https://datatracker.ietf.org/doc/html/rfc3550#section-6.5
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
header |V=2|P| SC | PT=SDES=202 | length |
+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
chunk | SSRC/CSRC_1 |
1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SDES items |
| … |
+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
chunk | SSRC/CSRC_2 |
2 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SDES items |
| … |
+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
Items are contiguous, i.e., items are not individually padded to a
32-bit boundary. Text is not null terminated because some multi-
octet encodings include null octets. The list of items in each chunk
MUST be terminated by one or more null octets, the first of which is
interpreted as an item type of zero to denote the end of the list.
No length octet follows the null item type octet, but additional null
octets MUST be included if needed to pad until the next 32-bit
boundary. Note that this padding is separate from that indicated by
the P bit in the RTCP header. A chunk with zero items (four null
octets) is valid but useless.