[vlc-devel] Matroska dummy

Steve Lhomme robux4 at gmail.com
Wed Feb 18 09:19:53 CET 2015

I'm looking at this issue https://trac.videolan.org/vlc/ticket/9623

This is a live stream from GStreamer that doesn't play in normal condition.
For playback to work you need to enable "--mkv-use-dummy" which allows
unknown elements in Matroska.

The problem is that a normal Matroska implementation *should* handle
unknown elements by default and skip them. Some vendors or users might add
their own stuff (like DivX does) and VLC wouldn't play the files.
libmatroska is not supposed to keep track of all known custom IDs floating
around and VLC be compiled with the latest for playback to work.

IMO this option is backward. The doc says "Read and discard unknown EBML
elements (not good for broken files)." It should be the other way around.
If you have a file that doesn't play, then you can try a command-line
option for playback to work.

I'd like to make this option always set, and introduce a new one if needed
like --mkv-strict which would mean the opposite.

The Gstreamer stream file is not broken. It justs puts the header and then
anything that comes from the live stream, even the remaining data from the
previous Cluster. That's the data we consider as garbage at the beggining.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.videolan.org/pipermail/vlc-devel/attachments/20150218/5cece6d1/attachment.html>

More information about the vlc-devel mailing list