+static int atom_cmp(const unsigned char *buf1, const char *buf2)
+{
+ const unsigned char *b2 = (unsigned char *)buf2;
+
+ if (buf1[0] != b2[0])
+ return 1;
+ if (buf1[1] != b2[1])
+ return 1;
+ if (buf1[2] != b2[2])
+ return 1;
+ if (buf1[3] != b2[3])
+ return 1;
+ return 0;
+}
+
+static int read_atom_header(unsigned char *buf, uint64_t *subsize, unsigned char type[5])
+{
+ int i;
+ uint64_t size = (buf[0] << 24) + (buf[1] << 16) + (buf[2] << 8) + buf[3];
+
+ memcpy(type, buf + 4, 4);
+ type[4] = '\0';
+
+ PARA_DEBUG_LOG("size: %llu, type: %s\n", (long long unsigned)size, type);
+ if (size != 1) {
+ *subsize = size;
+ return 8;
+ }
+ buf += 4;
+ size = 0;
+ for (i = 0; i < 8; i++)
+ size |= ((uint64_t)buf[i]) << ((7 - i) * 8);
+ *subsize = size;
+ return 16;
+}
+
+static char *get_tag(unsigned char *p, int size)
+{
+ char *buf;
+
+ assert(size > 0);
+ buf = para_malloc(size + 1);
+
+ memcpy(buf, p, size);
+ buf[size] = '\0';
+ PARA_DEBUG_LOG("size: %d: %s\n", size, buf);
+ return buf;
+}
+
+static void read_tags(unsigned char *buf, size_t buflen, struct afh_info *afhi)
+{
+ unsigned char *p = buf;
+
+ while (p + 32 < buf + buflen) {
+ unsigned char *q, type1[5], type2[5];
+ uint64_t size1, size2;
+ int ret, ret2;
+
+ ret = read_atom_header(p, &size1, type1);
+ ret2 = read_atom_header(p + ret, &size2, type2);
+
+ if (size2 <= 16 || atom_cmp(type2, "data")) {
+ p += size1;
+ continue;
+ }
+ size2 -= 16;
+ q = p + ret + ret2 + 8;
+ if (q + size2 > buf + buflen)
+ break;
+ if (!atom_cmp(type1, "©ART"))
+ afhi->tags.artist = get_tag(q, size2);
+ else if (!atom_cmp(type1, "©alb"))
+ afhi->tags.album = get_tag(q, size2);
+ else if (!atom_cmp(type1, "©nam"))
+ afhi->tags.title = get_tag(q, size2);
+ else if (!atom_cmp(type1, "©cmt"))
+ afhi->tags.comment = get_tag(q, size2);
+ else if (!atom_cmp(type1, "©day"))
+ afhi->tags.year = get_tag(q, size2);
+ p += size1;
+ }
+}
+
+static void read_meta(unsigned char *buf, size_t buflen, struct afh_info *afhi)
+{
+ unsigned char *p = buf;
+
+ while (p + 4 < buf + buflen) {
+
+ if (p[0] != 'i' || p[1] != 'l' || p[2] != 's' || p[3] != 't') {
+ p++;
+ continue;
+ }
+ p += 4;
+ return read_tags(p, buflen - (p - buf), afhi);
+ }
+}
+
+static void aac_get_taginfo(unsigned char *buf, size_t buflen,
+ struct afh_info *afhi)
+{
+ int i;
+ uint64_t subsize;
+ unsigned char type[5];
+
+ for (i = 0; i + 24 < buflen; i++) {
+ unsigned char *p = buf + i;
+ if (p[0] != 'm' || p[1] != 'e' || p[2] != 't' || p[3] != 'a')
+ continue;
+ PARA_INFO_LOG("found metadata at offset %d\n", i);
+ i += 8;
+ p = buf + i;
+ i += read_atom_header(p, &subsize, type);
+ p = buf + i;
+ return read_meta(p, buflen - i, afhi);
+ }
+ PARA_INFO_LOG("no meta data\n");
+}
+
+static ssize_t aac_compute_chunk_table(struct afh_info *afhi,
+ unsigned char *map, size_t numbytes)