuffer = DEFBUFFER;
+float sys_dacsr = DEFAULTSRATE;
+
+static int nt_whichapi = API_MMIO;
+static int nt_meters;        /* true if we're metering */
+static float nt_inmax;       /* max input amplitude */
+static float nt_outmax;      /* max output amplitude */
+static int nt_nwavein, nt_nwaveout;     /* number of WAVE devices in and out */
+
+typedef struct _sbuf {
+    HANDLE hData;
+    HPSTR  lpData;      // pointer to waveform data memory
+    HANDLE hWaveHdr;
+    WAVEHDR   *lpWaveHdr;   // pointer to header structure
+} t_sbuf;
+
+t_sbuf ntsnd_outvec[NAPORTS][MAXBUFFER];    /* circular buffer array */
+HWAVEOUT ntsnd_outdev[NAPORTS];             /* output device */
+static int ntsnd_outphase[NAPORTS];         /* index of next buffer to send */
+
+t_sbuf ntsnd_invec[NAPORTS][MAXBUFFER];     /* circular buffer array */
+HWAVEIN ntsnd_indev[NAPORTS];               /* input device */
+static int ntsnd_inphase[NAPORTS];          /* index of next buffer to read */
+
+static void nt_waveinerror(const char *s, int err) {
+    char t[256];
+    waveInGetErrorText(err, t, 256);
+    error(s,t);
+}
+
+static void nt_waveouterror(const char *s, int err) {
+    char t[256];
+    waveOutGetErrorText(err, t, 256);
+    error(s,t);
+}
+
+static void wave_prep(t_sbuf *bp, int setdone) {
+    WAVEHDR *wh;
+    short *sp;
+    int i;
+    /* Allocate and lock memory for the waveform data. The memory for waveform data must be globally allocated with
+     * GMEM_MOVEABLE and GMEM_SHARE flags. */
+    if (!(bp->hData = GlobalAlloc(GMEM_MOVEABLE | GMEM_SHARE, (DWORD) (CHANNELS_PER_DEVICE * SAMPSIZE * nt_realdacblksize))))
+        printf("alloc 1 failed\n");
+    if (!(bp->lpData = (HPSTR) GlobalLock(bp->hData)))
+        printf("lock 1 failed\n");
+    /*  Allocate and lock memory for the header. */
+    if (!(bp->hWaveHdr = GlobalAlloc(GMEM_MOVEABLE | GMEM_SHARE, (DWORD) sizeof(WAVEHDR))))
+        printf("alloc 2 failed\n");
+    if (!(wh = bp->lpWaveHdr = (WAVEHDR *) GlobalLock(bp->hWaveHdr)))
+        printf("lock 2 failed\n");
+    for (i = CHANNELS_PER_DEVICE * nt_realdacblksize, sp = (short *)bp->lpData; i--; ) *sp++ = 0;
+    wh->lpData = bp->lpData;
+    wh->dwBufferLength = (CHANNELS_PER_DEVICE * SAMPSIZE * nt_realdacblksize);
+    wh->dwFlags = 0;
+    wh->dwLoops = 0L;
+    wh->lpNext = 0;
+    wh->reserved = 0;
+        /* optionally (for writing) set DONE flag as if we had queued them */
+    if (setdone) wh->dwFlags = WHDR_DONE;
+}
+
+static UINT nt_whichdac = WAVE_MAPPER, nt_whichadc = WAVE_MAPPER;
+
+int mmio_do_open_audio() {
+    PCMWAVEFORMAT  form;
+    int i, j;
+    UINT mmresult;
+    int nad, nda;
+    static int naudioprepped = 0, nindevsprepped = 0, noutdevsprepped = 0;
+    if (sys_verbose) post("%d devices in, %d devices out", nt_nwavein, nt_nwaveout);
+    form.wf.wFormatTag = WAVE_FORMAT_PCM;
+    form.wf.nChannels = CHANNELS_PER_DEVICE;
+    form.wf.nSamplesPerSec = sys_dacsr;
+    form.wf.nAvgBytesPerSec = sys_dacsr * (CHANNELS_PER_DEVICE * SAMPSIZE);
+    form.wf.nBlockAlign = CHANNELS_PER_DEVICE * SAMPSIZE;
+    form.wBitsPerSample = 8 * SAMPSIZE;
+    if (nt_nwavein <= 1 && nt_nwaveout <= 1) nt_noresync();
+    if (nindevsprepped < nt_nwavein) {
+        for (i = nindevsprepped; i < nt_nwavein; i++)
+            for (j = 0; j < naudioprepped; j++)
+                wave_prep(&ntsnd_invec[i][j], 0);
+        nindevsprepped = nt_nwavein;
+    }
+    if (noutdevsprepped < nt_nwaveout) {
+        for (i = noutdevsprepped; i < nt_nwaveout; i++)
+            for (j = 0; j < naudioprepped; j++)
+                wave_prep(&ntsnd_outvec[i][j], 1);
+        noutdevsprepped = nt_nwaveout;
+    }
+    if (naudioprepped < nt_naudiobuffer) {
+        for (j = naudioprepped; j < nt_naudiobuffer; j++) {
+            for (i = 0; i < nt_nwavein;  i++) wave_prep(&ntsnd_invec [i][j], 0);
+            for (i = 0; i < nt_nwaveout; i++) wave_prep(&ntsnd_outvec[i][j], 1);
+        }
+        naudioprepped = nt_naudiobuffer;
+    }
+    for (nad=0; nad < nt_nwavein; nad++) {
+        /* Open waveform device(s), sucessively numbered, for input */
+        mmresult = waveInOpen(&ntsnd_indev[nad], nt_whichadc+nad, (WAVEFORMATEX *)(&form), 0L, 0L, CALLBACK_NULL);
+        if (sys_verbose) printf("opened adc device %d with return %d\n", nt_whichadc+nad,mmresult);
+        if (mmresult != MMSYSERR_NOERROR) {
+            nt_waveinerror("waveInOpen: %s", mmresult);
+            nt_nwavein = nad; /* nt_nwavein = 0 wini */
+        } else {
+            for (i = 0; i < nt_naudiobuffer; i++) {
+                mmresult = waveInPrepareHeader(ntsnd_indev[nad], ntsnd_invec[nad][i].lpWaveHdr, sizeof(WAVEHDR));
+                if (mmresult != MMSYSERR_NOERROR) nt_waveinerror("waveinprepareheader: %s", mmresult);
+                mmresult = waveInAddBuffer(    ntsnd_indev[nad], ntsnd_invec[nad][i].lpWaveHdr, sizeof(WAVEHDR));
+                if (mmresult != MMSYSERR_NOERROR) nt_waveinerror("waveInAddBuffer: %s", mmresult);
+            }
+        }
+    }
+    /* quickly start them all together */
+    for (nad = 0; nad < nt_nwavein; nad++) waveInStart(ntsnd_indev[nad]);
+    for (nda = 0; nda < nt_nwaveout; nda++) {
+        /* Open a waveform device for output in sucessiv device numbering*/
+        mmresult = waveOutOpen(&ntsnd_outdev[nda], nt_whichdac + nda, (WAVEFORMATEX *)(&form), 0L, 0L, CALLBACK_NULL);
+        if (sys_verbose) post("opened dac device %d, with return %d", nt_whichdac +nda, mmresult);
+        if (mmresult != MMSYSERR_NOERROR) {
+            post("Wave out open device %d + %d",nt_whichdac,nda);
+            nt_waveouterror("waveOutOpen device: %s",  mmresult);
+            nt_nwaveout = nda;
+        }
+    }
+    return 0;
+}
+
+void mmio_close_audio() {
+    int errcode;
+    int nda, nad;
+    if (sys_verbose) post("closing audio...");
+    for (nda=0; nda < nt_nwaveout; nda++) /*if (nt_nwaveout) wini */ {
+       errcode = waveOutReset(ntsnd_outdev[nda]);
+       if (errcode != MMSYSERR_NOERROR) printf("error resetting output %d: %d", nda, errcode);
+       errcode = waveOutClose(ntsnd_outdev[nda]);
+       if (errcode != MMSYSERR_NOERROR) printf("error closing output %d: %d",nda , errcode);
+    }
+    nt_nwaveout = 0;
+    for(nad=0; nad < nt_nwavein;nad++) /* if (nt_nwavein) wini */ {
+        errcode = waveInReset(ntsnd_indev[nad]);
+        if (errcode != MMSYSERR_NOERROR) printf("error resetting input: %d", errcode);
+        errcode = waveInClose(ntsnd_indev[nad]);
+        if (errcode != MMSYSERR_NOERROR) printf("error closing input: %d", errcode);
+    }
+    nt_nwavein = 0;
+}
+
+#define ADCJITTER 10    /* We tolerate X buffers of jitter by default */
+#define DACJITTER 10
+
+static int nt_adcjitterbufsallowed = ADCJITTER;
+static int nt_dacjitterbufsallowed = DACJITTER;
+
+/* ------------- MIDI time stamping from audio clock ------------ */
+
+#ifdef MIDI_TIMESTAMP
+
+static double nt_hibuftime;
+static double initsystime = -1;
+
+/* call this whenever we reset audio */
+static void nt_resetmidisync() {
+    initsystime = clock_getsystime();
+    nt_hibuftime = sys_getrealtime();
+}
+
+/* call this whenever we're idled waiting for audio to be ready.
+   The routine maintains a high and low water point for the difference between real and DAC time. */
+
+static void nt_midisync() {
+    double jittersec, diff;
+    if (initsystime == -1) nt_resetmidisync();
+    jittersec = (nt_dacjitterbufsallowed > nt_adcjitterbufsallowed ?
+        nt_dacjitterbufsallowed : nt_adcjitterbufsallowed)
+            * nt_realdacblksize / sys_getsr();
+    diff = sys_getrealtime() - 0.001 * clock_gettimesince(initsystime);
+    if (diff > nt_hibuftime) nt_hibuftime = diff;
+    if (diff < nt_hibuftime - jittersec) {
+        post("jitter excess %d %f", dac, diff);
+        nt_resetmidisync();
+    }
+}
+
+static double nt_midigettimefor(LARGE_INTEGER timestamp) {
+    /* this is broken now... used to work when "timestamp" was derived from
+        QueryPerformanceCounter() instead of the gates approved timeGetSystemTime() call in the MIDI callback routine below. */
+    return nt_tixtotime(timestamp) - nt_hibuftime;
+}
+#endif /* MIDI_TIMESTAMP */
+
+static int nt_fill = 0;
+#define WRAPFWD(x) ((x) >= nt_naudiobuffer ? (x) - nt_naudiobuffer: (x))
+#define WRAPBACK(x) ((x) < 0 ? (x) + nt_naudiobuffer: (x))
+#define MAXRESYNC 500
+
+#if 0 /* this is used for debugging */
+static void nt_printaudiostatus() {
+    int nad, nda;
+    for (nad = 0; nad < nt_nwavein; nad++) {
+        int phase = ntsnd_inphase[nad];
+        int phase2 = phase, phase3 = WRAPFWD(phase2), count, ntrans = 0;
+        int firstphasedone = -1, firstphasebusy = -1;
+        for (count = 0; count < nt_naudiobuffer; count++) {
+            int donethis = (ntsnd_invec[nad][phase2].lpWaveHdr->dwFlags & WHDR_DONE);
+            int donenext = (ntsnd_invec[nad][phase3].lpWaveHdr->dwFlags & WHDR_DONE);
+            if (donethis && !donenext) {
+                if (firstphasebusy >= 0) goto multipleadc;
+                firstphasebusy = count;
+            }
+            if (!donethis && donenext) {
+                if (firstphasedone >= 0) goto multipleadc;
+                firstphasedone = count;
+            }
+            phase2 = phase3;
+            phase3 = WRAPFWD(phase2 + 1);
+        }
+        post("nad %d phase %d busy %d done %d", nad, phase, firstphasebusy, firstphasedone);
+        continue;
+    multipleadc:
+        startpost("nad %d phase %d: oops:", nad, phase);
+        for (count = 0; count < nt_naudiobuffer; count++) {
+            char buf[80];
+            sprintf(buf, " %d", (ntsnd_invec[nad][count].lpWaveHdr->dwFlags & WHDR_DONE));
+            poststring(buf);
+        }
+        endpost();
+    }
+    for (nda = 0; nda < nt_nwaveout; nda++) {
+        int phase = ntsnd_outphase[nad];
+        int phase2 = phase, phase3 = WRAPFWD(phase2), count, ntrans = 0;
+        int firstphasedone = -1, firstphasebusy = -1;
+        for (count = 0; count < nt_naudiobuffer; count++) {
+            int donethis = (ntsnd_outvec[nda][phase2].lpWaveHdr->dwFlags & WHDR_DONE);
+            int donenext = (ntsnd_outvec[nda][phase3].lpWaveHdr->dwFlags & WHDR_DONE);
+            if (donethis && !donenext) {
+                if (firstphasebusy >= 0) goto multipledac;
+                firstphasebusy = count;
+            }
+            if (!donethis && donenext) {
+                if (firstphasedone >= 0) goto multipledac;
+                firstphasedone = count;
+            }
+            phase2 = phase3;
+            phase3 = WRAPFWD(phase2 + 1);
+        }
+        if (firstphasebusy < 0) post("nda %d phase %d all %d", nda, phase, (ntsnd_outvec[nad][0].lpWaveHdr->dwFlags & WHDR_DONE));
+        else post("nda %d phase %d busy %d done %d", nda, phase, firstphasebusy, firstphasedone);
+        continue;
+    multipledac:
+        startpost("nda %d phase %d: oops:", nda, phase);
+        for (count = 0; count < nt_naudiobuffer; count++) {
+            char buf[80];
+            sprintf(buf, " %d", (ntsnd_outvec[nad][count].lpWaveHdr->dwFlags & WHDR_DONE));
+            poststring(buf);
+        }
+        endpost();
+    }
+}
+#endif /* 0 */
+
+/* this is a hack to avoid ever resyncing audio pointers in case for whatever
+reason the sync testing below gives false positives. */
+
+static int nt_resync_cancelled;
+
+static void nt_noresync() {
+    nt_resync_cancelled = 1;
+}
+
+static void nt_resyncaudio() {
+    UINT mmresult;
+    int nad, nda, count;
+    if (nt_resync_cancelled) return;
+    /* for each open input device, eat all buffers which are marked ready. The next one will thus be "busy". */
+    post("resyncing audio");
+    for (nad = 0; nad < nt_nwavein; nad++) {
+        int phase = ntsnd_inphase[nad];
+        for (count = 0; count < MAXRESYNC; count++) {
+            WAVEHDR *inwavehdr = ntsnd_invec[nad][phase].lpWaveHdr;
+            if (!(inwavehdr->dwFlags & WHDR_DONE)) break;
+            if (inwavehdr->dwFlags & WHDR_PREPARED) waveInUnprepareHeader(ntsnd_indev[nad], inwavehdr, sizeof(WAVEHDR));
+            inwavehdr->dwFlags = 0L;
+            waveInPrepareHeader(ntsnd_indev[nad], inwavehdr, sizeof(WAVEHDR));
+            mmresult = waveInAddBuffer(ntsnd_indev[nad], inwavehdr, sizeof(WAVEHDR));
+            if (mmresult != MMSYSERR_NOERROR) nt_waveinerror("waveInAddBuffer: %s", mmresult);
+            ntsnd_inphase[nad] = phase = WRAPFWD(phase + 1);
+        }
+        if (count == MAXRESYNC) post("resync error 1");
+    }
+    /* Each output buffer which is "ready" is filled with zeros and queued. */
+    for (nda = 0; nda < nt_nwaveout; nda++) {
+        int phase = ntsnd_outphase[nda];
+        for (count = 0; count < MAXRESYNC; count++) {
+            WAVEHDR *outwavehdr = ntsnd_outvec[nda][phase].lpWaveHdr;
+            if (!(outwavehdr->dwFlags & WHDR_DONE)) break;
+            if (outwavehdr->dwFlags & WHDR_PREPARED) waveOutUnprepareHeader(ntsnd_outdev[nda], outwavehdr, sizeof(WAVEHDR));
+            outwavehdr->dwFlags = 0L;
+            memset((char *)(ntsnd_outvec[nda][phase].lpData), 0, (CHANNELS_PER_DEVICE * SAMPSIZE * nt_realdacblksize));
+            waveOutPrepareHeader(   ntsnd_outdev[nda], outwavehdr, sizeof(WAVEHDR));
+            mmresult = waveOutWrite(ntsnd_outdev[nda], outwavehdr, sizeof(WAVEHDR));
+            if (mmresult != MMSYSERR_NOERROR) nt_waveouterror("waveOutAddBuffer: %s", mmresult);
+            ntsnd_outphase[nda] = phase = WRAPFWD(phase + 1);
+        }
+        if (count == MAXRESYNC) post("resync error 2");
+    }
+#ifdef MIDI_TIMESTAMP
+    nt_resetmidisync();
+#endif
+}
+
+#define LATE 0
+#define RESYNC 1
+#define NOTHING 2
+static int nt_errorcount;
+static int nt_resynccount;
+static double nt_nextreporttime = -1;
+
+void nt_logerror(int which) {
+#if 0
+    post("error %d %d", count, which);
+    if (which < NOTHING) nt_errorcount++;
+    if (which == RESYNC) nt_resynccount++;
+    if (sys_getrealtime() > nt_nextreporttime) {
+        post("%d audio I/O error%s", nt_errorcount, (nt_errorcount > 1 ? "s" : ""));
+        if (nt_resynccount) post("DAC/ADC sync error");
+        nt_errorcount = nt_resynccount = 0;
+        nt_nextreporttime = sys_getrealtime() - 5;
+    }
+#endif
+}
+
+/* system buffer with t_sample types for one tick */
+t_sample *sys_soundout;
+t_sample *sys_soundin;
+float sys_dacsr;
+
+int mmio_send_dacs() {
+    HMMIO hmmio;
+    UINT mmresult;
+    HANDLE hFormat;
+    int i, j;
+    short *sp1, *sp2;
+    float *fp1, *fp2;
+    int nextfill, doxfer = 0;
+    if (!nt_nwavein && !nt_nwaveout) return 0;
+    if (nt_meters) {
+        int i, n;
+        float maxsamp;
+        for (i = 0, n = 2 * nt_nwavein * sys_dacblocksize, maxsamp = nt_inmax; i < n; i++) {
+            float f = sys_soundin[i];
+            if (f > maxsamp) maxsamp = f;
+            else if (-f > maxsamp) maxsamp = -f;
+        }
+        nt_inmax = maxsamp;
+        for (i = 0, n = 2 * nt_nwaveout * sys_dacblocksize, maxsamp = nt_outmax; i < n; i++) {
+            float f = sys_soundout[i];
+            if (f > maxsamp) maxsamp = f;
+            else if (-f > maxsamp) maxsamp = -f;
+        }
+        nt_outmax = maxsamp;
+    }
+    /* the "fill pointer" nt_fill controls where in the next I/O buffers we will write and/or read.  If it's zero, we
+       first check whether the buffers are marked "done". */
+    if (!nt_fill) {
+        for (int nad=0; nad<nt_nwavein; nad++) {
+            int phase = ntsnd_inphase[nad];
+            WAVEHDR *inwavehdr = ntsnd_invec[nad][phase].lpWaveHdr;
+            if (!(inwavehdr->dwFlags & WHDR_DONE)) goto idle;
+        }
+        for (int nda=0; nda<nt_nwaveout; nda++) {
+            int phase = ntsnd_outphase[nda];
+            WAVEHDR *outwavehdr = ntsnd_outvec[nda][phase].lpWaveHdr;
+            if (!(outwavehdr->dwFlags & WHDR_DONE)) goto idle;
+        }
+        for (int nad=0; nad<nt_nwavein; nad++) {
+            int phase = ntsnd_inphase[nad];
+            WAVEHDR *inwavehdr = ntsnd_invec[nad][phase].lpWaveHdr;
+            if (inwavehdr->dwFlags & WHDR_PREPARED) waveInUnprepareHeader(ntsnd_indev[nad], inwavehdr, sizeof(WAVEHDR));
+        }
+        for (int nda=0; nda<nt_nwaveout; nda++) {
+            int phase = ntsnd_outphase[nda];
+            WAVEHDR *outwavehdr = ntsnd_outvec[nda][phase].lpWaveHdr;
+            if (outwavehdr->dwFlags & WHDR_PREPARED) waveOutUnprepareHeader(ntsnd_outdev[nda], outwavehdr, sizeof(WAVEHDR));
+        }
+    }
+    /* Convert audio output to fixed-point and put it in the output buffer. */
+    fp1 = sys_soundout;
+    for (int nda=0; nda<nt_nwaveout; nda++) {
+        int phase = ntsnd_outphase[nda];
+        for (i=0, sp1=(short *)(ntsnd_outvec[nda][phase].lpData)+CHANNELS_PER_DEVICE*nt_fill; i<2; i++, fp1 += sys_dacblocksize, sp1++) {
+            for (j = 0, fp2 = fp1, sp2 = sp1; j < sys_dacblocksize; j++, fp2++, sp2 += CHANNELS_PER_DEVICE) {
+                int x1 = 32767.f * *fp2;
+                if (x1 > 32767) x1 = 32767;
+                else if (x1 < -32767) x1 = -32767;
+                *sp2 = x1;
+            }
+        }
+    }
+    memset(sys_soundout, 0, (sys_dacblocksize *sizeof(t_sample)*CHANNELS_PER_DEVICE)*nt_nwaveout);
+    /* vice versa for the input buffer */
+    fp1 = sys_soundin;
+    for (int nad=0; nad<nt_nwavein; nad++) {
+        int phase = ntsnd_inphase[nad];
+        for (i=0, sp1=(short *)(ntsnd_invec[nad][phase].lpData)+CHANNELS_PER_DEVICE*nt_fill; i < 2; i++, fp1 += sys_dacblocksize, sp1++) {
+            for (j = 0, fp2 = fp1, sp2 = sp1; j < sys_dacblocksize; j++, fp2++, sp2 += CHANNELS_PER_DEVICE) {
+                *fp2 = ((float)(1./32767.)) * (float)(*sp2);
+            }
+        }
+    }
+    nt_fill = nt_fill + sys_dacblocksize;
+    if (nt_fill == nt_realdacblksize) {
+        nt_fill = 0;
+        for (int nad=0; nad<nt_nwavein; nad++) {
+            int phase = ntsnd_inphase[nad];
+            HWAVEIN device = ntsnd_indev[nad];
+            WAVEHDR *inwavehdr = ntsnd_invec[nad][phase].lpWaveHdr;
+            waveInPrepareHeader(device, inwavehdr, sizeof(WAVEHDR));
+            mmresult = waveInAddBuffer(device, inwavehdr, sizeof(WAVEHDR));
+            if (mmresult != MMSYSERR_NOERROR) nt_waveinerror("waveInAddBuffer: %s", mmresult);
+            ntsnd_inphase[nad] = WRAPFWD(phase + 1);
+        }
+        for (int nda=0; nda<nt_nwaveout; nda++) {
+            int phase = ntsnd_outphase[nda];
+            HWAVEOUT device = ntsnd_outdev[nda];
+            WAVEHDR *outwavehdr = ntsnd_outvec[nda][phase].lpWaveHdr;
+            waveOutPrepareHeader(device, outwavehdr, sizeof(WAVEHDR));
+            mmresult = waveOutWrite(device, outwavehdr, sizeof(WAVEHDR));
+            if (mmresult != MMSYSERR_NOERROR) nt_waveouterror("waveOutWrite: %s", mmresult);
+            ntsnd_outphase[nda] = WRAPFWD(phase + 1);
+        }
+        /* check for DAC underflow or ADC overflow. */
+        for (int nad=0; nad<nt_nwavein; nad++) {
+            int phase = WRAPBACK(ntsnd_inphase[nad] - 2);
+            WAVEHDR *inwavehdr = ntsnd_invec[nad][phase].lpWaveHdr;
+            if (inwavehdr->dwFlags & WHDR_DONE) goto late;
+        }
+        for (int nda=0; nda<nt_nwaveout; nda++) {
+            int phase = WRAPBACK(ntsnd_outphase[nda] - 2);
+            WAVEHDR *outwavehdr = ntsnd_outvec[nda][phase].lpWaveHdr;
+            if (outwavehdr->dwFlags & WHDR_DONE) goto late;
+        }
+    }
+    return 1;
+late:
+    nt_logerror(LATE);
+    nt_resyncaudio();
+    return 1;
+idle:
+    /* If more than nt_adcjitterbufsallowed ADC buffers are ready on any input device, resynchronize */
+    for (int nad=0; nad<nt_nwavein; nad++) {
+        int phase = ntsnd_inphase[nad];
+        WAVEHDR *inwavehdr = ntsnd_invec[nad][WRAPFWD(phase + nt_adcjitterbufsallowed)].lpWaveHdr;
+        if ( inwavehdr->dwFlags & WHDR_DONE) {nt_resyncaudio(); return 0;}
+    }
+    /* test dac sync the same way */
+    for (int nda=0; nda<nt_nwaveout; nda++) {
+        int phase = ntsnd_outphase[nda];
+        WAVEHDR *outwavehdr = ntsnd_outvec[nda][WRAPFWD(phase + nt_dacjitterbufsallowed)].lpWaveHdr;
+        if (outwavehdr->dwFlags & WHDR_DONE) {nt_resyncaudio(); return 0;}
+    }
+#ifdef MIDI_TIMESTAMP
+    nt_midisync();
+#endif
+    return 0;
+}
+
+/* ------------------- public routines -------------------------- */
+
+void mmio_open_audio(int naudioindev, int *audioindev,
+int nchindev, int *chindev, int naudiooutdev, int *audiooutdev,
+int nchoutdev, int *choutdev, int rate) /* IOhannes */ {
+    int nbuf;
+    nt_realdacblksize = (sys_blocksize ? sys_blocksize : DEFREALDACBLKSIZE);
+    nbuf = sys_advance_samples/nt_realdacblksize;
+    if (nbuf >= MAXBUFFER) {
+        post("pd: audio buffering maxed out to %d", (int)(MAXBUFFER * ((nt_realdacblksize * 1000.)/44100.)));
+        nbuf = MAXBUFFER;
+    }
+    else if (nbuf < 4) nbuf = 4;
+    post("%d audio buffers", nbuf);
+    nt_naudiobuffer = nbuf;
+    if (nt_adcjitterbufsallowed > nbuf - 2) nt_adcjitterbufsallowed = nbuf - 2;
+    if (nt_dacjitterbufsallowed > nbuf - 2) nt_dacjitterbufsallowed = nbuf - 2;
+    nt_nwavein = sys_inchannels / 2;
+    nt_nwaveout = sys_outchannels / 2;
+    nt_whichadc = (naudioindev  < 1 ? (nt_nwavein  > 1 ? WAVE_MAPPER : -1) : audioindev[0]);
+    nt_whichdac = (naudiooutdev < 1 ? (nt_nwaveout > 1 ? WAVE_MAPPER : -1) : audiooutdev[0]);
+    if (naudiooutdev > 1 || naudioindev > 1) post("separate audio device choice not supported; using sequential devices.");
+    mmio_do_open_audio();
+}
+
+#if 0
+/* list the audio and MIDI device names */
+void mmio_listdevs() {
+    UINT  wRtn, ndevices;
+    unsigned int i;
+    ndevices = waveInGetNumDevs();
+    for (i = 0; i < ndevices; i++) {
+        WAVEINCAPS wicap;
+        wRtn = waveInGetDevCaps(i, (LPWAVEINCAPS) &wicap, sizeof(wicap));
+        if (wRtn) nt_waveinerror("waveInGetDevCaps: %s", wRtn);
+        else post("audio input device #%d: %s", i+1, wicap.szPname);
+    }
+    ndevices = waveOutGetNumDevs();
+    for (i = 0; i < ndevices; i++) {
+        WAVEOUTCAPS wocap;
+        wRtn = waveOutGetDevCaps(i, (LPWAVEOUTCAPS) &wocap, sizeof(wocap));
+        if (wRtn) nt_waveouterror("waveOutGetDevCaps: %s", wRtn);
+        else post("audio output device #%d: %s", i+1, wocap.szPname);
+    }
+}
+#endif
+
+void mmio_getdevs(char *indevlist, int *nindevs, char *outdevlist, int *noutdevs, int *canmulti, int maxndev, int devdescsize) {
+    int  wRtn, ndev, i;
+    *canmulti = 2;  /* supports multiple devices */
+    ndev = waveInGetNumDevs();
+    if (ndev > maxndev) ndev = maxndev;
+    *nindevs = ndev;
+    for (i = 0; i < ndev; i++) {
+        WAVEINCAPS wicap;
+        wRtn = waveInGetDevCaps(i, (LPWAVEINCAPS) &wicap, sizeof(wicap));
+        sprintf(indevlist + i * devdescsize, (wRtn ? "???" : wicap.szPname));
+    }
+    ndev = waveOutGetNumDevs();
+    if (ndev > maxndev) ndev = maxndev;
+    *noutdevs = ndev;
+    for (i = 0; i < ndev; i++) {
+        WAVEOUTCAPS wocap;
+        wRtn = waveOutGetDevCaps(i, (LPWAVEOUTCAPS) &wocap, sizeof(wocap));
+        sprintf(outdevlist + i * devdescsize, (wRtn ? "???" : wocap.szPname));
+    }
+}
+
+struct t_audioapi api_mmio = {
+	mmio_open_audio,
+	mmio_close_audio,
+	mmio_send_dacs,
+	mmio_getdevs,
+};