TrueHD 6ch fails to be parsed

[eugenesv]

Summary of the bug:

somewhere between
ffmpeg-2021-09-22-git-447cf53774-essentials_build and
ffmpeg-2021-09-30-git-3ee4502753-essentials_build

a bug was introduced that prevents conversion on 5.1 channel TrueHD files (2 channel files work fine) with the following error:

---

[truehd @ 000002b45a68f700] Assignment of matrix channel 0 to invalid output channel -22 is not implemented. Update your FFmpeg version to the newest one from Git. If the problem still occurs, it means that your file has a feature which has not been implemented.
[truehd @ 000002b45a68f700] If you want to help, upload a sample of this file to https://streams.videolan.org/upload/ and contact the ffmpeg-devel mailing list. (ffmpeg-devel@ffmpeg.org)
[truehd @ 000002b45a68f700] No restart header present in substream 0.
[truehd @ 000002b45a68f700] No samples to output.

---

How to reproduce:

ffmpeg version 2021-09-30-git-3ee4502753-essentials_build-www.gyan.dev Copyright (c) 2000-2021 the FFmpeg developers

% ffmpeg.exe -i in6ch.thd

(again, this works with ffmpeg-2021-09-22-git-447cf53774-essentials_build)

[Balling]

It is commit 57f0b36367d4e5ccd4d2da7f69c3cac45b6236ee to be precise. If you are decoding stuff from before that commit with a different ffmpeg created with cd7e25b14a2a27b73874b5f79a04ae5db738f7f6 encoder modification... P.S. Though apparently it has problem even on HEAD of master.

Not going to analyse it further though.

[Balling]

Were these files created by ffmpeg native truehd encoder? Or by Plex ffmpeg modification? Or what?

[eugenesv]

Replying to Balling:

Were these files created by ffmpeg native truehd encoder? Or by Plex ffmpeg modification? Or what?

No, don't know how these were created, they're from an external source. But when I create TrueHD files with ffmpeg, I get the same error for 6ch and none for 2ch

[Balling]

Well, this issue is fixed in 946493eb3e072b499909f606625480c928834a44. The file on ​https://anonfiles.com/reXbf3S0u0/TrueHD_track02_truehd is still broken.