Encoding Configuration Properties

The EIL provides a very powerful configuration system. All configuration properties, except for the basic frame information, are set via a JSON configuration string in the EILInitSettings structure.

The configuration system is supported by a comprehensive built-in system of optimised parameter defaults. The EIL employs ideal settings for both the LCEVC encoder and base encoder, based upon key parameters passed to it by the application, e.g., resolution, bitrate, tune.

Properties can be anonymously queried by the EIL_QueryPropertyGroups API, and, if the user knows the name of properties, by the EIL_QueryProperty API.

Properties specified within the JSON string override any setting provided by the database. Therefore, it is important that an application takes care to specify only properties within the JSON string that the user has explicitly set. For example, in a command-line program, only the options specified by the user in the command line should be included in the JSON string, or, from a GUI, only the options that the user has manually specified a choice for should be included in the JSON string.

The JSON string is processed utilising strong typing correlating to the target property type. If the types are not adhered to, then the EIL will fail to initialise. The user must take care to generate a JSON string that utilises the correct JSON type for each property type. The following table outlines the types and their JSON equivalents:

EILPropertyType	JSON type
EIL_PT_Int32	Number
EIL_PT_Int64	Number
EIL_PT_Uint32	Number
EIL_PT_Uint64	Number
EIL_PT_Float	Number
EIL_PT_Double	Number
EIL_PT_String	String
EIL_PT_Boolean	Boolean, string (‘0’ = false), or number (0 = false)
EIL_PT_Blob	Not used for properties

The JSON string is formatted with a top-level object, and a member per property, as shown in the following example:

{
 "encoding_downsample_luma" : "cubic",
 "temporal_enabled" : true,
 …
}

For additional convenience, properties have been assigned to logical groupings, and can optionally contain a description about what the property does. This is so a user may dynamically generate a command-line parser, or a UI, for the publicly available properties