MKV & Samsung wave

[DivineInterv]

Hi,
I bought a Samsung wave recently which supports mkv files albeit without subtitles (external srt files are supported) or multi-track support (it just plays the default track).

I have noticed that it displays the thumbnails instantly for some mkv files whereas for some it takes a few seconds and still displays a default video icon.

I accidentally found out that files which have something called "Cover" (from MediaInfo) display thumbnails.
I have attached an image showing the same.

My question is, what it is & how to embed it?

I am a novice w.r.t. AV tinkering but am fairly accustomed to using tools such as miniCoder, mkvMerge GUI, mkvExtract GUI.

Thank you for reading this.

[Baldrick]

In mkvmergegui I think you should add the cover image under the attachment tab, see http://www.bunkus.org/videotools/mkvtoolnix/doc/mkvmerge-gui.html#attachments . So try load your mkv, under attachment add an image, make a new mkv and see how it works.

[DivineInterv]

@Baldrik
That was it. So Cover actually denotes the presence of attachments? It worked for a few files. Attaching absolutely anything worked, be it a tiny square jpg or a dummy text file.

But I think, my deduction was wrong >_<. I found two files without "cover" that were exactly the same (except the length. difference of a few mins). One displays thumbnail but the other doesn't. Maybe its a flawed mkv implementation of Samsung's part.

I have attached the file details I got from MediaInfo.
02 displays thumbnail whereas 01 doesn't.

Can you please take a look?