editer shows 'no sound', mpg plays with sound

[oldvideote]

i hope this is the correct/a suitable forum section.

i have following problem:
on my win98se computer 2 mpg files, a.mpg and b.mpg (as an example!)
both are videos with sound.

(all on the same machine):

i have the VLC player
i have Magix Video de Luxe 2005 for editing a.s.o.

when i open (play) a.mpg with the VLC player, i get motion and sound : Good
when i open (play) b.mpg with the VLC player, i get motion and sound : Good

when i want to edit a.mpg with Magix and open it and move the file to the time-line,
i get a sequence of video pictures and below that a sound track : Good
when i play that video in Magix, motion and sound is present: Good

when i want to edit b.mpg with Magix and open it and move the file to the time-line,
i get a sequence of video pictures and below that NOTHING (no sound track) : Bad
when i play that same video in Magix, motion is present, but NO SOUND : Bad.

i want to do editing on the b.mpg file (it is a recorded tv-program, using mythtv (actually
a knoppmyth setup).

as VLC plays both videos well, i argue the sound is present in b.mpg.

is Magix using a wrong codec?
what can i do to make Magix behave as wanted?
is there another cause for this problem?

would appreciate your help!
tx,
rob

[guns1inger]

Use a tool like g-spot to look at the content of the video. Wild guess would suggest that it is AC3 audio, which a lot of low end editors cannot work with.

[oldvideote]

AC3 has to do with the sound card (onboard in my system)?

remember one of both films gives sound when it plays..

to GSpot:
downloaded the recent version 207: doesn't run on win98se
downloaded the last version for win98se: GSpot221.
works, but after startup and loading a mpg file to be examined, most boxes are empty 'n.a.' a.s.o.

when i open the playable mpg file in GSpot, and after rendering, the program says:
Video Src Type: MPEG1 Payload
Audio Src: MPEG1 Audio Payload
rendering successfull; will be playable.
when i try to play (using associated player = Win Media Player), the film plays fine, with sound.

when i open the un-playable (sound!) file, GSpot after rendering says:
Video Src Type: MPEG2_Video
Audio Src: MPEG1 Payload
and that the film will be playable.
but: doing as above, the film plays not, no picture, no sound in WMP

this last film is the one produced by Mythtv.
can the problem be the Mpeg2/Mpeg1 combination within one film??

[guns1inger]

AC3 is just an audio encoding method (codec). It is also known as Dolby Digital.

The version of g-spot you are able to run is old, and doesn't process mpeg files very well. Mpeg1 audio will be Mpeg1-Layer2, also sometimes called mpeg2 audio. If both clips do have this audio, and one doesn't play, it may be that it is corrupt. While a robust player like VLC, which is designed to play partial and damaged file, may well play it, it may be damaged such that your editor cannot. You could try streaming it out of VLC to a new format to see if it fixes things, or try loading it into virtualdubmpeg2 to see if it errors out.

Being on Windows 98 does limit your options a lot though.