apps/metadata/metadata_common.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2005 Dave Chapman
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21 #include <stdio.h>
  22 #include "string-extra.h"
  23 #include <stdlib.h>
  24 #include <ctype.h>
  25 #include <inttypes.h>
  26
  27 #include "system.h"
  28 #include "metadata.h"
  29 #include "metadata_common.h"
  30 #include "metadata_parsers.h"
  31 #include "replaygain.h"
  32 #include "misc.h"
  33
  34 /* Read a string from the file. Read up to size bytes, or, if eos != -1,
  35  * until the eos character is found (eos is not stored in buf, unless it is
  36  * nil). Writes up to buf_size chars to buf, always terminating with a nil.
  37  * Returns number of chars read or -1 on read error.
  38  */
  39 long read_string(int fd, char* buf, long buf_size, int eos, long size)
  40 {
  41     long read_bytes = 0;
  42     char c;
  43
  44     while (size != 0)
  45     {
  46         if (read(fd, &c, 1) != 1)
  47         {
  48             read_bytes = -1;
  49             break;
  50         }
  51
  52         read_bytes++;
  53         size--;
  54
  55         if ((eos != -1) && (eos == (unsigned char) c))
  56         {
  57             break;
  58         }
  59
  60         if (buf_size > 1)
  61         {
  62             *buf++ = c;
  63             buf_size--;
  64         }
  65     }
  66
  67     *buf = 0;
  68     return read_bytes;
  69 }
  70 /* Read an unsigned 8-bit integer from a file. */
  71 int read_uint8(int fd, uint8_t* buf)
  72 {
  73   size_t n;
  74
  75   n = read(fd, (char*) buf, 1);
  76   return n;
  77 }
  78
  79 #ifdef ROCKBOX_LITTLE_ENDIAN
  80 /* Read an unsigned 16-bit integer from a big-endian file. */
  81 int read_uint16be(int fd, uint16_t* buf)
  82 {
  83   size_t n;
  84
  85   n = read(fd, (char*) buf, 2);
  86   *buf = betoh16(*buf);
  87   return n;
  88 }
  89 /* Read an unsigned 32-bit integer from a big-endian file. */
  90 int read_uint32be(int fd, uint32_t* buf)
  91 {
  92   size_t n;
  93
  94   n = read(fd, (char*) buf, 4);
  95   *buf = betoh32(*buf);
  96   return n;
  97 }
  98 /* Read an unsigned 64-bit integer from a big-endian file. */
  99 int read_uint64be(int fd, uint64_t* buf)
 100 {
 101   size_t n;
 102   uint8_t data[8];
 103   int i;
 104
 105   n = read(fd, data, 8);
 106
 107   for (i=0, *buf=0; i<=7; i++) {
 108        *buf <<= 8;
 109        *buf |= data[i];
 110   }
 111   return n;
 112 }
 113 #else
 114 /* Read unsigned integers from a little-endian file. */
 115 int read_uint16le(int fd, uint16_t* buf)
 116 {
 117   size_t n;
 118
 119   n = read(fd, (char*) buf, 2);
 120   *buf = letoh16(*buf);
 121   return n;
 122 }
 123 int read_uint32le(int fd, uint32_t* buf)
 124 {
 125   size_t n;
 126
 127   n = read(fd, (char*) buf, 4);
 128   *buf = letoh32(*buf);
 129   return n;
 130 }
 131 int read_uint64le(int fd, uint64_t* buf)
 132 {
 133   size_t n;
 134   uint8_t data[8];
 135   int i;
 136
 137   n = read(fd, data, 8);
 138
 139   for (i=7, *buf=0; i>=0; i--) {
 140        *buf <<= 8;
 141        *buf |= data[i];
 142   }
 143
 144   return n;
 145 }
 146 #endif
 147
 148 /* Read an unaligned 64-bit little endian unsigned integer from buffer. */
 149 uint64_t get_uint64_le(void* buf)
 150 {
 151     unsigned char* p = (unsigned char*) buf;
 152
 153     return p[0] | (p[1] << 8)  | (p[2] << 16) | (p[3] << 24) | ((uint64_t)p[4] << 32) |
 154                   ((uint64_t)p[5] << 40) | ((uint64_t)p[6] << 48) | ((uint64_t)p[7] << 56);
 155 }
 156
 157 /* Read an unaligned 32-bit little endian long from buffer. */
 158 unsigned long get_long_le(void* buf)
 159 {
 160     unsigned char* p = (unsigned char*) buf;
 161
 162     return p[0] | (p[1] << 8) | (p[2] << 16) | (p[3] << 24);
 163 }
 164
 165 /* Read an unaligned 16-bit little endian short from buffer. */
 166 unsigned short get_short_le(void* buf)
 167 {
 168     unsigned char* p = (unsigned char*) buf;
 169
 170     return p[0] | (p[1] << 8);
 171 }
 172
 173 /* Read an unaligned 32-bit big endian long from buffer. */
 174 unsigned long get_long_be(void* buf)
 175 {
 176     unsigned char* p = (unsigned char*) buf;
 177
 178     return (p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3];
 179 }
 180
 181 /* Read an unaligned 32-bit little endian long from buffer. */
 182 long get_slong(void* buf)
 183 {
 184     unsigned char* p = (unsigned char*) buf;
 185
 186     return p[0] | (p[1] << 8) | (p[2] << 16) | (p[3] << 24);
 187 }
 188
 189 unsigned long get_itunes_int32(char* value, int count)
 190 {
 191     static const char hexdigits[] = "0123456789ABCDEF";
 192     const char* c;
 193     int r = 0;
 194
 195     while (count-- > 0)
 196     {
 197         value = skip_whitespace(value);
 198
 199         while (*value && !isspace(*value))
 200         {
 201             value++;
 202         }
 203     }
 204
 205     value = skip_whitespace(value);
 206
 207     while (*value && ((c = strchr(hexdigits, toupper(*value))) != NULL))
 208     {
 209         r = (r << 4) | (c - hexdigits);
 210         value++;
 211     }
 212
 213     return r;
 214 }
 215
 216 #if CONFIG_CODEC == SWCODEC
 217 /* Skip an ID3v2 tag if it can be found. We assume the tag is located at the
 218  * start of the file, which should be true in all cases where we need to skip it.
 219  * Returns true if successfully skipped or not skipped, and false if
 220  * something went wrong while skipping.
 221  */
 222 bool skip_id3v2(int fd, struct mp3entry *id3)
 223 {
 224     char buf[4];
 225
 226     read(fd, buf, 4);
 227     if (memcmp(buf, "ID3", 3) == 0)
 228     {
 229         /* We have found an ID3v2 tag at the start of the file - find its
 230            length and then skip it. */
 231         if ((id3->first_frame_offset = getid3v2len(fd)) == 0)
 232             return false;
 233
 234         if ((lseek(fd, id3->first_frame_offset, SEEK_SET) < 0))
 235             return false;
 236
 237         return true;
 238     } else {
 239         lseek(fd, 0, SEEK_SET);
 240         id3->first_frame_offset = 0;
 241         return true;
 242     }
 243 }
 244
 245 /* Parse the tag (the name-value pair) and fill id3 and buffer accordingly.
 246  * String values to keep are written to buf. Returns number of bytes written
 247  * to buf (including end nil).
 248  */
 249 long parse_tag(const char* name, char* value, struct mp3entry* id3,
 250     char* buf, long buf_remaining, enum tagtype type)
 251 {
 252     long len = 0;
 253     char** p;
 254
 255     if ((((strcasecmp(name, "track") == 0) && (type == TAGTYPE_APE)))
 256         || ((strcasecmp(name, "tracknumber") == 0) && (type == TAGTYPE_VORBIS)))
 257     {
 258         id3->tracknum = atoi(value);
 259         p = &(id3->track_string);
 260     }
 261     else if (strcasecmp(name, "discnumber") == 0 || strcasecmp(name, "disc") == 0)
 262     {
 263         id3->discnum = atoi(value);
 264         p = &(id3->disc_string);
 265     }
 266     else if (((strcasecmp(name, "year") == 0) && (type == TAGTYPE_APE))
 267         || ((strcasecmp(name, "date") == 0) && (type == TAGTYPE_VORBIS)))
 268     {
 269         /* Date's can be in any format in Vorbis. However most of them
 270          * are in ISO8601 format so if we try and parse the first part
 271          * of the tag as a number, we should get the year. If we get crap,
 272          * then act like we never parsed it.
 273          */
 274         id3->year = atoi(value);
 275         if (id3->year < 1900)
 276         { /* yeah, not likely */
 277             id3->year = 0;
 278         }
 279         p = &(id3->year_string);
 280     }
 281     else if (strcasecmp(name, "title") == 0)
 282     {
 283         p = &(id3->title);
 284     }
 285     else if (strcasecmp(name, "artist") == 0)
 286     {
 287         p = &(id3->artist);
 288     }
 289     else if (strcasecmp(name, "album") == 0)
 290     {
 291         p = &(id3->album);
 292     }
 293     else if (strcasecmp(name, "genre") == 0)
 294     {
 295         p = &(id3->genre_string);
 296     }
 297     else if (strcasecmp(name, "composer") == 0)
 298     {
 299         p = &(id3->composer);
 300     }
 301     else if (strcasecmp(name, "comment") == 0)
 302     {
 303         p = &(id3->comment);
 304     }
 305     else if (strcasecmp(name, "albumartist") == 0)
 306     {
 307         p = &(id3->albumartist);
 308     }
 309     else if (strcasecmp(name, "album artist") == 0)
 310     {
 311         p = &(id3->albumartist);
 312     }
 313     else if (strcasecmp(name, "ensemble") == 0)
 314     {
 315         p = &(id3->albumartist);
 316     }
 317     else if (strcasecmp(name, "grouping") == 0)
 318     {
 319         p = &(id3->grouping);
 320     }
 321     else if (strcasecmp(name, "content group") == 0)
 322     {
 323         p = &(id3->grouping);
 324     }
 325     else if (strcasecmp(name, "contentgroup") == 0)
 326     {
 327         p = &(id3->grouping);
 328     }
 329     else if (strcasecmp(name, "musicbrainz_trackid") == 0
 330         || strcasecmp(name, "http://musicbrainz.org") == 0 )
 331     {
 332         p = &(id3->mb_track_id);
 333     }
 334     else
 335     {
 336         parse_replaygain(name, value, id3);
 337         p = NULL;
 338     }
 339
 340     /* Do not overwrite already available metadata. Especially when reading
 341      * tags with e.g. multiple genres / artists. This way only the first
 342      * of multiple entries is used, all following are dropped. */
 343     if (p!=NULL && *p==NULL)
 344     {
 345         len = strlen(value);
 346         len = MIN(len, buf_remaining - 1);
 347         len = MIN(len, ID3V2_MAX_ITEM_SIZE); /* Limit max. item size. */
 348
 349         if (len > 0)
 350         {
 351             len++;
 352             strlcpy(buf, value, len);
 353             *p = buf;
 354         }
 355         else
 356         {
 357             len = 0;
 358         }
 359     }
 360
 361     return len;
 362 }
 363 #endif