v0.20.4

Fixes and improvements

Raspberry Pi Camera

• add docker images with libcamera included (#110)
• return an error when rpiCamera in used in two paths (#1257)

RTSP server

• return error in case of unexpected interleaved frames (bluenviron/gortsplib@2a5b3e3)
• allow invalid RTCP packets (bluenviron/gortsplib@99855bd)

RTSP source

• allow invalid RTCP packets (bluenviron/gortsplib@99855bd)