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Subtitle Guidelines

BBC © 2016

Version 1.0
18th January 2016

1 Introduction

1.1 Purpose and scope

This document brings together guideline documents previously published by Ofcom and the BBC. It is intended to serve as the basis for all subtitle work across the BBC (Prepared and live, online and broadcast, internal and supplied), and to guide subtitle creators and developers.

This document describes ‘closed’ subtitles only (i.e. they can be switched off by the user and are not ‘burnt in’ to the image). Its intended audience is:

  • Subtitle authors (respeaker, stenographer, editor)
  • Content producers and distributors
  • Software developers (tools for authoring, validation, conversion and presentation)
  • Quality control and compliance

This chart is a high-level view of current subtitle workflows:

Diagram showing high level view of subtitle workflow

1.2 References

BBC-ASP: ‘BBC Access Services Presentation & Style Guidelines’ (internal document). 2012

BBC-OSE: ‘bbc.co.uk Online Subtitling Editorial Guidelines V1.1’. 2009.

EBU-STL: ‘Specification of the EBU Subtitling data exchange format', TECH. 3264-E. 1991

EBU-TT 1.0: 'Part 1 Subtitling Format Definition', Tech3350

EBU-TT 1.1: 'Part 1 Subtitling Format Definition', Tech3350

ITC-GSS: ‘ITC Guidance on Standards for Subtitling’. 1999.

Ofcom-IQLS: ‘The quality of live subtitling - Improving the viewer experience’. 2013

1.3 Document contents

This document describes the delivery format of files that carry subtitle information and how they should be authored for correct presentation. The appendices include resources such as the Teletext character set, a sample file and a validation schema.

1.4 Document conventions

Subtitle example

Subtitle counter-example

broadcast - applies only to subtitles for broadcast (linear).

online - applies only to subtitles for non-linear (online).

When no broadcast or online flag is indicated, the text applies to both broadcast and online.

experimental - applies to features that are considered to be available as experimental options only and should not be included for general use.

FILE FORMAT

2 Files

Prepared subtitles must be delivered as a 2-file set for broadcast and as a single file for online-only.

Platform

Format

Extension

Specification

Notes

Broadcast and online

EBU-STL

.stl

https://tech.ebu.ch/docs/tech/tech3264.pdf

Required for linear broadcast legacy systems.

EBU-TT

.xml

https://tech.ebu.ch/files/live/sites/tech/
files/shared/tech/tech3350v1-0.pdf
(to be replaced by v1.1)

With the STL embedded. See below.

online EBU-TT-D .ebuttd.xml https://tech.ebu.ch/docs/tech/tech3380.pdf  

Note that the above standards support a larger set of characters than is allowed by the BBC. For linear playout, all characters for presentation must be in the set in Appendix 1.

2.1 STL file

2.1.1 File name

The file name must follow this pattern: [UID with slash removed].stl

For example:

UID

File name

DRIB511W/02

DRIB511W02.stl

2.1.2 General subtitle information (GSI) block

Subtitles must conform to the EBU specification TECH 3264-E. However, the BBC requires certain values in particular elements of the General Subtitle Information Block. See the table below.

GSI block data

Short

Value

Notes

Example

Code Page Number

CPN

850

Required


Disk Format Code

DFC

25.01

Required


Display Standard Code

DSC

1

Required


Character Code Table

CCT

0

Required


Language Code

LC

09

Required


Original Programme Title

OPT


Required

Snow White

Original Episode Title

OET

Tape number

Required if a tape number exists.

HDS147457

Translated Programme Title

TPT


Required if translated


Translated Episode Title

TET


Optional

Series 1, Episode 1

Translator's Name

TN

Up to 32 characters

Optional

Jane Doe

Translator's Contact Details

TCD

Up to 32 characters

Optional


Subtitle List Reference Code

SLR

On-air UID

broadcast Required for Prepared linear

ABC D123W/02

Creation Date

CD

YYMMDD

Required

150125

Revision Date

RD

YYMMDD

Required

150128

Revision Number

RN

0 – 99

Required

1

Total Number of TTI Blocks

TNB

0 – 99,999

Required. Must accurately reflect the number of blocks in the file.

767

Total Number of Subtitles

TNS

0 – 99,999

Required. Must accurately reflect the number of subtitles in the file.

767

Total Number of Subtitle Groups

TNG

1

Required. Fixed at 1.

1

Maximum Number of Displayable Characters in any text row

MNC

0 – 99

Required

58

Maximum Number of Displayable Rows

MNR

11

Required


Time Code: Status

TCS

1

Required


Time Code: Start-of-Programme

TCP

HHMMSSFF

Required

10000000, 20000000

Time Code: First in-cue

TCF

00000000

Required. Subtitle zero must be present.


Total Number of Disks

TND

Number of files

Required. Almost always 1 except for very long programmes where the subtitles may be split into multiple files (one per 'disk').

1

Disk Sequence Number

DSN

The file number of this file.

Required. Always 1 when there is one STL file in the sequence.

1

Country of Origin

CO

3-letter country code

Required

GBR

Publisher

PUB

Up to 32 characters

Required

Company name

Editor's Name

EN

Up to 32 characters

Required

John Doe

Editor's Contact Details

ECD

Up to 32 characters

Optional


Spare bytes

SB

Empty

Optional


User-Defined Area

UDA

Up to 576 characters

Not used.


 

2.1.3 Timecode

The Time Code Out (TCO) values in STL files are inclusive of the last frame; in other words the subtitle shall be visible on the frame indicated in the TCO value but not on subsequent frames. This differs from the end time expressions in EBU-TT and TTML, which are exclusive.

2.2 EBU-TT file

When present, the STL file(s) must be embedded in an EBU-TT document. See below for further details.

Embedded STL files may be omitted if the subtitles are created live and then captured.

2.2.1 File name

The file name has this format:

[ebuttm:documentIdentifier]-prerecorded.xml

See the rules for constructing ebuttm:documentIdentifier below.

2.2.2 <tt:tt> attributes

The following table lists standard EBU-TT elements and their required values.

Attribute

Value

Notes

Example

xml:space


Optional

preserve

ttp:timeBase

smpte

Required


ttp:framerate


Required. Must match the frame rate of the associated video.

25

ttp:frameRateMultiplier


Optional. Include if a non-integer framerate is used in the associated video.

1 1

ttp:markerMode

discontinuous

Required.


ttp:dropMode


Optional. Required if a non-integer framerate with a drop mode is used.

nonDrop

ttp:cellResolution

40 24

Required. This value is used to preserve Teletext positioning.


xml:lang


required

en-GB

2.2.3 <ebuttm:documentMetadata> elements (v1.0)

The below table lists the required document metadata values for the currently used EBU-TT 1.0. This should be replaced under change control by EBU-TT Part 1 version 1.1 (see below).

Element

Value

Notes

Example

ebuttm:documentEbuttVersion

v1.0

required


ebuttm:documentIdentifier

See below.

Required if not live

ABCD123W02-1

ebuttm:documentOriginatingSystem

Software and version

required

TTProducer 1.7.0.0

ebuttm:documentCopyright

BBC

required


ebuttm:documentReadingSpeed

Calculated per document

required

176

ebuttm:documentTargetAspectRatio

4:3 (16:9 allowed for online use only)

required


ebuttm:documentIntendedTargetFormat

Required if also targeting broadcast applications.

required

WSTTeletextSubtitles

ebuttm:documentOriginalProgrammeTitle


required

Snow White

ebuttm:documentOriginalEpisodeTitle


required

Series 1, Episode 1

ebuttm:documentSubtitleListReferenceCode

[UID]

required

ABC D123W/02

ebuttm:documentCreationDate

YYYY-MM-DD

required

2015-01-20

ebuttm:documentRevisionDate

YYYY-MM-DD

Required

2015-01-20

ebuttm:documentRevisionNumber



1

ebuttm:documentTotalNumberOfSubtitles

Calculated per document

required

767

ebuttm:documentMaximumNumberOfDisplayableCharacterInAnyRow



37

ebuttm:documentStartOfProgramme

10:00:00:00 or 20:00:00:00

Required


ebuttm:documentCountryOfOrigin

GBR

Required


ebuttm:documentPublisher

Name

Required

Company name

ebuttm:documentEditorsName

Name

Required

John Doe

Document identifier

The document identifier is obtained by reading the string from the embedded STL's GSI “Reference Code” field (On Air UID) and then deleting any spaces and "/" character. This string is appended with a hyphen and the value of the Revision Number field in the STL's GSI block.

2.2.4 <ebuttm:documentMetadata> elements (v1.1)

The below table lists the required document metadata values for the EBU-TT 1.1.

Element

Value

Notes

Example

ebuttm:conformsToStandard

urn:ebu:tt:exchange:2015-09

Required


ebuttm:documentIdentifier

[OnAir UID] -[sub file version]

Required if not live

ABCD123W02-1

ebuttm:documentOriginatingSystem

Software and version

required

TTProducer 1.7.0.0

ebuttm:documentCopyright

BBC

required


ebuttm:documentReadingSpeed

Calculated per document

required

176

ebuttm:documentTargetAspectRatio

4:3 (16:9 allowed for online use only)

required


ebuttm:documentTargetActiveFormatDescriptor

one of the AFD codes specified in SMPTE ST 2016-1:2009 Table 1



ebuttm:documentIntendedTargetBarData

Bar Data from SMPTE ST 2016-1:2009 Table 3. Note additional attributes may be required. See the EBU-TT specification.

Optional


ebuttm:documentIntendedTargetFormat

The English name of one of the of the formats listed in

www.ebu.ch/metadata/cs/EBU-TTSubtitleTargetFormatCodeCS.xml

The URI to the term should be specified by using the link attribute.

Required


ebuttm:documentCreationMode

live | prepared

Required


ebuttm:documentContentType

hardOfHearingSubtitles

Required


ebuttm:sourceMediaIdentifier

[OnAir UID][version #]-[sub file version]

Required

ABCD123W02-1

ebuttm:relatedMediaIdentifier


Optional


ebuttm:relatedObjectIdentifier


Optional


ebuttm:appliedProcessing


Optional


ebuttm:relatedMediaDuration


Optional


ebuttm:documentBeginDate

the corresponding date of

creation of the earliest begin time expression (i.e. the begin time

expression that is the first coordinate in the document time line).

Optional


ebuttm:localTimeOffset

Timezone (in ISO 8601) when ttp:timebase is "clock" and ttp:clockmode is "local".

Optional

Z, +01:00

ebuttm:referenceClockIdentifier

Allows the reference clock source to be identified. Permitted only when ttp:timeBase="clock" AND ttp:clockMode="local" OR when ttp:timeBase="smpte".

Optional



Channel, transmission or other distribution

Optional

BBC1, CBeebies

ebuttm:documentTransitionStyle

Includes attributes only (inUnit and outUnit)

Optional


The following elements support the information that is present in the GSI block of the STL file. If more than one STL source file is used to generate an EBU-TT document, the GSI metadata cannot be mapped into ebuttm:documentMetadata unless the value of a GSI field is the same across all STL documents.

ebuttm:documentOriginalProgrammeTitle

Original programme title

required

Snow White

ebuttm:documentOriginalEpisodeTitle


Use bbctt:otherId (see below


ebuttm:documentTranslatedProgrammeTitle


required if translated


ebuttm:documentTranslatedEpisodeTitle


Optional

Series 1, Episode 1

ebuttm:documentTranslatorsName

Up to 32 characters

Optional

Jane Doe

ebuttm:documentTranslatorsContactDetails

Up to 32 characters

Optional


ebuttm:documentSubtitleListReferenceCode

On-air UID

broadcastRequired for Prepared linear

ABC D123W/02

ebuttm:documentCreationDate

YY-MM-DD

Required

2012-06-30

ebuttm:documentRevisionDate

YYYY-MM-DD

Required

15-01-28

ebuttm:documentRevisionNumber

0 – 99

Required

1

ebuttm:documentTotalNumberOfSubtitles

Non-negative integer

Required

767

ebuttm:documentMaximumNumberOfDisplayableCharacterInAnyRow

0 – 37

Required

58

ebuttm:documentStartOfProgramme

HH:MM:SS:FF

Required

10000000, 20000000

ebuttm:documentCountryOfOrigin

3-letter country code

Required

GBR

ebuttm:documentPublisher

Up to 32 characters

Required

Company name

ebuttm:documentEditorsName

Up to 32 characters

Required

John Doe

ebuttm:documentEditorsContactDetails

Up to 32 characters

Optional


ebuttm:documentUserDefinedArea

Up to 576 characters

Not used.


ebuttm:stlCreationDate

If the STL file is embedded using ebuttm:binaryData, do not use this element. Instead, use the creationDate attribute of ebuttm:binaryDataElement.

Optional


ebuttm:stlRevisionDate

If the STL file is embedded, use the revisionDate attribute of ebuttm:binaryDataElement.

Optional


ebuttm:stlRevisionNumber

If the STL file is embedded, use the revisionNumber attribute of ebuttm:binaryDataElement.

Optional


ebuttm:subtitleZero

If present, copy the content of subtitle zero from the STL

Optional


2.2.5 Extended BBC metadata

In addition to the standard EBU-TT elements listed above, the BBC requires the below metadata elements within a <bbctt:metadata> element. The <bbctt:metadata> element is the last child of <tt:metadata>. See Appendix 2 for a sample XML and Appendix 3 for the XSD.

bbctt:schemaVersion

Cardinality

1..1

Parent

bbctt:metadata

Description

The BBC metadata scheme used. Currently v1.0.

Value

v1.0

Example

<bbctt:schemaVersion>v1.0</bbctt:schemaVersion>

bbctt:timedTextType

Cardinality

1..1

Parent

bbctt:metadata

Description

Indicates whether subtitles were live or prepared. If live subtitles are modified following broadcast, this value must be changed to preRecorded.

Value

preRecorded| audioDescription | recordedLive | editedLive

Example

<bbctt:timedTextType>preRecorded</bbctt:timedTextType>

bbctt:timecodeType

Cardinality

1..1

Parent

bbctt:metadata

Description

Indicates whether timecode uses programme (pre-recorded) or UTC time (live)

Value

programme | timeOfDay

Example

<bbctt:timecodeType>programme</bbctt:timecodeType>

bbctt:programmeId

Cardinality

0..1

Parent

bbctt:metadata

Description

Required if not live.

Value

UID

Example

<bbctt:programmeId>DRIB511W/02</bbctt:programmeId>

bbctt:otherId type="tapeNumber"

Cardinality

0..1. Required if not live.

Parent

bbctt:metadata

Description

Use tape number for programmes that have a material reference.
Use Mat ID for programmes delivered as file.

Value


Example

<bbctt:otherId type="tapeNumber">HDS147457</bbctt:otherId>

bbctt:houseStyle owner=""

Cardinality

0..*

Parent

bbctt:metadata

Description

Required if live.

Value


Example


bbctt:recordedLiveService

Cardinality

0..*.. Required for a live recording if intended for broadcast. broadcast

Parent

bbctt:metadata

Description

Live only.

Value


Example


bbctt:div type=””

Cardinality

0..*

Parent

bbctt:metadata

Description

Generic container of type “shotChange” or “Script”

Value

<systemInfo>, <chapter>, <item> or <event> elements

Example

<bbctt:div type="shotChange"> <bbctt:systemInfo>Quantum Video Indexer v5.0</bbctt:systemInfo>

<bbctt:event begin="09:59:30:00" id="sc1" /> </bbctt:div>

bbctt:systemInfo

Cardinality

1..1

Parent

bbctt:div

Description

The system that produced the sibling elements.

Value

Single instance of bbctt:systemInfo and multiple instances of bbctt:event

Example

<bbctt:systemInfo>Quantum Video Indexer v5.0</bbctt:systemInfo>

bbctt:event

Cardinality

0..*

Parent

bbctt:div

Description

A single event, e.g. a shot change in a bbctt:div of type “shotChange”

Attributes

Attribute

Required?

Type

Begin

Yes

ebuttdt:timingType

End

AD fades only

ebuttdt:timingType

Endlevel

AD fades only

Integer

Id

No

NCName

Pan

AD fades only

integer

Type

No

NCName

Value

This is an empty element. Information is represented as element attributes.

Example

<bbctt:event begin="01:23:45:25" id="sc1"/>

bbctt:chapter id=””

Cardinality

1..*

Parent

bbctt:div

Description

A single event, e.g. a shot change in a bbctt:div of type “shotChange”

Value

This is an empty element. Information is represented as element attributes.

Example


bbctt:item

Cardinality

1..1

Parent

bbctt:div

Description

Generic container for the programme script elements.


Attribute

Required?

Type

id

Yes

string

Begin

No

ebuttdt:timingType

End

No

ebuttdt:timingType

Value

<bbctt:p>, <bbctt:itemid>, <bbctt:title>, <bbctt:associatedFile>

Example

<bbctt:item xml:id="it1">

<bbctt:p>

<bbctt:span ttm:role="x-direction">Snow White</bbctt:span> </bbctt:p> <bbctt:p>

<bbctt:span ttm:role="x-direction">(CONT’D) </bbctt:span> </bbctt:p> </bbctt:item>

bbctt:itemId

Cardinality

0..*

Parent

bbctt:item

Description

Used to link an item with an external system

Value

bbctt:itemId

Example


bbctt:title

Cardinality

0..1

Parent

bbctt:item

Description

Used to link an item with an external system

Value

String

Example


bbctt:associatedFile

Cardinality

0..1

Parent

bbctt:item

Description

Used to link an item with an external system

Value

bbctt:associatedFile

Example


bbctt:p

Cardinality

1..*

Parent

bbctt:item

Description

A single script element (paragraph)

Value

Single bbctt:span element

Example

<bbctt:p>

<bbctt:span ttm:role="x-direction">Snow White</bbctt:span> </bbctt:p>

bbctt:span

Cardinality

1..1

Parent

bbctt:p

Description

A single line of script

Value

Dialogue or direction text

Example

<bbctt:span ttm:role="dialog" ttm:agent="sp9">Snow white, wake up!</bbctt:span>

2.2.6 Embedded STL

The STL file(s), if present, must be embedded within the EBU-TT file, within the element ebuttm:binaryData:

ebuttm:binaryData

Cardinality

0..*

Parent

tt:metadata

Description

Transitional requirement.

Value

The complete STL file, BASE64 encoded. Type: EBU Tech 3264

Example

<ebuttm:binaryData textEncoding="BASE64" binaryDataType="EBU Tech 3264" fileName="DRIB511W02.STL">ODUwU1RMMjUuMDExMD….</ebuttm:binaryData>

2.3 EBU-TT-D file

online The file must conform to EBU-TT-D standard. Subtitles must be relative to a programme begin time of 00:00:00.000. The timebase must be set to 'media'.

online The file must be named [UID with slash removed].ebuttd.xml 

Note that embedded STL files are not permitted within EBU-TT-D documents.

2.4 Timecode

broadcast Prepared subtitles for linear programmes must use the SMPTE timebase with a start of programme aligned to the source media. This is usually (but not always) 10:00:00:00. See the BBC’s DPP delivery specifications.

online Prepared subtitles for online exclusives must be relative to a programme begin time of 00:00:00.000 .

Subtitles created live and captured must use the clock timebase with time expressions in UTC.

PRESENTATION

Good subtitling is an art that requires negotiating conflicting requirements. On the whole, you should aim for subtitles that are faithful to the audio. However, you will need to balance this against considerations such as the action on the screen, speed of speech or editing and visual content.

For example, if you subtitle a scene where a character is speaking rapidly, these are some of the decisions you may have to make:

  • Can viewers read the subtitles at the rate of speech
  • Should you edit out some words to allow more time
  • Can subtitles carry over to the scene so they ‘catch up’ with the rapper
  • Should you use cumulative subtitles to convey the rhythm of speech (for example, if rapping)
  • If there are shot changes within the sequence, should the subtitles be synchronised with those
  • Should you use one, two or three lines of subtitles
  • Should you change the position of the subtitle to avoid obscuring important visual information or to indicate the speaker

Clearly, it is not possible (or advisable) to provide a set of hard rules that cover all situations. Instead, this document provides some guidelines and practical advice. Their implementation will depend on the content, the genre and on the subtitler’s expertise.

3 Editing text

3.1 Prefer verbatim

If there is time for verbatim speech, do not edit unnecessarily. Your aim should be to give the viewer as much access to the soundtrack as you possibly can within the constraints of time, space, shot changes, and on-screen visuals, etc. You should never deprive the viewer of words/sounds when there is time to include them and where there is no conflict with the visual information.

However, if you have a very "busy" scene, full of action and disconnected conversations, it might be confusing if you subtitle fragments of speech here and there, rather than allowing the viewer to watch what is going on.

Don't automatically edit out words like "but", "so" or "too". They may be short but they are often essential for expressing meaning.

Similarly, conversational phrases like "you know", "well", "actually" often add flavour to the text.

3.2 Don’t simplify

It is not necessary to simplify or translate for deaf or hard-of-hearing viewers. This is not only condescending, it is also frustrating for lip-readers.

3.3 Retain speaker’s first and last words

If the speaker is in shot, try to retain the start and end of his/her speech, as these are most obvious to lip-readers who will feel cheated if these words are removed.

3.4 Edit evenly

Do not take the easy way out by simply removing an entire sentence. Sometimes this will be appropriate, but normally you should aim to edit out a bit of every sentence.

3.5 Keep names

Avoid editing out names when they are used to address people. They are often easy targets, but can be essential for following the plot.

3.6 Preserve the style

Your editing should be faithful to the speaker's style of speech, taking into account register, nationality, era, etc. This will affect your choice of vocabulary. For instance:

  • register: mother vs mum; deceased vs dead; intercourse vs sex;
  • nationality: mom vs mum; trousers vs pants;
  • era: wireless vs radio; hackney cab vs taxi.

Similarly, make sure if you edit by using contractions that they are appropriate to the context and register. In a formal context, where a speaker would not use contractions, you should not use them either.

Regional styles must also be considered: e.g. it will not always be appropriate to edit "I've got a cat" to "I've a cat"; and "I used to go there" cannot necessarily be edited to "I'd go there."

3.7 Consider the previous subtitle

Having edited one subtitle, bear your edit in mind when creating the next subtitle. The edit can affect the content as well as the structure of anything that follows.

3.8 Keep the form of the verb

Avoid editing by changing the form of a verb. This sometimes works, but more often than not the change of tense produces a nonsense sentence. Also, if you do edit the tense, you have to make it consistent throughout the rest of the text.

3.9 Keep words that can be easily lip-read

Sometimes speakers can be clearly lip-read - particularly in close-ups. Do not edit out words that can be clearly lip-read. This makes the viewer feel cheated. If editing is unavoidable, then try to edit by using words that have similar lip-movements. Also, keep as close as possible to the original word order.

3.10 Subtitle illegible text

If the onscreen graphics are not easily legible because of the streamed image size or quality, the subtitles must include any text contained within those graphics which provide contextual information. This must include the speaker’s identity, what they do and any organisations they represent. Other displayed information affected by legibility problems that must be included in the subtitle includes; phone numbers, email addresses, postal addresses, website URLs, or other contact information.

If the information contained within the graphics is off-topic from what is being spoken, then the information should not be replicated in the subtitle.

3.11 Strong language

Do not edit out strong language unless it is absolutely impossible to edit elsewhere in the sentence - deaf or hard-of-hearing viewers find this extremely irritating and condescending.

If the BBC has decided to edit any strong language, then your subtitles must reflect this in the following ways.

3.11.1 Bleeped words

If the offending word is bleeped, put the word BLEEP in the appropriate place in the subtitle - in caps, in a contrasting colour and without an exclamation mark.

BLEEP

If only the middle section of a word is bleeped, do not change colour mid-word:

f-BLEEP-ing

3.11.2 Dubbed words

If the word is dubbed with a euphemistic replacement - e.g. frigging - put this in. If the word is non-standard but spellable put this in, too:

frerlking

If the word is dubbed with an unrecognisable sequence of noises, leave them out.

3.11.3 Muted words

If the sound is dipped for a portion of the word, put up the sounds that you can hear and three dots for the dipped bit:

Keep your f...ing nose out of it!.

Never use more than three dots.

If the word is mouthed, use a label:

So (MOUTHS) f...ing what?

4 Line breaks

4.1 Line length

The maximum space available for subtitle text is determined by the platform:

Platform

Max length

Notes

broadcast

37 characters, reduced if coloured text is used

Teletext constraint

online

68% of the width of a 16:9 video and 90% of the width of a 4:3 video

the number of characters that generate this width is determined by the font used at the given font size (see fonts).

4.2 Subtitles should contain single sentences

Each subtitle should comprise a single complete sentence. Depending on the speed of speech, there are exceptions to this general recommendation (see live subtitling, short and long sentences below)

4.3 Avoid 3 lines or more

A maximum subtitle length of two lines is recommended. Three lines may be used if you are confident that no important picture information will be obscured. When deciding between one long line or two short ones, consider line breaks, number of words, pace of speech and the image.

4.4 Break at natural points

Subtitles and lines should be broken at logical points. The ideal line-break will be at a piece of punctuation like a full stop, comma or dash. If the break has to be elsewhere in the sentence, avoid splitting the following parts of speech:

  • article and noun (e.g. the + table; a + book)
  • preposition and following phrase (e.g. on + the table; in + a way; about + his life)
  • conjunction and following phrase/clause (e.g. and + those books; but + I went there)
  • pronoun and verb (e.g. he + is; they + will come; it + comes)
  • parts of a complex verb (e.g. have + eaten; will + have + been + doing)

However, since the dictates of space within a subtitle are more severe than between subtitles, line breaks may also take place after a verb. For example:

We are aiming to get
a better television service.

Line endings that break up a closely integrated phrase should be avoided where possible.

We are aiming to get a
better television service.

Line breaks within a word are especially disruptive to the reading process and should be avoided. Ideal formatting should therefore compromise between linguistic and geometric considerations but with priority given to linguistic considerations.

4.5 Breaks in justified subtitles

broadcast Left, right and centre justification can be useful to identify speaker position, especially in cases where there are more than three speakers on screen. In such cases, line breaks should be inserted at linguistically coherent points, taking eye-movement into careful consideration. For example:

We all hope
you are feeling much better.

This is left justified. The eye has least distance to travel from ‘hope’ to ‘you’.

We all hope you are
feeling much better.

This is centre justified. The eye now has least distance to travel from ‘are’ to ‘feeling’.

Problems occur with justification when a short sentence or phrase is followed by a longer one.

Oh.
He didn’t tell me you would be here.

In this case, there is a risk that the bottom line of the subtitle is read first.

Oh.
He didn’t tell me you would be here.

This could result in only half of the subtitle being read.

Allowances would therefore have to be made by breaking the line at a linguistically non-coherent point:

Oh. He didn’t tell me
you would be here.

Oh. He didn’t tell me you would be
here.

online Note that the iPlayer does not currently support horizontal positioning.

4.6 Consider the image

When making a choice between one long line or two short lines, you should consider the background picture. In general, ‘long and thin’ subtitles are less disruptive of picture content than are ‘short and fat’ subtitles, but this is not always the case. Also take into account the number of words, line breaks etc.

4.7 Consider speaker positioning

broadcast In dialogue sequences it is often helpful to use horizontal displacement in order to distinguish between different speakers. ‘Short and fat’ subtitles permit greater latitude for this technique.

4.8 Short sentences

Short sentences may be combined into a single subtitle if the available reading time is limited. However, you should also consider the image and the action on screen. For example, consecutive subtitles may reflect better the pace of speech.

4.9 Long sentences

In most cases verbatim subtitles are preferred to edited subtitles (see this research by BBC R&D) so avoid breaking long sentences into two shorter sentences. Instead, allow a single long sentence to extend over more than one subtitle. Sentences should be segmented at natural linguistic breaks such that each subtitle forms an integrated linguistic unit. Thus, segmentation at clause boundaries is to be preferred. For example:

When I jumped on the bus...

..I saw the man who had taken
the basket from the old lady.

Segmentation at major phrase boundaries can also be accepted as follows:

On two minor occasions
immediately following the war,...

..small numbers of people
were seen crossing the border.

There is considerable evidence from the psycho-linguistic literature that normal reading is organised into word groups corresponding to syntactic clauses and phrases, and that linguistically coherent segmentation of text can significantly improve readability.

Random segmentation must certainly be avoided:

On two minor occasions
immediately following the war, small...

..numbers of people, etc.

In the examples given above, sequences of dots (three at the end of a to-be-continued subtitle, and two at the beginning of a continuation) are used to mark the fact that a segmentation is taking place. Many viewers have found this technique helpful.

4.10 Prioritise editing and timing over line breaks

Good line-breaks are extremely important because they make the process of reading and understanding far easier. However, it is not always possible to produce good line-breaks as well as well-edited text and good timing. Where these constraints are mutually exclusive, then well-edited text and timing are more important than line-breaks.

5 Timing

The recommended subtitle speed is 160-180 words-per-minute (WPM). However, viewers tend to prefer verbatim subtitles, so the rate may be adjusted to match the pace of the programme.

5.1 Target minimum timing

Based on the recommended rate of 160-180 words per minute, you should aim to leave a subtitle on screen for a minimum period of around 0.3 seconds per word (e.g. 1.2 seconds for a 4-word subtitle). However, timings are ultimately an editorial decision that depends on other considerations, such as the speed of speech, text editing and shot synchronisation. When assessing the amount of time that a subtitle needs to remain on the screen, think about much more than the number of words on the screen; this would be an unacceptably crude approach.

5.2 When to give less time

Do not dip below the target timing unless there is no other way of getting round a problem. Circumstances which could mean giving less reading time are:

5.2.1 Shot changes

Give less time if the target timing would involve clipping a shot, or crossing into an unrelated, "empty" [containing no speech] shot. However, always consider the alternative of merging with another subtitle.

5.2.2 Lip reading

Give less time to avoid editing out words that can be lip-read, but only in very specific circumstances: i.e. when a word or phrase can be read very clearly even by non-lip-readers, and if it would look ridiculous to take out or change the word.

5.2.3 Catchwords

Avoid editing out catchwords if a phrase would become unrecognisable if edited.

5.2.4 Retaining humour

Give less time if a joke would be destroyed by adhering to the standard timing, but only if there is no other way around the problem, such as merging or crossing a shot.

5.2.5 Critical information

In a news item or factual content, the main aim is to convey the “what, when, who, how, why”. If an item is already particularly concise, it may be impossible to edit it into subtitles at standard timings without losing a crucial element of the original.

5.2.6 Very technical items

These may be similarly hard to edit. For instance, a detailed explanation of an economic or scientific story may prove almost impossible to edit without depriving the viewer of vital information. In these situations a subtitler should be prepared to vary the timing to convey the full meaning of the original.

5.3 When to give extra time

Try to allow extra reading time for your subtitles in the following circumstances:

5.3.1 Unfamiliar words

Try to give more generous timings whenever you consider that viewers might find a word or phrase extremely hard to read without more time.

5.3.2 Several speakers

Aim to give more time when there are several speakers in one subtitle.

5.3.3 Labels

Allow an extra second for labels where possible, but only if appropriate.

5.3.4 Visuals and graphics

When there is a lot happening in the picture, e.g. a football match or a map, allow viewers enough time both to read the subtitle and to take in the visuals.

5.3.5 Placed subtitles

If, for example, two speakers are placed in the same subtitle, and the person on the right speaks first, the eye has more work to do, so try to allow more time.

5.3.6 Long figures

Give viewers more time to read long figures (e.g. 12,353).

5.3.7 Shot changes

Aim for longer timing if your subtitle crosses one shot or more, as viewers will need longer to read it.

5.3.8 Slow speech

Slower timings should be used to keep in sync with slow speech.

5.4 Use consistent timing

It is also very important to keep your timings consistent. For instance, if you have given 3:12 for one subtitle, you must not then give 4:12 to subsequent subtitles of similar length - unless there is a very good reason: e.g. slow speaker/on-screen action.

5.5 Gaps

If there is a pause between two pieces of speech, you may leave a gap between the subtitles - but this must be a minimum of one second, preferably a second and a half. Anything shorter than this produces a very jerky effect. Try to not squeeze gaps in if the time can be used for text.

6 Synchronisation

6.1 Match subtitle to speech onset

Impaired viewers make use of visual cues from the faces of television speakers. Therefore subtitle appearance should coincide with speech onset. Subtitle disappearance should coincide roughly with the end of the corresponding speech segment, since subtitles remaining too long on the screen are likely to be re-read by the viewer.

When two or more people are speaking, it is particularly important to keep in sync. Subtitles for new speakers must, as far as possible, come up as the new speaker starts to speak. Whether this is possible will depend on the action on screen and rate of speech.

The same rules of synchronisation should apply with off-camera speakers and even with off-screen narrators, since viewers with a certain amount of residual hearing make use of auditory cues to direct their attention to the subtitle area.

6.2 Match subtitle to pace of speaking

The subtitles should match the pace of speaking as closely as possible. Ideally, when the speaker is in shot, your subtitles should not anticipate speech by more than 1.5 seconds or hang up on the screen for more than 1.5 seconds after speech has stopped.

However, if the speaker is very easy to lip-read, slipping out of sync even by a second may spoil any dramatic effect and make the subtitles harder to follow. The subtitle should not be on the screen after the speaker has disappeared.

Note that some decoders might override the end timing of a subtitle so that it stays on screen until the next one appears. This is a non-compliant behaviour that the subtitle author and broadcaster have no control over.

6.3 Display subtitles when lips are moving

A subtitle (or an explanatory label) should always be on the screen if someone's lips are moving. If a speaker speaks very slowly, then the subtitles will have to be slow, too - even if this means breaking the timing conventions. If a speaker speaks very fast, you have to edit as much as is necessary in order to meet the timing requirements (see timing).

6.4 Keep lag behind speech to a minimum

Your aim is to minimise lag between speech and the appearance of the subtitle. But sometimes, in order to meet other requirements (e.g. matching shots), you will find it difficult to avoid slipping slightly out of sync. In this case, subtitles should never appear more than 2 seconds after the words were spoken. This should be avoided by editing the previous subtitles.

It is permissible to slip out of sync when you have a sequence of subtitles for a single speaker, providing the subtitles are back in sync by the end of the sequence.

If the speech belongs to an out-of-shot speaker or is voice-over commentary, then it's not so essential for the subtitles to keep in sync.

6.5 Do not pre-empt an effect

Do not bring in any dramatic subtitles too early. For example, if there is a loud bang at the end of, say, a two-second shot, do not anticipate it by starting the label at the beginning of the shot. Wait until the bang actually happens, even if this means a fast timing.

6.6 Keep speakers separate

Do not simultaneously caption different speakers if they are not speaking at the same time.

7 Matching shots

7.1 Match subtitles to shot

It is likely to be less tiring for the viewer if shot changes and subtitle changes occur at the same time. Many subtitles therefore start on the first frame of the shot and end on the last frame.

7.2 Maintain a minimum gap when mismatched

If you have to let a subtitle hang over a shot change, do not remove it too soon after the cut. The duration of the overhang will depend on the content.

7.3 Avoid straddling shot changes

Avoid creating subtitles that straddle a shot change (i.e. a subtitle that starts in the middle of shot one and ends in the middle of shot two). To do this, you may need to split a sentence at an appropriate point, or delay the start of a new sentence to coincide with the shot change.

7.4 Merge subtitles for short shots

If one shot is too fast for a subtitle, then you can merge the speech for two shots – provided your subtitle then ends at the second shot change.

Bear in mind, however, that it will not always be appropriate to merge the speech from two shots: e.g. if it means that you are thereby "giving the game away" in some way. For example, if someone sneezes on a very short shot, it is more effective to leave the "Atchoo!" on its own with a fast timing (or to merge it with what comes afterwards) than to anticipate it by merging with the previous subtitle.

7.5 End subtitle with speech

Where possible, avoid extending a subtitle into the next shot when the speaker has stopped speaking, particularly if this is a dramatic reaction shot.

7.6 End subtitle with scene

Never carry a subtitle over into the next shot if this means crossing into another scene or if it is obvious that the speaker is no longer around (e.g. if they have left the room).

7.7 Wait for scene change to subtitle speaker

Some film techniques introduce the soundtrack for the next scene before the scene change has occurred. If possible, the subtitler should wait for the scene change before displaying the subtitle. If this is not possible, the subtitle should be clearly labelled to explain the technique.

JOHN: And what have we here?

8 Identifying speakers

8.1 Use colours

Where necessary, use colours to distinguish speakers from each other (see Colours).

Where the speech for two or more speakers of different colours is combined in one subtitle, their speech runs on: i.e. you don't start a new line for each new speaker.

Did you see Jane? I thought she went home.

However, if two or more WHITE text speakers are interacting, you have to start a new line for each new speaker. Each piece of speech may then be placed underneath the relevant speaker rather than being centred (see Identifying Speakers).

8.2 Use horizontal positioning

broadcast Where colours cannot be used you can distinguish between speakers with placing.

Put each piece of speech on a separate line or lines and place it underneath the relevant speaker. You may have to edit more to ensure that the lines are short enough to look placed.

Try to make sure that pieces of speech placed right and left are "joined at the hip" if possible, so that the eye does not have to leap from one side of the screen to the other.

Not:

When characters move about while speaking, the caption should be positioned at the discretion of the subtitler to identify the position of the speaker as clearly as possible.

8.3 Use dashes

Put each piece of speech on a separate line and insert a white dash (not a hyphen) before each piece of speech, thereby clearly distinguishing different speakers' lines. The dashes should be aligned so that they are proud of the text.

The longest line should be centred on the screen, with the shorter line/lines left-aligned with it (not centred). If one of the lines is long, inevitably all the text will be towards the left of the screen, but generally the aim is to keep the lines in the centre of the screen.

Note that dashes only work as a clear indication of speakers when each speaker is in a separate consecutive shot.

8.4 Use single quotes for voice-over

If you need to distinguish between an in-vision speaker and a voice-over speaker, use single quotes for the voice-over, but only when there is likely to be confusion without them (single quotes are not normally necessary for a narrator, for example). Confusion is most likely to arise when the in-vision speaker and the voice-over speaker are the same person.

Put a single quote-mark at the beginning of each new subtitle (or segment, in live), but do not close the single quotes at the end of each subtitle/segment - only close them when the person has finished speaking, as is the case with paragraphs in a book.

'I've lived in the Lake District since I was a boy.

'I never want to leave this area.
I've been very happy here.

'I love the fresh air and the beautiful scenery.'

If more than one speaker in the same subtitle is a voice-over, just put single quotes at the beginning and end of the subtitle.

'What do you think about it? I'm not sure.'

The single quotes will be in the same colour as the adjoining text.

8.5 Use single quotes for out-of-vision speaker

When two white text speakers are having a telephone conversation, you will need to distinguish the speakers. Using single quotes placed around the speech of the out-of-vision speaker is the recommended approach. They should be used throughout the conversation, whenever one of the speakers is out of vision.

Hello. Victor Meldrew speaking.
'Hello, Mr Meldrew. I'm calling about your car.'

Single quotes are not necessary in telephone conversations if the out-of-vision speaker has a colour.

8.6 Use double quotes for mechanical speech

Double quotes "..." can suggest mechanically reproduced speech, e.g. radio, loudspeakers etc., or a quotation from a person or book.

8.7 Use arrows for off-screen voices

Generally, colours should be used to identify speakers. However, when an out-of-shot speaker needs to be distinguished from an in-shot speaker of the same colour, or when the source of off-screen/off-camera speech is not obvious from the visible context, insert a ‘greater than’ (>) or ‘less than’ (<) symbols to indicate the off-camera speaker.

If the out-of-shot speaker is on the left or right, type a left or right arrow (< or >) next to his or her speech and place the speech to the appropriate side. Left arrows go immediately before the speech, followed by one space; right arrows immediately after the speech, preceded by one space. Make the arrow clearly visible by keeping it clear of any other lines of text, i.e. the text following the arrow and the text in any lines below it are aligned.

NOT:

The arrows are always typed in white regardless of the text colour of the speaker.

If an off-screen speaker is neither to the right nor the left, but straight ahead, do not use an arrow.

8.8 Use labels for off-screen voices

If you are unable to use an arrow, use a label to identify the speaker. Type the name of the speaker in white caps (regardless of the colour of the speaker's text), immediately before the relevant speech.

If there is time, place the speech on the line below the label, so that the label is as separate as possible from the speech. If this is not possible, put the label on the same line as the speech, centred in the usual way.

JAMES:
What are you doing with that hammer?

JAMES: What are you doing?

If you do not know the name of the speaker, indicate the gender or age of the speaker if this is necessary for the viewer's understanding:

MAN: I was brought up in a close-knit family.

When two or more people are speaking simultaneously, do the following, regardless of their colours:

Two people:

BOTH: Keep quiet! (all white text)

Three or more:

ALL: Hello! (all white text)

TOGETHER: Yes! No! (different colours with a white label)

9 Colours

9.1 Use white on black

Most subtitles are typed in white text on a black background to ensure optimum legibility.

9.2 Avoid coloured background

Background colours are no longer used. Use labels to identify non-human speakers:

ROBOT: Hello, sir

Use left-aligned sound labels for alerts:

BUZZER

9.3 Speaker colours

A limited range of colours can be used to distinguish speakers from each other. In order of priority:

Colour

RGB hex

Notes

White

#FFFFFF


Yellow

#FFFF00


Cyan

#00FFFF


Green

#00FF00

In CSS, EBU-TT and TTML this is named colour ‘Lime’.

All of the above colours must appear on a black background to ensure maximum legibility.

9.4 Apply speaker colour consistently

Once a speaker has a colour, s/he should keep that colour. Avoid using the same colour for more than one speaker - it can cause a lot of confusion for the viewer.

The exception to this would be content with a lot of shifting main characters like EastEnders, where it is permissible to have two characters per colour, providing they do not appear together. If the amount of placing needed would mean editing very heavily, you can use green as a "floater": that is, it can be used for more than one minor character, again providing they never appear together.

9.5 Multiple speakers in white

White can be used for any number of speakers. If two or more white speakers appear in the same scene, you have to use one of a number of devices to indicate who says what - see Identifying Speakers.

10 Typography

10.1 Fonts

Subtitle fonts are determined by the platform, the delivery mechanism and the client as detailed below. Since fonts have different character widths, the final pixel width of a line of subtitles cannot be accurately determined when authoring. See also Line Breaks.

Platform

Delivery

Description

broadcast

DVB

The subtitle encoder creates bitmap images for each subtitle using the Tiresias font

broadcast

Teletext

The set top box or television determines the font - this is most commonly used on the Sky platform

online

IP (XML)

The client determines the font using information from within the subtitle data (e.g. 'SansSerif'). Generally it is better to use system font for readability (e.g. Helvetica for iOS and Roboto for Android). Use of non-platform fonts can adversely impact clarity of presented text.

10.2 Size

Font size should be set to fit within a line height of 8% of the active video height. Use mixed upper and lower case.

The width of the background is calculated per line, rather than being the largest rectangle that can fit all the displayed lines in.

On both sides of every line, the background colour should extend by the width of 0.5 ‘m’.

Image showing line height being 8% of active video height, character height being sized to fit

10.3 Supported characters

10.3.1 Broadcast

If the subtitles are intended for broadcast, a limited set of characters must be used.

Use alphanumeric and English punctuation characters:

A-Z a-z 0-9 ! ) ( , . ? : -

The following characters can be used:

> < & @ # % + * = / £ $ ¢ ¥ © ® ¼ ½ ¾ ¾ ™

Do not use accents.

Additional characters are supported but not normally used (see Appendix 1)

10.3.2 Characters permitted online

In addition to the characters above, the following characters are allowed if the subtitles are intended for online use only.

online € ♫ (replaces # to indicate music).

11 Positioning

The subtitles should overlay the image.

online For online subtitles, the subtitle rendering area (root container in EBU-TT-D) should exactly overlap the video player area unless controls or other overlays are visible, in which case the system should take steps to avoid the subtitles being obscured by the overlays. These could include:

  • Scaling the root container to avoid overlap
  • Detecting and resolving screen area clashes by moving subtitles around
  • Pausing the presentation while the overlays are visible.

11.1 Vertical positioning

The normally accepted position for subtitles is towards the bottom of the screen (Teletext lines 20 and 22. Line 18 is used if three subtitle lines are required). In obeying this convention it is most important to avoid obscuring ‘on-screen’ captions, any part of a speaker’s mouth or any other important activity. Certain special programme types carry a lot of information in the lower part of the screen (e.g. snooker, where most of the activity tends to centre around the black ball) and in such cases top screen positioning will be a more acceptable standard.

Generally, vertical displacement should be used to avoid obscuring important information (such as captions) while horizontal displacement should be reserved for indicating speakers (see Identifying Speakers).

In some case, vertical displacement may not be sufficient, for example when placing the captions above a graphic would cover a face. In such cases, prioritise the important information over speaker identification.

Image showing use of horizontal displacement instead of vertical displacement where vertical would obscure a face

11.2 Under image positioning

Some platform (e.g. online media player) support subtitles under the image. If the media player is embedded in the page the layout should change to accommodate the subtitle display.

When subtitles are displayed under the image area, vertical displacement will be ignored by the device and only horizontal positioning will be used (e.g. to identify speakers).

12 Intonation and emotion

12.1 Sarcasm

To indicate a sarcastic statement, use an exclamation mark in brackets (without a space in between):

Charming(!)

To indicate a sarcastic question, use a question mark in brackets:

You're not going to work today, are you(?)

12.2 Stress

Use caps to indicate when a word is stressed. Do not overuse this device - text sprinkled with caps can be hard to read. However, do not underestimate how useful the occasional indication of stress can be for conveying meaning:

It's the BOOK I want, not the paper.

I know that, but WHEN will you be finished?

The word "I" is a special case. If you have to emphasise it in a sentence, make it a different colour from the surrounding text. However, this is rare and should be used sparingly and only when there is no other way to emphasise the word.

Use caps also to indicate when words are shouted or screamed:

HELP ME!

However, avoid large chunks of text in caps as they can be hard to read.

12.2.1 Italics

online experimental Subtitles for online exclusives can use italics for emphasis instead of caps. If this approach is adopted italics should be used in most instances, with caps reserved for heavier emphasis (e.g. shouting).

Note that there is currently little research to indicate the effectiveness of italics for emphasis in subtitles.

12.3 Whisper

To indicate whispered speech, a label is most effective.

WHISPERS:
Don't let him near you.

However, when time is short, place brackets around the whispered speech:

(Don't let him near you.)

If the whispered speech continues over more than one subtitle, brackets can start to look very messy, so a label in the first subtitle is preferable.

Brackets can also be used to indicate an aside, which may or may not be whispered.

12.4 Incredulous question

Indicate questions asked in an incredulous tone by means of a question mark followed by an exclamation mark (no space):

You mean you're going to marry him?!

13 Accents

13.1 Indicate accent only when required

Do not indicate accent as a matter of course, but only where it is relevant for the viewer's understanding. This is rarely the case in serious/straight news reports, but may well be relevant in lighter factual items. For example, you would only indicate the nationality of a foreign scientist being interviewed on Horizon or the Ten O’Clock News if it were relevant to the subject matter and the viewer could not pick the information up from any other source, e.g. from their actual words or any accompanying graphics. However, in a drama or comedy where a character's accent is crucial to the plot or enjoyment, the subtitles must establish the accent when we first see the character and continue to reflect it from then on.

13.2 Indicate accent sparingly

When it is necessary to indicate accent, bear in mind that, although the subtitler's aim should always be to reproduce the soundtrack as faithfully as possible, a phonetic representation of a speaker's foreign or regional accent or dialect is likely to slow up the reading process and may ridicule the speaker. Aim to give the viewer a flavour of the accent or dialect by spelling a few words phonetically and by including any unusual vocabulary or sentence construction that can be easily read. For a Cockney speaker, for instance, it would be appropriate to include quite a few "caffs", "missus" and "ain'ts", but not to replace every single dropped "h" and "g" with an apostrophe.

13.3 Incorrect grammar

You should not correct any incorrect grammar that forms an essential part of dialect, e.g. the Cockney “you was”.

A foreign speaker may make grammatical mistakes that do not render the sense incomprehensible but make the subtitle difficult to read in the given time. In this case, you should either give the subtitle more time or change the text as necessary:

I and my wife is being marrying four years since and are having four childs, yes

This could be changed to:

I and my wife have been married four years and have four childs, yes

13.4 Use label

The speech text alone may not always be enough to establish the origin of an overseas/regional speaker. In that case, and if it is necessary for the viewer's understanding of the context of the content, use a label to make the accent clear:

AMERICAN ACCENT:
All the evidence points to a plot.

14 Difficult speech

14.1 Edit lightly

Remember that what might make sense when it is heard might make little or no sense when it is read. So, if you think the viewer will have difficulty following the text, you should make it read clearly. This does not mean that you should always sub-edit incoherent speech into beautiful prose. You should aim to tamper with the original as little as possible - just give it the odd tweak to make it intelligible. (Also see Accents)

14.2 Consider the dramatic effect

The above is more applicable to factual content, e.g. News and documentaries. Do not tidy up incoherent speech in drama when the incoherence is the desired effect.

14.3 Use labels for incoherent speech

If a piece of speech is impossible to make out, you will have to put up a label saying why:

(SLURRED): But I love you!

Avoid subjective labels such as "UNINTELLIGIBLE" or "INCOMPREHENSIBLE" or "HE BABBLES INCOHERENTLY".

14.4 Use labels for inaudible speech

Speech can be inaudible for different reasons. The subtitler should put up a label explaining the cause.

APPLAUSE DROWNS SPEECH

TRAIN DROWNS HIS WORDS

MUSIC DROWNS SPEECH

HE MOUTHS

14.5 Explain pauses in speech

Long speechless pauses in can sometimes lead the viewer to wonder whether the subtitles have failed. It can help in such cases to insert explanatory text such as:

INTRODUCTORY MUSIC

LONG PAUSE

ROMANTIC MUSIC

14.6 Break up subtitles slow speech

If a speaker speaks very slowly or falteringly, break your subtitles more often to avoid having slow subtitles on the screen. However, do not break a sentence up so much that it becomes difficult to follow.

14.7 Indicate stammer

If a speaker stammers, give some indication (but not too much) by using hyphens between repeated sounds. This is more likely to be needed in drama than factual content. Letters to show a stammer should follow the case of the first letter of the word.

I'm g-g-going home

W-W-What are you doing?

15 Hesitation and interruption

15.1 Indicate hesitation only if important

If a speaker hesitates, do not edit out the "ums" and "ers" if they are important for characterisation or plot. However, if the hesitation is merely incidental and the "ums" actually slow up the reading process, then edit them out. (This is most likely to be the case in factual content, and too many "ums" can make the speaker appear ridiculous.)

15.2 Within a single subtitle

When the hesitation or interruption is to be shown within a single subtitle, follow these rules:

15.2.1 Pause within a sentence

To indicate a pause within a sentence, insert three dots at the point of pausing, then continue the sentence immediately after the dots, without leaving a space.

Everything that matters...is a mystery

You may need to show a pause between two sentences within one subtitle. For example, where a phone call is taking place and we can only witness one side of it, there may not be time to split the sentences into separate subtitles to show that someone we can't see or hear is responding. In this case, you should put two dots immediately before the second sentence.

How are you? …Oh, I'm glad to hear that.

A very effective technique is cumulative subtitle, where the first part appears before the second, and both remain on screen until the next subtitle. Use this method only when the content justifies it; standard prepared subtitles should be displayed in blocks.

15.2.2 Unfinished sentence

If the speaker simply trails off without completing a sentence, put three dots at the end of his/her speech. If s/he then starts a new sentence, no continuation dots are necessary.

Hello, Mr... Oh, sorry! I've forgotten your name

15.2.3 Unfinished question/exclamation

If the unfinished sentence is a question or exclamation, put three dots (not two) before the question mark or exclamation mark.

What do you think you're...?!

15.2.4 Interruption

If a speaker is interrupted by another speaker or event, put three dots at the end of the incomplete speech.

15.3 Across subtitles

When the hesitation or interruption occurs in the middle of a sentence that is split across two subtitles, do the following:

15.3.1 Indicate time lapse with dots

Where there is no time-lapse between the two subtitles, put three dots at the end of the first subtitle but no dots in the second one.

I think...
I would like to leave now.

Where there is a time-lapse between the two subtitles, put three dots at the end of the first subtitle and two dots at the beginning of the second, so that it is clear that it is a continuation.

I'd like...

...a piece of chocolate cake

Remember that dots are only used to indicate a pause or an unfinished sentence. You do not need to use dots every time you split a sentence across two or more subtitles.

16 Humour

In humorous sequences, it is important to retain as much of the humour as possible. This will affect the editing process as well as when to leave the screen clear.

16.1 Separate punchlines

Try wherever possible to keep punchlines separate from the preceding text.

16.2 Reactions

Where possible, allow viewers to see actions and facial expressions which are part of the humour by leaving the screen clear or by editing. Try not to use reaction shots containing no speech in order to gain time.

16.3 Keep catchphrases

Never edit characters' catchphrases.

17 Music and songs

17.1 Label source music

All music that is part of the action, or significant to the plot, must be indicated in some way. If it is part of the action, e.g. somebody playing an instrument/a record playing/music on a jukebox or radio, then write the label in upper case:

SHE WHISTLES A JOLLY TUNE

POP MUSIC ON RADIO

MILITARY BAND PLAYS SWEDISH NATIONAL ANTHEM

17.2 Describe incidental music

If the music is “incidental music” (i.e. not part of the action) and well known or identifiable in some way, the label begins “MUSIC:” followed by the name of the music (music titles should be fully researched). “MUSIC” is in caps (to indicate a label), but the words following it are in upper and lower case, as these labels are often fairly long and a large amount of text in upper case is hard to read.

MUSIC: "The Dance Of The Sugar Plum Fairy”
by Tchaikovsky

MUSIC: “God Save The Queen”

MUSIC: A waltz by Victor Herbert

MUSIC: The Swedish National Anthem

(The Swedish National Anthem does not have quotation marks around it as it is not the official title of the music.)

17.3 Combine source and incidental music

Sometimes a combination of these two styles will be appropriate:

HE HUMS “God Save The Queen”

SHE WHISTLES “The Dance Of The Sugar Plum Fairy”
by Tchaikovsky

17.4 Label mood music only when required

If the music is "incidental music" but is an unknown piece, written purely to add atmosphere or dramatic effect, do not label it. However, if the music is not part of the action but is crucial for the viewer’s understanding of the plot, a sound-effect label should be used:

EERIE MUSIC

17.5 Indicate song lyrics with #

Song lyrics are almost always subtitled - whether they are part of the action or not. Every song subtitle starts with a white hash mark (#) and the final song subtitle has a hash mark at the start and the end:

# These foolish things remind me of you #

There are two exceptions:

  • In cases where you consider the visual information on the screen to be more important than the song lyrics, leave the screen free of subtitles.
  • Where snippets of a song are interspersed with any kind of speech, and it would be confusing to subtitle both the lyrics and the speech, it is better to put up a music label and to leave the lyrics unsubtitled.

17.6 Avoid editing lyrics

Song lyrics should generally be verbatim, particularly in the case of well-known songs (such as God Save The Queen), which should never be edited. This means that the timing of song lyric subtitles will not always follow the conventional timings for speech subtitles, and the subtitles may sometimes be considerably faster.

If, however, you are subtitling an unknown song, specially written for the content and containing lyrics that are essential to the plot or humour of the piece, there are a number of options:

  • edit the lyrics to give viewers more time to read them
  • combine song-lines wherever possible
  • do a mixture of both - edit and combine song-lines.

NB: If you do have to edit, make sure that you leave any rhymes intact.

17.7 Synchronise with audio

Song lyric subtitles should be kept closely in sync with the soundtrack. For instance, if it takes 15 seconds to sing one line of a hymn, your subtitle should be on the screen for 15 seconds.

Song subtitles should also reflect as closely as possible the rhythm and pace of a performance, particularly when this is the focus of the editorial proposition. This will mean that the subtitles could be much faster or slower than the conventional timings.

There will be times where the focus of the content will be on the lyrics of the song rather than on its rhythm - for example, a humorous song like Ernie by Benny Hill. In such cases, give the reader time to read the lyrics by combining song-lines wherever possible. If the song is unknown, you could also edit the lyrics, but famous songs like Ernie must not be edited.

Where shots are not timed to song-lines, you should either take the subtitle to the end of the shot (if it's only a few frames away) or end the subtitle before the end of the shot (if it's 12 frames or more away).

17.8 Centre lyrics subtitles

All song-lines should be centred on the screen.

17.9 Punctuation

It is generally simpler to keep punctuation in songs to a minimum, with punctuation only within lines (when it is grammatically necessary) and not at the end of lines (except for question marks). You should, though, avoid full stops in the middle of otherwise unpunctuated lines. For example,

Turn to wisdom. Turn to joy
There’s no wisdom to destroy

Could be changed to:

# Turn to wisdom, turn to joy
There’s no wisdom to destroy

In formal songs, however, e.g. opera and hymns, where it could be easier to determine the correct punctuation, it is more appropriate to punctuate throughout.

The last song subtitle should end with a full stop, unless the song continues in the background.

If the subtitles for a song don't start from its first line, show this by using two continuation dots at the beginning:

# ..Now I need a place to hide away
# Oh, I believe in yesterday. #

Similarly, if the song subtitles do not finish at the end of the song, put three dots at the end of the line to show that the song continues in the background or is interrupted:

# I hear words I never heard in the Bible... #

18 Sound effects

18.1 Subtitle effects only when necessary

As well as dialogue, all editorially significant sound effects must be subtitled. This does not mean that every single creak and gurgle must be covered - only those which are crucial for the viewer's understanding of the events on screen, or which may be needed to convey flavour or atmosphere, or enable them to progress in gameplay, as well as those which are not obvious from the action. A dog barking in one scene could be entirely trivial; in another it could be a vital clue to the story-line. Similarly, if a man is clearly sobbing or laughing, or if an audience is clearly clapping, do not label.

Do not put up a sound-effect label for something that can be subtitled. For instance, if you can hear what John is saying, JOHN SHOUTS ORDERS would not be necessary.

18.2 Describe sounds, not actions

Sound-effect labels are not stage directions. They describe sounds, not actions:

GUNFIRE

not:

THEY SHOOT EACH OTHER

18.3 Format

A sound effect should be typed in white caps. It should sit on a separate line and be placed to the left of the screen - unless the sound source is obviously to the right, in which case place to the right.

18.4 Subject + verb

Sound-effect labels should be as brief as possible and should have the following structure: subject + active, finite verb:

FLOORBOARDS CREAK

JOHN SHOUTS ORDERS

Not:

CREAKING OF FLOORBOARDS

Or

FLOORBOARDS CREAKING

Or

ORDERS ARE SHOUTED BY JOHN

18.5 In-vision translations

If a speaker speaks in a foreign language and in-vision translation subtitles are given, use a label to indicate the language that is being spoken. This should be in white caps, ranged left above the in-vision subtitle, followed by a colon. Time the label to coincide with the timing of the first one or two in-vision subtitles. Bring it in and out with shot-changes if appropriate.

Screen shot of Japanese temple with burnt-in translation and subtitle IN JAPANESE:

If there are a lot of in-vision subtitles, all in the same language, you only need one label at the beginning - not every time the language is spoken.

If the language spoken is difficult to identify, you can use a label saying TRANSLATION:, but only if it is not important to know which language is being spoken. If it is important to know the language, and you think the hearing viewer would be able to detect a language change, then you must find an appropriate label.

18.6 Animal noises

The way in which subtitlers convey animal noises depends on the content style. In factual wildlife, for instance, lions would be labelled:

LIONS ROAR

However, in an animation or a game, it may be more appropriate to convey animal noises phonetically. For instance, "LIONS ROAR" would become something like:

Rrrarrgghhh!

19 Numbers

19.1 Spelling out

Unless otherwise specified below, spell out all numbers from one to ten, but use numerals for all numbers over 10.

Spell out any number that begins a sentence.

Spell out non-emphatic numbers:

She gave me hundreds of reasons

If there is more than one number in a sentence or list, it may be more appropriate to display them as numerals instead of words:

On her 21st birthday party, 54 guests turned up

Numerals over 4 digits must include appropriately placed commas.

For sports, competitions, games or quizzes, always use numerals to display points, scores or timings.

19.2 Dates

For displaying the day of the month, use the appropriate numeral followed by lowercase “th”, “st” or “nd”: April 2nd

19.3 Money

19.3.1 Sterling

Use the numerals plus the £ sign for all monetary amounts except where the amount is less than £1.00.

For amounts less than £1.00 the word “pence” should be used after the numeral: 78 pence

If the word “pound” is used in sentence without referring to a specific amount, then the word must be used, not the symbol.

19.3.2 Other currencies

Spell out other currencies, including Euro (the Euro symbol is not supported in Teletext. It can be used for online only programmes).

You can use $ for Dollar.

19.4 Time

Indicate the time of the day using numerals in a manner which reflects the spoken language:

The time now is 4:30

The alarm went off at 4 o’clock

19.5 Measurement

Never use symbols for units of measurement.

Abbreviations can be used to fit text in a line, but if the unit of measurement is the subject do not abbreviate.

20 Cumulative subtitles

A cumulative subtitle consists of two or three parts - usually complete sentences. Each part will appear on screen at a different time, in sync with its speaker, but all parts will have an identical out-cue.

20.1 Use only when necessary

Cumulatives should only be used when there is a good reason to delay part of the subtitle (e.g. dramatic impact/song rhythm) and no other way of doing it - i.e. there is insufficient time available to split the subtitle completely.

This is most likely to happen in an interchange between speakers, where the first speaker talks much faster than the second. Delaying the speech of the second person by using a cumulative means that the first subtitle will still be on screen long enough to be read, while at the same time the speech is kept in sync.

20.2 Common scenarios

Cumulatives are particularly useful in the following situations:

  • For jokes - to keep punch lines separate
  • In quizzes - to separate questions and answers
  • In songs - e.g. for backing singers. They are particularly effective when one line starts before the previous one finishes
  • To delay dramatic responses (However, if a response is not expected, a cumulative can give the game away)
  • When an exclamation/sound effect label occurs just before a shot-change, and would otherwise need to be merged with the preceding subtitle
  • To distinguish between two or more white speakers in the same shot

20.3 Timing

Avoid having any segment of the cumulative on screen for less than one second, unless it is a music clip.

The total reading time should always be sufficient for the overall duration of the subtitle (except music clip).

Make sure that there is sufficient time to read the final part of a cumulative

You will often find that a cumulative has to go onto three lines, when the amount of text, if merged, would fit onto two. In this case, aim for a timing of at least 5:12 seconds.

If you use cumulatives in children’s content, observe children’s timings.

20.4 Avoid cumulative where shots change

Be wary of timing the appearance of the second/third line of a cumulative to coincide with a shot-change, as this may cause the viewer to reread the first line.

20.5 Avoid obscuring important information

Remember that using a cumulative will often mean that more of the picture is covered. Don’t use cumulatives if they will cover mouths, or other important visuals

20.6 Stick to three lines

Stick to a maximum of three lines unless you are subtitling a fast quiz like University Challenge where it is preferable to show the whole question in one subtitle and where you will not be obscuring any interesting visuals

21 Children's subtitling

The following guidelines are recommended for the subtitling of programmes targeted at children below the age of 11 years (ITC).

21.1 Editing

There should be a match between the voice and subtitles as far as possible.

A strategy should be developed where words are omitted rather than changed to reduce the length of sentences.

For example,

Can you think why they do this?

Why do they do this?

Can you think of anything you could do with all the heat produced in the incinerator?

What could you do with the heat from the incinerator?

Difficult words should also be omitted rather than changed. For example:

First thing we're going to do is make his big, ugly, bad-tempered head.

First we're going to make his big, ugly head.

All she had was her beloved rat collection.

She only had her beloved rat collection.

Where possible the grammatical structure should be simplified while maintaining the word order.

You can see how metal is recycled if we follow the aluminium.

See how metal is recycled by following the aluminium.

We need energy so our bodies can grow and stay warm.

We need energy to grow and stay warm.

Difficult and complex words in an unfamiliar context should remain on screen for as long as possible. Few other words should be used. For example:

Nurse, we'll test the reflexes again.

Nurse, we'll test the reflexes.

Air is displaced as water is poured into the bottle.

The water in the bottle displaces the air.

Care should be taken that simplifying does not change the meaning, particularly when meaning is conveyed by the intonation of words.

Numbers, including price, weight etc are easier than words to read and remember. They should, therefore, be presented in numerical form. For example:

It takes about one kilojoule of energy to lift someone off their feet.

It takes 1kJ of energy to lift someone.

We took a gram of margarine and placed it in a dish.

We put 1 gram of margarine in a dish.

Often, the aim of schools programmes is to introduce new vocabulary and to familiarize pupils with complex terminology. When subtitling schools programmes, introduce complex vocabulary in very simple sentences and keep it on screen for as long as possible.

21.2 Preferred timing

In general, subtitles for children should follow the speed of speech. However, there may be occasions when matching the speed of speech will lead to subtitle rate that is not appropriate for the age group. The producer/assistant producer should seek advice on the appropriate subtitle timing for a programme.

21.3 Avoid variable timing

There will be occasions when you will feel the need to go faster or slower than the standard timings - the same guidelines apply here as with adult timings (see Timing). You should however avoid inconsistent timings e.g. a two-line subtitle of 6 seconds immediately followed by a two-line subtitle of 8 seconds, assuming equivalent scores for visual context and complexity of subject matter.

21.4 Allow more time for visuals

More time should be given when there are visuals that are important for following the plot, or when there is particularly difficult language.

21.5 Syntax and Vocabulary

Do not simplify sentences, unless the sentence construction is very difficult or sloppy.

Avoid splitting sentences across subtitles. Unless this is unavoidable, keep to complete clauses.

Vocabulary should not be simplified.

There should be no extra spaces inserted before punctuation.

22 Live subtitling (BBC-ASP, OFCOM-IQLS, OFCOM-GSS)

22.1 General

The subtitler should have a direct pre-broadcast-encoding feed from the broadcaster, so they can hear the output a few seconds earlier than if relying on the broadcast­ service.

Maintain a regular subtitle output with no long gaps (unless it is obvious from the picture that there is no commentary) even if this means subtitling the picture or providing background information rather than subtitling the commentary.

Aim for continuity in subtitles by following through a train of thought where possible, rather than sampling the commentary at intervals.

Do not subtitle over existing video captions where avoidable (in news, this is often unavoidable, in which case a speaker's name can be included in the subtitle if available).

22.2 Preparation

Find out specialist vocabulary, and specific editorial guidelines for the genre (e.g. sport). Familiarise yourself with Prepared segments that have been subtitled and their place in the running order, but be prepared for the order to change.

When available to the subtitler, pre-recorded segments should be subtitled prior to broadcast (not live) and cued out at the appropriate moment.

When cueing prepared texts for scripted parts of the programme:

  • Try to cue the texts of pre-recorded segments so that they closely match the spoken words in terms of start time.
  • Do not cue texts out rapidly to catch up if you get left behind - skip some and continue from the correct place.
  • Try to include speakers' names if available where in-vision captions have been obliterated.

22.3 Editing

Subtitles should use upper and lower case as appropriate.

Standard spelling and punctuation should be used at all times, even on the fastest programmes.

Produce complete sentences even for short comments because this makes the result look less staccato and hurried.

Strong or inappropriate language must not appear on screen in error.

For news programmes, current affairs programmes and most other genres, subtitles should be verbatim, up to a subtitling speed of around 130-150wpm. Above that speed, some editing would be expected.

For some genres, such as in-play sporting action, the subtitling may be edited more heavily so as to convey vital commentary information while allowing better access to the visuals. (BBC-SPG)

22.4 Corrections

Any serious or misleading errors in real-time subtitling should be corrected clearly and promptly. The correction should be preceded by two dashes:

The minster’s shrew is unchanged -- view.

However be aware that too many on-air corrections, or corrections that are not sufficiently prompt, can actually make the subtitles harder for a viewer to follow.

Ultimately the subtitler may have to decide whether to make a correction or omit some speech in order to catch up. Sometimes this can be done without detracting from the integrity of the subtitling, but this is not always the case. Do not correct minor errors where the reader can reasonably be expected to deduce the intended meaning (e.g. typos and misspellings).

If necessary, an apology should be made at the end of the programme. If possible, repeat the subtitle with the error corrected.

22.5 Formatting

Live subtitles should appear word by word, from left to right, to allow maximum reading time. Live subtitles are justified left (not centred).

Two-lines of scrolling text should be used.

For live subtitling, use a reduced set of formatting techniques. Focus on colour and vertical positioning.

  • A change of speaker should always be indicated by a change of colour.
  • Scrolling subtitles, while usually appearing at the bottom of the screen, should be raised as appropriate in order to avoid any vital action, visual information, name labels, etc.

23 Appendix 1: Teletext character set

Characters in code table 00 - Latin alphabet. Reproduced from EBU TECH. 3264-E.

Table showing Teletext character set

24 Appendix 2: Sample EBU-TT file

This is an example of a prepared subtitle file. This is not a complete file: multiple instances of elements have been removed and long values shortened. Not all possible elements are included (for example, elements required for live subtitles are not included).

Sample file: EBU-TT v1.0 pre-prepared

25 Appendix 3: BBC metadata XSD

This is the XSD for the BBC metadata section of the EBU-TT document. It includes elements for audio description and signs-language documents that can be omitted for subtitle files. To validate the document fully an EBU-TT schema should also be used.

Sample file: XML Schema Definition for BBC EBU-TT matadata