Extron electronics SMP 111, Руководство пользователя

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SMP 111 • Reference Information 105
Estimating Storage Requirements for a Recording
Estimating Storage per Recording Hour
You need to know video and audio bit rates configured in your Extron SMP 111. For these
examples, the calculations assume that the bit rates remain constant during the recording.
If you are using VBR (variable bit rate, which is the default) then the actual bit rates are often
slightly lower than this estimate. In some cases they can be higher.
To estimate storage per recording hour:
1. Find the SMP 111 video bit rate and audio bit rate (in the web UI go to
Configuration
>
Encoding & Metadata
>
Encoding Presets
), which are in kbps (kilobits per second).
2. Insert those bit rates into the following equation:
[(video bit rate + audio bit rate) *3600 seconds per hour] / 8 bits per byte
*1000 =
x MBph (megabytes per hour)
Example:
Using the default “720p High” encoder preset, with
• Video bit rate = 5000 kbps
• Audio bit rate = 192 kbps
For a 1‑hour recording (3600 seconds),
•
([5000 + 192] * 3600) / 8000 = 2336.4 MBph or 2.34 GBph
For the default encoder presets of an SMP 111, the following are the estimated storage
requirements for each hour of recording:
Estimated Storage Requirements
Encoder Preset Video bit rate
(kbps)
Audio bit rate
(kbps)
MB per hour GB per hour
1080p High 8000 320 3744.0 3.74
1080p Low 6000 128 2757.6 2.76
720p High 5000 192 2336.4 2.34
720p Low 3000 128 1470.6 1.41
480p High 2500 128 1182.6 1.18
480p Low 1500 80 711.0 0.71
VGA High 3500 128 1632.6 1.63
VGA Low 2500 128 1182.6 1.18
SMP 111 max. rates 10000 320 4644.0 4.64
SMP 111 min. rates 200 80 126.0 0.13
NOTE: If you choose from one of several encoding rates, do the above calculation
for each of the possible rates. You will also need to estimate how often each of the
encoding rates is selected.
To estimate the number of hours of recordings that can be stored on a specific size of hard
drive:
• Determine the SMP 111 video bit rate and audio bit rate, in kbps (kilobits per second).
• Insert those bit rates into the following equation:
[(hard drive size in GB * 8,000,000) / (video bit rate + audio bit rate)]/3600 =
x hours