#10698: VOBsub overlay leaks memory after subtitle stream EOF
-------------------------------------+-------------------------------------
Reporter: Leon | Type: defect
Status: new | Priority: normal
Component: ffmpeg | Version: git-
Keywords: overlay | master
framesync memleak memory vobsub | Blocked By:
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
-------------------------------------+-------------------------------------
Summary of the bug:
When overlaying VOBsub (`.idx` + `.sub`) onto a video stream using the
`overlay` video filter, ffmpeg starts to use a lot of memory after the
subtitle stream has gone EOF.
This behavior seems to be independent of the video codec, I tested it with
`h264`, `hevc` and `vp8`, and it happens with all of them.
It doesn't happen with SubRip `.srt` or MicroDVD `.sub` subtitles (at
least not with the files I tested), so maybe it only happens with bitmap
subtitle formats.
Furthermore, this only happens when at least one of `shortest=1` or
`eof_action=endall` is used as parameters for the overlay filter.
How to reproduce:
Create a test mkv that will be used as an input for the transcode (lower
values for `-t` suffice, since the subtitles are EOF immediately, but too
low values may result in the transcode finishing before a significant
increase in memory usage can be observed):
{{{
% ffmpeg -f lavfi -i color -f lavfi -i anullsrc=sample_rate=1 -t 5000 -c:v
libx264 test.mkv
}}}
Download and extract the subtitles I'll link here or below once the ticket
has been created.
Run the transcode:
{{{
% ffmpeg -i test.mkv -i test.idx -map 0:0 -map 0:1 -map -0:0
-filter_complex '[0:0][1:0]overlay=shortest=1' out.mkv
}}}
Additional information:
{{{
% ffmpeg -version
ffmpeg version N-112854-g44e9cccffa Copyright (c) 2000-2023 the FFmpeg
developers
built with gcc 13.2.1 (GCC) 20230801
configuration: --prefix=/usr --disable-static --disable-stripping
--disable-htmlpages --enable-amf --enable-avisynth --enable-cuda-llvm
--enable-lto --enable-fontconfig --enable-gmp --enable-gnutls --enable-gpl
--enable-ladspa --enable-libaom --enable-libass --enable-libbluray
--enable-libbs2b --enable-libdav1d --enable-libdrm --enable-libfreetype
--enable-libfribidi --enable-libgsm --enable-libiec61883 --enable-libjack
--enable-libjxl --enable-libmodplug --enable-libmp3lame --enable-
libopencore_amrnb --enable-libopencore_amrwb --enable-libopenjpeg
--enable-libopenmpt --enable-libopus --enable-libpulse --enable-librav1e
--enable-librsvg --enable-libsoxr --enable-libspeex --enable-libsrt
--enable-libssh --enable-libsvtav1 --enable-libtheora --enable-libv4l2
--enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpl
--enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265
--enable-libxcb --enable-libxml2 --enable-libxvid --enable-libzimg
--enable-nvdec --enable-nvenc --enable-opencl --enable-opengl --enable-
shared --enable-version3 --enable-vulkan
libavutil 58. 32.100 / 58. 32.100
libavcodec 60. 35.100 / 60. 35.100
libavformat 60. 18.100 / 60. 18.100
libavdevice 60. 4.100 / 60. 4.100
libavfilter 9. 13.100 / 9. 13.100
libswscale 7. 6.100 / 7. 6.100
libswresample 4. 13.100 / 4. 13.100
libpostproc 57. 4.100 / 57. 4.100
}}}
I also ran the transcode with valgrind massif to try to find out what's
allocating that much memory. It seems to be frames of the video stream
(maybe they aren't free'd?)
Screenshot of massif visualizer:
[[Image(https://screens.totally.rip/2023/11/6563bebb486bb.png)]]
I'll also upload the massif outfile via the VideoLAN File Uploader once
the ticket is created.
This issue may be related to #6922, as it also uses the `overlay` filter
with `eof_action=endall`, but I didn't test that.
Please let me know if I can add any additional useful information!
Best Regards,
Leon
--
Ticket URL: <https://trac.ffmpeg.org/ticket/10698>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker_______________________________________________
FFmpeg-trac mailing list
FFmpeg-trac@avcodec.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-trac
To unsubscribe, visit link above, or email
ffmpeg-trac-requ...@ffmpeg.org with subject "unsubscribe".
