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
Generated preview images will be available in this URL template:
http://<SERVER_NAME>:5080/<APP_NAME>/previews/<STREAM_ID>.png
With v2.4.3 and later, "_finished" suffix is added to PNG file after streaming has finished. So that it will be in the following template
http://<SERVER_NAME>:5080/<APP_NAME>/previews/<STREAM_ID>_finished.png
The absolute path of the preview image is as follows:
<ANT_MEDIA_SERVER_DIR>/webapps/<APP_NAME>/previews/<STREAM_ID>.png
In addition to this, you can also upload preview images to Amazon S3. Please check out the instructions for S3 Integration.
Configuration parameters
You can add/change following properties to the <ANT_MEDIA_SERVER_DIR>`/webapps/`<APP_NAME>`/WEB-INF/red5-web.properties
settings.previewHeight
: Preview image is saved as 480p default. If you want to increase the resolution, add the following parameter into red5-web.properties file.
settings.previewHeight=360
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.
settings.createPreviewPeriod=1000
settings.previewOverwrite
: Default value is false. If it is false, when a new stream is received with the same stream id, _N (increasing number) suffix is added to the preview file name. If it is true, a new preview file will overwrite the old one.
settings.previewOverwrite=false
settings.addDateTimeToMp4FileName
: Default value is false. If true, adds date-time value to file names. If false, it does not add date-time values to file names.
settings.addDateTimeToMp4FileName=false
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.
settings.previewGenerate
: Default value is true. If false, preview images will not be generated.
settings.previewGenerate=true
Keep in mind that if you change the configuration files, you also need to restart Ant Media Server for changes to take effect.
systemctl restart antmedia
You can also enable thumbnail generating options from web panel after version 2.4.3:
![](@site/static/img/Screenshot from 2022-03-30 16-40-21.png)