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Live Subtitling

Last updated: 2024-04-10 16:48:40
    The live subtitling function converts voice information into subtitles by real-time Automatic Speech Recognition (ASR) during live streaming, and subsequently translates them into the target language.Currently, this feature offers voice translation services for 16 language pairs, including Chinese-English, Chinese-Japanese, and Chinese-Korean.In practical applications, please select the proper type according to your business needs and audience group.
    This document describes how to create, modify, and delete subtitle templates through the console.

    Points of Attention

    A template takes effect about 5 to 10 minutes after successfully created.
    To use the live subtitling function, after binding a subtitle template to a transcoding template, you should obtain the subtitle stream with the suffix of a playback address corresponding to the name of a transcoding template.
    Live subtitling function is a premium service. Utilizing this function will incur live transcoding fees and ASR fees of MPS. Cross-language translation may generate voice translation fees of MPS. For the specific billing rules, please refer to billing document.

    Prerequisites for Use

    The CSS service has been activated.

    Creating Subtitle Template

    1. Log in to the CSS console. Choose Feature Configuration > Live Subtitles.
    Due to the use of the live subtitling function, creating a service role and authorizing the current account role to use MPS product services are required for the first creation of a subtitle template.
    2. Click Grant access to enter the CAM role management page.
    3. On the role management page, click Grant. After completing identity authentication to finish the MPS authorization, you can utilize the MPS service normally.
    4. After successful authorization, select the service agreement and click Start. The system will automatically activate the MPS product and open the live subtitling management page.
    5. Click Create template to enter the subtitle template creation page and configure the template as follows:
    The font selection for subtitles will vary depending on the Source language, Target language, and Subtitles you select. Please select the appropriate type according to your actual needs.
    Configuration Item
    Template Name
    The prefix for the template name is fixed to "subtitle". The template name cannot exceed 30 characters and only supports English letters and digits.
    Template Description
    Subtitle template description. It contains up to 100 characters, only supporting letters, digits, underscores, and dashes.
    Source language
    The default language is Chinese, and English, Japanese, and Korean are also supported.
    Target language
    It is set to None by default. Switching to any of the three other options not selected in the source language is supported. For instance, if English is selected as the source language, the available options for the target language include No Selection, Chinese, and Japanese, Korean.
    Cross-language translation will incur voice translation fees of MPS. ASR fees will be generated without translation. For more details, please see Content II.
    If you need to translate it into other languages, please submit a ticket to contact us.
    Source is suported by default. Target and Source + target are also supported.
    Through the three options of Source language, Target language, and Subtitles, Supports subtitles in the following sixteen language types:
    Original Chinese subtitles
    Chinese translated into English
    Chinese translated into Japanese
    Chinese translated into Korean
    Original English subtitles
    English translated into Chinese
    English translated into Japanese
    English translated into Korean
    Original Japanese subtitles
    Japanese translated into Chinese
    Japanese translated into English
    Japanese translated into Korean
    Original Korean subtitles
    Korean translated into Chinese
    Korean translated into English
    Korean translated into Japanese
    Preset styles
    The default option is Small text without bar. You may select Small text without bar, Large text without bar, Small text with bar, or Large text with bar to configure the settings. Once selected, the system will automatically set the corresponding subtitle style, which can be manually modified.
    Line spacing
    The vertical distance percentage represents the ratio of the vertical distance to the vertical width of the subtitles from the bottom of the screen. The vertical position of the subtitles is configured by adjusting the vertical distance percentage.
    Value range: 0 - 100%.
    The horizontal distance percentage represents the ratio of the horizontal distance to the horizontal width of the subtitles and the side of the screen. The horizontal position of the subtitles is configured by adjusting the horizontal distance percentage.
    Value range: 0 - 50%.
    The font selection for subtitles will vary depending on the Source language, Target language, and Subtitles you select.
    Options include Heiti, SimSun, Dynacw Diamond Black, and Helvetica.
    Options are 1 or 2, with 2 selected by default.
    When lines exceed the displayed range, only the latest content will be displayed.
    Characters per line
    Value range: 1-100. Default value: 40. One Chinese character count as one word. One English character or number counts as half a word. The fewer the characters per line are, the larger the font size is.
    The default font color is black. The color can be customized.
    The default background color is black. The customization of level of transparency is supported.
    Test subtitle
    Entering the subtitle test content is to add new subtitles to videos for previewing the subtitle effects.
    You can preview the subtitle effects configured in the current template. The subtitle effects are only for reference. The content is not translated.
    Preview window size
    Set the subtitle preview window size:
    Default values for width and height: 1920px for width and 1080px for height.
    Value range for width and height: 360px - 4096px.
    6. Click Save to save the current template.

    Binding Transcoding Template

    1. Log in to the CSS console. Choose Feature Configuration > Live Subtitles.
    2. The system allows subtitle templates to bind transcoding templates or adaptive bitrate templates. Both transcoding templates and adaptive bitrate templates have similar subsequent use procedures. A transcoding template serves as an example for decription below:
    2.1 Direct association with transcoding templates:
    2.1.1 Associate a transcoding template after it is successfully created: After the successful creation of a transcoding template, click Bind transcoding template in the upper left corner.
    2.1.2 Select Transcoding template or Adaptive bitrate template according to your actual business requirements, then click Confirm.
    2.2 In order to bind a playback domain to the corresponding transcoding template, the subtitle effects will be output at the same time when the transcoding stream is obtained subsequently (add _ transcoding template name after the corresponding live stream StreamName to generate a transcoding stream address).
    Once the transcoding template is bound, the subtitle function configured in the transcoding template will be synchronously activated.


    1. Log in to the CSS console. Choose Feature Configuration > Live Subtitles.
    2. Select the transcoding template associated with a domain name and click Unbind.
    3. Confirm whether to unbind the current associated domain. Click Confirm to unbind it.

    Modifying a Template

    1. Log in to the CSS console. Choose Feature Configuration > Live Subtitles.
    2. Select the successfully created subtitle template and click Edit on the right to go to the template information modification page. Click Save to finish the modification.

    Deleting a Template

    If the template has already been associated, you must first unbind it before you proceed with the deletion process.
    Note that a template cannot be restored after deleted. Be careful when performing operations.
    1. Log in to the CSS console. Choose Feature Configuration > Live Subtitles.
    2. Select the successfully created subtitle template and click Delete above.
    3. Confirm whether to delete the current subtitle template, then click Confirm to successfully delete it.
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