(preroll count field) is (value) but (expected value) is recommended due to (reason)
ISO IEC 23003-3 (USAC):numPreRollFrames: Recommendation in order to be sure that the current frame, which is an independent frame, can provide valid decoded content. Else it may lead to an audio content gap during a content switch.
ISO IEC 14496-12 (MPEG-4 ISO base media file format):roll_distance: Recommendation in order to be sure that the current frame, which is an independent frame, can provide valid decoded content. Else it may lead to an audio content gap during a content switch.
ISO IEC 23003-3:
Configure or update the USAC encoder in order to put the following count of pre-roll frames:
- 1 if no SBR
- 2 if SBR without harmonic patching
- 3 if SBR with harmonic patching
then reencode the content
ISO IEC 14496-12:
If the stream format encoder is correctly set (see above), it may be a muxer error, check that the muxer correctly fills sbgp with the right roll_distance, then remux the content.