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3.10 RTP, RTCP
Remote Lectures
This facilitates the process of generating hint tracks. Hint tracks are used to
specify how an audiovisual track should be fragmented for presentation over
a network. [39, 40]
3.10
RTP (Real-time Transport Protocol)
RTCP (Real-time Transport Control Protocol)
RTP is a protocol defined in rfc1889 for the transport of real-time data.
Examples of real-time data include audio and video. It can be used to provide
streaming video, as well as interactive services through the use of RTCP. RTP
is made up of two parts, a data part and a control part.
Each stream (e.g. video or audio track) is transmitted separately and it
is the job of the decoder to combine them properly at the client side.
RTP has been designed to provide support for the detection of lost information, security, and content identification. It also can contain information
to help rebuild the timing of a video or audio stream.
RTCP has been designed to monitor the quality of service and to provide
information about which clients are engaging in a session
RTP does not provide any quality of service (QoS) or timeliness guarantees, it relies on lower-layer services for this. It does not provide any
guarantees about the order of packet delivery, or guarantee they will be delivered. The sequence numbers in the RTP header allow the correct order of
packets to be determined.
RTP is usually transmitted using the UDP/IP protocol. However, it is
transport independent so it may theoretically be used over any protocol.
For this project, UDP/IP should suffice as it allows for both unicast and
multicasting of packets. [41, 42, 38]
3.10.1
RTP Packet
Figure 3.1 shows the layout of an RTP packet.
3.10.2
MPEG-4 Video over RTP
RFC 3016 defines a protocol for which MPEG-4 Video and appropriately encoded audio can be broadcast in a consistent way over RTP. The audio standard defined is Low-overhead MPEG-4 Audio Transport Multiplex (LATM).
However, this is not the format that MP4Live or Darwin Streaming Server use
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