Re: [VCDImager Bugs/Devel] SVCD sub header causing sound sync with Toshiba

[William Hardy]

Herbert, thanks for your prompt response.

In message <address@hidden>, Herbert 
Valerio Riedel <address@hidden> writes

[..]
> yes, it is a bug... but not in vcdimager, it's either the svcd spec, or
> your firmware... and in any way, a rather obscure one... :-)
>
> the SVCD specs have a simplified subheader coding wrt to VCD2.x which
> basically is:
>
>  SVCD 1.0
>  ~~~~~~~~
>
>   empty sector:  fn=0 cn=0 sm=%00100000 ci=0
>   data sector:   fn=0 cn=0 sm=%x0001000 ci=0
>   mpeg sector:   fn=1 cn=1 sm=%x11x001x ci=0x80
>
> (see libvcd/vcd_cd_sector.h for more...)
>
> the mpeg sector applies to every sector that 'contain mpeg program
> stream'... which is clearly the case even for just the sequence
> header...
So this could be a case of ambiguous spec writing or a mistake by the 
Toshiba software engineers!  They presumably consider this sector should 
be 'empty'.
[..]
> I'm willing to add this as an option; but I'd like to know how old this
> toshiba model is, and whether it helps playback for vcd2.0 as well (or
> whether it doesn't affect vcd2.0 playback at all...)

The SD 220E is one of Toshiba's current models here in the UK.  I have 
only had mine since just before Christmas.  It has won awards in some of 
the local magazines, and is quite a popular player.

The sound synchronisation for VCD 2.0 has never been a problem, only for 
SVCD.  From the DVD players list on vcdhelp.com (now DVDRhelp.com) I 
have found that a lot of people have found this.  The generally accepted 
fix is to re-select the audio stream once the disc is playing, i.e. 
switch to audio2 and then back to audio1.  This is known as the 'Angle 
button trick. This does in fact work, but is very annoying, as it causes 
an interruption to the sound, and the synchronisation is again lost when 
the next track starts to play.

Therefore I was determined to find a proper solution - not just for my 
benefit, but other users as well.

I note that the problem also manifests itself to some extent on the 
earlier SD 210E.  This may well be the same problem.

I have tried making a VCD2.0 with my modified VCDImager.  It played just 
fine on both PC and Toshiba player.

BTW, Toshiba recommend using the VOB Instant CD package for writing 
SVCDs.  I found this very unstable on my system, and the version I tried 
produced quite non-standard SVCDs (besides costing money!)  However they 
do work for the reasons I previously explained!

Do you have any objections to me making my modified version more widely 
available, e.g. with a post to the DVDRhelp forum, as an interim until 
we have agreed the final solution?  It would also be useful for others 
to check out to see if they have the same experiences.

Regards,
--
Bill.
address@hidden       http://www.billh.demon.co.uk