[FFmpeg-user] ffmpeg is oom-killed when converting an image to AVIF

[Dmitry Katsubo]

Dear FFmpeg users,

I've encountered OOM "issue" when encoding PNG image to AVIF using ffmpeg. I have an example of successful conversion for the image about 6000x1800x32, but a bit larger image 7147×1783×32 causes OOM.

Any idea why image raster of 7147×1783×4 ~ 50 MB requires ~ 3 GB of memory (which is at least ×50 more memory than raster)? And how to workaround the issue?

Many thanks in advance!

$ ffmpeg -i test.png -c:v libaom-av1 -crf 30 test.avif
ffmpeg version 5.1.3-1 Copyright (c) 2000-2022 the FFmpeg developers
  built with gcc 12 (Debian 12.2.0-14)
  configuration: --prefix=/usr --extra-version=1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping
--enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libdav1d --enable-libflite
--enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libglslang --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg
--enable-libopenmpt --enable-libopus --enable-libpulse --enable-librabbitmq --enable-librist --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex
--enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx265 --enable-libxml2
--enable-libxvid --enable-libzimg --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --disable-sndio --enable-libjxl
--enable-pocketsphinx --enable-librsvg --enable-libmfx --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --enable-libplacebo
--enable-librav1e --enable-shared
Input #0, png_pipe, from 'test.png':
  Duration: N/A, bitrate: N/A
  Stream #0:0: Video: png, rgba(pc), 7147x1783 [SAR 2835:2835 DAR 7147:1783], 25 fps, 25 tbr, 25 tbn
Stream mapping:
  Stream #0:0 -> #0:0 (png (native) -> av1 (libaom-av1))
Press [q] to stop, [?] for help
[libaom-av1 @ 0x55b79026db40] v3.6.0
Output #0, avif, to 'test.avif':
  Metadata:
    encoder         : Lavf59.27.100
  Stream #0:0: Video: av1 (av01 / 0x31307661), gbrp(pc, gbr/unknown/unknown, progressive), 7147x1783 [SAR 1:1 DAR 7147:1783], q=2-31, 25 fps, 12800 tbn (default)
    Metadata:
      encoder         : Lavc59.37.100 libaom-av1
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: N/A
Killed    1 fps=0.6 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x

# free -t
               total        used        free      shared  buff/cache   available
Mem:         8017020     4833284     1275188      119672     2330812     3183736
Swap:         102396      102396           0
Total:       8119416     4935680     1275188

>From /var/log/kernel.log

kernel: ffmpeg invoked oom-killer: gfp_mask=0x140dca(GFP_HIGHUSER_MOVABLE|__GFP_COMP|__GFP_ZERO), order=0, oom_score_adj=0
kernel: CPU: 0 PID: 466425 Comm: ffmpeg Not tainted 6.1.0-10-amd64 #1  Debian 6.1.38-1
kernel: Call Trace:
kernel:  <TASK>
kernel:  dump_stack_lvl+0x44/0x5c
kernel:  dump_header+0x4a/0x211
kernel:  oom_kill_process.cold+0xb/0x10
kernel:  out_of_memory+0x1fd/0x4c0
kernel:  __alloc_pages_slowpath.constprop.0+0xc73/0xdc0
kernel:  __alloc_pages+0x305/0x330
kernel:  __folio_alloc+0x17/0x50
kernel:  ? policy_node+0x51/0x70
kernel:  vma_alloc_folio+0x9c/0x370
kernel:  __handle_mm_fault+0x92f/0xfa0
kernel:  handle_mm_fault+0xdb/0x2d0
kernel:  do_user_addr_fault+0x19c/0x570
kernel:  exc_page_fault+0x70/0x170
kernel:  asm_exc_page_fault+0x22/0x30
kernel: RIP: 0033:0x7f3cf8f7204a
...
kernel: Mem-Info:
kernel: active_anon:153032 inactive_anon:1662278 isolated_anon:0
kernel:  active_file:382 inactive_file:2194 isolated_file:98
kernel:  unevictable:11644 dirty:356 writeback:0
kernel:  slab_reclaimable:48560 slab_unreclaimable:43800
kernel:  mapped:9888 shmem:25129 pagetables:11368
kernel:  sec_pagetables:0 bounce:0
kernel:  kernel_misc_reclaimable:0
kernel:  free:24673 free_pcp:174 free_cma:0
kernel: 28496 total pagecache pages
kernel: 332 pages in swap cache
kernel: Free swap  = 0kB
kernel: Total swap = 102396kB
kernel: 2068610 pages RAM
kernel: 0 pages HighMem/MovableOnly
kernel: 64355 pages reserved
kernel: 0 pages hwpoisoned
kernel: Tasks state (memory values in pages):
kernel: [  pid  ]   uid   tgid total_vm     rss pgtables_bytes swapents oom_score_adj name
kernel: [ 466425]  1000 466425  1093593  808340        7086080        0             0 ffmpeg
...
kernel: oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null),cpuset=user.slice,mems_allowed=0,global_oom,task_memcg=/user.slice/user-1000.slice/session-c1.scope,task=ffmpeg,pid=466425,uid=1000
kernel: Out of memory: Killed process 466425 (ffmpeg) total-vm:4374372kB, anon-rss:3233360kB, file-rss:0kB, shmem-rss:0kB, UID:1000 pgtables:6920kB oom_score_adj:0


-- 
With best regards,
Dmitry