https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88521
Bug ID: 88521
Summary: gcc 9.0 from r266355 miscompile x265 for mingw-w64
target
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: mateuszb at poczta dot onet.pl
Target Milestone: ---
Target: mingw-w64
x265 compiled by gcc 9.0 r266355 (or newer) for mingw-w64 makes wrong encoding
(awful quality).
Comparison of encoding by x265 compiled by gcc 9.0 r266354 vs. r266355 (see
bitrate and Avg QP):
f:\speed\2.9+15>x265r354 --crf 20 --no-asm
../Bosphorus_1920x1080_120fps_420_8bit_YUV.y4m w1.hevc && x265r355 --crf 20
--no-asm ../Bosphorus_1920x1080_120fps_420_8bit_YUV.y4m w2.hevc
y4m [info]: 1920x1080 fps 30/1 i420p8 frames 0 - 599 of 600
raw [info]: output file: w1.hevc
x265 [info]: HEVC encoder version 2.9+16-c829b5b75a9f
x265 [info]: build info [Windows][GCC 9.0.0][64 bit] 10bit
x265 [info]: using cpu capabilities: none!
x265 [info]: Main 10 profile, Level-4 (Main tier)
x265 [info]: Thread pool created using 12 threads
x265 [info]: Slices : 1
x265 [info]: frame threads / pool features : 3 / wpp(17 rows)
x265 [info]: Coding QT: max CU size, min CU size : 64 / 8
x265 [info]: Residual QT: max TU size, max depth : 32 / 1 inter / 1 intra
x265 [info]: ME / range / subpel / merge : hex / 57 / 2 / 2
x265 [info]: Keyframe min / max / scenecut / bias: 25 / 250 / 40 / 5.00
x265 [info]: Lookahead / bframes / badapt : 20 / 4 / 2
x265 [info]: b-pyramid / weightp / weightb : 1 / 1 / 0
x265 [info]: References / ref-limit cu / depth : 3 / on / on
x265 [info]: AQ: mode / str / qg-size / cu-tree : 1 / 1.0 / 32 / 1
x265 [info]: Rate Control / qCompress : CRF-20.0 / 0.60
x265 [info]: tools: rd=3 psy-rd=2.00 rskip signhide tmvp strong-intra-smoothing
x265 [info]: tools: lslices=6 deblock sao
x265 [info]: frame I: 3, Avg QP:19.68 kb/s: 32315.52
x265 [info]: frame P: 148, Avg QP:21.03 kb/s: 12782.31
x265 [info]: frame B: 449, Avg QP:26.54 kb/s: 1167.18
x265 [info]: Weighted P-Frames: Y:0.0% UV:0.0%
x265 [info]: consecutive B-frames: 0.7% 0.7% 0.7% 96.7% 1.3%
encoded 600 frames in 113.81s (5.27 fps), 4187.99 kb/s, Avg QP:25.15
y4m [info]: 1920x1080 fps 30/1 i420p8 frames 0 - 599 of 600
raw [info]: output file: w2.hevc
x265 [info]: HEVC encoder version 2.9+16-c829b5b75a9f
x265 [info]: build info [Windows][GCC 9.0.0][64 bit] 10bit
x265 [info]: using cpu capabilities: none!
x265 [info]: Main 10 profile, Level-4 (Main tier)
x265 [info]: Thread pool created using 12 threads
x265 [info]: Slices : 1
x265 [info]: frame threads / pool features : 3 / wpp(17 rows)
x265 [info]: Coding QT: max CU size, min CU size : 64 / 8
x265 [info]: Residual QT: max TU size, max depth : 32 / 1 inter / 1 intra
x265 [info]: ME / range / subpel / merge : hex / 57 / 2 / 2
x265 [info]: Keyframe min / max / scenecut / bias: 25 / 250 / 40 / 5.00
x265 [info]: Lookahead / bframes / badapt : 20 / 4 / 2
x265 [info]: b-pyramid / weightp / weightb : 1 / 1 / 0
x265 [info]: References / ref-limit cu / depth : 3 / on / on
x265 [info]: AQ: mode / str / qg-size / cu-tree : 1 / 1.0 / 32 / 1
x265 [info]: Rate Control / qCompress : CRF-20.0 / 0.60
x265 [info]: tools: rd=3 psy-rd=2.00 rskip signhide tmvp strong-intra-smoothing
x265 [info]: tools: lslices=6 deblock sao
x265 [info]: frame I: 3, Avg QP:39.68 kb/s: 13494.72
x265 [info]: frame P: 148, Avg QP:19.37 kb/s: 18426.52
x265 [info]: frame B: 449, Avg QP:51.00 kb/s: 77.51
x265 [info]: Weighted P-Frames: Y:0.0% UV:0.0%
x265 [info]: consecutive B-frames: 0.7% 0.7% 0.7% 96.7% 1.3%
encoded 600 frames in 103.13s (5.82 fps), 4670.69 kb/s, Avg QP:43.14
