/*************************************************************************** * __________ __ ___. * Open \______ \ ____ ____ | | _\_ |__ _______ ___ * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ * \/ \/ \/ \/ \/ * $Id$ * * Copyright (C) 2002 by Daniel Stenberg * * All files in this archive are subject to the GNU General Public License. * See the file COPYING in the source tree root for full license agreement. * * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY * KIND, either express or implied. * ****************************************************************************/ /* * Parts of this code has been stolen from the Ample project and was written * by David Härdeman. It has since been extended and enhanced pretty much by * all sorts of friendly Rockbox people. * * A nice reference for MPEG header info: * http://rockbox.haxx.se/docs/mpeghdr.html * */ #include #include #include #include #include #include "file.h" #include "debug.h" #include "atoi.h" #include "id3.h" /* Some utility macros used in getsonglength() */ #define BYTE0(x) ((x >> 24) & 0xFF) #define BYTE1(x) ((x >> 16) & 0xFF) #define BYTE2(x) ((x >> 8) & 0xFF) #define BYTE3(x) ((x >> 0) & 0xFF) #define UNSYNC(b1,b2,b3,b4) (((b1 & 0x7F) << (3*7)) | \ ((b2 & 0x7F) << (2*7)) | \ ((b3 & 0x7F) << (1*7)) | \ ((b4 & 0x7F) << (0*7))) /* Table of bitrates for MP3 files, all values in kilo. * Indexed by version, layer and value of bit 15-12 in header. */ const int bitrate_table[2][3][16] = { { {0,32,64,96,128,160,192,224,256,288,320,352,384,416,448,0}, {0,32,48,56, 64,80, 96, 112,128,160,192,224,256,320,384,0}, {0,32,40,48, 56,64, 80, 96, 112,128,160,192,224,256,320,0} }, { {0,32,48,56,64,80,96,112,128,144,160,176,192,224,256,0}, {0, 8,16,24,32,40,48, 56, 64, 80, 96,112,128,144,160,0}, {0, 8,16,24,32,40,48, 56, 64, 80, 96,112,128,144,160,0} } }; /* Table of samples per frame for MP3 files. * Indexed by layer. Multiplied with 1000. */ const int bs[4] = {0, 384000, 1152000, 1152000}; /* Table of sample frequency for MP3 files. * Indexed by version and layer. */ const int freqtab[][4] = { {11025, 12000, 8000, 0}, /* MPEG version 2.5 */ {44100, 48000, 32000, 0}, /* MPEG Version 1 */ {22050, 24000, 16000, 0}, /* MPEG version 2 */ }; /* * Removes trailing spaces from a string. * * Arguments: buffer - the string to process * * Returns: void */ static void stripspaces(char *buffer) { int i = 0; while(*(buffer + i) != '\0') i++; for(;i >= 0; i--) { if(*(buffer + i) == ' ') *(buffer + i) = '\0'; else if(*(buffer + i) == '\0') continue; else break; } } /* * Sets the title of an MP3 entry based on its ID3v1 tag. * * Arguments: file - the MP3 file to scen for a ID3v1 tag * entry - the entry to set the title in * * Returns: true if a title was found and created, else false */ static bool setid3v1title(int fd, struct mp3entry *entry) { char buffer[31]; int offsets[3] = {-95,-65,-125}; int i; for(i=0;i<3;i++) { if(-1 == lseek(fd, offsets[i], SEEK_END)) return false; buffer[30]=0; read(fd, buffer, 30); stripspaces(buffer); if(buffer[0]) { switch(i) { case 0: strcpy(entry->id3v1buf[0], buffer); entry->artist = entry->id3v1buf[0]; break; case 1: strcpy(entry->id3v1buf[1], buffer); entry->album = entry->id3v1buf[1]; break; case 2: strcpy(entry->id3v1buf[2], buffer); entry->title = entry->id3v1buf[2]; break; } } } return true; } /* * Sets the title of an MP3 entry based on its ID3v2 tag. * * Arguments: file - the MP3 file to scen for a ID3v2 tag * entry - the entry to set the title in * * Returns: true if a title was found and created, else false */ static void setid3v2title(int fd, struct mp3entry *entry) { int minframesize; int size; int readsize = 0, headerlen; char *title = NULL; char *artist = NULL; char *album = NULL; char *tracknum = NULL; char header[10]; unsigned short int version; int titlen=0, artistn=0, albumn=0, tracknumn=0; char *buffer = entry->id3v2buf; /* 10 = headerlength */ if(entry->id3v2len < 10) return; /* Check version */ lseek(fd, 0, SEEK_SET); if(10 != read(fd, header, 10)) return; version = (unsigned short int)header[3]; /* Read all frames in the tag */ size = entry->id3v2len - 10; if(size >= (int)sizeof(entry->id3v2buf)) size = sizeof(entry->id3v2buf)-1; if(size != read(fd, buffer, size)) return; *(buffer + size) = '\0'; /* Set minimum frame size according to ID3v2 version */ if(version > 2) minframesize = 12; else minframesize = 8; /* * We must have at least minframesize bytes left for the * remaining frames to be interesting */ while(size - readsize > minframesize) { /* Read frame header and check length */ if(version > 2) { memcpy(header, (buffer + readsize), 10); readsize += 10; headerlen = UNSYNC(header[4], header[5], header[6], header[7]); } else { memcpy(header, (buffer + readsize), 6); readsize += 6; headerlen = (header[3] << 16) + (header[4] << 8) + (header[5]); } /* Continue if the frame length seems bad */ if(headerlen > size) continue; /* Check for certain frame headers */ if(!strncmp(header, "TPE1", strlen("TPE1")) || !strncmp(header, "TP1", strlen("TP1"))) { readsize++; headerlen--; if(headerlen > (size - readsize)) headerlen = (size - readsize); artist = buffer + readsize; artistn = headerlen; readsize += headerlen; } else if(!strncmp(header, "TIT2", strlen("TIT2")) || !strncmp(header, "TT2", strlen("TT2"))) { readsize++; headerlen--; if(headerlen > (size - readsize)) headerlen = (size - readsize); title = buffer + readsize; titlen = headerlen; readsize += headerlen; } else if(!strncmp(header, "TALB", strlen("TALB"))) { readsize++; headerlen--; if(headerlen > (size - readsize)) headerlen = (size - readsize); album = buffer + readsize; albumn = headerlen; readsize += headerlen; } else if(!strncmp(header, "TRCK", strlen("TRCK"))) { readsize++; headerlen--; if(headerlen > (size - readsize)) headerlen = (size - readsize); tracknum = buffer + readsize; tracknumn = headerlen; readsize += headerlen; } else { readsize += headerlen; } } if(artist) { entry->artist = artist; artist[artistn]=0; } if(title) { entry->title = title; title[titlen]=0; } if(album) { entry->album = album; album[albumn]=0; } if(tracknum) { tracknum[tracknumn] = 0; entry->tracknum = atoi(tracknum); } } /* * Calculates the size of the ID3v2 tag. * * Arguments: file - the file to search for a tag. * * Returns: the size of the tag or 0 if none was found */ static int getid3v2len(int fd) { char buf[6]; int offset; /* Make sure file has a ID3 tag */ if((-1 == lseek(fd, 0, SEEK_SET)) || (read(fd, buf, 6) != 6) || (strncmp(buf, "ID3", strlen("ID3")) != 0)) offset = 0; /* Now check what the ID3v2 size field says */ else if(read(fd, buf, 4) != 4) offset = 0; else offset = UNSYNC(buf[0], buf[1], buf[2], buf[3]) + 10; return offset; } static int getfilesize(int fd) { int size; /* seek to the end of it */ size = lseek(fd, 0, SEEK_END); if(-1 == size) return 0; /* unknown */ return size; } /* * Calculates the size of the ID3v1 tag. * * Arguments: file - the file to search for a tag. * * Returns: the size of the tag or 0 if none was found */ static int getid3v1len(int fd) { char buf[3]; int offset; /* Check if we find "TAG" 128 bytes from EOF */ if((lseek(fd, -128, SEEK_END) == -1) || (read(fd, buf, 3) != 3) || (strncmp(buf, "TAG", 3) != 0)) offset = 0; else offset = 128; return offset; } /* check if 'head' is a valid mp3 frame header */ static bool mp3frameheader(unsigned long head) { if ((head & 0xffe00000) != 0xffe00000) /* bad sync? */ return false; if (!((head >> 17) & 3)) /* no layer? */ return false; if (((head >> 12) & 0xf) == 0xf) /* bad bitrate? */ return false; if (!((head >> 12) & 0xf)) /* no bitrate? */ return false; if (((head >> 10) & 0x3) == 0x3) /* bad sample rate? */ return false; if (((head >> 19) & 1) == 1 && ((head >> 17) & 3) == 3 && ((head >> 16) & 1) == 1) return false; if ((head & 0xffff0000) == 0xfffe0000) return false; return true; } /* * Calculates the length (in milliseconds) of an MP3 file. * * Modified to only use integers. * * Arguments: file - the file to calculate the length upon * entry - the entry to update with the length * * Returns: the song length in milliseconds, * 0 means that it couldn't be calculated */ static int getsonglength(int fd, struct mp3entry *entry) { unsigned int filetime = 0; unsigned long header=0; unsigned char tmp; unsigned char frame[156]; unsigned char* xing; enum { MPEG_VERSION2_5, MPEG_VERSION1, MPEG_VERSION2 } version; int layer; int bitindex; int bitrate; int freqindex; int frequency; int chmode; int bytecount; int bittable; /* which bitrate table to use */ long bpf; long tpf; /* Start searching after ID3v2 header */ if(-1 == lseek(fd, entry->id3v2len, SEEK_SET)) return 0; /* Fill up header with first 24 bits */ for(version = 0; version < 3; version++) { header <<= 8; if(!read(fd, &tmp, 1)) return 0; header |= tmp; } /* Loop trough file until we find a frame header */ bytecount = 0; restart: do { header <<= 8; if(!read(fd, &tmp, 1)) return 0; header |= tmp; /* Quit if we haven't found a valid header within 128K */ bytecount++; if(bytecount > 0x20000) return 0; } while(!mp3frameheader(header)); /* * Some files are filled with garbage in the beginning, * if the bitrate index of the header is binary 1111 * that is a good indicator */ if((header & 0xF000) == 0xF000) goto restart; #ifdef DEBUG_VERBOSE fprintf(stderr, "We found %x-%x-%x-%x and checksync %i and test %x\n", BYTE0(header), BYTE1(header), BYTE2(header), BYTE3(header), CHECKSYNC(header), (header & 0xF000) == 0xF000); #endif /* MPEG Audio Version */ switch((header & 0x180000) >> 19) { case 0: /* MPEG version 2.5 is not an official standard */ version = MPEG_VERSION2_5; bittable = MPEG_VERSION2; /* use the V2 bit rate table */ break; case 2: /* MPEG version 2 (ISO/IEC 13818-3) */ version = MPEG_VERSION2; bittable = MPEG_VERSION2; break; case 3: /* MPEG version 1 (ISO/IEC 11172-3) */ version = MPEG_VERSION1; bittable = MPEG_VERSION1; break; default: goto restart; } /* Layer */ switch((header & 0x060000) >> 17) { case 1: layer = 3; break; case 2: layer = 2; break; case 3: layer = 1; break; default: goto restart; } /* Bitrate */ bitindex = (header & 0xF000) >> 12; bitrate = bitrate_table[bittable-1][layer-1][bitindex]; if(bitrate == 0) goto restart; /* Sampling frequency */ freqindex = (header & 0x0C00) >> 10; frequency = freqtab[version][freqindex]; if(frequency == 0) goto restart; #ifdef DEBUG_VERBOSE DEBUGF( "Version %i, lay %i, biti %i, bitr %i, freqi %i, freq %i, chmode %d\n", version, layer, bitindex, bitrate, freqindex, frequency, chmode); #endif entry->version = version; entry->layer = layer; entry->frequency = frequency; /* Calculate bytes per frame, calculation depends on layer */ switch(layer) { case 1: bpf = bitrate_table[bittable - 1][layer - 1][bitindex]; bpf *= 48000; bpf /= freqtab[version][freqindex] << (bittable - 1); break; case 2: case 3: bpf = bitrate_table[bittable - 1][layer - 1][bitindex]; bpf *= 144000; bpf /= freqtab[version][freqindex] << (bittable - 1); break; default: bpf = 1; } /* Calculate time per frame */ tpf = bs[layer] / (freqtab[version][freqindex] << (bittable - 1)); entry->bpf = bpf; entry->tpf = tpf; /* OK, we have found a frame. Let's see if it has a Xing header */ if(read(fd, frame, sizeof frame) < 0) return -1; /* Channel mode (stereo/mono) */ chmode = (header & 0xc0) >> 6; /* calculate position of Xing VBR header */ if ( version == 1 ) { if ( chmode == 3 ) /* mono */ xing = frame + 17; else xing = frame + 32; } else { if ( chmode == 3 ) /* mono */ xing = frame + 9; else xing = frame + 17; } if (xing[0] == 'X' && xing[1] == 'i' && xing[2] == 'n' && xing[3] == 'g') { /* Yes, it is a VBR file */ entry->vbr = true; entry->vbrflags = xing[7]; if (entry->vbrflags & VBR_FRAMES_FLAG) /* Is the frame count there? */ { int framecount = (xing[8] << 24) | (xing[9] << 16) | (xing[10] << 8) | xing[11]; filetime = framecount * tpf; } if (entry->vbrflags & VBR_BYTES_FLAG) /* is byte count there? */ { int bytecount = (xing[12] << 24) | (xing[13] << 16) | (xing[14] << 8) | xing[15]; bitrate = bytecount * 8 / filetime; } if (entry->vbrflags & VBR_TOC_FLAG) /* is table-of-contents there? */ { memcpy( entry->toc, xing+16, 100 ); } } entry->bitrate = bitrate; /* If the file time hasn't been established, this may be a fixed rate MP3, so just use the default formula */ if(filetime == 0) { /* * Now song length is * ((filesize)/(bytes per frame))*(time per frame) */ filetime = entry->filesize/bpf*tpf; } return filetime; } /* * Checks all relevant information (such as ID3v1 tag, ID3v2 tag, length etc) * about an MP3 file and updates it's entry accordingly. * * Arguments: entry - the entry to check and update with the new information * * Returns: void */ bool mp3info(struct mp3entry *entry, char *filename) { int fd; fd = open(filename, O_RDONLY); if(-1 == fd) return true; memset(entry, 0, sizeof(struct mp3entry)); strncpy(entry->path, filename, sizeof(entry->path)); entry->title = NULL; entry->filesize = getfilesize(fd); entry->id3v2len = getid3v2len(fd); entry->tracknum = 0; if ( entry->id3v2len && entry->id3v2len <= sizeof( entry->id3v2buf ) ) setid3v2title(fd, entry); entry->length = getsonglength(fd, entry); entry->id3v1len = getid3v1len(fd); if(entry->id3v1len && !entry->title) setid3v1title(fd, entry); close(fd); if(!entry->length || (entry->filesize < 8 )) /* no song length or less than 8 bytes is hereby considered to be an invalid mp3 and won't be played by us! */ return true; return false; } #ifdef DEBUG_STANDALONE char *secs2str(int ms) { static char buffer[32]; int secs = ms/1000; ms %= 1000; snprintf(buffer, sizeof(buffer), "%d:%02d.%d", secs/60, secs%60, ms/100); return buffer; } int main(int argc, char **argv) { int i; for(i=1; i", mp3.artist?mp3.artist:"", mp3.album?mp3.album:"", secs2str(mp3.length), mp3.length/1000, mp3.bitrate, mp3.frequency); } return 0; } #endif /* ----------------------------------------------------------------- * local variables: * eval: (load-file "rockbox-mode.el") * end: */