Embed Captions for Broadcast
Embed Captions for Broadcast injects EIA-608 and CEA-708 closed caption data directly into your source video file for delivery to broadcast. Unlike subtitle sidecar files, the embedded output contains the caption data as a data stream inside the video container, which is required by broadcast standards in many territories. Critically, the video and audio tracks are not re-encoded: the original video data passes through unchanged, preserving the quality and format of your source file. This feature is available to Pro plan subscribers on the web version of Closed Caption Creator.
Preparing for Export​
Before submitting an embed job, ensure your project contains a completed Event Group with the captions you wish to embed. If you do not yet have captions, you can generate them quickly using the Automatic Transcription feature available in the AI Tools menu.
To open the Embed Captions window, go to File > Export, select Embed Captions, and click Next. You will need to provide three pieces of information: the source video file from your local drive, the Event Group containing the captions, and the frame rate of the video. It is important to provide your video file in the same format you intend to deliver, since the video track is not transcoded.
Pricing​
Embed jobs are billed per submission. The base cost is $2.00 per job, with an additional $0.40 per gigabyte of source video (minimum 1 GB, rounded to the nearest whole gigabyte). The total estimated cost is displayed in the window before you submit, based on the detected file size.
Submitting and Downloading Your File​
Once you click Submit Job, the source video file is uploaded to the Closed Caption Creator cloud service. An upload progress indicator will display while the file transfers, which may take several minutes for large files. Once the upload is complete, the embedding process begins on the server. When the job finishes, you will receive an email notification containing a download link for your completed file. Processed files are retained for 14 days before being automatically removed. If you do not receive the email or encounter issues downloading your file, contact support with your job reference.
Avid Media Composer Workflow​
For post-production workflows using Avid Media Composer, Closed Caption Creator can export a self-contained AAF file containing the 608/708 caption data for direct import into the Media Composer timeline. This workflow is available on the Pro plan.
In Closed Caption Creator, open the Export panel by clicking the Export icon in the top toolbar and selecting Subtitle File. Change the file extension to RAW and ensure the AAF Embed (Self-Contained) option is selected from the embed type dropdown. Next, map your caption track to the correct caption service — in most cases your primary language should be assigned to Program A, Channel 1. Click Export when ready.
Back in Avid Media Composer, create a new data track on your timeline for the caption data. Click and drag the exported AAF file onto that track. A progress dialog will appear confirming that the captions are being converted and loaded. Once complete, captions will appear over the programme monitor during playback.
After outputting your finished sequence, you can verify the result by opening the exported MXF file in MediaInfo, where both a 608 and a 708 text stream should be listed alongside the video and audio tracks. You can also confirm caption playback by importing the MXF into a third-party application such as Adobe Premiere Pro, which will create two separate caption tracks — one for 608 and one for 708 — that can be played back directly in the timeline.
Troubleshooting​
If the upload fails or times out, check your internet connection and try again with a stable connection. For very large files, consider using a wired network connection rather than Wi-Fi. If the embed completes but the output file does not contain captions, verify that the correct Event Group was selected and that it contains events within the programme's timecode range. If the frame rate specified does not match the source video, timing errors may appear in the embedded captions.