ref: 28aa893ed1c280992d6fadb949db5d2221d91a48
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 int st_autostartread(ft_t ft) { char *type; char header[20]; int rc; int loop; type = 0; /* 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_read(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_read(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_read(ft, header, 1, 8) == 8) { if (strncmp(header + 4, "WAVE", 4) == 0) type = "wav"; } } else if (strncmp(header, "Crea", 4) == 0) { if (st_read(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_read(ft, header, 1, 1) == 1 && *header == 'D') { /* Once we've found SOUND see if its smp or sndt */ if (st_read(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_read(ft, header, 1, 3) == 3) { if (strncmp(header, "_1A", 3) == 0) type = "sph"; } } else if (strncmp(header, "ALaw", 4) == 0) { if (st_read(ft, header, 1, 11) == 11) { if (strncmp(header, "SoundFile**", 11) == 0) { type = "wve"; } } } else if (strncmp(header, "Ogg", 3) == 0) { type = "ogg"; } } /* 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 == 0) { loop = 61; while (loop--) { if (st_read(ft, header, 1, 1) != 1) loop = 0; } if (st_read(ft, header, 1, 4) == 4 && strncmp(header, "FSSD", 4) == 0) { loop = 63; while (loop--) { if (st_read(ft, header, 1, 1) != 1) loop = 0; } if (st_read(ft, header, 1, 4) == 0 && strncmp(header, "HCOM", 4) == 0) type = "hcom"; } } st_rewind(ft); } /* if (seekable) */ if (type == 0) { /* 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; } ft->filetype = type; rc = st_gettype(ft); /* Change ft->h to the new format */ if(rc != ST_SUCCESS) { st_fail_errno(ft,ST_EFMT,"Do not understand format type: %s\n",type); return (rc); } st_report("Detected file format type: %s\n", type); return ((* ft->h->startread)(ft)); } int st_autostartwrite(ft_t ft) { st_fail_errno(ft,ST_EFMT,"Type AUTO can only be used for input!"); return(ST_EOF); }