view src/nas.c @ 788:026c5bf9c134

[xemacs-hg @ 2002-03-21 07:29:57 by ben] chartab.c: Fix bugs in implementation and doc strings. config.h.in: Add foo_checking_assert_at_line() macros. Not clear whether these are actually useful, though; I'll take them out if not. symsinit.h, emacs.c: Some improvements to the timeline. Rearrange a bit the init calls. Add call for reinit_vars_of_object_mswindows() and declare in symsinit.h. event-Xt.c, event-gtk.c, event-msw.c, event-stream.c, event-tty.c, events.c, events.h: Introduce new event methods for printing, comparing, and hashing magic events, to avoid event-type-specific stuff that had crept into events.c. (And was crashing, since the channel in MS Windows magic events may be nil.) Implement the methods in event-{tty,gtk,Xt,mswindows}.c. Make wrapping functions event_stream_{compare,hash,format}_magic_event() to check if everything's OK and call the actual callback. Fix events.c to use the new methods. Add a new event-stream-operation EVENT_STREAM_NOTHING -- event stream not actually required to be able to do anything, just be open. (#### This event-stream-operation stuff needs to be rethought.) Fixed describe_event() in event-Xt.c to print its output to a stream, not always to stderr, so it can be used elsewhere. (e.g. in print-event when a magic event is encountered?) lisp.h, lrecord.h: Define new assert_at_line(), for use in asserts inside of inline functions. The assert will report the line and file of the inline function, which is almost certainly not what you want as it's useless. what you want to see is where the pseudo-macro was called from. So, when error-checking is on, we pass in the line and file into the macros, for accurate printout using assert_at_line(). Happens only when error-checking is defined so doesn't slow down non-error-checking builds. Fix XCHAR, XINT, XCHAR_OR_INT, XFOO, and wrap_foo() in this fashion. lstream.c, lstream.h: Add resizing_buffer_to_lisp_string(). objects-gtk.c: Fix typo. objects-msw.c: Implement a smarter way of determining whether a font matches a charset. Formerly we just looked at the "script" element of the font spec, converted it to a code page, and compared it with the code page derived from the charset. Now, as well as doing this, we ask the font for the list of unicode ranges it supports, see what range the charset falls into (#### bogus! need to do this char-by-char), and see if any of the font's supported ranges include the charset's range. also do some caching in Vfont_signature_data of previous inquiries. charset.h, text.c, mule-charset.c: New fun; extracted out of Fmake_char() and declare prototype in charset.h. text.h: introduce assert_by_line() to make REP_BYTES_BY_FIRST_BYTE report the file and line more accurately in an assertion failure. unicode.c: make non-static (used in objects-msw.c), declare in charset.h. mule\mule-category.el: Start implementing a category API compatible with FSF. Not there yet. We need improvements to char-tables. mule\mule-charset.el: Copy translation table code from FSF 21.1 and fix up. Eventually we'll have them in XEmacs. (used in ccl) Not here quite yet, and we need some improvements to char-tables. mule\cyril-util.el, mule\cyrillic.el, mule\devan-util.el, mule\ethio-util.el, mule\korea-util.el, mule\mule-tty-init.el, mule\tibet-util.el, mule\viet-util.el, mule\vietnamese.el: Fix numerous compilation warnings. Fix up code related to translation tables and other types of char-tables. menubar-items.el: Move the frame commands from the View menu to the File menu, to be consistent with how most other programs do things. Move less-used revert/recover items to a submenu. Make "recover" not prompt for a file, but recover the current buffer. TODO.ben-mule-21-5: Create bug list for latest problems.
author ben
date Thu, 21 Mar 2002 07:31:30 +0000
parents 023b83f4e54b
children 6728e641994e
line wrap: on
line source

/* nas.c --- XEmacs support for the Network Audio System server.
 *
 * Author: Richard Caley <R.Caley@ed.ac.uk>
 *
 * Copyright 1994 Free Software Foundation, Inc.
 * Copyright 1993 Network Computing Devices, Inc.
 *
 * Permission to use, copy, modify, distribute, and sell this software and
 * its documentation for any purpose is hereby granted without fee, provided
 * that the above copyright notice appear in all copies and that both that
 * copyright notice and this permission notice appear in supporting
 * documentation, and that the name Network Computing Devices, Inc. not be
 * used in advertising or publicity pertaining to distribution of this 
 * software without specific, written prior permission.
 * 
 * THIS SOFTWARE IS PROVIDED 'AS-IS'.  NETWORK COMPUTING DEVICES, INC.,
 * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING WITHOUT
 * LIMITATION ALL IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE, OR NONINFRINGEMENT.  IN NO EVENT SHALL NETWORK
 * COMPUTING DEVICES, INC., BE LIABLE FOR ANY DAMAGES WHATSOEVER, INCLUDING
 * SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES, INCLUDING LOSS OF USE, DATA,
 * OR PROFITS, EVEN IF ADVISED OF THE POSSIBILITY THEREOF, AND REGARDLESS OF
 * WHETHER IN AN ACTION IN CONTRACT, TORT OR NEGLIGENCE, ARISING OUT OF OR IN
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/* Synched up with: Not in FSF. */

/* This file Mule-ized by Ben Wing, 5-15-01. */

/* There are four compile-time options.
 *
 * XTOOLKIT	This will be part of an Xt program.
 * 
 * XTEVENTS	The playing will be supervised asynchronously by the Xt event
 *		loop.  If not set, playing will be completed within the call
 *		to play_file etc. 
 *
 * ROBUST_PLAY	Causes errors in nas to be caught.  This means that the
 *		program will attempt not to die if the nas server does.
 *
 * CACHE_SOUNDS	Causes the sounds to be played in buckets in the NAS
 *		server.  They are named by their comment field, or if that is
 *		empty by the filename, or for play_sound_data by a name made up
 *		from the sample itself.
 */

/* CHANGES:
 *	10/8/94, rjc	Changed names from netaudio to nas
 *			Added back asynchronous play if nas library has
 *			correct error facilities.
 *      4/11/94, rjc    Added wait_for_sounds to be called when user wants to
 *			be sure all play has finished.
 *      1998-10-01 rlt  Added support for WAVE files.
 */

#include <config.h>
#include "lisp.h"

#include "sound.h"

#include "sysdep.h"
#include "syssignal.h"

/* NAS <= 1.2p5 defines {BIG,LITTLE}_ENDIAN in <audio/fileutil.h>,
   conflicting with GNU libc (at least); newer versions avoid this
   name space pollution.

   DO NOT USE THOSE MACROS in this file.  Use NAS_{BIG,LITTLE}_ENDIAN.

   It would be slightly more reliable to do this via configure, but that
   seems unnecessarily complex.
*/
#undef LITTLE_ENDIAN
#undef BIG_ENDIAN

#include <audio/audiolib.h>
#include <audio/soundlib.h>
#include <audio/snd.h>
#include <audio/wave.h>
#include <audio/fileutil.h>

/* NAS <= 1.2p5 <audio/fileutil.h> doesn't define the NAS_ versions */
#ifndef NAS_LITTLE_ENDIAN
# define NAS_LITTLE_ENDIAN LITTLE_ENDIAN
# define NAS_BIG_ENDIAN BIG_ENDIAN
#endif

#define XTOOLKIT
#define XTEVENTS
#define ROBUST_PLAY
#define CACHE_SOUNDS

    /*
     * For old NAS libraries, force playing to be synchronous
     * and declare the long jump point locally.
     */

#if defined (NAS_NO_ERROR_JUMP)
# undef XTEVENTS
# include <setjmp.h>
jmp_buf AuXtErrorJump;
#endif

#ifdef XTOOLKIT
# include <X11/Intrinsic.h>
# include <audio/Xtutil.h>
#endif

#if defined (ROBUST_PLAY)
static AuBool CatchIoErrorAndJump (AuServer *aud);
static AuBool CatchErrorAndJump (AuServer *aud, AuErrorEvent *event);
SIGTYPE sigpipe_handle (int signo);
#endif

extern Lisp_Object Vsynchronous_sounds;

static Sound SoundOpenDataForReading (UChar_Binary *data, int length);

static AuServer       *aud;

/* count of sounds currently being played. */
static int sounds_in_play;


#ifdef XTOOLKIT
static Display *aud_server;
static XtInputId input_id;
#else
static Extbyte *aud_server;
#endif /* XTOOLKIT */

Extbyte *
nas_init_play (
#ifdef XTOOLKIT
	   Display *display
#else
	   Extbyte *server
#endif
	   );
Extbyte *
nas_init_play (
#ifdef XTOOLKIT
	   Display *display
#else
	   Extbyte *server
#endif
	   )
{
  Extbyte *err_message;
  SIGTYPE (*old_sigpipe) (int);

#ifdef XTOOLKIT
  Extbyte * server = DisplayString (display);
  XtAppContext app_context = XtDisplayToApplicationContext (display);

  aud_server = display;
#else

  aud_server = server;
#endif

#ifdef ROBUST_PLAY
  old_sigpipe = EMACS_SIGNAL (SIGPIPE, sigpipe_handle);
  if (setjmp (AuXtErrorJump))
    {
      EMACS_SIGNAL (SIGPIPE, old_sigpipe);
#ifdef emacs
      start_interrupts ();
#endif  
      return "error in NAS";
    }
#endif

#if defined (ROBUST_PLAY) && !defined (NAS_NO_ERROR_JUMP)
  AuDefaultIOErrorHandler = CatchIoErrorAndJump;
  AuDefaultErrorHandler = CatchErrorAndJump;
#endif

#ifdef emacs
  stop_interrupts ();
#endif  
  aud = AuOpenServer (server, 0, NULL, 0, NULL, &err_message);
#ifdef emacs
  start_interrupts ();
#endif  
  if (!aud)
    {
#ifdef ROBUST_PLAY
      EMACS_SIGNAL (SIGPIPE, old_sigpipe);
#endif
      if (err_message == NULL)
	return "Can't connect to audio server";
      else
	return err_message;
    }

#if defined (ROBUST_PLAY)
# if defined (NAS_NO_ERROR_JUMP)
  aud->funcs.ioerror_handler = CatchIoErrorAndJump;
  aud->funcs.error_handler = CatchErrorAndJump;
# else /* !NAS_NO_ERROR_JUMP */
  AuDefaultIOErrorHandler = NULL;
  AuDefaultErrorHandler = NULL;
# endif
#endif

#ifdef XTEVENTS
  input_id = AuXtAppAddAudioHandler (app_context, aud); 
#endif

#ifdef CACHE_SOUNDS
  AuSetCloseDownMode (aud, AuCloseDownRetainPermanent, NULL);
#endif

#ifdef ROBUST_PLAY
  EMACS_SIGNAL (SIGPIPE, old_sigpipe);
#endif

  sounds_in_play = 0;

  return NULL;
}

static void
nas_close_down_play (void)

{
  AuCloseServer (aud);
  sound_warn ("disconnected from audio server");
}

 /********************************************************************\
 *                                                                    *
 * Callback which is run when the sound finishes playing.             *
 *                                                                    *
 \********************************************************************/

static void
doneCB (AuServer       *auserver,
	AuEventHandlerRec *handler,
	AuEvent        *ev,
	AuPointer       data)
{
  int         *in_play_p = (int *) data;

  (*in_play_p) --;
}

#ifdef CACHE_SOUNDS

 /********************************************************************\
 *                                                                    *
 * Play a sound by playing the relevant bucket, if any or             *
 * downloading it if not.                                             *
 *                                                                    *
 \********************************************************************/

static void
do_caching_play (Sound s,
		 int volume,
		 UChar_Binary *buf)

{
  AuBucketAttributes *list, b;
  AuBucketID      id;
  int n;

  AuSetString (AuBucketDescription (&b),
	       AuStringLatin1, strlen (SoundComment (s)), SoundComment (s));

  list = AuListBuckets (aud, AuCompCommonDescriptionMask, &b, &n, NULL);

  if (list == NULL)
    {
      AuPointer my_buf;

      if (buf==NULL)
	{
	  if ((my_buf= (AuPointer) malloc (SoundNumBytes (s)))==NULL)
	    {
	      return;
	    }

	  if (SoundReadFile ((Extbyte *) my_buf, SoundNumBytes (s), s) != SoundNumBytes (s))
	    {
	      free (my_buf);
	      return;
	    }
	}
      else
	my_buf = (AuPointer) buf;

      id = AuSoundCreateBucketFromData (aud, 
					s,
					my_buf,
					AuAccessAllMasks, 
					NULL,
					NULL);
      if (buf == NULL)
	free (my_buf);
    }
  else /* found cached sound */
    {
      id = AuBucketIdentifier (list);
      AuFreeBucketAttributes (aud, n, list);
    }

  sounds_in_play++;

  AuSoundPlayFromBucket (aud, 
			 id, 
			 AuNone,
			 AuFixedPointFromFraction (volume, 100), 
			 doneCB, (AuPointer) &sounds_in_play,
			 1,
			 NULL, NULL,
			 NULL, NULL);

}
#endif /* CACHE_SOUNDS */


void nas_wait_for_sounds (void);
void 
nas_wait_for_sounds (void)

{
  AuEvent         ev;

  while (sounds_in_play>0)
    {
      AuNextEvent (aud, AuTrue, &ev);
      AuDispatchEvent (aud, &ev);
    }
}

int nas_play_sound_file (Extbyte *sound_file, int volume);
int
nas_play_sound_file (Extbyte *sound_file,
		     int volume)
{
  SIGTYPE (*old_sigpipe) (int);

#ifdef ROBUST_PLAY
  old_sigpipe = EMACS_SIGNAL (SIGPIPE, sigpipe_handle);
  if (setjmp (AuXtErrorJump))
    {
      EMACS_SIGNAL (SIGPIPE, old_sigpipe);
      return 0;
    }
#endif

  if (aud==NULL)
    {
      if (aud_server != NULL)
	{
	  Extbyte *m;
	  /* attempt to reconect */
	  if ((m = nas_init_play (aud_server)) != NULL)
	    {
	      
#ifdef ROBUST_PLAY
	      EMACS_SIGNAL (SIGPIPE, old_sigpipe);
#endif
	      return 0;
	    }
	}
      else
	{
	  sound_warn ("Attempt to play with no audio init\n");
#ifdef ROBUST_PLAY
	  EMACS_SIGNAL (SIGPIPE, old_sigpipe);
#endif
	  return 0;
	}
    }

#ifndef CACHE_SOUNDS
  sounds_in_play++;
  AuSoundPlayFromFile (aud,
		       sound_file,
		       AuNone,
		       AuFixedPointFromFraction (volume,100),
		       doneCB, (AuPointer) &sounds_in_play,
		       NULL,
		       NULL,
		       NULL,
		       NULL);
#else
  /* Cache the sounds in buckets on the server */

  {
    Sound s;

    if ((s = SoundOpenFileForReading (sound_file))==NULL)
      {
#ifdef ROBUST_PLAY
	EMACS_SIGNAL (SIGPIPE, old_sigpipe);
#endif
	return 0;
      }

    if (SoundComment (s) == NULL || SoundComment (s)[0] == '\0')
      {
	SoundComment (s) = FileCommentFromFilename (sound_file);
      }

    do_caching_play (s, volume, NULL);

    SoundCloseFile (s);

  }
#endif /* CACHE_SOUNDS */

#ifndef XTEVENTS
  nas_wait_for_sounds ();
#else
  if (!NILP (Vsynchronous_sounds))
    nas_wait_for_sounds ();
#endif

#ifdef ROBUST_PLAY
  EMACS_SIGNAL (SIGPIPE, old_sigpipe);
#endif

  return 1;
}

int nas_play_sound_data (UChar_Binary *data, int length, int volume);
int
nas_play_sound_data (UChar_Binary *data, int length, int volume)
{
  Sound s;
  int offset;
  SIGTYPE (*old_sigpipe) (int);

#if !defined (XTEVENTS)
  AuEvent         ev;
#endif

#ifdef ROBUST_PLAY
  old_sigpipe = EMACS_SIGNAL (SIGPIPE, sigpipe_handle);
  if (setjmp (AuXtErrorJump) != 0)
    {
      EMACS_SIGNAL (SIGPIPE, old_sigpipe);
      return 0;
    }
#endif


  if (aud == NULL) {
    if (aud_server != NULL)
      {
	Extbyte *m;
	/* attempt to reconect */
	if ((m = nas_init_play (aud_server)) != NULL)
	  {
#ifdef ROBUST_PLAY
	    EMACS_SIGNAL (SIGPIPE, old_sigpipe);
#endif
	    return 0;
	  }
      }
    else
      {
	sound_warn ("Attempt to play with no audio init\n");
#ifdef ROBUST_PLAY
	EMACS_SIGNAL (SIGPIPE, old_sigpipe);
#endif
	return 0;
      }
  }

  if ((s=SoundOpenDataForReading (data, length))==NULL)
    {
      sound_warn ("unknown sound type");
#ifdef ROBUST_PLAY
      EMACS_SIGNAL (SIGPIPE, old_sigpipe);
#endif
      return 0;
    }

  if (SoundFileFormat (s) == SoundFileFormatSnd)
    {
      /* hack, hack */
      offset = ((SndInfo *) (s->formatInfo))->h.dataOffset;
    }
  else if (SoundFileFormat (s) == SoundFileFormatWave)
    {
      offset = ((WaveInfo *) (s->formatInfo))->dataOffset;
    }
  else
    {
      sound_warn ("only understand snd and wave files at the moment");
      SoundCloseFile (s);
#ifdef ROBUST_PLAY
      EMACS_SIGNAL (SIGPIPE, old_sigpipe);
#endif
      return 0;
    }

#ifndef CACHE_SOUNDS
  sounds_in_play++;
  AuSoundPlayFromData (aud,
		       s,
		       data+offset,
		       AuNone,
		       AuFixedPointFromFraction (volume,100),
		       doneCB, (AuPointer) &sounds_in_play,
		       NULL,
		       NULL,
		       NULL,
		       NULL);
#else
  /* Cache the sounds in buckets on the server */

  do_caching_play (s, volume, data+offset);
#endif /* CACHE_SOUNDS */


#ifndef XTEVENTS
  nas_wait_for_sounds ();
#else
  if (!NILP (Vsynchronous_sounds))
    nas_wait_for_sounds ();
#endif

  SoundCloseFile (s); 

#ifdef ROBUST_PLAY
  EMACS_SIGNAL (SIGPIPE, old_sigpipe);
#endif

  return 1;
}

#if defined (ROBUST_PLAY)

 /********************************************************************\
 *                                                                    *
 * Code to protect the client from server shutdowns.                  *
 *                                                                    *
 * This is unbelievably horrible.                                     *
 *                                                                    *
 \********************************************************************/

static AuBool
CatchIoErrorAndJump (AuServer *old_aud)
{
  if (old_aud)
    sound_warn ("Audio Server connection broken"); 
  else
    sound_warn ("Audio Server connection broken because of signal");

#ifdef XTEVENTS
#ifdef XTOOLKIT
  AuXtAppRemoveAudioHandler (aud, input_id); 
#endif

  if (aud)
    AuCloseServer (aud);
  aud = NULL;
  sounds_in_play = 0;

  longjmp (AuXtErrorJump, 1);

#else /* not XTEVENTS */

  if (aud)
    AuCloseServer (aud);
  aud = NULL;
  sounds_in_play = 0;
  longjmp (AuXtErrorJump, 1);
 
#endif /* XTEVENTS */
  return 0;
}

SIGTYPE
sigpipe_handle (int signo)
{
  CatchIoErrorAndJump (NULL);
}

static AuBool
CatchErrorAndJump (AuServer *old_aud,
		   AuErrorEvent *event)
{
  return CatchIoErrorAndJump (old_aud);
}

#endif /* ROBUST_PLAY */

 /********************************************************************\
 *                                                                    *
 * This code is here because the nas Sound library doesn't            *
 * support playing from a file buffered in memory. It's a fairly      *
 * direct translation of the file-based equivalent.                   *
 *                                                                    *
 * Since we don't have a filename, samples with no comment field      *
 * are named by a section of their content.                           *
 *                                                                    *
 \********************************************************************/

/* Create a name from the sound. */

static Extbyte *
NameFromData (const Char_Binary *buf,
	      int len)

{
  Extbyte name[9];
  int i;
  Extbyte *s;

  buf+=len/2;
  len -= len/2;

  i=0;
  while (i<8 && len >0)
    {
      while (*buf < 32 && len>0)
	{
	  buf++;
	  len--;
	}
      name[i]= *buf;
      i++;
      buf++;
      len--;
    }

  name[i]='\0';

  if (i==8)
    {
      strcpy (s = (Extbyte *) malloc (10), name);
    }
  else 
    {
      strcpy (s = (Extbyte *) malloc (15), "short sound");
    }

  return s;
}

/* Code to do a pseudo-open on a data buffer. Only for snd files at the
   moment. 
 */

static SndInfo *
SndOpenDataForReading (const Char_Binary *data,
		       int length)

{
  SndInfo        *si;
  int             size;

  if (!(si = (SndInfo *) malloc (sizeof (SndInfo))))
    return NULL;

  si->comment = NULL;
  si->writing = 0;

  memcpy (&si->h, data, sizeof (SndHeader));

  if (NAS_LITTLE_ENDIAN)
    {
      Char_Binary            n;
    
      swapl (&si->h.magic, n);
      swapl (&si->h.dataOffset, n);
      swapl (&si->h.dataSize, n);
      swapl (&si->h.format, n);
      swapl (&si->h.sampleRate, n);
      swapl (&si->h.tracks, n);
    }

  if (si->h.magic != SND_MAGIC_NUM)
    {
      free (si);
      return NULL;
    }

  size = si->h.dataOffset - sizeof (SndHeader);

  if (size)
    {
      if (!(si->comment = (Extbyte *) malloc (size + 1)))
	{
	  free (si);
	  return NULL;
	}

      memcpy (si->comment,  data+sizeof (SndHeader), size);

      *(si->comment + size) = 0;
      if (*si->comment == '\0')
	si->comment =
	  NameFromData (data+si->h.dataOffset, length-si->h.dataOffset);
    }
  else
    si->comment = NameFromData (data+si->h.dataOffset, length-si->h.dataOffset);

  si->h.dataSize = length-si->h.dataOffset;

  si->fp=NULL;

  return si;
}

/* Stuff taken from wave.c from NAS.  Just like snd files, NAS can't
   read wave data from memory, so these functions do that for us. */

#define Err()		{ return NULL; }
#define readFourcc(_f)	dread(_f, sizeof(RIFF_FOURCC), 1)
#define cmpID(_x, _y)							      \
    strncmp((Char_Binary *) (_x), (Char_Binary *) (_y), sizeof(RIFF_FOURCC))
#define PAD2(_x)	(((_x) + 1) & ~1)

/* These functions here are for faking file I/O from buffer. */

/* The "file" position */
static size_t file_posn;
/* The length of the "file" */
static size_t file_len;
/* The actual "file" data. */
static const void* file_data;

/* Like fopen, but for a buffer in memory */
static void
dopen (const void* data, size_t length)
{
   file_data = data;
   file_len = length;
   file_posn = 0;
}

/* Like fread, but for a buffer in memory */
static int
dread (void* buf, size_t size, size_t nitems)
{
  size_t nread = size * nitems;
  
  if (file_posn + nread <= file_len)
    {
      memcpy(buf, (Char_Binary *) file_data + file_posn, size * nitems);
      file_posn += nread;
      return nitems;
    }
  else
    {
      return EOF;
    }
}

/* Like fgetc, but for a buffer in memory */
static int
dgetc (void)
{
  if (file_posn < file_len)
    return ((Char_Binary *)file_data)[file_posn++];
  else
    return -1;
}

/* Like fseek, but for a buffer in memory */
static int
dseek (long offset, int from)
{
  if (from == 0)
    file_posn = offset;
  else if (from == 1)
    file_posn += offset;
  else if (from == 2)
    file_posn = file_len + offset;

  return 0;
}

/* Like ftell, but for a buffer in memory */
static long
dtell (void)
{
  return file_posn;
}

/* Data buffer analogs for FileReadS and FileReadL in NAS. */

static unsigned short
DataReadS (int swapit)
{
  unsigned short us;

  dread(&us, 2, 1);
  if (swapit)
    us = FileSwapS(us);
  return us;
}

static AuUint32
DataReadL (int swapit)
{
  AuUint32 ul;

  dread(&ul, 4, 1);
  if (swapit)
    ul = FileSwapL(ul);
  return ul;
}

static int
readChunk (RiffChunk *c)
{
  int             status;
  Char_Binary            n;

  if ((status = dread(c, sizeof(RiffChunk), 1)))
    if (NAS_BIG_ENDIAN)
      swapl(&c->ckSize, n);

  return status;
}

/* A very straight-forward translation of WaveOpenFileForReading to
   read the wave data from a buffer in memory. */

static WaveInfo *
WaveOpenDataForReading (const Char_Binary *data,
			int length)
{
  RiffChunk       ck;
  RIFF_FOURCC     fourcc;
  AuInt32            fileSize;
  WaveInfo       *wi;

    
  if (!(wi = (WaveInfo *) malloc(sizeof(WaveInfo))))
    return NULL;

  wi->comment = NULL;
  wi->dataOffset = wi->format = wi->writing = 0;

  dopen(data, length);
    
  if (!readChunk(&ck) ||
      cmpID(&ck.ckID, RIFF_RiffID) ||
      !readFourcc(&fourcc) ||
      cmpID(&fourcc, RIFF_WaveID))
    Err();

  fileSize = PAD2(ck.ckSize) - sizeof(RIFF_FOURCC);

  while (fileSize >= sizeof(RiffChunk))
    {
      if (!readChunk(&ck))
	Err();

      fileSize -= sizeof(RiffChunk) + PAD2(ck.ckSize);

      /* LIST chunk */
      if (!cmpID(&ck.ckID, RIFF_ListID))
	{
	  if (!readFourcc(&fourcc))
	    Err();

	  /* INFO chunk */
	  if (!cmpID(&fourcc, RIFF_ListInfoID))
	    {
	      ck.ckSize -= sizeof(RIFF_FOURCC);

	      while (ck.ckSize)
		{
		  RiffChunk       c;

		  if (!readChunk(&c))
		    Err();

		  /* ICMT chunk */
		  if (!cmpID(&c.ckID, RIFF_InfoIcmtID))
		    {
		      if (!(wi->comment = (Extbyte *) malloc(c.ckSize)) ||
			  !dread(wi->comment, c.ckSize, 1))
			Err();

		      if (c.ckSize & 1)
			dgetc(); /* eat the pad byte */
		    }
		  else
		    /* skip unknown chunk */
		    dseek(PAD2(c.ckSize), 1);

		  ck.ckSize -= sizeof(RiffChunk) + PAD2(c.ckSize);
		}
	    }
	  else
	    /* skip unknown chunk */
	    dseek(PAD2(ck.ckSize) - sizeof(RIFF_FOURCC), 1);
	}
      /* wave format chunk */
      else if (!cmpID(&ck.ckID, RIFF_WaveFmtID) && !wi->format)
	{
	  AuInt32            dummy;

	  wi->format = DataReadS(NAS_BIG_ENDIAN);
	  wi->channels = DataReadS(NAS_BIG_ENDIAN);
	  wi->sampleRate = DataReadL(NAS_BIG_ENDIAN);

	  /* we don't care about the next two fields */
	  dummy = DataReadL(NAS_BIG_ENDIAN);
	  dummy = DataReadS(NAS_BIG_ENDIAN);

	  if (wi->format != RIFF_WAVE_FORMAT_PCM)
	    Err();

	  wi->bitsPerSample = DataReadS(NAS_BIG_ENDIAN);

	  /* skip any other format specific fields */
	  dseek(PAD2(ck.ckSize - 16), 1);
	}
      /* wave data chunk */
      else if (!cmpID(&ck.ckID, RIFF_WaveDataID) && !wi->dataOffset)
	{
	  long endOfFile;

	  wi->dataOffset = dtell();
	  wi->dataSize = ck.ckSize;
	  dseek(0, 2);
	  endOfFile = dtell();

	  /* seek past the data */
	  if (dseek(wi->dataOffset + PAD2(ck.ckSize), 0) ||
	      dtell() > endOfFile)
	    {
	      /* the seek failed, assume the size is bogus */
	      dseek(0, 2);
	      wi->dataSize = dtell() - wi->dataOffset;
	    }

	  wi->dataOffset -= sizeof(long);
	}
      else
	/* skip unknown chunk */
	dseek(PAD2(ck.ckSize), 1);
    }

  if (!wi->dataOffset)
    Err();

  wi->numSamples = wi->dataSize / wi->channels / (wi->bitsPerSample >> 3);

  if (!wi->comment)
    wi->comment = NameFromData (data + wi->dataOffset,
				length - wi->dataOffset);

  wi->fp = NULL;
    
  return wi;
}


static Sound
SoundOpenDataForReading (UChar_Binary *data,
			 int length)

{
  Sound s;

  if (!(s = (Sound) malloc (sizeof (SoundRec))))
    return NULL;

  if ((s->formatInfo = SndOpenDataForReading ((Char_Binary *) data, length)) != NULL)
    {
      if (!((int(*)(Sound))(SoundFileInfo[SoundFileFormatSnd].toSound)) (s))
	{
	  SndCloseFile ((SndInfo *) (s->formatInfo));
	  free (s);
	  return NULL;
	}
    }
  else if ((s->formatInfo = WaveOpenDataForReading ((Char_Binary *) data, length)) != NULL)
    {
      if (!((int(*)(Sound))(SoundFileInfo[SoundFileFormatWave].toSound)) (s))
	{
	  WaveCloseFile ((WaveInfo *) (s->formatInfo));
	  free (s);
	  return NULL;
	}
    }

  return s;
}