|
|
Are capabilities in the capabilityTable field of TerminalCapabilitySet listed in order of preference? (Q78) |
|
The information in this article applies to: H.245
Are capabilities in the capabilityTable field of TerminalCapabilitySet listed in order of preference?
No, neither the order or entry number indicate preference. In the following terminal capability set, the EP prefers to receive H.263 over H.261, G.723.1 over G.711, and G.711 A-Law over U-Law. The preference is expressed in the capability descriptor, not in the order or according to the entry number of capabilities in the capability table. Although there is only one capability descriptor here, there could be several. Unlike the entry numbers for capability table entries, low values for capability descriptor numbers indicate preferred modes.
| Entry # | Capability |
|---|---|
| 5 | rcv audio G.723.1 maxFrames: 4 silenceSuppression: 1 |
| 1 | rcv video H.263 SQCIF: 1 QCIF: 1 CIF: 1 maxBitRate: 3840 tempSpat |
| 7 | rcv audio G.711 U LAW 64K maxFrames: 200 |
| 6 | rcv audio G.711 A LAW 64K maxFrames: 200 |
| 3 | rcv video H.261 QCIF: 1 CIF: 1 tempSpat maxBitRate: 3840 |
| 12 | rcv dataApp nonStd H.221 ID: { 0xb5(United States) 0x0 0x7674(Smith Micro Software, Inc.) } maxBitRate: 1280 |
| Descriptor # | Capabilities |
|---|---|
| 0 | ( 1 or 3 ) and ( 5 or 6 or 7 ) and ( 12 ) |
Design by Terrapane