Create a subbuffer of the payload of the RTP packet in buffer.
offset bytes are skipped in the payload and the subbuffer will be of size len. If len is -1 the
total payload starting from offset is subbuffered.
| this |
the RTP packet |
| offset |
the offset in the payload |
| len |
the length in the payload |
|
A new buffer with the specified data of the payload. |