TANDBERG E5780, Справочное руководство

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ProMPEG FEC Support for IP Streaming in E57xx Encoders
Page K-4 Reference Guide: evolution 5000 E5780 and E5782 Encoder
ST.RE.E10135.4
K.2.2 Configuring ProMPEG FEC
Protocol/ProMPEG FEC Option
When ProMPEG FEC is enabled this setting allows the IP output of the E57xx to be
configured to work in FEC Column only mode or FEC Row and Column mode.
When either of these settings is selected the MPEG transport stream is set to operate in RTP
mode.
If FEC Column only mode is selected a FEC stream is sent out on the same IP address as the
MPEG transport stream but with the UDP destination port set to + 2 from the MPEG transport
stream.
If FEC Row and Column mode is selected two FEC streams are sent out on the same IP
address as the MPEG transport stream but with the Column FEC stream’s UDP destination
port number set to + 2 and the Row FEC stream’s UDP destination port number set to + 4
from the MPEG transport stream.
Nbr of Columns (L) Option
This setting configures the number of Columns in the matrix, and determines the number of
MPEG packets used when calculating the Row FEC packets.
Nbr of Rows (D) Option
This setting configures the number of Rows in the matrix, and determines the number of
MPEG packets used when calculating the Column FEC packets.
K.2.3 ProMPEG FEC Constraints
Matrix Limitations in Columns only mode:
L * D
≤
100
1
≤
L
≤
20
4
≤
D
≤
20
Matrix Limitations in Rows and Columns mode:
L * D
≤
100
4
≤
L
≤
20
4
≤
D
≤
20
Column only Overheads:
Overhead = L + (D * L) = 1 + 1
(D * L) D
Worst case is 4 rows = (1/4) + 1 = 25%
Best case is 20 rows = (1/20) + 1 = 5%
Row and Column Overheads:
Overhead = D + L + (D * L)
(D * L)
Worst case is 4x4 = (4+4+16) / 16 = 50%
Best case is 10x10 = (10+10+100) / 100 = 5%