TelVue CloudCast User Manual

Page 4

TelVue

CloudCast

User Manual / v. 4.1.0 / June 2014

is a trademark of TelVue Corporation 800-885-8886 / www.telvue.com

Resolution

400 x 300 (w/ lower bitrate)

640 x 480 (w/ higher bitrate)

960 x 540 (w/ lower bitrate)

1280 x 720 (w/ higher bitrate)

Image Scanning

Progressive

Frame Rate

29.97 or 30

Audio Codec

AAC

Sampling Rate

44.1 kHz

44.1 or 48 kHz

Audio Channels

Stereo for better quality, Mono
for smaller filesize

Audio Bit Rate

60-84 Kbps

128 Kbps

If you want to learn more about these settings, read on…

Video File Format:
If you are exporting your content from a non-linear editor such as Final Cut Pro or Adobe Premiere,
H.264 the presets for streaming video that are available should work just fine.

If you need to transcode an existing video, the following programs can encode to H.264:

TelVue® Turbo™ Workflow Accelerator

Telestream Episode

Sorenson Media Squeeze

Handbrake

And many others

In many cases custom presets are not required. Many of these programs include presets for Google,
YouTube, Apple TV, or other services. Look for these or similar presets under headings like Web
Delivery or Online in your program of choice. If, however, you are prompted to choose your own
parameters, here are some basic guidelines:

Bit rate and Resolution:
These are the most important parameters when transcoding video and directly relate to the quality of
the viewing experience. A consideration for the widest possible viewing audience should be made –
meaning that you should chose a medium to low resolution and bit rate to play well on mobile devices
and users without fast connections.
If the recommended settings above do not stream smoothly, you can experiment by changing the
resolution and bit rate to lower values.

Variable or Constant Bit Rate:
Most encoders allow you to chose CBR (constant bit rate) or VBR (variable bit rate). VBR will vary the
bitrate of the encoding to use more bits per second during high movement / action scenes and lower
bits per second with low movement scenes. This provides overall better quality.

However, because these videos will be streamed over the Internet, VBR video may cause issues and
stuttering in the video (buffering) if the viewer’s device has to suddenly download many more bits per
second and doesn’t have the bandwidth to support it. If using VBR, make sure that the “ceiling” or
“limit” bit rate is not too high.

Aspect Ratio:
The term “HD” is most commonly paired with a 16:9 aspect ratio, sometimes called widescreen. “SD”
usually indicates a 4:3 aspect ratio.