Closed captioning (also commonly referred to as subtitling in Europe) is the process of adding text to a video to provide additional or interpretive information. Closed captions typically show a transcript of the audio portion of a program as it occurs (either verbatim or in edited form), sometimes including non-speech elements.
Closed Captioning Software – What Does Encoding.com Offer?
Encoding.com is the first and only encoding software to offer universal closed captioning support for delivery to all devices. Our powerful, reliable, scalable feature set for closed caption workflows enables digital video distributors to achieve critical business objectives such as:
- Assuring compliance with impending Video Accessibility Act deadlines
- Expanding the size and demographic of their audience
- Reducing time-to-market
- Delivering support for popular learning tools
Encoding.com’s full-featured video closed captioning software makes it simple to:
- Utilize all formats including cea-608/708, DFXP, SAMI, SCC, SRT, TTML 3GPP Time Text, and WebVTT which is used with HTML5
- Our video closed captioning software seamlessly integrates with any existing digital video authoring and distribution workflow
- Extract, inject, copy and mux closed captions tracks into sidecar (text) files or digital video
- Extract standard closed caption tracks from source files and convert them into sidecar files
- Copy closed caption or timed text tracks from source videos to output videos
- Mux a sidecar file with a source video to encode closed caption tracks into output videos.
Mux a sidecard caption file with a video
Extract embedded captions into various sidecar formats
Convert one caption format into another
Closed Captions
By offering a complete suite of live closed captioning features, Encoding.com enables customers to ingest and output closed captions in useful ways. For example:
Input Formats
MP4 with a sidecar file in WebVTT format
MP4 with caption track in CEA-608 format
MP4 with caption track in CEA-708 format
MP4 with caption track in MPEG-4 Part 17 format
3GP with caption track in 3GPP Timed Text format
MPEG-2 with caption track in CEA-608 format
ASF with caption track in CEA-608 format
MOV with a sidecar file in SCC format
FLV with a caption track in SRT MP4 with a sidecar file in DFXP format
MP4 with a sidecar file in DFXP format
MP4 with a sidecar file in SAMI format
MP4 with a sidecar file in SCC format
Output Formats
MP4 with a SCC sidecar file
MP4 with a SRT sidecar file
MP4 with CEA-608 caption track
MP4 with MPEG-4 TT subtitle track
3GP with 3GPP TT subtitle track
HLS with CEA-608 caption track
MPEG-2 with CEA-608 caption track
MOV with a SCC sidecar file
Encoding.com strives to integrate our live closed captioning software seamlessly with your existing workflow. You can fully specify your video closed caption workflow in the instructions you send to our system, so you have complete flexibility. Other software packages and services make assumptions about closed caption workflows. The problem with this approach is you run the risk of making inaccurate assumptions. For example, one cloud-based service currently on the market will automatically copy analog captions (if present in the source video) into an MP4 output file. This output is useless in the real world for several reasons:
- Most mobile devices (laptops, tablets and phones) don’t have the decoder all flat screens use to display closed caption tracks.
- MPEG-4 standard specifies subtitles instead of closed captions. That’s why iOS devices expect the standard MPEG-4 Part 17 subtitles in an MP4 file.
- Video players in Android devices require sidecars (SRT files, mostly).
- Browser-based players generally require sidecar files to display closed captions for the same reason. It is possible to add analog closed captions to an MP4, but it is also pointless.
- HTML5 video requires the use of the WebVTT format with use of the ‘track’ element and can also use text descriptions, chapters for content navigation, and time-aligned metadata for with audio or video content.
Automating such an irregular workflow wastes resources, confuses customers, slows things down and can upset project managers. That’s why we decided to enable customers to specify how to process their closed captions workflow with our API.
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FCC Closed Captioning Regulations & Standards
The FCC released its latest regulations for closed captioning in 2015 adding in regulations for online video clips. A summary of upcoming regulations for video which need closed captioning editing are as follows:
- Pre-recorded programming that is not edited for Internet distribution must be captioned if it is shown on television with captions on or after September 30, 2012.
- Pre-recorded programming that is edited for Internet distribution must be captioned if it is shown on television with captions on or after September 30, 2013.
- Live and near-live programming must be captioned if it is shown on television with captions on or after March 30, 2013. Near-live programming is video programming that is performed and recorded less than 24 hours prior to the time it was first shown on television.
- Programming that is already in the video programming distributor’s or provider’s library before it is shown on television with captions must be captioned:
- Within 45 days after it is shown on television with captions on or after March 30, 2014 and before March 30, 2015
- Within 30 days after it is shown on television with captions on or after March 30, 2015 and before March 30, 2016
- Within 15 days after it is shown on television with captions on or after March 30, 2016
And now, video programming distributors, including broadcasters, cable operators and satellite providers, have three new dates to meet when it comes to captioning short clips, such as TV show promos or teasers. Clips containing a single excerpt of a program that is exactly what was presented on television, with no video or audio changes, must be captioned by Jan. 1, 2016. Montages, or clips which contain multiple straight-lift clips, must be captioned for online video by Jan. 1, 2017. Live or near-live television programming, like news or sports clips, have until July 1, 2017, to be in compliance. In addition, distributors have a 12-hour grace period after live programming is shown, and an 8-hour grace period after near-live programming, to caption their online clips. Video clips that are in distributors’ libraries before the compliance deadline are exempt from the rules, as are third party websites and apps.
Record Keeping – Section 79.1(c)(3)
Programs with existing captions must be passed through to live television by the broadcaster. This is in addition to stations being required to keep their captioning equipment up-to-date and in working order, and keep 2- years of records of this maintenance and upkeep. In addition, they must document how they monitor and transmit closed captions, as well as all of the technical equipment checks that were performed on their captioning infrastructure.
Compliance Procedures & Reporting – Section 79.1(e)(11)(v)
This section outlines requirements for filing a complaint against a station that is not in compliance. Complaints must include channel number, network, call sign, TV program in violation, and details of the captioning problem. It also offer broadcasters guidelines on how these complaints are handled by the FCC. First, the station is notified by the FCC that a complaint has been registered against them. From there, the station has 30 days to reply with a statement that outlines the corrective steps they have taken to fix the issues outlined in the complaint. If complaints for a given issues re-occur within 30 days, the station must submit and action plan to the FCC that outlines what the station is doing to correct these issues. Then, the station must complete spot-checks of it’s captioning equipment and procedures to ensure compliance. The station must then report to the FCC within 180 days. If this is not completed and non-compliance continues, the station may be required to pay fines. Stations using Electronic Newsroom Techniques (ENT) must submit to the FCC, with the help of viewers who rely on captions, a report on their experiences using the ENT procedures. This must be done by June 30, 2015.
Captioning Quality Requirements – Section 79.1(j)(1)
Broadcasters are now required to document the captioning certification of from the programmers that it receives content from. Documentation must include proof that the programmer meets existing quality standards, follows established best practices, and if they are exempt, have documented their exemption. A certificate of exemption must exist if this is the case. Stations can usually fulfill this obligation with certification found on the programmer’s web site or other public listing. If the station requests certification from the programmer, they have 30 days to respond accordingly. If the programmer fails to do this, the station must report it to the FCC within 30 days. If stations comply with these procedure they will not be held liable.
Captioning Best Practices – Section 79.1(k)
These are guidelines for the improvement of caption quality. These basically ensure that the content programmers are following established guidelines for delivering closed captions with content. For instance, programmers should provide captioning vendors with scripts, spelling of proper nouns, or song lyrics to streamline the captioning process and accuracy.
Typically, broadcasters are more aware of the these regulations than content creators. As of today, broadcasters will begin the process of educating programmers on the new requirements to ensure compliance.
Processing Closed Captions with Encoding.com’s API
The live Closed Captioning feature set is available within our API to rapidly upgrade our customers’ digital video authoring and distribution workflows. The new feature set permits customers to extract closed captions from source files stored somewhere on the Internet and convert them into sidecar files. Customers can also copy a closed caption or timed text track from a source video into an output video. And we allow customers to mux a sidecar file (in SRT or SCC format) with a source video to encode a valid closed caption track into their output videos. The idea is to use the cloud to empower customers to easily increase their addressable audience while saving money and obeying the law.
The parameters for closed captioning are as follows:
- source: Specify the source URL of your closed caption file. Acceptable file formats are SCC, SubRip, DFXP (TTML), and SAMI.
- copy: Do you have analog captions in a library of ASF, MOV, MXF, MPEG-2, or some other kind of files? Do you need HTTP Live Streaming output but don’t want to waste time extracting and muxing pesky sidecar files? Do you have 3GPP Timed Text captions in 3GP files and need them in MP4 files instead? Customers have both these problems. solves them. It rocks. The copy parameter allows you to re-mux existing closed captions in cea-608 or cea-708 formats to your encoded output. Encoding.com will attempt to extract the existing closed captions and mux them back.
- extract: Extraction of a closed caption sidecar file is often necessary. Browser-based video players can’t read closed caption tracks in digital videos. Android video players mostly require sidecar files as well. Editing and authoring suites depend on sidecar files to make it easier for video editors to do their jobs.
- Encoding.com is the only cloud transcoding provider to support extraction of closed caption “sidecar" files from the most common closed caption tracks in HD television (CEA-708) and SD television (CEA-608) programming. We also extract the closed captions from 3GPP TT or MPEG-4 Part 17 tracks in a video file. You can produce output video in any format while extracting a caption track as a SCC or SRT sidecar.
- mux_type: Muxing a sidecar with a video file is a common requirement. Editors often use SCC sidecars to exchange timed text information among authoring tools, files and/or colleagues. DVD publishers convert SCC files into analog closed captions to encode into their MPEG-2 creations. Digital captions have to become analog captions before they can be inserted into HTTP Live Streaming files for delivery to iOS apps. There are other common workflows.
<format>
<!-- Format fields -->
<closed_captions>
<source>[CCSource]</source>
<copy>[yes|no]</copy>
<extract>[srt|scc|dfxp]</extract>
<mux_type>[cea-608|cea-708|timed-text|webvtt|burn-in]</mux_type> <language>[LanguageCode]</language>
<time_offset>[TimeOffset]</time_offset>
</closed_captions>
</format>