Stream Conversion - VBrick dme Admin Manual

As an example, consider an implementation that might include DME-1 with a .vod file that
points to a .vod file on DME-2. DME-2, in turn, within the .vod file could point to a stream
on DME-3.In this manner, a request to DME-1 will auto generate all the necessary linkages
to connect to the stream provided by DME-3 (connecting through DME-2).This is useful
because only one stream returns to DME-1, and anyone attaching to view the stream on
DME-2 does not create another stream from DME-3.So, in all cases of viewing from DME-2
there would be only 1 stream from DME-3.Likewise, in viewing from DME-1 only creates
one stream to DME-2 and one stream from DME-2 to DME-3.All the streams are viewable
on each of the DMEs while minimizing the bandwidth.
Finally, all the streams are automatically dropped when all viewers disconnect.

Stream Conversion

To access the Stream Conversion fields:

1. Navigate to
The
Stream Conversion
modification of live streams in a number of ways. Here, you can transrate a stream to a lower
bitrate, a different resolution, etc. The conversion process does not modify the resolution of
the incoming stream, but creates a new stream that can used/viewed.
To help illustrate the use of this feature, here are a couple of use cases:
1. Locally creating an adaptive bitrate stream. Consider a remote DME that has limited
bandwidth. It may be necessary to push/pull a single higher bitrate stream to that DME,
and then transrate it to a number of reduced bitrate/resolution streams. Then, within the
HLS Streaming page, they can be combined into a single stream for adaptive playback
reflecting the unique needs of the remote viewers.
2. Create a Mobile sized Resolution and Bitrate stream. The DME can, if needed, take a
stream and using this feature reduce the bitrate and resolution to be better provisioned to
smaller form-factor mobile players.
Important Usage Note. This feature provides multiple levels of customization for stream
size, resolution, and bitrate. However, software-based transrating features often require a
great deal of CPU support depending on the complexity of the transrating. For example, with
Vbrick's internal benchmarks and using multiple, representative streams with the "HDTV
1080 – High Motion" predefined profile, it was found that, depending on your DME model,
the CPU was impacted differently (e.g., on a DME 7530 there was 80-100% CPU utilization,
while the 7550 saw 45-70% peaking to 90, and the 7570 a 6-9% utilization). This profile
requires a great deal of processing. Looking at the opposite end, using the "Small Form
Factor" profile, a 10-30%, 6-10% and negligible utilization for DMEs 7530, 7550, and 7570
respectively, are observed. Please keep in mind that these impacts are additive based on the
number of transrates the DME is performing. These examples are provided to illustrate the
differences in CPU impacts and the necessity for end-user qualification and testing.
Therefore, when using this feature please use a representative stream(s) (i.e, resolution,
bitrate, framerate, motion) to (1) test the quality of the transrated output, (2) monitor the
CPU usage because high usage will have an impact on the DME performance, and lastly (3)
perform multiple conversions to create a representative computational load mirroring how
you will use the DME in production.
To use this feature, first select an input stream. An output stream will be automatically
named, but if you rename it – the name must be unique, and best to be unique across all of
140
>
Output Configuration Stream Conversion
page provides a generalized transrating capability which allows
.
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