[FFmpeg-trac] #10891(avcodec:new): Some output frames have artifacts when decoded with multithreading

[FFmpeg]

#10891: Some output frames have artifacts when decoded with multithreading
---------------------------------+--------------------------------------
             Reporter:  HolyWu   |                     Type:  defect
               Status:  new      |                 Priority:  normal
            Component:  avcodec  |                  Version:  git-master
             Keywords:           |               Blocked By:
             Blocking:           |  Reproduced by developer:  0
Analyzed by developer:  0        |
---------------------------------+--------------------------------------
 Summary of the bug:
 Here are comparisons for 008, 011, and 014 pngs between threads 1 and
 threads 16.
 [https://slow.pics/c/s3uVPjB9]

 How to reproduce:
 {{{
 % ffmpeg -report -threads 16 -i 00006.MTS 00006_threads16/%03d.png
 ffmpeg started on 2024-03-04 at 11:56:25
 Report written to "ffmpeg-20240304-115625.log"
 Log level: 48
 ffmpeg version N-113925-g1a4e0eb374-20240303 Copyright (c) 2000-2024 the
 FFmpeg developers
   built with gcc 13.2.0 (crosstool-NG 1.25.0.232_c175b21)
   configuration: --prefix=/ffbuild/prefix --pkg-config-flags=--static
 --pkg-config=pkg-config --cross-prefix=x86_64-w64-mingw32- --arch=x86_64
 --target-os=mingw32 --enable-gpl --enable-version3 --disable-debug
 --disable-w32threads --enable-pthreads --enable-iconv --enable-libxml2
 --enable-zlib --enable-libfreetype --enable-libfribidi --enable-gmp
 --enable-lzma --enable-fontconfig --enable-libharfbuzz --enable-libvorbis
 --enable-opencl --disable-libpulse --enable-libvmaf --disable-libxcb
 --disable-xlib --enable-amf --enable-libaom --enable-libaribb24 --enable-
 avisynth --enable-chromaprint --enable-libdav1d --enable-libdavs2
 --disable-libfdk-aac --enable-ffnvcodec --enable-cuda-llvm --enable-frei0r
 --enable-libgme --enable-libkvazaar --enable-libaribcaption --enable-
 libass --enable-libbluray --enable-libjxl --enable-libmp3lame --enable-
 libopus --enable-librist --enable-libssh --enable-libtheora --enable-
 libvpx --enable-libwebp --enable-lv2 --enable-libvpl --enable-openal
 --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenh264
 --enable-libopenjpeg --enable-libopenmpt --enable-librav1e --enable-
 librubberband --enable-schannel --enable-sdl2 --enable-libsoxr --enable-
 libsrt --enable-libsvtav1 --enable-libtwolame --enable-libuavs3d
 --disable-libdrm --enable-vaapi --enable-libvidstab --enable-vulkan
 --enable-libshaderc --enable-libplacebo --enable-libx264 --enable-libx265
 --enable-libxavs2 --enable-libxvid --enable-libzimg --enable-libzvbi
 --extra-cflags=-DLIBTWOLAME_STATIC --extra-cxxflags= --extra-
 ldflags=-pthread --extra-ldexeflags= --extra-libs=-lgomp --extra-
 version=20240303
   libavutil      58. 40.100 / 58. 40.100
   libavcodec     60. 41.100 / 60. 41.100
   libavformat    60. 23.100 / 60. 23.100
   libavdevice    60.  4.100 / 60.  4.100
   libavfilter     9. 17.100 /  9. 17.100
   libswscale      7.  6.100 /  7.  6.100
   libswresample   4. 14.100 /  4. 14.100
   libpostproc    57.  4.100 / 57.  4.100
 Input #0, mpegts, from '00006.MTS':
   Duration: 00:00:11.07, start: 0.888889, bitrate: 15919 kb/s
   Program 1
   Stream #0:0[0x1011]: Video: h264 (High) (HDMV / 0x564D4448), yuv420p(top
 first), 1920x1080 [SAR 1:1 DAR 16:9], 29.97 fps, 59.94 tbr, 90k tbn
   Stream #0:1[0x1100]: Audio: ac3 (AC-3 / 0x332D4341), 48000 Hz, stereo,
 fltp, 256 kb/s
   Stream #0:2[0x1200]: Subtitle: hdmv_pgs_subtitle (pgssub)
 ([144][0][0][0] / 0x0090), 1920x1080
 Stream mapping:
   Stream #0:0 -> #0:0 (h264 (native) -> png (native))
 Press [q] to stop, [?] for help
 Output #0, image2, to '00006_threads16/%03d.png':
   Metadata:
     encoder         : Lavf60.23.100
   Stream #0:0: Video: png, rgb24(pc, gbr/unknown/unknown, top coded first
 (swapped)), 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 200 kb/s, 29.97 fps,
 29.97 tbn
       Metadata:
         encoder         : Lavc60.41.100 png
 [out#0/image2 @ 00000226312faa40] video:955656KiB audio:0KiB subtitle:0KiB
 other streams:0KiB global headers:0KiB muxing overhead: unknown
 frame=  331 fps= 42 q=-0.0 Lsize=N/A time=00:00:11.04 bitrate=N/A
 speed=1.41x
 }}}
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/10891>
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