[Matroska-devel] Comments on the "Audio Tags Example, Simple CD layout" at matroska.org

Vegard Pettersen vegard_p at broadpark.no
Sun Sep 26 19:57:24 CEST 2004

I'm working my way through the chapters and tag examples at matroska.org, and 
I have a few viewpoints that may or may not be overly critical.
I couldn't find a mailing list for the website, so I hope using this list is 

Referring to 
http://www.matroska.org/technical/specs/tagging/example-audio.html#intro, I 
find this example confusing and possibly wrong.
The statement: "Tracks 01 to 04 are linked together and are actually making 
just one "virtual" track to the listener.", I find unclear and inaccurate.

Just because there are no pregaps between some tracks does not change the fact 
that each track can be sought to. The meaning of "a virtual track" appears to 
me to only make sense if you ignore the concept of indices in a track. When a 
track has indices above INDEX 01, not all CD audio players can seek to such a 
seekpoint, very few people bother doing that, and I don't know of _any_ 
CD-ROM players that seek to such seekpoints. Therefore, making a track with 
indices over INDEX 01 would have the effect of making "one virtual track for 
the listener", whilst a number of tracks with pregaps of zero seconds is 
still a number of individual, seekable tracks.

Furthermore, I do not find the reason for grouping the four first tracks into 
a "00:00 - 12:28 : Baby Wants To Bleep/Rock" based on the CD-information 
available at amazon.com 
( http://www.amazon.com/exec/obidos/tg/detail/-/B000042VQM/qid=1096218210/sr=8-3/ref=sr_8_xs_ap_i3_xgl15/104-7128524-5572701?v=glance&s=music&n=507846#product-details ), 
( http://www.freedb.org/freedb_search_fmt.php?cat=newage&id=5b0a6e09 ),
or at discogs.com ( http://www.discogs.com/release/8788 ).

I see this grouping as an artificial construct based on length of pregaps, and 
it is confusing.

Referring to 
this is also slightly confusing.
"In this case the file contains one continuous audio track of 44:28. Chapters 
are used to virtually split the content in many parts, ie the CD tracks. A 
basic ripping application would rip the CD tracks as follows"
What exactly is the combined meaning of "one continous audio track" and "the 
CD tracks"? Is the cd one continous track, like the early release of "Mike 
Oldfield_Amarok" ( http://www.freedb.org/freedb_search_fmt.php?cat=misc&id=020e0601 ), 
or is the meaning that there is one track with many indices which for some 
reason is split into tracks?
Seeing that "mkvextract cuesheet foo.mka" and mkvmerge now both handle indices 
over INDEX 01 (mosu, can I commit this to the svn for mkvtoolnix or should I 
just send the modified files to you in mail?), maybe this example should be 
modified. I think it might be less vague if there was a CUE-file included in 
the example as well.

Referring to: 
the meaning of "meaningfull" again escapes me... with a cuesheet, it is 
possible to burn a wav having pregaps less than two seconds, so grouping the 
"no pause between"-tracks into is completely artificial. 
Sure, I understand the argument that "you can do it if you want to", I just 
don't see the point. Is it indended to make gapless playback easier or 
something? If so, I don't see why that should be the responsibility of a 
container format, that's in my view a player / demuxer's responsibility.

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