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Generating thumbnails from streams

Ant Media Server can generate periodic previews (snapshots) of the incoming streams on the fly. This guide will help you learn configuration parameters for generating and using previews.

In order to activate preview generation, you just need to add at least one adaptive bitrate. You can do that in the dashboard using Application > Your App > Settings > Add New Bitrate

Go to Application > Your App > Settings > click on basic > switch to Advance and search for generatePreview and set it to true.

After making the changes, save the settings.

Generated preview images will be available in this URL template:


With v2.4.3 and later, the _finished suffix is added to the PNG file after streaming has finished. So that it will be in the following template


The absolute path of the preview image is as follows:


In addition to this, you can also upload preview images to Amazon S3. Please check out the instructions for S3 Integration.

Configuration parameters

Similarly, you can add/change other preview-related properties in the Advance settings of the application we changed above.

previewHeight: The preview image is saved as 480p by default. If you want to increase the resolution, change the following parameter in the advance settings.


createPreviewPeriod: Preview image creation period in milliseconds. The default value is 5000 ms. As an example, if you change it as follows, it will create a preview every second.


previewOverwrite: The default value is false. If it is false, when a new stream is received with the same stream ID, the _N (increasing number) suffix is added to the preview file name. If it is true, a new preview file will overwrite the old one.


addDateTimeToMp4FileName: The default value is false. If true, it adds a date-time value to file names. If false, it does not add date-time values to file names.


As an alternative, you can also enable this feature on the web panel by enabling the tick box under Application >` Your App >` Settings >` Add Date-Time to Record File Names and saving the settings.

previewGenerate: The default value is true. If false, preview images will not be generated.


You can also enable thumbnail-generating options from the web panel after version 2.4.3: