5.1 script, FFmpeg 8, VLC, and YouTube

[Kurville]

The FFmpeg script for "5.1(side)" is working but... when trying to play it back with the IAMF-enabled version of VLC, VLC crashes.

And trying to upload it to YouTube results in an incomplete processing ("traitement abandonné" in French).

[jwcullen]

Thanks for all of your interest and your reports.

I see that FFmpeg inserts "demixing" data for 5.1 (spec name DemixingInfoParameterData). FFmpeg is OK for doing this. iamf-tools decoder is a bit buggy here. We can fix this at iamf-tools.

[jwcullen]

Try uploading "5.1(side)" created with ffmpeg to YouTube again.

[Kurville]

It worked! Was the change done on YouTube's side? In any case, thanks!

The file:

Done with this FFmpeg:

ffmpeg version 8.0 Copyright (c) 2000-2025 the FFmpeg developers
built with Apple clang version 17.0.0 (clang-1700.0.13.3)
configuration: --prefix=/opt/homebrew/Cellar/ffmpeg/8.0_1 --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 60. 8.100 / 60. 8.100
libavcodec 62. 11.100 / 62. 11.100
libavformat 62. 3.100 / 62. 3.100
libavdevice 62. 1.100 / 62. 1.100
libavfilter 11. 4.100 / 11. 4.100
libswscale 9. 1.100 / 9. 1.100
libswresample 6. 1.100 / 6. 1.100

[jwcullen]

Yes, YouTube was impacted by the iamf-tools bug.

For the VLC half of this issue - it would be better to file a bug there. At this point it seems we have ruled out iamf-tools as a possible culprit. VLC uses their own implementation to decode and render IAMF.

You were making a file with ffmpeg, ingesting it via VLC, and the iamf-tools docs on how to use ffmpeg seem OK.

For further evidence that the file is OK, you could try decoding a culprit file with libiamf.

[Kurville]

Ok, thanks.