String containing custom AAC options to send to the Faac encoder.
For advanced users, this string allows applying all of the possible AAC encoding options available with Faac. See Appendix C - Faac command line for the complete set of available options.
This property is used only if the EncodeFormats.FormatToUse property is set to ENCODING_FORMAT_AAC and the EncodeFormats.AAC.EncodeMode property is set to AAC_ENCODE_QUALITY.
IMPORTANT NOTE: As you may know, the Faac command line is as follows:
usage: Faac [options] <infile> [outfile]
Contents of the CustomString property are related to the [options] field only so you must omit entering the word faac and omit to specify the <infile> and [outfile] settings also. You should also omit the -P and -X options which are already applied internally.
For further details about encoding in AAC and MP4 format refer to the AAC object section.
For further information about available encoding formats see the EncodeFormats object.