#2686: Native AAC encoder collapses at high bitrates on some samples -------------------------------------+------------------------------------- Reporter: Kamedo2 | Owner: Type: defect | Status: open Priority: normal | Component: avcodec Version: git-master | Resolution: Keywords: aac | Blocked By: regression | Reproduced by developer: 1 Blocking: | Analyzed by developer: 0 | -------------------------------------+-------------------------------------
Comment (by klaussfreire): Sadly, no. I thought so, but further tests (at various bitrates) show saturation. Not the same issue as the original in the OP, but an issue nevertheless. I have only attacked M/S coding and some bit allocation inefficiencies, but the improvement seemed to improve those issues during initial tests since tonal band encoding improved significantly, but it's still not enough it seems to avoid clipping due to quantization noise. Since the original signal is saturated already, I may have a relatively easy fix for it: all quantization noise risks the same artifacts, but I believe there is only one fix, which involves tweaking rounding of strong signals. That needs careful calibration, however, in order to avoid modifying behavior on non-clipping signals (since rounding towards zero generally induces higher SNR), but I'll be travelling soon and won't be able to work much on it till jan 1st. -- Ticket URL: <https://trac.ffmpeg.org/ticket/2686#comment:237> FFmpeg <http://ffmpeg.org> FFmpeg issue tracker _______________________________________________ FFmpeg-trac mailing list FFmpeg-trac@avcodec.org http://avcodec.org/mailman/listinfo/ffmpeg-trac