Caption and Subtitle Filters

Transform has extensive support for captions and subtitles. Captions and subtitle both represent timed text but differ in the following way:

Captions are carried as metadata attached to the samples in a video stream.
Subtitles are carried as a separate stream independent of the video and audio.

Format Conversion

Transform supports a broad range of Subtitle Formats. A subtitle stream can be converted to a different format using the ciem subtitle converter. For example the following composition will convert DVB Teletext dvbt to WebVTT vtt format:

---
input:
  container:
  - name: input1
    video: []
    audio: []
    subtitle:
    - name: s1
output:
  container:
  - type: 'vtt '
    name: output1
    subtitle:
    - route:
        name: s1
      filter:
      - type: ciem
        properties:
          OutputFormat: 'vtt '

{
  "input": {
    "container": [
      {
        "name": "input1",
        "video": [],
        "audio": [],
        "subtitle": [
          {
            "name": "s1"
          }
        ]
      }
    ]
  },
  "output": {
    "container": [
      {
        "type": "vtt ",
        "name": "output1",
        "subtitle": [
          {
            "route": {
              "name": "s1"
            },
            "filter": [
              {
                "type": "ciem",
                "properties": {
                  "OutputFormat": "vtt "
                }
              }
            ]
          }
        ]
      }
    ]
  }
}

The ciem subtitle converter supports the following properties:

Property	Type	Description
`OutputFormat`	string	Subtitle format as a four character code.
`CaptionRetimeRate`	number	Specifies the rate multiplier applied to caption and subtitle times. For example a rate of 1.001 compensates for drop frame.
`CaptionOffsetTime`	number	Specifies the offset (in seconds) applied to caption and subtitle times.
`CaptionRetimeStartTime`	number	Specifies the start time (in seconds) of the retimed captions and subtitles.
`CaptionRippleTimecode`	number	Specifies the offset (in seconds) applied to caption and subtitle timecode values.
`CaptionOutputFrameRate`	number	Specifies the output frame rate for captions and subtitles.
`CaptionOutputDropFrame`	boolean	Indicates whether timecode values should be specified in drop frame format.
`StartingTimecodeMode`	integer	Specifies the mode use to convert caption and subtitle timecode values to 0 based times: `0` Subtract the value of the `StartFrame` property. `1` Subtract the first frame timecode. `2` Subtract the starting timecode rounded to the nearest hour. For example 10:00:01:00 is converted to 00:00:01:00.
`StartFrame`	integer	Specifies the starting frame number.
`PadOutputDuration`	boolean	Pads the output duration by 1 second to ensure that program ends on an empty frame rather than a caption or subtitle.

Captions

Property	Type	Description
`CaptionReformatRollUpToPopon`	integer	Specifies the number of text lines used to reformat roll-up captions to pop-on captions.
`Encode708WideMode`	boolean	Enables or disables CEA-708 wide mode (42 column). Note that some decoders do not properly handle wide mode.
`SccSourceField`	integer	Specifies the field number used when decoding SCC captions: `0` Field 1 (CC1/CC2) `1` Field 2 (CC3/CC4)
`SubtitleCaptionChannel`	int	Specifies the caption channel, caption service or Teletext page to decode: `0`-`3` CEA-608 CC1-CC3 `10` - `15` CEA-708 Service 1-6 `888` Teletext Page

DVB Subtitles

Property	Type	Description
`SubtitleDvbPageNumber`	integer	Specifies the subtitle page number.
`SubtitleDvbAncillaryPageNumber`	integer	Specifies the subtitle ancillary page number.
`SubtitleDvbColorDepth`	integer	Specifies the size of the bitmap color palette in bits, allowable values are `4`, `16` or `256`.
`SubtitleDvbType`	integer	Specifies the DVB subtitle type according to ETSI EN 300 468 Table 26: `16` Normal `32` Hard of hearing

EBU STL

Property	Type	Description
`SubtitleTeletextDIsplayStandard`	integer	Specifies the Display Standard Code (DSC): `0` Open subtitling `1` Level-1 teletext `2` Level-2 teletext

Teletext

Property	Type	Description
`SubtitleTeletextPage`	integer	Specifies the page number (e.g. 888).
`SubtitleTeletextHeight`	boolean	Enables or disables double height mode (default is `true`).
`SubtitleTeletextFillType`	int	Specifies the type of filler data: `0` Packet 31 (default) `1` Null page headers `2` None
`SubtitleTeletextNationalOption`	int	Specifies the national option character set. See ETSI EN 300 706, default is 0 (english).
`SubtitleTeletextVancLine1` `SubtitleTeletextVancLine2`	int	Specifies the VANC line numbers.
`SubtitleTeletextVbiLine1` `SubtitleTeletextVbiLine2` `SubtitleTeletextVbiLine3` `SubtitleTeletextVbiLine4` `SubtitleTeletextVbiLine5`	int	Specifies the VBI line numbers.

TTML

Property	Type	Description
`SubtitleTtmlProfile`	integer	Specifies a particular TTML output variant: `0` Basic `1` SMPTE ST2052 `2` ISMC1 `3` iTT `4`EBU-TT `5` ISMC1_1 Defaults to basic for subtitle inputs and ST2052 for caption inputs.
`TtmlTimeExpressionMode`	integer	Specifies the TTML time expression mode: `0` Default `1` HH:MM:SS:FF `2` HH:MM:SS.SSS `3` Frames `4` Ticks `5` Seconds Default is HH:MM:SS:FF for ST2052 and iTT, HH:MM:SS.SSS for other profiles.
`TtmlForceIncludeFrameRate`	boolean	Indicates whether to include the frame rate in the TTML.
`TtmlIncludeAspectRatio`	boolean	Indicates whether to include the aspect ratio in the TTML.

Web VTT

Property	Type	Description
`SubtitleWebVttTimestampMap`	string	Sets the value of the X-TIMESTAMP-MAP=MPEGTS: header.

XDS/V-chip

Property	Type	Description
`XdsProgramName`	string	Specifies the XDS program name.
`XdsProgramType`	string	Specifies the XDS program type.
`XdsRating`	string	Specifies the XDS V-chip content rating: `TV-MA` `TV-14` `TV-PG` `TV-Y7` `TV-Y` Rating flags are added in parentheses: `V` Violence/Fantasy Violence `S` Sexual Situations `L` Adult Language `D` Sexually Suggestive Dialog For example: `TV-MA (VSL)`
`XdsCgms`	string	Specifies the XDS CGMS value: `No copying is permitted` `PSP On; 4` `PSP On; 2` `PSP On; Split Burst Off` `One generation of copies may be made`

For example the following composition inserts CEA-708 captions from a sidecar SCC and adds a V-chip TV-MA (VSL) content rating:

---
input:
  container:
  - name: media-input
    video:
    - name: v1
  - name: subtitle-input
    subtitle:
    - name: s1
output:
  container:
  - name: output
    type: m2ts
    video:
    - route:
        name: v1
      merge:
        name: s1
        filter:
        - type: ciem
          properties:
            OutputFormat: c708
            XdsProgramName: Test Name
            XdsProgramType: Test Type
            XdsRating: TV-MA (VSL)
            XdsCgms: One generation of copies may be made
        - type: sccc
      encode:
        type: mcm2
        properties:
          OutputFormat: mp2v
          Profile: 4
          Level: 4
      attach:
      - type: c708
        root: a53c

{
  "input": {
    "container": [
      {
        "name": "media-input",
        "video": [
          {
            "name": "v1"
          }
        ]
      },
      {
        "name": "subtitle-input",
        "subtitle": [
          {
            "name": "s1"
          }
        ]
      }
    ]
  },
  "output": {
    "container": [
      {
        "name": "output",
        "type": "m2ts",
        "video": [
          {
            "route": {
              "name": "v1"
            },
            "merge": {
              "name": "s1",
              "filter": [
                {
                  "type": "ciem",
                  "properties": {
                    "OutputFormat": "c708",
                    "XdsProgramName": "Test Name",
                    "XdsProgramType": "Test Type",
                    "XdsRating": "TV-MA (VSL)",
                    "XdsCgms": "One generation of copies may be made"
                  }
                },
                {
                  "type": "sccc"
                }
              ]
            },
            "encode": {
              "type": "mcm2",
              "properties": {
                "OutputFormat": "mp2v",
                "Profile": 4,
                "Level": 4
              }
            },
            "attach": [
              {
                "type": "c708",
                "root": "a53c"
              }
            ]
          }
        ]
      }
    ]
  }
}

This example adds V-chip metadata while converting the input stream to CEA-708 format. See XDS Metadata for V-chip insertion to an existing closed caption stream.

Bitmap Format

The bmap format is used internally to render subtitles to graphic images for display. In this format each subtitle is represented by a canvas. The canvas has specific image dimensions and contains one or more regions positioned at specific image coordinates.

Each region has layout properties such as background fill, text justification, text alignment and text progression. A region typically contains one or more text strings. Each string has style properties that control text font, color and emphasis (bold, italic). The text is flowed into the region based on the layout properties.

Subtitle Bitmap Converter

This type of filter converts a subtitle stream to bitmap format. The following bitmap converters are available:

Type	Description
`c8bm`	Cavena 890 Subtitle Bitmap Converter
`ccbm`	Caption Bitmap Converter
`dcbm`	DCP Subtitle Bitmap Converter
`dvbm`	DVB Subtitle Bitmap Converter
`lcbm`	Lambda CAP Subtitle Bitmap Converter
`pabm`	Screen PAC Subtitle Bitmap Converter
`srbm`	SubRip SRT Bitmap Converter
`sfbm`	Spruce STL Bitmap Converter
`stbm`	EBU Subtitle Bitmap Converter
`tebm`	EBU Teletext Bitmap Converter
`ttbm`	TTML Bitmap Converter
`vtbm`	WebVTT Bitmap Converter

Bitmap converters support the following properties:

Property	Type	Filter	Description
`StringForegroundColor`	string		Specifies the foreground color of the subtitle text as a TTML color: `#rrggbbaa`, `rgba(r,g,b,a)` or `namedcolor`.
`StringBackgroundColor`	string		Specifies the background color of the subtitle text as a TTML color.
`RegionBackgroundColor`	string		Specifies the background color of the subtitle regions.
`CaptionChannel`	integer	`ccbm`	Specifies the caption decoder channel: 0-3 CEA-608 CC1-CC4, 10-15 CEA-708 Service 1-6.
`CaptionXDS`	boolean	`ccbm`	Indicates whether to display CEA-608 XDS (Extended Data Services).

Bitmap Style Converter

The ssty filter changes the style of the bmap subtitles. The converter supports the following properties:

Property	Type	Description
`SubtitleStringFontFamily`	string	Specifies the font family name.
`SubtitleStringFontFamilySecondary`	string	Specifies the font family name used for secondary subtitles.
`SubtitleStringForceBold`	boolean	Sets the force bold setting.
`SubtitleRegionBackgroundColor`	string	Sets the region background color. This property contains a TTML . `#rrggbb` `#rrggbbaa` `rgb(r,g,b)` `rgba(r,g,b,a)` `<namedcolor>`
`SubtitleStringBackgroundColor`	string	Sets the text background color. This property contains a TTML . See above.
`SubtitleStringForegroundColor`	string	Sets the text foreground color. This property contains a TTML . See above.
`SubtitleStringForegroundColorSecondary`	string	Sets the text foreground color used for secondary subtitles. This property contains a TTML . See above.
`SubtitleStringOutlineColor`	string	Sets the text outline color.
`SubtitleStringOutlineColorSecondary`	string	Sets the text outline color used for secondary subtitles.
`SubtitleStringOutlineSize`	double	Sets the text outline size.
`SubtitleStringOutlineSizeSecondary`	double	Sets the text outline size used for secondary subtitles.
`SubtitleRegionBackgroundColorOverrideMode`	integer	Sets whether the background color applies to all regions or only certain regions.
`SubtitleStringBackgroundColorOverrideMode`	integer	Sets whether the background color applies to all strings or only certain strings.
`SubtitleRegionFontScale`	double	Sets the region font scaling.
`SubtitleRegionFontScaleSecondary`	double	Sets the region font scaling used for secondary subtitles.
`SubtitleRegionMarginTop`	double	Sets the region top margin.
`SubtitleRegionMarginBottom`	double	Sets the region bottom margin.
`SubtitleRegionMarginLeft`	double	Sets the region left margin.
`SubtitleRegionMarginRight`	double	Sets the region right margin.
`SubtitleStringBackgroundPaddingType`	integer	Sets the text background padding type.
`SubtitleStringDropShadow`	boolean	Sets the drop shadow setting.
`SubtitleStringDropShadowBlurRadius`	boolean	Sets the drop shadow blur radius setting.
`SubtitleStringDropShadowColor`	boolean	Sets the drop shadow color setting.
`SubtitleStringDropShadowDistance`	boolean	Sets the drop shadow distance setting.

Bitmap Video Converter

The bmvc filter converts a subtitle stream in bmap format to a video stream in rgba format. The converter supports the following properties:

Property	Type	Description
`Timescale`	integer	The time scale of the video stream in ticks/seconds.
`FrameDuration`	integer	The nominal duration of each video frame in ticks.

Subtitle Overlay

Use the overlay operator to display open (or burned-in) subtitles. For example the following composition will overlay DVB teletext dvbt onto the video stream:

---
input:
  container:
  - name: input1
    video:
    - name: v1
    subtitle:
    - name: s1
      format: 'dvbt'
output:
  container:
  - name: output1
    type: 'mp4 '
    video:
    - overlay:
      - name: v1
      - name: s1
        filter:
        - type: 'dvbm'
        - type: 'ssty'
          properties:
            SubtitleStringFontFamily: helvetica
        - type: 'bmvc'
          properties:
            TimeScale: 30000
            FrameDuration: 1001

{
  "input": {
    "container": [
      {
        "name": "input1",
        "video": [
          {
            "name": "v1"
          }
        ],
        "subtitle": [
          {
            "name": "s1",
            "format": "dvbt"
          }
        ]
      }
    ]
  },
  "output": {
    "container": [
      {
        "name": "output1",
        "type": "mp4 ",
        "video": [
          {
            "overlay": [
              {
                "name": "v1"
              },
              {
                "name": "s1",
                "filter": [
                  {
                    "type": "dvbm"
                  },
                  {
                    "type": "ssty",
                    "properties": {
                      "SubtitleStringFontFamily": "helvetica"
                    }
                  },
                  {
                    "type": "bmvc",
                    "properties": {
                      "TimeScale": 30000,
                      "FrameDuration": 1001
                    }
                  }
                ]
              }
            ]
          }
        ]
      }
    ]
  }
}

Combining Subtitles

Use the combine operator to combine multiple subtitle streams. For example the following composition combines multiple sidecar subtitle files (each containing a different language) into a single subtitle stream:

---
input:
  container:
  - name: main-input
    video:
    - name: v1
    audio:
    - name: a1
  - name: sidecar-input1
    subtitle:
    - name: s1
  - name: sidecar-input2
    subtitle:
    - name: s2
output:
  container:
  - name: output
    type: m2ts
    video:
    - route:
        name: v1
    audio:
    - route:
        name: a1
    subtitle:
    - combine:
        type: txfi
        properties:
          OutputFormat: ttxt
        stream:
        - name: s1
          properties:
            Page: 888
            CharacterSet: Hebrew
        - name: s2
          properties:
            Page: 889
            CharacterSet: Arabic

{
  "input": {
    "container": [
      {
        "name": "main-input",
        "video": [
          {
            "name": "v1"
          }
        ],
        "audio": [
          {
            "name": "a1"
          }
        ]
      },
      {
        "name": "sidecar-input1",
        "subtitle": [
          {
            "name": "s1"
          }
        ]
      },
      {
        "name": "sidecar-input2",
        "subtitle": [
          {
            "name": "s2"
          }
        ]
      }
    ]
  },
  "output": {
    "container": [
      {
        "name": "output",
        "type": "m2ts",
        "video": [
          {
            "route": {
              "name": "v1"
            }
          }
        ],
        "audio": [
          {
            "route": {
              "name": "a1"
            }
          }
        ],
        "subtitle": [
          {
            "combine": {
              "type": "txfi",
              "properties": {
                "OutputFormat": "ttxt"
              },
              "stream": [
                {
                  "name": "s1",
                  "properties": {
                    "Page": 888,
                    "CharacterSet": "Hebrew"
                  }
                },
                {
                  "name": "s2",
                  "properties": {
                    "Page": 889,
                    "CharacterSet": "Arabic"
                  }
                }
              ]
            }
          }
        ]
      }
    ]
  }
}

Teletext Combiner

The txfi combiner accepts EBU STL stl input streams and produces an EBU Teletext ttxt stream. The combiner supports the following properties:

Property	Type	Description
`OutputFormat`	string	Specifies the output subtitle format as a four character code: `ttxt` EBU Teletext (default)
`VancLine1`	integer	Specifies the VANC line for field 1 Teletext data (default 12).
`VancLine2`	integer	Specifies the VANC line for field 2 Teletext data (default 575).
`VbiLine1`	integer	Specifies the first VBI line for Teletext data (default 21).
`VbiLine2`	integer	Specifies the second VBI line for Teletext data (default 334).
`VbiLine3`	integer	Specifies the third VBI line for Teletext data (default 0).
`VbiLine4`	integer	Specifies the fourth VBI line for Teletext data (default 0).
`VbiLine5`	integer	Specifies the fifth VBI line for Teletext data (default 0).
`FillType`	integer	Specifies the type of filler data. `0` Packet 31 (default) `1` Null page headers `2` None

The combiner supports the following properties for each input stream:

Property	Type	Description
`Page`	integer	Specifies the teletext page number.
`CharacterSet	string	Specifies the text encoding: `Latin` `Cyrillic-1` `Cyrillic-2` `Cyrillic-3` `Greek` `Hebrew` `Arabic` If not specified the default is the input EBU STL stream encoding.
`NationalOption`	integer	Specifies the National Option character set which adds special characters to the base Latin set. `0` English (default) `1` German `2` Swedish/Finnish `3` Italian `4` French `5` Portuguese/Spanish

Caption Metadata

Closed captions and Teletext are specific types of metadata carried in a video stream. Transform supports the following types of captions and teletext metadata:

Type	Description
`c608`	CEA-608 Closed Captions
`c708`	CEA-708 Closed Captions
`ttxt`	EBU Teletext (VBI or VANC)

Closed captions and Teletext may appear in multiple locations within a media container. Each location is represented by a specific metadata type. See Metadata Types the for more details.

Caption Subtitle Converter

The ccsc filter converts a video stream with caption or teletext metadata to the equivalent subtitle stream.

Subtitle Caption Converter

The sccc filter converts a subtitle stream to a video stream with the equivalent closed caption or teletext metadata.

Property	Type	Description
`SccFieldType`	string	Four character code either `c618` (field 1) or `c628` (field 2).

Caption Extraction

Use the detach operator to extract closed caption or teletext metadata from a video stream. By default the operator searches all known root locations for the caption metadata.

Use the route operator to convert a video stream to a subtitle stream using the caption or teletext metadata.

For example the following composition extracts c708 closed caption metadata to a sidecar scc container.

---
input:
  container:
  - name: input
    video:
    - name: v1
      detach:
      - type: c708
      - type: time
output:
  container:
  - name: output
    type: 'scc '
    subtitle:
    - route:
        name: v1
      filter:
      - type: ccsc
        properties:
          OutputFormat: c708
      - type: ciem
        properties:
          OutputFormat: 'scc '

{
  "input": {
    "container": [
      {
        "name": "input",
        "video": [
          {
            "name": "v1",
            "detach": [
              {
                "type": "c708"
              },
              {
                "type": "time"
              }
            ]
          }
        ]
      }
    ]
  },
  "output": {
    "container": [
      {
        "name": "output",
        "type": "scc ",
        "subtitle": [
          {
            "route": {
              "name": "v1"
            },
            "filter": [
              {
                "type": "ccsc",
                "properties": {
                  "OutputFormat": "c708"
                }
              },
              {
                "type": "ciem",
                "properties": {
                  "OutputFormat": "scc "
                }
              }
            ]
          }
        ]
      }
    ]
  }
}

This example also uses the detach operator to preserve the input timecode in the output SCC file. See Timecode Extraction for more details.

Caption Overlay

Use the overlay operator to display open (or burned-in) captions and teletext. For example the following composition will overlay c608 captions onto the video stream:

---
input:
  container:
  - name: input1
    video:
    - name: v1
      detach:
      - type: c608
output:
  container:
  - type: 'mp4 '
    name: output1
    video:
    - name: v2
      overlay:
      - name: v1
      - name: v1
        filter:
        - type: ccsc
          properties:
            OutputFormat: c608
        - type: ccbm
          properties:
            Immediate: true
            CaptionChannel: 0
        - type: ssty
          properties:
            SubtitleStringFontFamily: helvetica
        - type: bmvc
          properties:
            VariableFrameDuration: false
      encode:
        type: h264
        properties:
          OutputFormat: avc1

{
  "input": {
    "container": [
      {
        "name": "input1",
        "video": [
          {
            "name": "v1",
            "detach": [
              {
                "type": "c608"
              }
            ]
          }
        ]
      }
    ]
  },
  "output": {
    "container": [
      {
        "type": "mp4 ",
        "name": "output1",
        "video": [
          {
            "name": "v2",
            "overlay": [
              {
                "name": "v1"
              },
              {
                "name": "v1",
                "filter": [
                  {
                    "type": "ccsc",
                    "properties": {
                      "OutputFormat": "c608"
                    }
                  },
                  {
                    "type": "ccbm",
                    "properties": {
                      "Immediate": true,
                      "CaptionChannel": 0
                    }
                  },
                  {
                    "type": "ssty",
                    "properties": {
                      "SubtitleStringFontFamily": "helvetica"
                    }
                  },
                  {
                    "type": "bmvc",
                    "properties": {
                      "VariableFrameDuration": false
                    }
                  }
                ]
              }
            ],
            "encode": {
              "type": "h264",
              "properties": {
                "OutputFormat": "avc1"
              }
            }
          }
        ]
      }
    ]
  }
}

Caption Insertion

Use the merge operator to convert a subtitle stream to closed caption or teletext metadata.

Use the attach operator to insert the caption or teletext metadata into the video stream.

For example the following composition inserts c618 closed captions from a sidecar SCC container into the vertical blanking interval vbi of the video stream:

---
input:
  container:
  - name: main-input
    video:
    - name: v1
  - name: sidecar-input
    subtitle:
    - name: s1
output:
  container:
  - name: output
    type: 'mov '
    video:
    - width: 720
      height: 512
      format: UYVY
      route:
        name: v1
      merge:
        name: s1
        filter:
        - type: sccc
          properties:
            SccFieldType: c618
      attach:
      - type: c618
        root: 'vbi '
      encode:
        type: appr
        properties:
          OutputFormat: apcn

{
  "input": {
    "container": [
      {
        "name": "main-input",
        "video": [
          {
            "name": "v1"
          }
        ]
      },
      {
        "name": "sidecar-input",
        "subtitle": [
          {
            "name": "s1"
          }
        ]
      }
    ]
  },
  "output": {
    "container": [
      {
        "name": "output",
        "type": "mov ",
        "video": [
          {
            "width": 720,
            "height": 512,
            "format": "UYVY",
            "route": {
              "name": "v1"
            },
            "merge": {
              "name": "s1",
              "filter": [
                {
                  "type": "sccc",
                  "properties": {
                    "SccFieldType": "c618"
                  }
                }
              ]
            },
            "attach": [
              {
                "type": "c618",
                "root": "vbi "
              }
            ],
            "encode": {
              "type": "appr",
              "properties": {
                "OutputFormat": "apcn"
              }
            }
          }
        ]
      }
    ]
  }
}

Combining Captions

Use the combine operator with the merge operator to combine multiple subtitle streams and convert the output to caption or teletext metadata.

Use the attach operator to insert the caption or teletext metadata into the video stream.

For example the following composition converts multiple sidecar subtitle files to CEA-708 closed captions with multiple language services.

---
input:
  container:
  - name: main-input
    video:
    - name: v1
    audio:
    - name: a1
  - name: sidecar-input1
    subtitle:
    - name: s1
  - name: sidecar-input2
    subtitle:
    - name: s2
  - name: sidecar-input3
    subtitle:
    - name: s3
output:
  container:
  - name: output
    type: 'mp4 '
    video:
    - route:
        name: v1
      merge:
        combine:
          type: cfic
          properties:
            OutputFormat: c708
          stream:
          - name: s1
            filter:
            - type: ciem
              properties:
                OutputFormat: c708
            properties:
              InputChannel: 0
              InputField: 0
              OutputChannel: 0
              OutputService: 0
              Language: eng
          - name: s2
            filter:
            - type: ciem
              properties:
                OutputFormat: c708
            properties:
              InputChannel: 0
              InputField: 0
              OutputChannel: 1
              OutputService: 1
              Language: fra
          - name: s3
            filter:
            - type: ciem
              properties:
                OutputFormat: c708
            properties:
              InputChannel: 0
              InputField: 0
              OutputChannel: 2
              OutputService: 2
              Language: spa
        filter:
        - type: sccc
      attach:
      - type: c708
        root: a72c
    audio:
    - route:
        name: a1
    subtitle: []

{
  "input": {
    "container": [
      {
        "name": "main-input",
        "video": [
          {
            "name": "v1"
          }
        ],
        "audio": [
          {
            "name": "a1"
          }
        ]
      },
      {
        "name": "sidecar-input1",
        "subtitle": [
          {
            "name": "s1"
          }
        ]
      },
      {
        "name": "sidecar-input2",
        "subtitle": [
          {
            "name": "s2"
          }
        ]
      },
      {
        "name": "sidecar-input3",
        "subtitle": [
          {
            "name": "s3"
          }
        ]
      }
    ]
  },
  "output": {
    "container": [
      {
        "name": "output",
        "type": "mp4 ",
        "video": [
          {
            "route": {
              "name": "v1"
            },
            "merge": {
              "combine": {
                "type": "cfic",
                "properties": {
                  "OutputFormat": "c708"
                },
                "stream": [
                  {
                    "name": "s1",
                    "filter": [
                      {
                        "type": "ciem",
                        "properties": {
                          "OutputFormat": "c708"
                        }
                      }
                    ],
                    "properties": {
                      "InputChannel": 0,
                      "InputField": 0,
                      "OutputChannel": 0,
                      "OutputService": 0,
                      "Language": "eng"
                    }
                  },
                  {
                    "name": "s2",
                    "filter": [
                      {
                        "type": "ciem",
                        "properties": {
                          "OutputFormat": "c708"
                        }
                      }
                    ],
                    "properties": {
                      "InputChannel": 0,
                      "InputField": 0,
                      "OutputChannel": 1,
                      "OutputService": 1,
                      "Language": "fra"
                    }
                  },
                  {
                    "name": "s3",
                    "filter": [
                      {
                        "type": "ciem",
                        "properties": {
                          "OutputFormat": "c708"
                        }
                      }
                    ],
                    "properties": {
                      "InputChannel": 0,
                      "InputField": 0,
                      "OutputChannel": 2,
                      "OutputService": 2,
                      "Language": "spa"
                    }
                  }
                ]
              },
              "filter": [
                {
                  "type": "sccc"
                }
              ]
            },
            "attach": [
              {
                "type": "c708",
                "root": "a72c"
              }
            ]
          }
        ],
        "audio": [
          {
            "route": {
              "name": "a1"
            }
          }
        ],
        "subtitle": []
      }
    ]
  }
}

Caption Combiner

The cfic combiner supports CEA-608, CEA-708 and SCC closed captions. The combiner supports the following properties:

Property	Type	Description
`OutputFormat`	string	Specifies the output subtitle format. `c708` CEA-708 (default) `scc` Scenarist SCC
`DropFrame`	boolean	Indicates whether input SCC streams should be treated as drop frame. Note that all input streams must be the same frame rate and drop frame format.
`SccOutputField`	integer	Specifies the field number for an SCC output stream. `0` Field 1 (CC1/CC2) `1` Field 2 (CC3/CC4)

The combiner supports the following properties for each input stream:

Property	Type	Description
`InputField`	integer	Specifies the input field number for SCC streams: `0` Field 1 (CC1/CC2) `1` Field 2 (CC3/CC4)
`SourceChannel` `InputChannel`	integer	Specifies the input CEA-608 caption channel: `0` CC1 (default) `1` CC2 `2` CC3 `3` CC4
`OutputChannel`	integer	Specifies the output CEA-608 caption channel: `0` CC1 (default) `1` CC2 `2` CC3 `3` CC4
`OutputService`	integer	Specifies the output CEA-708 caption service: `0` Service 1 (default) `1` Service 2 `2` Service 3 `3` Service 4 `4` Service 5 `5` Service 6
`Language`	string	Specifies the output CEA-708 language code (ISO-639 alpha3). For example `eng` for English, `spa` for Spanish, etc.