VT Receiver
A guide to receiving streams via VT Receiver.
VT Receiver is a Windows app designed to receive feeds from VT Publisher, VT Guest, and The Web Guest Link. VT Receiver can make feeds available as an NDI® source, play out to a hardware device (ASIO, SDI) or create a virtual source in MPLink format.

Receiving feeds

  1. 1.
    Select one of the available sources in the "Source" tab (6).
  2. 2.
    Once selected, the preview of the feed will soon start to play.
  3. 3.
    Select desired protocol in tab 6 (SRT and H.265 are used by default and WebRTC will be enabled automatically in case if SRT connection was interrupted).
  4. 4.
    Select desired latency in the "Buffer" tab (11).
  5. 5.
    Select the output method in the "Output" tab (NDI®, a hardware device, or a virtual device) and hit "Start Output" (16).

Using VT Receiver

Here's what VT Receiver looks like.
Control
Function
1
The current version of the Video Transport software, the channels count in your current license, its validity date, and the latest release version.
2
The Publisher ID – your unique identifier, provides access to all feeds published under this ID. The Publisher ID is hardwired into your license and cannot be changed.
3
Copy and send to the remote contributor if you want someone to contribute via a browser. Learn more by reading about The Web Guest Link.
4
Connects to the submitted Publisher ID.
5
Global settings window. See the information below.
6
Lists the streams available (published) under this Publisher ID and license. Color indicator meaning: the stream is published and available (grey); the stream is being received currently (green); there is a problem with the stream (red).
Click the right mouse button on the selected source and select 'Settings', to enter the Source Settings window. Read the description below.
7
Select the protocol and encoder to use for transmission: SRT-HEVC (default, requires an Nvidia hardware codec), SRT-AVC (H.264 encoding), and WebRTC (H.264 encoding, selected automatically).
8
Video parameters of the stream: video format, number of audio channels.
9
Current frame rate.
10
Current bitrate.
11
Buffer size to configure latency. Learn more about latency configuration.
12
Current latency. If less than 350 ms, shows two values: the network latency of the stream (RTT) and real latency (Latency). Check here what is Latency(RTT) means in terms of our software.
13
Lost packets count and percentage. (audio/video/network)
14
Select the output destination: publish as NDI®, play out to a supported hardware device, or create a virtual device.
15
Start receiving selected stream
16
Start receiving selected stream
17
Controls to enable full-screen preview on available monitors; mute control. To exit the Full-screen mode just click the left mouse button again.
18
Decoding and connection mode stats from left to right:
Current protocol (WebRTC or VT 2.0 mode SRT), bitrate (Mbps), video codec, and GPU performance

Global settings window

Most of the following settings require a restart of the VT Receiver application.
Global settings window
Parameter
Description
Language
Select the preferred interface language for the VT Receiver app. Supported Languages: English, Russian and Simplified Chinese.
Default value is "English".
Show location in the channel name
Adds the VT Publisher's location name to the source name in the list.
Enabled by default.
Turn on gpu_pipeline (required for 10bit feature)
Enable this switch if you want to receive a video feed in 10bit.
Disabled by default.
Set the timeout for connection (in milliseconds)
Sets the maximum amount of time needed to establish a connection between your VT Receiver and a signaling server.
Default value is "3000" (milliseconds).
Use Nvidia decoder
Allows you to use NVIDIA GPU for decoding the receiving feeds.
Enabled by default.
Use Quicksync decoder
Allows you to use Intel Quicksync decoder for decoding the receiving feeds,
Disabled by default.
Allow to output 10bit video
Enables the 10bit video output feature. Requires gpu_pipeline setting.
Disabled by default.
Set the preview type
Here you can select render API for the native in-app Preview Window. Options are dx11, dx9 and dshow. Default option is is dx11.
Add RMS audio meters on the preview
Enable this to add RMS audio meters overlay on the preview to observe the sound levels.
Disabled by default.
VT 2.0 Buffering Progressbar
This is an experimental feature that is no longer supported and will be excluded in the next releases

Source settings window

Selected stream settings window
Parameter
Description
Output Video Enabled
Enables video output
Enabled by default.
Output Audio Enabled
Enables audio output.
Enabled by default.
Convert output format
Switch this on if you want to convert the output into a selected format.
Disabled by default.
Output Video Format
Select the desired video format to convert on output. Note that this parameter will only apply when the 'Convert output format' switch is enabled.
Audio Channels
Enter the Audio Channels numbers that you want to output.
Audio Gain
Applies custom gain to the audio tracks
SRT Passphrase
Enter the passphrase that you previously set on the Publisher side of this channel to setup secure SRT connection.
Empty by default.
SRT Receiver port
Specify the custom port number that you previously set on the Publisher side of this channel.
Empty by default.
SRT Receiver Buffer (min-max) in msec
Here you can set the custom buffer value. By default it displays value that is selected from the Buffer dropdown menu.

Latency configuration

There are several principal latency settings in Video Transport:
  1. 1.
    Real-time. In good conditions the technology is capable of bringing latency down to 50-100 ms. When using this option, make sure your network is good and stable – network issues will cause frame drops. Use Ultra-low if you want a compromise between reliability and latency on good connections.
  2. 2.
    Low. If reliability is more important than latency, increase the buffer. More latency gives our protocol more time for error correction (to resend the missing frames and restore the image). Use Reliable for predictable reliability even on low-quality connections.
  3. 3.
    Fixed. Depending on the quality of your network, you can choose one of the fixed buffer settings. This is the recommended mode for remote multi-camera production since it allows for several sources to arrive at the same time. Also to be used in creative scenarios, such as a group of musicians jamming together).
Possible values:
Setting
Meaning
Real-time
50-150 ms
Ultra-low
150-750 ms
Low
750-2500 ms
Reliable
2500-5000 ms
Fixed 150
150 ms
Fixed 350
350 ms
Fixed 750
750 ms

What is Latency(RTT)?

As you probably already saw Latency in the VT Receiver is represented by two different values in milliseconds.
The first value called Latency is the actual time in milliseconds that is required to send the stream from the VT Publisher and receive it into the VT Receiver. This time includes network transport between locations (RTT), decoding process in the VT Receiver, and buffering process in the VT Receiver.
The second value that you can see in the round brackets is the RTT (Round-trip time). In short, RTT is the time required for a packet to travel from the VT Publisher to the VT Receiver and back again. Actually, you can measure your network quality with that value.