aiff.c

刻录光盘的程序

/* @(#)aiff.c	1.2 99/12/19 Copyright 1998,1999 Heiko Eissfeldt */
#ifndef lint
static char     sccsid[] =
"@(#)aiff.c	1.2 99/12/19 Copyright 1998,1999 Heiko Eissfeldt";

#endif
/***
 * CopyPolicy: GNU Public License 2 applies
 * Copyright (C) by Heiko Eissfeldt
 *
 *
 * ---------------------------------------------------------------------
 *  definitions for aiff pcm output
 * ---------------------------------------------------------------------
 */

#include "config.h"
#include <stdio.h>
#if defined (HAVE_UNISTD_H) && (HAVE_UNISTD_H == 1)
#include <sys/types.h>
#include <unistd.h>
#endif
#include <strdefs.h>
#include <standard.h>
#include "mytype.h"
#include "byteorder.h"
#include "sndfile.h"

typedef UINT4 FOURCC;    /* a four character code */
typedef struct CHUNKHDR {
  FOURCC	ckid;          /* chunk ID */
  UINT4		dwSize;	/* chunk size */
} CHUNKHDR;

#define mmioFOURCC(ch0, ch1, ch2, ch3) \
  ((UINT4)(unsigned char)(ch3) | ((UINT4)(unsigned char)(ch2) << 8) | \
  ((UINT4)(unsigned char)(ch1) << 16) | ((UINT4)(unsigned char)(ch0) << 24))

#define FOURCC_FORM     mmioFOURCC ('F', 'O', 'R', 'M')
#define FOURCC_AIFF     mmioFOURCC ('A', 'I', 'F', 'F')
#define FOURCC_COMM     mmioFOURCC ('C', 'O', 'M', 'M')
#define FOURCC_SSND     mmioFOURCC ('S', 'S', 'N', 'D')

typedef struct AIFFHDR {
  CHUNKHDR	formChk;
  FOURCC	formType;

  CHUNKHDR	commChk;		/* Common chunk */
  /* from now on, alignment prevents us from using the original types :-(( */
  unsigned char numChannels[2];         /* Audio Channels */
  unsigned char numSampleFrames[4];     /* # of samples */
  unsigned char samplesize[2];          /* bits per sample */
  unsigned char sample_rate[10];        /* sample rate in extended float */

  unsigned char ssndChkid[4];           /* Sound data chunk */
  unsigned char dwSize[4];              /* size of chunk */
  unsigned char offset[4];              /* start of 1st sample */
  unsigned char blocksize[4];           /* aligned sound data block size */
} AIFFHDR;

static AIFFHDR AiffHdr;

/* format the sample rate into an
   bigendian 10-byte IEEE-754 floating point number
 */
static int Format_samplerate __PR((unsigned long rate, unsigned char the_rate[10]));

static int Format_samplerate(rate, the_rate)
	unsigned long rate;
	unsigned char the_rate[10];
{
  int i;

  /* normalize rate */
  for (i = 0; (rate & 0xffff) != 0; rate <<= 1, i++) {
    if ((rate & 0x8000) != 0) {
      break;
    }
  }

  /* set exponent and sign */
  the_rate[1] = 14-i;
  the_rate[0] = 0x40;           /* LSB = sign */

  /* 16-bit part of mantisse for sample rate */
  the_rate[3] = rate & 0xff;
  the_rate[2] = (rate >> 8) & 0xff;

  /* initialize lower digits of mantisse */
  the_rate[4] = the_rate[5] = the_rate[6] =
  the_rate[7] = the_rate[8] = the_rate[9] = 0;

  return 0;
}

static int InitSound __PR(( int audio, long channels, unsigned long rate, long nBitsPerSample, unsigned long expected_bytes ));

static int InitSound ( audio, channels, rate, nBitsPerSample, expected_bytes)
	int audio;
	long channels;
	unsigned long rate;
	long nBitsPerSample;
	unsigned long expected_bytes;
{
  UINT4 tmp;

  fillbytes(&AiffHdr, sizeof(AiffHdr), '\0');
  AiffHdr.formChk.ckid  = cpu_to_be32(FOURCC_FORM);
  AiffHdr.formChk.dwSize= cpu_to_be32(expected_bytes +
			offset_of(AIFFHDR,blocksize)+sizeof(AiffHdr.blocksize)
			- offsetof(AIFFHDR,formType));
  AiffHdr.formType	= cpu_to_be32(FOURCC_AIFF);

  AiffHdr.commChk.ckid	= cpu_to_be32(FOURCC_COMM);
  AiffHdr.commChk.dwSize= cpu_to_be32(offset_of(AIFFHDR,ssndChkid)
					- offset_of(AIFFHDR,numChannels));

  AiffHdr.numChannels[1]= channels;
  tmp = cpu_to_be32(expected_bytes/(channels * (nBitsPerSample/8)));
  AiffHdr.numSampleFrames[0] = tmp >> 24;
  AiffHdr.numSampleFrames[1] = tmp >> 16;
  AiffHdr.numSampleFrames[2] = tmp >> 8;
  AiffHdr.numSampleFrames[3] = tmp >> 0;
  AiffHdr.samplesize[1] = nBitsPerSample;
  Format_samplerate(rate, AiffHdr.sample_rate);

  memcpy(AiffHdr.ssndChkid, "SSND", 4);
  tmp = cpu_to_be32(expected_bytes + offset_of(AIFFHDR,blocksize)+sizeof(AiffHdr.blocksize) - offset_of(AIFFHDR, offset));
  AiffHdr.dwSize[0] = tmp >> 24;
  AiffHdr.dwSize[1] = tmp >> 16;
  AiffHdr.dwSize[2] = tmp >> 8;
  AiffHdr.dwSize[3] = tmp >> 0;

  return write (audio, &AiffHdr, sizeof (AiffHdr));
}

static int ExitSound __PR(( int audio, unsigned long nBytesDone ));

static int ExitSound ( audio, nBytesDone )
	int audio;
	unsigned long nBytesDone;
{
  UINT4 tmp;

  AiffHdr.formChk.dwSize= cpu_to_be32(nBytesDone + sizeof(AIFFHDR)
					- offsetof(AIFFHDR,commChk));
  tmp = cpu_to_be32(nBytesDone/(
        AiffHdr.numChannels[1] * AiffHdr.samplesize[1]/ULONG_C(8)));
  AiffHdr.numSampleFrames[0] = tmp >> 24;
  AiffHdr.numSampleFrames[1] = tmp >> 16;
  AiffHdr.numSampleFrames[2] = tmp >> 8;
  AiffHdr.numSampleFrames[3] = tmp >> 0;

  /* If an odd number of bytes has been written,
     extend the chunk with one dummy byte. This is a requirement for AIFF. */
  if ((nBytesDone & 1) && (lseek(audio, 1L, SEEK_CUR) == -1)) {
    return 0;
  }

  /* goto beginning */
  if (lseek(audio, 0L, SEEK_SET) == -1) {
    return 0;
  }
  return write (audio, &AiffHdr, sizeof (AiffHdr));
}

static unsigned long GetHdrSize __PR(( void ));

static unsigned long GetHdrSize( )
{
  return sizeof( AiffHdr );
}

struct soundfile aiffsound =
{
	InitSound,		/* init header method */
	ExitSound,		/* exit header method */
	GetHdrSize,		/* report header size method */
	1			/* needs big endian samples */
};