ac3 incomplete frame from matroska file

[kasper93]

Summary of the bug:

Audio doesn't play correctly.
Constant log:
[ac3] incomplete frame

Works fine after extracting the track

% ffmpeg -i XoHe.mkv -c copy out.ac3

Looks like demuxing issue?

How to reproduce:

% ffplay -i XoHe.mkv

ffmpeg version: bb9e4ff355684b0325d1632b89baab96cc24dc51

[kasper93]

​https://0x0.st/XoHe.mkv
mirror: ​https://www.mediafire.com/file/kqply112nljpnuq/XoHe.mkv/file

[mkver]

Your file is strangely muxed: It is AC-3 in the VfW compatibility mode ("A_MS/ACM"). More importantly, the Matroska Blocks don't correspond to the AC-3 frames at all: The latter have a length of 768 bytes, while the former have a length of 1001 (the first one of 1002) bytes. I'll see what I can do, but I recommend you to extract the AC-3 track and use the raw track to remux the file.