supportedEssentialProperties : update the default values.

[fd-vo]

Hello,

In the Settings.js file, we can see the default parameters for supportedEssentialProperties:

capabilities: {
filterUnsupportedEssentialProperties: true,
supportedEssentialProperties: [
{ schemeIdUri: Constants.FONT_DOWNLOAD_DVB_SCHEME },
{ schemeIdUri: Constants.COLOUR_PRIMARIES_SCHEME_ID_URI, value: /1|5|6|7/ },
{ schemeIdUri: Constants.URL_QUERY_INFO_SCHEME },
{ schemeIdUri: Constants.EXT_URL_QUERY_INFO_SCHEME },
{ schemeIdUri: Constants.MATRIX_COEFFICIENTS_SCHEME_ID_URI, value: /0|1|5|6/ },
{ schemeIdUri: Constants.TRANSFER_CHARACTERISTICS_SCHEME_ID_URI, value: /1|6|13|14|15/ },
...Constants.THUMBNAILS_SCHEME_ID_URIS.map(ep => {
return { 'schemeIdUri': ep };
})
],
useMediaCapabilitiesApi: true,
filterVideoColorimetryEssentialProperties: false,
filterHDRMetadataFormatEssentialProperties: false
},

Do you plan to add the values for High Dynamic Range using PQ10 :
Constants.COLOUR_PRIMARIES_SCHEME_ID_URI - value: 9
Constants.MATRIX_COEFFICIENTS_SCHEME_ID_URI - value: 9
Constants.TRANSFER_CHARACTERISTICS_SCHEME_ID_URI - value: 16

I know than we can add them by ourselves with our configuration but I think that the HDR can be supported by default.

Regards,

Fabien

[dsilhavy]

@stschr What is your opinion on this?

[stschr]

There are two different options we handle HDR-related EssentialProperties:

• the first option is to use the provided values when querying MediaCapabilities-API. This is done when both useMediaCapabilitiesApi and filterVideoColorimetryEssentialPropertiesare set to true.
• If this condition is not fulfilled, dash.js is 'blind' and needs to fall back to default values, which are configurable in supportedEssentialProperties (as you already figured out). As default I selected a set of values I considered the absolute minimum on all devices (i.e. SDR only).

My consideration is that, if MediaCapabilities-API is not an option, your application should have some knowledge on the platform it's running on. In that case, the App may update the default values accordingly.

If we have reasonable data to say that additional configurations are supported on all platforms, yes we could update the default values.