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Large video files (high-resolution, high-bitrate, or long-running) can be too heavy for participants to play back smoothly if you present the original file. For smooth playback, upload the file to the room first and present the transcoded version. Once a file is uploaded, it is stored in the cloud and played from there. Presenting does not depend on the host’s or co-host’s own internet connection.

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Why transcoding matters

When you upload a media file, Coresee transcodes it automatically into two versions: multi-rate HLS media and a proxy. Instead of sending one heavy stream to everyone, HLS offers several quality levels, so each participant receives the one that best fits their connection. The result is steadier playback for everyone in the room, whatever their network.

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Before you start

  • You are the host or co-host of the room. Only hosts and co-hosts can present media.
  • You have uploaded the file before the session, so transcoding is finished when you need it.

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Present a large media file

1

Upload the file to the room

Open the Files tab and select Upload files (or drag and drop the file into the list). You can do this from the room or from the room homepage before the session starts.
2

Wait for transcoding to finish

The file shows a processing state while Coresee creates the HLS and proxy versions. Larger files take longer, so upload well before you need to present. The file is ready once it no longer shows as processing.
3

Start the session

Presenting is only available inside a live room. Open the room and go to the Files tab.
4

Present the transcoded version

Select the file and choose Present. When asked to choose a format, select the transcoded version, not the original.
Do not present the original file. Original files are not optimized for live playback and can stutter, buffer, or fail for participants with slower connections.

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Presenting several large files

To play several clips back to back without loading each one manually, add the transcoded files to a Playlist.

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Best practices

  • Upload early. Transcoding time grows with file size. Upload the day before for very large files.
  • Do a test run. Present the file in a test session to confirm playback before your audience joins.
  • Check your participants’ connections. Playback quality depends on each participant’s own connection, so share the System Requirements with attendees ahead of the session.

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Troubleshooting

Transcoding is not finished. Wait for it to complete before presenting. Once done, it appears under Format on the Details page.
Confirm you are presenting the transcoded version, not the original. If the issue affects only one participant, ask them to check their connection against System Requirements
Check that the file is a supported media format and try the upload again. If it keeps failing, contact support at help@coresee.com