4.2 H.263 Payload Header in Draft Mode, Mode B, Interframe
Consider the following payload header in big-endian byte order.
-
0x9C, 0x66, 0x80, 0x06, 0x00, 0x00, 0x00, 0x00
This corresponds to payload header fields with the following values.
|
Field |
Value |
|---|---|
|
F |
1 |
|
P |
0 |
|
SBIT |
3 |
|
EBIT |
4 |
|
SRC |
3 (CIF) |
|
QUANT |
6 |
|
I |
0 (interframe) |
|
A |
0 |
|
S |
0 |
|
GOBN |
0 |
|
MBA |
6 |
|
HMV1 |
0 |
|
VMV1 |
0 |
|
HMV2 |
0 |
|
VMV2 |
0 |
The following code snippet expands the payload header to include the RTP packet that contains the payload:
-
0x40, 0x41, 0x22, 0x22, 0x00, 0x00, 0xFF, 0xFF, 0x00, 0x00, 0x00, 0x01, 0x9C, 0x66, 0x80, 0x06, 0x00, 0x00, 0x00, 0x00
In this case, the definition of the RTP header [MS-RTPME] is the following:
|
Field |
Value |
|---|---|
|
P |
0 |
|
X |
0 |
|
CC |
0 |
|
M |
0 |
|
PT |
65 |
|
Sequence Number |
8738 |
|
timestamp |
65535 |
|
SSRC |
1 |
The H.263 payload is recognized by the PT (payload type) field, with the value being negotiated in H.245 [H245].