/* * $Id$ * * Copyright (C) 2003 Ron Pedde (ron@pedde.com) * * 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 */ #ifdef HAVE_CONFIG_H # include "config.h" #endif #include #include #include #include #include #include "err.h" #include "mp3-scanner.h" #include "scan-aac.h" /* Forwards */ static time_t scan_aac_mac_to_unix_time(int t); /** * Convert mac time to unix time (different epochs) * * @param t time since mac epoch * @returns time since unix epoch */ time_t scan_aac_mac_to_unix_time(int t) { struct timeval tv; struct timezone tz; gettimeofday(&tv, &tz); return (t - (365L * 66L * 24L * 60L * 60L + 17L * 60L * 60L * 24L) + (tz.tz_minuteswest * 60)); } /** * Returns the offset of the atom specified by the given path or -1 if * not found. atom_path is a colon separated list of atoms specifying * a path from parent node to the target node. All paths must be specified * from the root. * * @param aac_fp the aac file being searched * @param atom_path the colon separated list of atoms * @param atom_length the size of the atom "drilled to" * @returns offset of the atom, or -1 if unsuccessful */ off_t scan_aac_drilltoatom(FILE *aac_fp,char *atom_path, unsigned int *atom_length) { long atom_offset; off_t file_size; char *cur_p, *end_p; char atom_name[5]; fseek(aac_fp, 0, SEEK_END); file_size = ftell(aac_fp); rewind(aac_fp); end_p = atom_path; while (*end_p != '\0') { end_p++; } atom_name[4] = '\0'; cur_p = atom_path; while (cur_p != NULL) { if ((end_p - cur_p) < 4) { return -1; } strncpy(atom_name, cur_p, 4); atom_offset = scan_aac_findatom(aac_fp, file_size, atom_name, atom_length); if (atom_offset == -1) { return -1; } DPRINTF(E_SPAM,L_SCAN,"Found %s atom at off %ld.\n", atom_name, ftell(aac_fp) - 8); cur_p = strchr(cur_p, ':'); if (cur_p != NULL) { cur_p++; /* FIXME * Hack to deal with atoms that have extra data in addition * to having child atoms. This should be dealt in a better fashion * than this (table with skip offsets or a real mp4 parser.) */ if (!strcmp(atom_name, "meta")) { fseek(aac_fp, 4, SEEK_CUR); } else if (!strcmp(atom_name, "stsd")) { fseek(aac_fp, 8, SEEK_CUR); } else if (!strcmp(atom_name, "mp4a")) { fseek(aac_fp, 28, SEEK_CUR); } } } return ftell(aac_fp) - 8; } /** * Given a file, search for a particular aac atom. * * @param fin file handle of the open aac file * @param max_offset how far to search (probably size of container atom) * @param which_atom what atom name we are searching for * @param atom_size this will hold the size of the atom found */ long scan_aac_findatom(FILE *fin, long max_offset, char *which_atom, unsigned int *atom_size) { long current_offset=0; int size; char atom[4]; while(current_offset < max_offset) { if(fread((void*)&size,1,sizeof(int),fin) != sizeof(int)) return -1; size=ntohl(size); if(size <= 7) /* something not right */ return -1; if(fread(atom,1,4,fin) != 4) return -1; if(strncasecmp(atom,which_atom,4) == 0) { *atom_size=size; return current_offset; } fseek(fin,size-8,SEEK_CUR); current_offset+=size; } return -1; } /** * main aac scanning routing. * * @param filename file to scan * @param pmp3 pointer to the MP3FILE to fill with data * @returns FALSE if file should not be added to database, TRUE otherwise */ int scan_get_aacinfo(char *filename, MP3FILE *pmp3) { FILE *fin; long atom_offset; unsigned int atom_length; long current_offset=0; int current_size; char current_atom[4]; char *current_data; unsigned short us_data; int genre; int len; int sample_size; int samples; unsigned int bit_rate; int ms; unsigned char buffer[2]; int time = 0; if(!(fin=fopen(filename,"rb"))) { DPRINTF(E_INF,L_SCAN,"Cannot open file %s for reading\n",filename); return FALSE; } fseek(fin,0,SEEK_END); pmp3->file_size = ftell(fin); fseek(fin,0,SEEK_SET); atom_offset=scan_aac_drilltoatom(fin, "moov:udta:meta:ilst", &atom_length); if(atom_offset != -1) { /* found the tag section - need to walk through now */ while(current_offset < atom_length) { if(fread((void*)¤t_size,1,sizeof(int),fin) != sizeof(int)) break; current_size=ntohl(current_size); if(current_size <= 7) /* something not right */ break; if(fread(current_atom,1,4,fin) != 4) break; len=current_size-7; /* for ill-formed too-short tags */ if(len < 22) len=22; current_data=(char*)malloc(len); /* extra byte */ memset(current_data,0x00,len); if(fread(current_data,1,current_size-8,fin) != current_size-8) break; if(!memcmp(current_atom,"\xA9" "nam",4)) { /* Song name */ pmp3->title=strdup((char*)¤t_data[16]); } else if(!memcmp(current_atom,"\xA9" "ART",4)) { pmp3->artist=strdup((char*)¤t_data[16]); } else if(!memcmp(current_atom,"\xA9" "alb",4)) { pmp3->album=strdup((char*)¤t_data[16]); } else if(!memcmp(current_atom,"\xA9" "cmt",4)) { pmp3->comment=strdup((char*)¤t_data[16]); } else if(!memcmp(current_atom,"\xA9" "wrt",4)) { pmp3->composer=strdup((char*)¤t_data[16]); } else if(!memcmp(current_atom,"\xA9" "grp",4)) { pmp3->grouping=strdup((char*)¤t_data[16]); } else if(!memcmp(current_atom,"\xA9" "gen",4)) { /* can this be a winamp genre??? */ pmp3->genre=strdup((char*)¤t_data[16]); } else if(!memcmp(current_atom,"tmpo",4)) { us_data=*((unsigned short *)¤t_data[16]); us_data=ntohs(us_data); pmp3->bpm=us_data; } else if(!memcmp(current_atom,"trkn",4)) { us_data=*((unsigned short *)¤t_data[18]); us_data=ntohs(us_data); pmp3->track=us_data; us_data=*((unsigned short *)¤t_data[20]); us_data=ntohs(us_data); pmp3->total_tracks=us_data; } else if(!memcmp(current_atom,"disk",4)) { us_data=*((unsigned short *)¤t_data[18]); us_data=ntohs(us_data); pmp3->disc=us_data; us_data=*((unsigned short *)¤t_data[20]); us_data=ntohs(us_data); pmp3->total_discs=us_data; } else if(!memcmp(current_atom,"\xA9" "day",4)) { pmp3->year=atoi((char*)¤t_data[16]); } else if(!memcmp(current_atom,"gnre",4)) { genre=(int)(*((char*)¤t_data[17])); genre--; if((genre < 0) || (genre > WINAMP_GENRE_UNKNOWN)) genre=WINAMP_GENRE_UNKNOWN; pmp3->genre=strdup(scan_winamp_genre[genre]); } else if (!memcmp(current_atom, "cpil", 4)) { pmp3->compilation = current_data[16]; } free(current_data); current_offset+=current_size; } } /* got the tag info, now let's get bitrate, etc */ atom_offset = scan_aac_drilltoatom(fin, "moov:mvhd", &atom_length); if(atom_offset != -1) { fseek(fin, 4, SEEK_CUR); fread((void *)&time, sizeof(int), 1, fin); time = ntohl(time); pmp3->time_added = scan_aac_mac_to_unix_time(time); fread((void *)&time, sizeof(int), 1, fin); time = ntohl(time); pmp3->time_modified = scan_aac_mac_to_unix_time(time); fread((void*)&sample_size,1,sizeof(int),fin); fread((void*)&samples,1,sizeof(int),fin); sample_size=ntohl(sample_size); samples=ntohl(samples); /* avoid overflowing on large sample_sizes (90000) */ ms=1000; while((ms > 9) && (!(sample_size % 10))) { sample_size /= 10; ms /= 10; } /* DWB: use ms time instead of sec */ pmp3->song_length=(int)((samples * ms) / sample_size); DPRINTF(E_DBG,L_SCAN,"Song length: %d seconds\n", pmp3->song_length / 1000); } pmp3->bitrate = 0; /* see if it is aac or alac */ atom_offset = scan_aac_drilltoatom(fin, "moov:trak:mdia:minf:stbl:stsd:alac", &atom_length); if(atom_offset != -1) { /* should we still pull samplerate, etc from the this atom? */ if(pmp3->codectype) { free(pmp3->codectype); } pmp3->codectype=strdup("alac"); } /* Get the sample rate from the 'mp4a' atom (timescale). This is also found in the 'mdhd' atom which is a bit closer but we need to navigate to the 'mp4a' atom anyways to get to the 'esds' atom. */ atom_offset=scan_aac_drilltoatom(fin, "moov:trak:mdia:minf:stbl:stsd:mp4a", &atom_length); if (atom_offset != -1) { fseek(fin, atom_offset + 32, SEEK_SET); /* Timescale here seems to be 2 bytes here (the 2 bytes before it are * "reserved") though the timescale in the 'mdhd' atom is 4. Not sure * how this is dealt with when sample rate goes higher than 64K. */ fread(buffer, sizeof(unsigned char), 2, fin); pmp3->samplerate = (buffer[0] << 8) | (buffer[1]); /* Seek to end of atom. */ fseek(fin, 2, SEEK_CUR); /* Get the bit rate from the 'esds' atom. We are already positioned in the parent atom so just scan ahead. */ atom_offset = scan_aac_findatom(fin, atom_length-(ftell(fin)-atom_offset), "esds", &atom_length); if (atom_offset != -1) { /* Roku Soundbridge seems to believe anything above 320K is * an ALAC encoded m4a. We'll lie on their behalf. */ fseek(fin, atom_offset + 22, SEEK_CUR); fread((void *)&bit_rate, sizeof(unsigned int), 1, fin); pmp3->bitrate = ntohl(bit_rate) / 1000; DPRINTF(E_DBG,L_SCAN,"esds bitrate: %d\n",pmp3->bitrate); if(pmp3->bitrate > 320) { pmp3->bitrate = 320; } } else { DPRINTF(E_DBG,L_SCAN, "Couldn't find 'esds' atom for bit rate.\n"); } } else { DPRINTF(E_DBG,L_SCAN, "Couldn't find 'mp4a' atom for sample rate.\n"); } /* Fallback if we can't find the info in the atoms. */ if (pmp3->bitrate == 0) { /* calculate bitrate from song length... Kinda cheesy */ DPRINTF(E_DBG,L_SCAN, "Guesstimating bit rate.\n"); atom_offset=scan_aac_drilltoatom(fin,"mdat",&atom_length); if ((atom_offset != -1) && (pmp3->song_length)) { pmp3->bitrate = atom_length / ((pmp3->song_length / 1000) * 128); } } fclose(fin); return TRUE; /* we'll return as much as we got. */ }