EVS XS - Choices of Bitrates When Using Avid Dnxhd or Apple Prores 422 with EVS XS Servers

XS Series DISK RECORDER - Version 10.03 - Hardware
Technical Reference Manual
Issue
10.03.B
EVS Broadcast Equipment SA
–
March 2010
19
(59.94Hz)
Apple ProRes 422 on EVS XS servers is only available at these bitrates.
CHOICES OF BITRATES WHEN USING AVID DNxHD® OR APPLE
PRORES 422 WITH EVS XS SERVERS
How to Read the Following Tables ?
1. Video Bitrate: value set by the user in the advanced parameters window of
the XS server
2. Fields/Block: number of video fields that can be stored in one disk block of
8MB, taking into account 8 audio tracks.
3. Actual Bandwidth: this is the actual disk/network bandwidth that is required
for the real time record or real time playback of one video stream and its
associated audio tracks.
4. Max. RT Channels: this is the maximum number of video channels (real time
record or real time playback) that one XS server can support for a given frame
rate and bitrate. Since an XS server can have a maximum of 4 local video
channels, any value higher than 4 means that these additional real time
access can be used over the XNet[2] SDTI network.
For mixed configuration with standard and super motion channels on the same
server, the following rule must be used to ensure that the settings do not
exceed the maximum bandwidth of the server: (nbr of standard channels x their
actual bandwidth) + (nbr of super motion channels x their actual bandwidth)
must be lower than or equal to 150 MB/s (SCSI disks) or 205 MB/s (SAS
disks).
5. Network transfers: the maximum bandwidth over the XNet[2] SDTI network is
approximately 110 MB/s. To determine the number of real time transfers that
can occur simultaneously over the network, this number must be divided by the
actual bandwidth given in the table for a selected bitrate.
Example: How many real time transfers can I do over an XNet[2] SDTI network
(set at 1485Mbps) if I work with Apple ProRes 422 at 145Mbps in “NTSC”?
Calculation:
Maximum SDTI bandwidth / Actual Bandwidth = real time transfers:
110MB/s / 18.4MB/s = 6 real time transfers.
Note: This number is the maximum that the network connection can support.
Of course it is also necessary that the XS where the material is stored has
enough local disk bandwidth to feed the network accesses, on top of its own
local channels (cfr point 4. Max. RT Channels).
To get information on the recording capacity of the servers according to the video
bitrates and the disks used, refer to section
1.7.4 ‘Recording Capacity for XS
Servers’ on page 11.