(container format) (container element for independent frame (IF)) indicates this frame is an independent frame (IF) but (content format) (content element) (content field) (value ) indicates this frame is not an independent frame (IF)
ISO IEC 14496-12 (MPEG-4 ISO base media file format):group_description_index: "gives the index of the sample group entry which describes the samples in this group"
group_description_index: "gives the index of the sample group entry which describes the samples in this group"
ISO IEC 23003-3 (USAC):usacIndependencyFlag: "Meaning of usacIndependencyFlag"
ISO IEC 14496-12:
Fix the muxer in order to correctly fill sbgp with group_description_index not 0 for this frame number, then remux the content.