Alternate Source Parameters

Parameter

Description

Allowed Values

Default Value

source

Specify the URL to an alternate source file. If there is not alternate, the main source will be used.

Valid URL.

None

type

Specify which streams will use types.

video – Everything but audio_only streams.
audio – for audio_only streams.
video_audio – for all streams.

video_audio

video_name

Specify the name of the video stream for the main source.

String

None

audio_name

Specify the name of the audio stream for the main source.

String

None

use_stream_id

Comma separated list of steam IDs.

String

None

language

Specify the language attribute for the main source.

Video langauge name.

None

auto

Automatically add all streams with a given type.

yes, no

no

alternate_default

Enable the alternate source as default.

auto, yes, no

auto

alternate_autoselect

If playback environment is matched, the aternate_source will be automatically selected.

yes, no

yes

dvs

Add signaling to manifest that alternate source is a Descriptive Video Services.

yes, no

no

characteristics

CHARACTERISTICS attribute value for the EXT-X-MEDIA tag in HLS manifest according to RFC 8216

Valid CHARACTERISTICS value
For example:
public.accessibility.describes-video

none

accessibility_scheme

"schemeIdUri" attribute value for the Accessibility tag in DASH manifest

Valid SCHEME value
For example:
urn:tva:metadata:cs:AudioPurposeCS:2007

none

accessibility_value

"value" attribute value for the Accessibility tag in DASH manifest

Valid string

none

natural_order

If set to yes then value of <use_stream_id /> will mean number of source's audio stream, not number of stream in all type streams list.

yes, no

no

damf_audio

DAMF Audio aux file

Valid URL

none

damf_metadata

DAMF Metadata aud file

Valid URL

none

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For auto parameter

If <auto /> is set to 'yes' for <alternate_source/> then:

  • Only auto alternate sources will be applied, other custom alternate_sources will be skipped.
  • all other options(except for <type/>) of <alternate_source/> section will be ignored.

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Note

<alternate_default /> and <alternate_autoselect /> are available only for advanced_hls, fmp4_hls, and advanced_fmp4 output formats.

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For alternate_default parameter

If <alternate_default /> is set to ‘yes<alternate_autoselect /> must be set to ‘yes’ too.

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For characteristics parameter

<characteristics /> parameter are available only for advanced_hls, fmp4_hls, and HLS manifests of advanced_fmp4 output formats.

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For accessibility_scheme and accessibility_value parameters

<accessibility_scheme /> and <accessibility_value /> parameters are available only for advanced_dash and DASH manifests of advanced_fmp4 output formats.

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For damf_audio and damf_metadata

The damf_audio and damf_metadata parameters available only for advanced_dash, advanced_fmp4, and fmp4_hls output formats.

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Dolby Atmos DAMF files

Dolby Atmos DAMF alternate source files are:

  • <source /> – XML file with DAMF file description (framerate, beds and objects number, FFoA, start time offset etc)
  • <damf_metadata /> – XML file with objects size and position coordinates over time
  • <damf_audio /> – CAF (Core Audio File) file. It may contains up to 128 tracks.