Fields under the segmentation switch are never reset on a new frame, and retain the value from the previous frame. This bugs out a bunch of hwaccel drivers when segmentation is disabled but update_map isn't reset because they don't ignore values behind switches. This commit also resets the temporal field, though it may not be required. We also do this for vp8 [1] so this commit is just mirroring the vp8 logic. This fixes an issue with certain samples [2] that causes blocky artifacts with vaapi, d3d11va and cuda (and possibly others). Mesa worked around [3] this by ignoring these fields if segmentation.enabled is 0, but d3d11va still displays blocky artifacts. [1] https://git.ffmpeg.org/gitweb/ffmpeg.git/blob/2e877090f958131accb8c7e5ac10e5b9865d1735:/libavcodec/vp8.c#l797 [2] https://github.com/mpv-player/mpv/issues/13533 [3] https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/27816
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| @@ -709,6 +709,12 @@ static int decode_frame_header(AVCodecContext *avctx, · 708 unmodified lines | ||
| 709 | 709 | s->s.h.segmentation.feat[i].skip_enabled = get_bits1(&s->gb); |
| 710 | 710 | } |
| 711 | 711 | } |
| 712 | + } else { | |
| 713 | + // Reset fields under segmentation switch if segmentation is disabled. | |
| 714 | + // This is necessary because some hwaccels don't ignore these fields | |
| 715 | + // if segmentation is disabled. | |
| 716 | + s->s.h.segmentation.temporal = 0; | |
| 717 | + s->s.h.segmentation.update_map = 0; | |
| 712 | 718 | } |
| 713 | 719 | |
| 714 | 720 | // set qmul[] based on Y/UV, AC/DC and segmentation Q idx deltas |