Contents

Additional data table

A table of variable length containing additional information.

Overview

Additional information is formatted as a series of tagged entries.

This field always contains a tagged entry indicating the RTP time scale for RTP data. All other tagged entries are optional.

Three data tags are currently defined for RTP data. One tag is defined for use with any type of data. You can create additional tags. Tags are identified using four-character codes. Tags using all lowercase letters are reserved by Apple. Ignore any tagged data you do not understand.

Table entries are structured like atoms. The structure of table entries is shown in the following table.

Field

Format

Bytes

Entry length

32-bit integer

4

Data tag

4-char code

4

Data

Variable

Entry length - 8

Tagged entries for the ’rtp ’ data format are defined as follows:

'tims'

A 32-bit integer specifying the RTP time scale. This entry is required for RTP data.

'tsro'

A 32-bit integer specifying the offset to add to the stored time stamp when sending RTP packets. If this entry is not present, use a random offset, as specified by the IETF. If this entry is 0, use an offset of 0 (no offset).

'snro'

A 32-bit integer specifying the offset to add to the sequence number when sending RTP packets. If this entry is not present, a random offset should be used, as specified by the IETF. If this entry is 0, use an offset of 0 (no offset).

See Also

Data fields