RFC 3016 (rfc3016) - Page 4 of 21

RTP Payload Format for MPEG-4 Audio/Visual Streams

RFC 3016       RTP Payload Format for MPEG-4 Audio/Visual  November 2000


   the audio data.  In order to indicate the dependency information of
   the scalable streams, a restriction is applied to the dynamic
   assignment rule of payload type (PT) values (see section 4.2).

   For MPEG-4 Audio coding tools, as is true for other audio coders, if
   the payload is a single audio frame, packet loss will not impair the
   decodability of adjacent packets.  Therefore, the additional media
   specific header for recovering errors will not be required for MPEG-4
   Audio.  Existing RTP protection mechanisms, such as Generic Forward
   Error Correction (RFC 2733) and Redundant Audio Data (RFC 2198), MAY
   be applied to improve error resiliency.

2. Conventions used in this document

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC-2119 [7].

3. RTP Packetization of MPEG-4 Visual bitstream

   This section specifies RTP packetization rules for MPEG-4 Visual
   content.  An MPEG-4 Visual bitstream is mapped directly onto RTP
   packets without the addition of extra header fields or any removal of
   Visual syntax elements.  The Combined Configuration/Elementary stream
   mode MUST be used so that configuration information will be carried
   to the same RTP port as the elementary stream.  (see 6.2.1 "Start
   codes" of ISO/IEC 14496-2 [2][9][4]) The configuration information
   MAY additionally be specified by some out-of-band means.  If needed
   for an H.323 terminal, H.245 codepoint
   "decoderConfigurationInformation" MUST be used for this purpose.  If
   needed by systems using MIME content type and SDP parameters, e.g.,
   SIP and RTSP, the optional parameter "config" MUST be used to specify
   the configuration information (see 5.1 and 5.2).

   When the short video header mode is used, the RTP payload format for
   H.263 SHOULD be used (the format defined in RFC 2429 is RECOMMENDED,
   but the RFC 2190 format MAY be used for compatibility with older
   implementations).













Kikuchi, et al.             Standards Track