wave_a.c

MIDI解码程序(用VC编写)

/*
    TiMidity++ -- MIDI to WAVE converter and player
    Copyright (C) 1999-2002 Masanao Izumo <[e-mail]>
    Copyright (C) 1995 Tuukka Toivonen <[e-mail]>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    wave_audio.c

    Functions to output RIFF WAVE format data to a file or stdout.

*/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif /* HAVE_CONFIG_H */
#include <stdio.h>

#ifdef __W32__
#include <io.h>
#endif

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif /* HAVE_UNISTD_H */

#ifdef STDC_HEADERS
#include <string.h>
#include <stdlib.h>
#elif HAVE_STRINGS_H
#include <strings.h>
#endif
#include <fcntl.h>

#ifdef __FreeBSD__
#include <stdio.h>
#endif
#include <ctype.h>

#include "timidity.h"
#include "common.h"
#include "output.h"
#include "controls.h"
#include "instrum.h"
#include "playmidi.h"
#include "readmidi.h"

static int open_output(void); /* 0=success, 1=warning, -1=fatal error */
static void close_output(void);
static int output_data(char *buf, int32 bytes);
static int acntl(int request, void *arg);

/* export the playback mode */

#define dpm wave_play_mode

PlayMode dpm = {
    DEFAULT_RATE,
#ifdef LITTLE_ENDIAN
    PE_16BIT|PE_SIGNED,
#else
    PE_16BIT|PE_SIGNED|PE_BYTESWAP,
#endif
    PF_PCM_STREAM,
    -1,
    {0,0,0,0,0},
    "RIFF WAVE file", 'w',
    NULL,
    open_output,
    close_output,
    output_data,
    acntl
};

#define UPDATE_HEADER_STEP (128*1024) /* 128KB */
static uint32 bytes_output, next_bytes;
static int already_warning_lseek;

#ifdef __W32G__
extern char *w32g_output_dir;
extern int w32g_auto_output_mode;
#endif

/*************************************************************************/

static char *orig_RIFFheader=
  "RIFF" "\377\377\377\377"
  "WAVE" "fmt " "\020\000\000\000" "\001\000"
  /* 22: channels */ "\001\000"
  /* 24: frequency */ "xxxx"
  /* 28: bytes/second */ "xxxx"
  /* 32: bytes/sample */ "\004\000"
  /* 34: bits/sample */ "\020\000"
  "data" "\377\377\377\377"
;


/* We support follows WAVE format:
 * 8 bit unsigned pcm
 * 16 bit signed pcm (little endian)
 * A-law
 * U-law
 */

/* Windows WAVE File Encoding Tags */
#define WAVE_FORMAT_PCM       0x01
#define WAVE_FORMAT_ALAW      0x06
#define WAVE_FORMAT_MULAW     0x07


static int wav_output_open(const char *fname)
{
  int t;
  char RIFFheader[44];
  int fd;

  if(strcmp(fname, "-") == 0)
    fd = 1; /* data to stdout */
  else {
    /* Open the audio file */
    fd = open(fname, FILE_OUTPUT_MODE);
    if(fd < 0) {
      ctl->cmsg(CMSG_ERROR, VERB_NORMAL, "%s: %s",
		fname, strerror(errno));
      return -1;
    }
  }

  /* Generate a (rather non-standard) RIFF header. We don't know yet
     what the block lengths will be. We'll fix that at close if this
     is a seekable file. */

  memcpy(RIFFheader, orig_RIFFheader, 44);

  if(dpm.encoding & PE_ALAW)
    RIFFheader[20] = WAVE_FORMAT_ALAW;
  else if(dpm.encoding & PE_ULAW)
    RIFFheader[20] = WAVE_FORMAT_MULAW;
  else
    RIFFheader[20] = WAVE_FORMAT_PCM;

  if(dpm.encoding & PE_MONO)
    RIFFheader[22] = 1;
  else
    RIFFheader[22] = 2;

  *((int *)(RIFFheader+24)) = LE_LONG(dpm.rate);

  t = dpm.rate;
  if(!(dpm.encoding & PE_MONO)) t *= 2;
  if(dpm.encoding & PE_24BIT)   t *= 3;
  else if(dpm.encoding & PE_16BIT)   t *= 2;
  *((int *)(RIFFheader+28)) = LE_LONG(t);

  if(dpm.encoding & PE_16BIT)
    t = 2;
  else if(dpm.encoding & PE_24BIT)
    t = 3;
  else
    t = 1;
  RIFFheader[34] = t * 8;
  if(!(dpm.encoding & PE_MONO))
    t *= 2;
  RIFFheader[32] = t;

  if(write(fd, RIFFheader, 44) == -1) {
    ctl->cmsg(CMSG_ERROR, VERB_NORMAL, "%s: write: %s",
	      dpm.name, strerror(errno));
    close_output();
    return -1;
  }

  /* Reset the length counter */
  bytes_output = 0;
  next_bytes = bytes_output + UPDATE_HEADER_STEP;
  already_warning_lseek = 0;

  return fd;
}

static int auto_wav_output_open(const char *input_filename)
{
  char *output_filename;

#ifndef __W32G__
  output_filename = create_auto_output_name(input_filename,"wav",NULL,0);
#else
  output_filename = create_auto_output_name(input_filename,"wav",w32g_output_dir,w32g_auto_output_mode);
#endif
  if(output_filename==NULL){
	  return -1;
  }
  if((dpm.fd = wav_output_open(output_filename)) == -1) {
    free(output_filename);
    return -1;
  }
  if(dpm.name != NULL)
    free(dpm.name);
  dpm.name = output_filename;
  ctl->cmsg(CMSG_INFO, VERB_NORMAL, "Output %s", dpm.name);
  return 0;
}

static int open_output(void)
{
    int include_enc, exclude_enc;

    include_enc = exclude_enc = 0;
    if(dpm.encoding & (PE_16BIT | PE_24BIT))
    {
#ifdef LITTLE_ENDIAN
	exclude_enc = PE_BYTESWAP;
#else
	include_enc = PE_BYTESWAP;
#endif /* LITTLE_ENDIAN */
	include_enc |= PE_SIGNED;
    }
	else if(!(dpm.encoding & (PE_ULAW|PE_ALAW)))
    {
	exclude_enc = PE_SIGNED;
    }

    dpm.encoding = validate_encoding(dpm.encoding, include_enc, exclude_enc);

#ifndef __W32G__
    if(dpm.name == NULL) {
      dpm.flag |= PF_AUTO_SPLIT_FILE;
      dpm.name = NULL;
    } else {
      dpm.flag &= ~PF_AUTO_SPLIT_FILE;
      if((dpm.fd = wav_output_open(dpm.name)) == -1)
	return -1;
    }
#else
	if(w32g_auto_output_mode>0){
      dpm.flag |= PF_AUTO_SPLIT_FILE;
      dpm.name = NULL;
    } else {
      dpm.flag &= ~PF_AUTO_SPLIT_FILE;
      if((dpm.fd = wav_output_open(dpm.name)) == -1)
		return -1;
    }
#endif

    return 0;
}

static int update_header(void)
{
    off_t save_point;
    int32 tmp;

    if(already_warning_lseek)
	return 0;

    save_point = lseek(dpm.fd, 0, SEEK_CUR);
    if(save_point == -1 || lseek(dpm.fd, 4, SEEK_SET) == -1)
    {
	ctl->cmsg(CMSG_WARNING, VERB_VERBOSE,
		  "Warning: %s: %s: Can't make valid header",
		  dpm.name, strerror(errno));
	already_warning_lseek = 1;
	return 0;
    }

    tmp = LE_LONG(bytes_output + 44 - 8);
    if(write(dpm.fd, &tmp, 4) == -1)
    {
	lseek(dpm.fd, save_point, SEEK_SET);
	return -1;
    }
    lseek(dpm.fd, 40, SEEK_SET);
    tmp = LE_LONG(bytes_output);
    write(dpm.fd, &tmp, 4);

    lseek(dpm.fd, save_point, SEEK_SET);
    ctl->cmsg(CMSG_INFO, VERB_DEBUG,
	      "%s: Update RIFF WAVE header (size=%d)", dpm.name, bytes_output);

    return 0;
}

static int output_data(char *buf, int32 bytes)
{
    int n;

    if(dpm.fd == -1)
      return -1;

    while(((n = write(dpm.fd, buf, bytes)) == -1) && errno == EINTR)
	;
    if(n == -1)
    {
	ctl->cmsg(CMSG_ERROR, VERB_NORMAL, "%s: %s",
		  dpm.name, strerror(errno));
	return -1;
    }

    bytes_output += bytes;

#if UPDATE_HEADER_STEP > 0
    if(bytes_output >= next_bytes)
    {
	if(update_header() == -1)
	    return -1;
	next_bytes = bytes_output + UPDATE_HEADER_STEP;
    }
#endif /* UPDATE_HEADER_STEP */
    return n;
}

static void close_output(void)
{
    if(dpm.fd != 1 && /* We don't close stdout */
       dpm.fd != -1)
    {
	update_header();
	close(dpm.fd);
	dpm.fd = -1;
    }
}

static int acntl(int request, void *arg)
{
  switch(request) {
  case PM_REQ_PLAY_START:
    if(dpm.flag & PF_AUTO_SPLIT_FILE)
      return auto_wav_output_open(current_file_info->filename);
    break;
  case PM_REQ_PLAY_END:
    if(dpm.flag & PF_AUTO_SPLIT_FILE) {
      close_output();
      return 0;
    }
    break;
  case PM_REQ_DISCARD:
    return 0;
  }
  return -1;
}