In this case len is always at least 1, since it is checked against RTP_VP9_DESC_REQUIRED_SIZE + 1 and then it is reduced by RTP_VP9_DESC_REQUIRED_SIZE before entering the has_pic_id check. Bug-Id: CID 1270811
The code was tested with live555 server. Signed-off-by: Martin Storsjö <martin@martin.st>