+int ff_init_vlc_from_lengths(VLC *vlc_arg, int nb_bits, int nb_codes,
+ const int8_t *lens, int lens_wrap,
+ const void *symbols, int symbols_wrap, int symbols_size,
+ int offset, int flags, void *logctx)
+{
+ VLCcode localbuf[LOCALBUF_ELEMS], *buf = localbuf;
+ VLC localvlc, *vlc;
+ uint64_t code;
+ int ret, j, len_max = FFMIN(32, 3 * nb_bits);
+
+ ret = vlc_common_init(vlc_arg, nb_bits, nb_codes, &vlc, &localvlc,
+ &buf, flags);
+ if (ret < 0)
+ return ret;
+
+ j = code = 0;
+ for (int i = 0; i < nb_codes; i++, lens += lens_wrap) {
+ int len = *lens;
+ if (len > 0) {
+ unsigned sym;
+
+ buf[j].bits = len;
+ if (symbols)
+ GET_DATA(sym, symbols, i, symbols_wrap, symbols_size)
+ else
+ sym = i;
+ buf[j].symbol = sym + offset;
+ buf[j++].code = code;
+ } else if (len < 0) {
+ len = -len;
+ } else
+ continue;
+ if (len > len_max || code & ((1U << (32 - len)) - 1)) {
+ av_log(logctx, AV_LOG_ERROR, "Invalid VLC (length %u)\n", len);
+ goto fail;
+ }
+ code += 1U << (32 - len);
+ if (code > UINT32_MAX + 1ULL) {
+ av_log(logctx, AV_LOG_ERROR, "Overdetermined VLC tree\n");
+ goto fail;