ref: 5164b5505f256c06eb3a84f4d8a8a93055af9d41
dir: /src/auto.c/
/*
* May 19, 1992
* Copyright 1992 Guido van Rossum And Sundry Contributors
* This source code is freely redistributable and may be used for
* any purpose. This copyright notice must be maintained.
* Guido van Rossum And Sundry Contributors are not responsible for
* the consequences of using this software.
*/
/*
* A meta-handler that recognizes most file types by looking in the
* first part of the file. The file must be seekable!
* (IRCAM sound files are not recognized -- these don't seem to be
* used any more -- but this is just laziness on my part.)
*/
#include "sox_i.h"
#include <string.h>
#if defined(DOS) || defined(WIN32)
#define LASTCHAR '\\'
#else
#define LASTCHAR '/'
#endif
static int sox_autostartread(ft_t ft)
{
char *type = NULL;
char header[256];
int rc, loop;
/* Attempt to auto-detect filetype using magic values. Abort loop
* and use file extension if any errors are detected.
*/
if (ft->seekable)
{
/* Most files only have 4-byte magic headers at first of
* file. So we start checking for those filetypes first.
*/
memset(header,0,4);
if (sox_readbuf(ft, header, 1, 4) == 4)
{
/* Look for .snd or dns. header of AU files */
if ((strncmp(header, ".snd", 4) == 0) ||
(strncmp(header, "dns.", 4) == 0) ||
((header[0] == '\0') &&
(strncmp(header+1, "ds.", 3) == 0)) ||
((strncmp(header, "sd.", 3) == 0) &&
(header[3] == '\0')))
type = "au";
else if (strncmp(header, "FORM", 4) == 0)
{
/* Need to read more data to see what type of FORM file */
if (sox_readbuf(ft, header, 1, 8) == 8)
{
if (strncmp(header + 4, "AIFF", 4) == 0)
type = "aiff";
else if (strncmp(header + 4, "AIFC", 4) == 0)
type = "aiff";
else if (strncmp(header + 4, "8SVX", 4) == 0)
type = "8svx";
else if (strncmp(header + 4, "MAUD", 4) == 0)
type = "maud";
}
}
else if (strncmp(header, "RIFF", 4) == 0)
{
if (sox_readbuf(ft, header, 1, 8) == 8)
if (strncmp(header + 4, "WAVE", 4) == 0)
type = "wav";
}
else if (strncmp(header, "Crea", 4) == 0)
{
if (sox_readbuf(ft, header, 1, 15) == 15)
if (strncmp(header, "tive Voice File", 15) == 0)
type = "voc";
}
else if (strncmp(header, "SOUN", 4) == 0)
{
/* Check for SOUND magic header */
if (sox_readbuf(ft, header, 1, 1) == 1 && *header == 'D')
{
/* Once we've found SOUND see if its smp or sndt */
if (sox_readbuf(ft, header, 1, 12) == 12)
{
if (strncmp(header, " SAMPLE DATA", 12) == 0)
type = "smp";
else
type = "sndt";
}
else
type = "sndt";
}
}
else if (strncmp(header, "2BIT", 4) == 0)
type = "avr";
else if (strncmp(header, "NIST", 4) == 0)
{
if (sox_readbuf(ft, header, 1, 3) == 3)
if (strncmp(header, "_1A", 3) == 0)
type = "sph";
}
else if (strncmp(header, "ALaw", 4) == 0)
{
if (sox_readbuf(ft, header, 1, 11) == 11)
if (strncmp(header, "SoundFile**", 11) == 0)
type = "wve";
}
else if (strncmp(header, "Ogg", 3) == 0)
type = "ogg";
else if (strncmp(header, "fLaC", 4) == 0)
type = "flac";
else if ((memcmp(header, "XAI\0", 4) == 0) ||
(memcmp(header, "XAJ\0", 4) == 0) ||
(memcmp(header, "XA\0\0", 4) == 0))
type = "xa";
} /* read 4-byte header */
/* If we didn't find type yet then start looking for file
* formats that the magic header is deeper in the file.
*/
if (type == NULL)
{
for (loop = 0; loop < 60; loop++)
if (sox_readbuf(ft, header, 1, 1) != 1)
break;
if (sox_readbuf(ft, header, 1, 4) == 4 &&
strncmp(header, "FSSD", 4) == 0)
{
for (loop = 0; loop < 62; loop++)
if (sox_readbuf(ft, header, 1, 1) != 1)
break;
if (sox_readbuf(ft, header, 1, 4) == 0 &&
strncmp(header, "HCOM", 4) == 0)
type = "hcom";
}
}
sox_rewind(ft);
if (type == NULL) {
if (prc_checkheader(ft, header))
type = "prc";
sox_rewind(ft);
}
} /* if (seekable) */
if (type == NULL)
{
/* Use filename extension to determine audio type. */
/* First, chop off any path portions of filename. This
* prevents the next search from considering that part. */
if ((type = strrchr(ft->filename, LASTCHAR)) == NULL)
type = ft->filename;
/* Now look for an filename extension */
if ((type = strrchr(type, '.')) != NULL)
type++;
else
type = NULL;
}
if (type == NULL)
{
sox_fail_errno(ft,SOX_EFMT, "Could not determine file type.");
return (SOX_EOF);
}
free(ft->filetype);
ft->filetype = strdup(type);
rc = sox_gettype(ft, sox_true); /* Change ft->h to the new format */
if(rc != SOX_SUCCESS)
{
sox_fail_errno(ft,SOX_EFMT,"Do not understand format type: %s",type);
return (rc);
}
sox_debug("Detected file format type: %s", type);
set_endianness_if_not_already_set(ft);
return (* ft->h->startread)(ft);
}
static int sox_autostartwrite(ft_t ft)
{
sox_fail_errno(ft,SOX_EFMT,"Type AUTO can only be used for input!");
return(SOX_EOF);
}
static const char *autonames[] = {
"auto",
NULL
};
static sox_format_t sox_auto_format = {
autonames,
NULL,
SOX_FILE_DEVICE | SOX_FILE_PHONY,
sox_autostartread,
sox_format_nothing_read_io,
sox_format_nothing,
sox_autostartwrite,
sox_format_nothing_write_io,
sox_format_nothing,
sox_format_nothing_seek
};
const sox_format_t *sox_auto_format_fn(void)
{
return &sox_auto_format;
}