ref: fadd72c4bb4c3ca41eeefadece1f399b534a81ed
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 "st_i.h" #include <string.h> #if defined(DOS) || defined(WIN32) #define LASTCHAR '\\' #else #define LASTCHAR '/' #endif static int st_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 (st_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 (st_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 (st_readbuf(ft, header, 1, 8) == 8) if (strncmp(header + 4, "WAVE", 4) == 0) type = "wav"; } else if (strncmp(header, "Crea", 4) == 0) { if (st_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 (st_readbuf(ft, header, 1, 1) == 1 && *header == 'D') { /* Once we've found SOUND see if its smp or sndt */ if (st_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 (st_readbuf(ft, header, 1, 3) == 3) if (strncmp(header, "_1A", 3) == 0) type = "sph"; } else if (strncmp(header, "ALaw", 4) == 0) { if (st_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 (st_readbuf(ft, header, 1, 1) != 1) break; if (st_readbuf(ft, header, 1, 4) == 4 && strncmp(header, "FSSD", 4) == 0) { for (loop = 0; loop < 62; loop++) if (st_readbuf(ft, header, 1, 1) != 1) break; if (st_readbuf(ft, header, 1, 4) == 0 && strncmp(header, "HCOM", 4) == 0) type = "hcom"; } } st_rewind(ft); if (type == NULL) { if (prc_checkheader(ft, header)) type = "prc"; st_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) { st_fail_errno(ft,ST_EFMT, "Could not determine file type."); return (ST_EOF); } free(ft->filetype); ft->filetype = strdup(type); rc = st_gettype(ft, st_true); /* Change ft->h to the new format */ if(rc != ST_SUCCESS) { st_fail_errno(ft,ST_EFMT,"Do not understand format type: %s",type); return (rc); } st_debug("Detected file format type: %s", type); set_endianness_if_not_already_set(ft); return (* ft->h->startread)(ft); } static int st_autostartwrite(ft_t ft) { st_fail_errno(ft,ST_EFMT,"Type AUTO can only be used for input!"); return(ST_EOF); } static const char *autonames[] = { "auto", NULL }; static st_format_t st_auto_format = { autonames, NULL, ST_FILE_DEVICE | ST_FILE_PHONY, st_autostartread, st_format_nothing_read_io, st_format_nothing, st_autostartwrite, st_format_nothing_write_io, st_format_nothing, st_format_nothing_seek }; const st_format_t *st_auto_format_fn(void) { return &st_auto_format; }