[FFmpeg-trac] #11370(ffmpeg:new): Transcoding single-frame APNG to AVIF results in very long encoding time

[FFmpeg]

#11370: Transcoding single-frame APNG to AVIF results in very long encoding time
-------------------------------------+-------------------------------------
             Reporter:  9e80         |                     Type:  defect
               Status:  new          |                 Priority:  normal
            Component:  ffmpeg       |                  Version:  7.1
             Keywords:  apng, avif,  |               Blocked By:
  libaom                             |
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 Summary of the bug:
 I will attach input APNG and logfile. Encoding takes many hours on beefy
 hardware. I do not know the exact amount of time, perhaps 12-16 hours.
 Single frame of input APNG seems to be decoded and passed to libaom
 encoder many times instead of one time as with transcoding to e.g. WEBP.
 How to reproduce:
 {{{
 % ffmpeg -report -i
 9e80eb2ff0613c3d6c83d204985fd5163c961ff6a5b2f64821ed5ea344b2d019.png -y
 deleteme.avif
 ffmpeg started on 2024-12-24 at 09:55:18
 Report written to "ffmpeg-20241224-095518.log"
 Log level: 48
 ffmpeg version 7.1 Copyright (c) 2000-2024 the FFmpeg developers
   built with Apple clang version 16.0.0 (clang-1600.0.26.4)
   configuration: --prefix=/opt/homebrew/Cellar/ffmpeg/7.1_3 --enable-
 shared --enable-pthreads --enable-version3 --cc=clang --host-cflags=
 --host-ldflags='-Wl,-ld_classic' --enable-ffplay --enable-gnutls --enable-
 gpl --enable-libaom --enable-libaribb24 --enable-libbluray --enable-
 libdav1d --enable-libharfbuzz --enable-libjxl --enable-libmp3lame
 --enable-libopus --enable-librav1e --enable-librist --enable-librubberband
 --enable-libsnappy --enable-libsrt --enable-libssh --enable-libsvtav1
 --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-
 libvmaf --enable-libvorbis --enable-libvpx --enable-libwebp --enable-
 libx264 --enable-libx265 --enable-libxml2 --enable-libxvid --enable-lzma
 --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-
 libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-
 libopenjpeg --enable-libspeex --enable-libsoxr --enable-libzmq --enable-
 libzimg --disable-libjack --disable-indev=jack --enable-videotoolbox
 --enable-audiotoolbox --enable-neon
   libavutil      59. 39.100 / 59. 39.100
   libavcodec     61. 19.100 / 61. 19.100
   libavformat    61.  7.100 / 61.  7.100
   libavdevice    61.  3.100 / 61.  3.100
   libavfilter    10.  4.100 / 10.  4.100
   libswscale      8.  3.100 /  8.  3.100
   libswresample   5.  3.100 /  5.  3.100
   libpostproc    58.  3.100 / 58.  3.100
 Input #0, apng, from
 '9e80eb2ff0613c3d6c83d204985fd5163c961ff6a5b2f64821ed5ea344b2d019.png':
   Duration: N/A, bitrate: N/A
   Stream #0:0: Video: apng, rgba(pc, gbr/unknown/unknown), 816x624, 100k
 tbr, 100k tbn
 Stream mapping:
   Stream #0:0 -> #0:0 (apng (native) -> av1 (libaom-av1))
 Press [q] to stop, [?] for help
 [libaom-av1 @ 0x152705ca0] 3.11.0
 [libaom-av1 @ 0x152705ca0] Neither bitrate nor constrained quality
 specified, using default CRF of 32
 Output #0, avif, to 'deleteme.avif':
   Metadata:
     encoder         : Lavf61.7.100
   Stream #0:0: Video: av1 (av01 / 0x31307661), gbrp(pc,
 gbr/unknown/unknown, progressive), 816x624, q=2-31, 100k fps, 100k tbn
 (default)
       Metadata:
         encoder         : Lavc61.19.100 libaom-av1
       Side data:
         cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: N/A
 ^C^C^CReceived > 3 system signals, hard exiting=00:00:00.00 bitrate=
 0.0kbits/s dup=349999 drop=0 speed=6.72e-05x
 }}}
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/11370>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker