Closed Captions (CEA-608 & CEA-708)
Broadcast and streaming closed captions have to decode cleanly on a real decoder, not just look right in an editor. I author pop-on CEA-608 and CEA-708 captions, embed true 608 and 708 in an MXF OP1A wrapper, and deliver an SCC sidecar, a SMPTE ST 2052-1 Timed Text XML and a burned-in preview MP4, all independently QC-verified with caption-inspector.
SDH adds the speaker ID and the sound cue plain captions drop.
Closed captions in the CEA-608 and CEA-708 broadcast standards are authored in English, the language I have delivered for broadcast and streaming. Vietnamese is my native language for subtitle work.
Which caption format do you need?
The delivery format depends on where the file plays. Here is how the broadcast and web standards compare.
| Format | Standard | Where it plays | Characters | Best for |
|---|---|---|---|---|
| CEA-608 | Legacy line 21 | SD broadcast, fallback | Latin, no CJK | Backward compatibility |
| CEA-708 | Modern digital | HD / ATSC, streaming | Extended Latin | HD broadcast |
| SCC | 608 sidecar | Broadcast handoff | 608 set | Sidecar delivery, QC |
| SMPTE ST 2052-1 | 708 Timed Text | Streaming, archive | Unicode | 708 interchange |
| SRT / WebVTT | Web subtitle | Web players, OTT | Unicode, any language | Web, multilingual |
Why captions that look fine still fail
A caption file can look perfect in an editor and still break on a broadcast decoder. These are the failures I check for on every file.
English SDH for six episodes of a US streaming series, delivered to a US media-localization agency. True CEA-608 and CEA-708 embedded in an MXF OP1A wrapper, with an SCC sidecar and a burned-in preview, every file independently decoded and verified with caption-inspector.
Client and title withheld under NDA.
What you receive
Spec checklist
Toolchain
Author
Built withSubtitle Edit · AegisubCompatible withEZTitles · OOONAEncode & embed
Built withFFmpegCompatible withTelestream MacCaption · Telestream VantageQC decode
Built withcaption-inspector · CCExtractorCompatible withInterra BATON Captions
How it works
Scope and spec
You send the video and target profile. I confirm frame rate, timecode, caption style and the delivery formats you need.
Author
I time and write the captions or subtitles to the reading-speed, line-length and positioning rules for the target.
Encode and wrap
I produce the deliverables: SCC, MXF OP1A embed, SMPTE ST 2052-1 or DCP XML, plus a burned-in preview.
QC and deliver
I decode the result independently with caption-inspector, fix anything that drifts, and deliver with a report.
Three-layer QC before anything ships
Broadcast and cinema files fail on decoders, not in an editor preview. Every delivery goes through three passes and an independent decode.
1. Rough pass
Spot and draft every caption against the script, source audio and shot changes.
2. Alignment and timing
Tune reading speed, line breaks and positioning; align to shot changes and clear names and lower-thirds.
3. Independent senior QC
Decode the result on a separate decoder, check conformance to the target spec, and sign it off.
Indicative rate
$2.5–5 / minute
Related captioning services
Frequently asked questions
What is the difference between CEA-608 and CEA-708?
CEA-608 is the legacy line-21 caption standard; CEA-708 is the modern digital standard for HD and streaming. I author both and embed true 608 and 708 together in the MXF OP1A wrapper, so the file plays correctly on old and new decoders.
How do I know the captions decode correctly?
Every file is decoded independently with caption-inspector (the Comcast open-source QC tool), so you can see the exact 608 and 708 output and positioning before you air it.
How much do closed captions cost?
Indicative rates are $2.5–5 per minute depending on turnaround and source quality. Send the video and I send an exact quote within 10 minutes.
⏱ Typical response within 10 minutes