/**********************************************************************MPEG-4 Audio VMaudio i/o streams (.au format)This software module was originally developed byHeiko Purnhagen (University of Hannover)and edited byin the course of development of the MPEG-2 NBC/MPEG-4 Audio standardISO/IEC 13818-7, 14496-1,2 and 3. This software module is animplementation of a part of one or more MPEG-2 NBC/MPEG-4 Audio toolsas specified by the MPEG-2 NBC/MPEG-4 Audio standard. ISO/IEC givesusers of the MPEG-2 NBC/MPEG-4 Audio standards free license to thissoftware module or modifications thereof for use in hardware orsoftware products claiming conformance to the MPEG-2 NBC/ MPEG-4 Audiostandards. Those intending to use this software module in hardware orsoftware products are advised that this use may infringe existingpatents. The original developer of this software module and his/hercompany, the subsequent editors and their companies, and ISO/IEC haveno liability for use of this software module or modifications thereofin an implementation. Copyright is not released for non MPEG-2NBC/MPEG-4 Audio conforming products. The original developer retainsfull right to use the code for his/her own purpose, assign or donatethe code to a third party and to inhibit third party from using thecode for non MPEG-2 NBC/MPEG-4 Audio conforming products. Thiscopyright notice must be included in all copies or derivative works.Copyright (c) 1999.Source file: austream.c$Id: austream.c,v 1.5 1999/08/09 17:34:19 purnhage Exp $Authors:HP    Heiko Purnhagen, Uni Hannover <purnhage@tnt.uni-hannover.de>NM    Nikolaus Meine, Uni Hannover <meine@tnt.uni-hannover.de>Changes:16-sep-98   HP/NM   born, based on au_io.c06-aug-99   HP      fixed bug in AuOpenRead() numSample**********************************************************************//* Audio i/o streaming with stdin/stdout support. *//* Header format: .au (Sun audio file format, aka SND or AFsp) *//* Sample format: 16 bit twos complement, uniform quantisation *//* Data size set to -1 (=unknown) *//* Multi channel data is interleaved: l0 r0 l1 r1 ... *//* Total number of samples (over all channels) is used. */#include <stdio.h>#include <stdlib.h>#include <string.h>#include "austream.h"#include "common_m4a.h"/* ---------- declarations ---------- */#define min(a,b) ((a) < (b) ? (a) : (b))#define max(a,b) ((a) > (b) ? (a) : (b))/* ---------- declarations (structures) ---------- */struct AuStreamStruct		/* audio stream handle */{  FILE *f;			/* stream handle */  long currentSample;		/* number of samples read/written */  int eof;			/* eof/error flag */  int write;			/* write (not read) flag */};/* ---------- variables ---------- */static int AUdebugLevel = 0;	/* debug level *//* ---------- local functions ---------- */static void putshort (short x, AuStream *s){  register int a;  putc((x>>8)&255,s->f);  a = putc(x&255,s->f);  if (a==EOF)    s->eof = 1;}static void putint (long x, AuStream *s){  int a;  putc((x>>24)&255,s->f);  putc((x>>16)&255,s->f);  putc((x>>8)&255,s->f);  a = putc(x&255,s->f);  if (a==EOF)    s->eof = 1;}static short getshort (AuStream *s){  register int a,b;    if (s->eof)    return 0;    a = getc(s->f);  b = getc(s->f);  if (b==EOF) {    s->eof = 1;    return 0;  }  return (a<<8)|b;}static long getint (AuStream *s){  int a,b;  if (s->eof)    return 0;    a = getc(s->f)<<24;  a |= getc(s->f)<<16;  a |= getc(s->f)<<8;  b = getc(s->f);  if (b==EOF) {    s->eof = 1;    return 0;  }  return a|b;}/* ---------- functions ---------- *//* AuInit() *//* Init audio i/o streams. */void AuInit (  int debugLevel)		/* in: debug level */				/*     0=off  1=basic  2=full */{  AUdebugLevel = debugLevel;  if (AUdebugLevel) {    printf("AuInit: debugLevel=%d\n",AUdebugLevel);  }}/* AuOpenRead() *//* Open audio stream for reading. */AuStream *AuOpenRead (  char *streamName,		/* in: stream name, "-" for stdin */  int *numChannel,		/* out: number of channels */  float *fSample,		/* out: sampling frequency [Hz] */  long *numSample)		/* out: number of samples in stream */				/*      or -1 if not available */				/* returns: */				/*  audio stream (handle) */				/*  or NULL if error */{  AuStream *s;  long h,ofs,dsize,formc,srate,nchan;  if (AUdebugLevel)    printf("AuOpenRead: fileName=\"%s\"\n",streamName);  if ((s=(AuStream*)malloc(sizeof(AuStream)))==NULL)    CommonExit(-1,"AuOpenRead: Can not allocate memory");  s->currentSample = 0;  s->eof = 0;  s->write = 0;  if (streamName[0]=='-' && streamName[1]==0)    s->f = stdin;  else    s->f = fopen(streamName,"rb");  if (s->f==NULL) {    CommonWarning("AuOpenRead: Can not open \"%s\"",streamName);    free(s);    return NULL;  }  h = getint(s);  if (h!=0x2e736e64) {		/* magic string: .snd */    CommonWarning("AuOpenRead: Wrong magic string in \"%s\"",streamName);    free(s);    return NULL;  }  ofs = getint(s);  dsize = getint(s);  formc = getint(s);		/* 3 = 16 bit uniform 2compl */  srate = getint(s);  nchan = getint(s);  for (h=24; h<ofs; h++)    if (getc(s->f)==EOF)      s->eof = 1;  if (s->eof || nchan<1 || formc!=3) {    CommonWarning("AuOpenRead: Unsupported audio format in \"%s\"",streamName);    free(s);    return NULL;  }  *numChannel = nchan;  *fSample = srate;  *numSample = (dsize<0)?-1:dsize/2;  if (AUdebugLevel)    printf("AuOpenRead: numChannel=%d  fSample=%.1f numSample=%ld\n",	   *numChannel,*fSample,*numSample);  return s;}/* AuOpenWrite() *//* Open audio stream for writing. */AuStream *AuOpenWrite (  char *streamName,		/* in: stream name, "-" for stdout */  int numChannel,		/* in: number of channels */  float fSample)		/* in: sampling frequency [Hz] */				/* returns: */				/*  audio stream (handle) */				/*  or NULL if error */{  AuStream *s;  if (AUdebugLevel) {    printf("AuOpenWrite: fileName=\"%s\"\n",streamName);    printf("AuOpenWrite: numChannel=%d  fSample=%.1f\n",	   numChannel,fSample);  }  if ((s=(AuStream*)malloc(sizeof(AuStream)))==NULL)    CommonExit(-1,"AuOpenWrite: Can not allocate memory");  s->currentSample = 0;  s->eof = 0;  s->write = 1;  if (streamName[0]=='-' && streamName[1]==0)    s->f = stdout;  else    s->f = fopen(streamName,"wb");  if (s->f==NULL) {    CommonWarning("AuOpenWrite: Can not open \"%s\"",streamName);    free(s);    return NULL;  }  putint(0x2e736e64,s);	/* magic string: .snd */  putint(28,s);		/* header size */  putint(-1,s);		/* -1 = data size unknown */  putint(3,s);		/* 3 = 16 bit uniform 2compl */  putint((int)(fSample+.5),s);  putint(numChannel,s);  putint(0,s);		/* info string	*/  if (s->eof) {    CommonWarning("AuOpenWrite: Can not write to \"%s\"",streamName);    free(s);    return NULL;  }  return s;}/* AuReadData() *//* Read data from audio stream. */long AuReadData (  AuStream *stream,		/* in: audio stream (handle) */  short *data,			/* out: data[] */  long numSample)		/* in: number of samples to be read */				/* returns: */				/*  number of samples read */{  long i;  if (AUdebugLevel > 1)    printf("AuReadData: numSample=%ld\n",numSample);  if (stream->write)    CommonExit(1,"AuReadData: stream not in read mode");  i = 0;  while (!stream->eof && i<numSample)    data[i++] = getshort(stream);  stream->currentSample += i;  return i;}/* AuWriteData() *//* Write data to audio stream. */void AuWriteData (  AuStream *stream,		/* in: audio stream (handle) */  short *data,			/* in: data[] */  long numSample)		/* in: number of samples to be written */{  long i;  if (AUdebugLevel > 1)    printf("AuWriteData: numSample=%ld\n",numSample);  if (!stream->write)    CommonExit(1,"AuWriteData: audio file not in write mode");  for (i=0; i<numSample; i++)    putshort(data[i],stream);  stream->currentSample += numSample;  if (stream->eof)    CommonWarning("AuWriteDate: Can not write to au stream");}/* AuClose() *//* Close audio stream.*/void AuClose (  AuStream *stream)		/* in: audio stream (handle) */{  if (AUdebugLevel)    printf("AuClose: currentSample=%ld\n",stream->currentSample);  if (stream->f!=stdin && stream->f!=stdout)    fclose(stream->f);  free(stream);}/* end of austream.c */