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ScoopTeam - User manual - Draft 0002
2.2.2. Double codec mode
In this configuration, two independent connections can be set over the selected network interface (ISDN
or IP) towards possibly two remote devices. One mono codec is operating for each connection, one for
the Program link and one for the Coordination link.
The mobile voice channel is not used in this arrangement.
The table below synthetically describes the capabilities of either codec in the different cases:
Table 3 – Double codec - Available coding depending on network
2.2.3. Details on the coding algorithms
The following bring some precisions about the important features of the various algorithms and
protocols available.
G711 coding
Application: telephony, coordination. Low latency.
G711 is the standard coding used for voice transmission on public telephone networks, and features 300
to 3400 Hz audio bandwidth. This algorithm is typically used for links over IP networks with IP
telephones or VoIP gateways. Via ISDN (
NYA
), G711 is used for links with telephones or hybrid devices.
G722 coding
Application: commentaries, coordination. Low latency.
This mono coding algorithm at a 64 kbit/s bit rate is a reference for commentaries, and features a 50-
7000 Hz bandwidth.
For ISDN, three synchronisation modes are possible:
“Statistical recovery” byte synchronisation method (alias SRT);
H221 synchronisation; in this case, 1.6 kbit/s from the compressed data are used for this; (
NYA
)
H221 synchronisation and H242 protocol. This is only available for the ISDN mode.
(
NYA
)
No specific synchronisation is required for the IP mode.
16
24
48
G711
64
NYA
G722
64
G722-H221
64
NYA
G722-H242
64
NYA
MPEG L2
NYA
64
MPEG L2
128
AAC-LC
16 => 56
AAC-LC
64
AAC-LC
96
AAC-LC
128
AAC-LC
192
HE-AAC
16 => 56
HE-AAC
64
AAC-LC LOAS
64
HE-AAC LOAS
64
OPUS
12 => 192
IP
Codec
Frequency (kHz) Net bit rate
(kbit/s)
ISDN
