216   struct ContentEncryption {  struct in mkvparser::ContentEncoding
220     unsigned long long algo;
221     unsigned char* key_id;
222     long long key_id_len;
223     unsigned char* signature;
224     long long signature_len;
225     unsigned char* sig_key_id;
226     long long sig_key_id_len;
227     unsigned long long sig_algo;
228     unsigned long long sig_hash_algo;
230     ContentEncAESSettings aes_settings;