Overview

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The Cinegy Subtitling Service is designed to insert the required subtitle information into an incoming IP stream and currently supports DVB Bitmap and Teletext insertion according to the existing broadcast standards. SRT and STL subtitle file types are supported.

The Cinegy Subtitling Service is a part of the common Cinegy workflow and can be used together with Cinegy Air for on-the-fly embedding subtitle data into an IP stream, based on a subtitle file. This service is implemented as a sidecar to the main Cinegy Air service.

Note
 To use the Cinegy Subtitling Service we recommend using Cinegy Air v21.9 and above.

The integration with Cinegy Air is implemented using the same architectural methods as the previous Cavena and Screen integrations (by using Cinegy Air subtitling events).

Common Architecture

The Cinegy Subtitling Service receives the master IP stream and performs data insertion based on subtitle files placed into a designated directory. The required subtitle files are recognized by the "Subtitle ID" metadata which can be linked to every item in the Cinegy Air playlist. The Cinegy Subtitling Service reads from compatible subtitle files in a pre-defined folder referred to as a "Subtitle repository".

The "Subtitle ID" value can be specified either manually in the Cinegy Air playlist column for each item or automatically through the conversion by Cinegy Traffic Gateway of an external file.

Note
 The subtitle file name should include the contents of the "Subtitle ID" field but may also contain other characters.
Note
 The "Subtitle ID" field can only be edited if the "Metadata editing" option is enabled in the Cinegy Air Configuration. The "Subtitle ID" can contain alphanumerical characters.

The Cinegy Subtitling Service can work in two modes, covering different scenarios: insertion mode and overwrite mode.

Note
 The simple and quick configuration of insertion and overwrite modes are described in detail in Quick start guide.

Insertion Mode

Insertion mode is used when a signal from an engine does not contain any subtitle data and the Cinegy Subtitling Service should generate a new subtitle stream with a predefined PID:

insertion mode

In this mode, the Cinegy Subtitling Service waits for an item with a valid (non-empty) Subtitle ID and then starts reading the subtitle data from the corresponding file and generating a new subtitle stream.

Important
 This scenario describes the architectural model for the system producing a pure IP output. Refer to the Inserting Baseband Teletext section to learn how to embed Teletext data into an SDI output.

Cinegy Playout Engine Settings

Note
 The following configuration is relevant for scenarios where either the DVB Bitmap subtitle encoder or multiple Teletext streams, are used with Cinegy Air v21.9 and above.

On the Cinegy Playout Engine side, you should ensure that there is always enough space in the transport stream to add subtitle data. Therefore, with DVB Bitmaps, for example, you have to increase the output data rate by about 30% in comparison to the video bitrate.

For example, if you configured a 35 Mbs video stream, you need to increase the data rate to about 50 Mbs:

transport rate configuration
Important
 Refer to the Transport Settings paragraph in the Cinegy Playout Manual for details on configuring IP output transport settings.

Overwrite Mode

Overwrite mode can be used when the output transport stream from the Cinegy Playout Engine already contains some Teletext subtitle data. This can be obtained from either VANC data in source MXF files or passed through from an incoming IP live stream with Teletext subtitles embedded. Only MXF-based file items in the Cinegy Air playlist that require local Teletext subtitling can be "overwritten".

The Cinegy Subtitle Service preserves/passes through all Teletext subtitle data in the main stream when no file is found according to the specified FileSearchPolicy. If an appropriate file is found, the original Teletext subtitles will be replaced with new data from the subtitle file.

Overwrite mode
Note
 Please note that the predefined Teletext PID remains unchanged, only subtitle data will be altered.
Note
 In Overwrite mode, only one Teletext encoder is supported; therefore, the DVB Bitmap encoder configuration should be removed from the Cinegy Subtitling Service channel configuration section.
Important
 This scenario describes the architectural model for a system working in the pure IP output. Refer to the Baseband Teletext Inserter section to learn how to embed Teletext data into an SDI output.

Cinegy Playout Engine Settings

In this scenario you need to define the Teletext stream for the output stream in the Cinegy Playout Engine Configurator:

teletext stream configuration

Here you define the following Teletext settings:

  • Teletext stream PID – select the checkbox and define the PID value to enable MXF VANC tracks in the playlist containing OP42/47 Teletext data packets to be read and inserted.

  • Teletext bit rate – define the Teletext bit rate value.

  • Teletext descriptor – define various Teletext properties which will be stored in the Teletext description. This option consists of three parts, separated by colons : Language:Type:Number, where:

    • Language is specified using an ISO 639-2/T language code (e.g. ENG, SPA, etc.).

    • Type defines the Teletext type. This descriptor can have the following values:

      1

      Initial Teletext page.

      2

      Teletext subtitle page.

      3

      Additional information page.

      4

      Program schedule page.

      5

      Teletext subtitle page for the hearing impaired.

    • Number is identified by its single-digit magazine number and its two-digit page number.

Important
 Refer to the Transport Settings paragraph in the Cinegy Playout Manual for details on configuring IP output transport settings.

Baseband Teletext Inserter

The sections above describe the architectural model for a system producing a pure IP output. The additional Cinegy Encode service is required to convert the IP output from the Cinegy Subtitling Service into an SDI output with the Teletext data included.

baseband-teletext-inserter
Caution
 Note that this architectural model works with Teletext only, since a DVB Bitmap cannot be inserted into baseband.