[VCDImager] SVCD ISO file differences between I-Author and vcdimager

[Joachim Jachemich]

Hi there,

first of all, thanks to Herbert for a great tool for producing SVCD's.
Using vcdimager I'm finally able to put an hour of movie on a 90 min
CD-R in acceptable quality. The burned images run flawlessly on my
SEG (Yamakawa 705-Clone) settop player...after I got the GOP
settings in TMPGenc right, even FF/FR and searching does work
correctly.

Nevertheless, there's a remarkable difference between I-Author edited
SVCD's an vcdimager ones when it comes to displaying total and
remaining times on the player, especially when there's more than one
mpeg2 track on the cd. I-Author edited cd's do display (more or less)
accurate times, whereas an image mastered with vcdimager does
display the correct timing only for the first track, starting with the
second track, timing display seems to be more or less random digits.

After investigating the ISO files (TRACKS.SVD esp.) produced by I-Author

and vcdimager, resp., it seems that I-Author uses a different layout for

the TRACKS.SVD file that leads to a correct timing display.

In detail, the header of the TRACKS.SVD structure seems identical, i.e.
ID, version, rsvd byte and number_of_tracks is the same, but the
playing time(s) are encoded in a different way: I-Author seems to
make use of a 5-byte structure - 3 bytes msf playing time, and
a two byte field that somehow encodes the audio characteristics of
the stream. Additionally I-Author encodes the accumulated track
playing times within TRACKS.SVD- not the individual ones as vcdimager
does.

Any experiences / advice around ?

regards

jj