Re: [VCDImager Bugs/Devel] vcdimager progress info...

[Andrew Stevens]

Hi all,

> > I've gotten held up on warnings/errors from vcdxml about an MPEG I
> > created via Gimp's GAP tools (using mpeg_encode as the encoder).  Any
> > clue as to what this means in practical terms?
> >
> > --DEBUG: adding sequence #0, MGraphics3/SVP-title.mpg
> >    INFO: scanning mpeg sequence item #4 for scanpoints...
>
> [...]
>
> > --DEBUG: pos != len (2321 != 2324)
>
> well, this is just for debugging... nothing to worry about for now :)
>
> > **ERROR: mpeg scan: pack header code expected, but 0x000001b9 found
> > (buflen = 2324)
>
> that's the problem mentioned before on the list...
>
> quick fix unless the new mjpeg tools get released: just remove the last
> 2324 bytes from that mpeg file...

Should now be fixed in CVS.  No error messages when applied to freshly muxed 
system stream. I'll be uploading a new tarball to sourceforge tonight.

ASIDE: Anyone remind what mpeg_encode in Gimp's GAP tools actually is?
Is it the latest mjpegtools in a script?

> >   - mpeg_encode used to create the video stream
> >   - toolame used for audio stream
> >   - vcdmplex used to create system stream (and it bitched about some
--------^

This is not the mjpegtools mulitplexer... but it sounds like Rainer made the 
same (wrong) guess as me about stream end markers ;-)


> >      potential buffer underruns; i guess i need to play with bitrates?)

Buffer under-runs occur when the (peak) bit-rate required for timely delivery 
of the video exceeds that available in the multiplexed stream.  Fix: reduce 
the rate you're encoding at or increase the mulitplexed data rate.  There is 
possibly some tuning required to mpeg2enc's rate control.  In CVS I've set it
slightly more conservatively (the penalty is a slight decrease in utilisation
overall).

        Andrew