MPEGAV folder in a VCD is empty. Can't play VCD on DVDCombo?

[plomon]

hi there,

I've a strange problem with my VCD. A DVD-ROM cum CD-RW drive is attached to my system(i.e., a DVD Combo Drive). When I put the VCD into the drive, and started browsing it, I found that the MPEGAV folder isn't opening. I tried windows media player, windvd, vlc mediaplayer, real player. but, none of them were able to play the vcd.


Strangely, this VCD is playing on a VCD player(used for TVs). But, it isn't playing on a computer. The strangest thing is that the folder named as MPEGAV isn't opening while in windows explorer, and although being opening while browsing for files in windvd or vlc mediaplayer, is showing zero contents in that folder i.e., there are absolutely no files in that folder. As, we all know there should be a AVSEQ01.DAT file in ever MPEGAV folder of a VCD. but, that isn't there in this case. However, surprisingly, the VCD is playing on VCD player, but not on a computer.


anybody, pls help me solve this probelm. pls suggest a suitable solution for the problem.

[adam]

Try looking in the segment directory first off. Mpeg sequences can be stored there. This is usually done for interactive elements like menus but you could just as easily put the movie in there.

If there is nothing there, it is possible that the disk contains some errors which are causing Windows to misread its contents. You could try accessing that directory via dos or you might have better luck using a program like VCDGear to extract the video track....where ever it may be.

[mats.hogberg]

Don't know about WinDVD, but PowerDVD plays VCD fine.
VCD isn't really a regular ISO CD, and the mpeg video isn't really in a file, but rather in sectors on the disc. I have too found that computers have problems reading such a disc properly.
Try extracting the mpg with VCDGear for computer playback.

/Mats

[plomon]

Don't know about WinDVD, but PowerDVD plays VCD fine.
VCD isn't really a regular ISO CD, and the mpeg video isn't really in a file, but rather in sectors on the disc. I have too found that computers have problems reading such a disc properly.
Try extracting the mpg with VCDGear for computer playback.

/Mats

sorry for the delay, i got vcdgear working just now, even after opening vcdgear, it doesn't show any signs of tracks or dat files present in the VCD.

i need more help on how the movie is stored in different sectors or on a single track, and how vcdgear helps extracting the movie content out of these sectors or track(s).

[plomon]

i hope u guys understood the actual problem. i'll repeat it once again for better clarity:

there isn't any file present in the MPEGAV folder of the VCD when opened on a computer. none of the softwares were able to play the VCD on the computer(including PowerDVD). however, the vcd plays on a tv using a vcd player.

moreoever, when vcdgearis opened and i clicked on the video-cd mode, i found no tracks liste in the section named as "VideoCD Track List". pls tell me what to do, and how to tackle such a strange problem.

[adam]

Have you tried browsing the segement directory?

[Cornucopia]

#1-Make sure you're not pre-filtering for only *.mpg in your browse/open dialogs.

#2-You should either find AVSEQ##.DAT or MUSIC##.DAT files in MPEGAV folder, and/or you should find ITEM####.DAT files in the SEGMENT folder, just as adam said.

#3-Try ISOBuster. Somebody may have change the files attributes to hidden. ISOBuster should be able to see them though, and extract/convert from M2F2 sectors to raw mpg.

Scott

[adam]

One more thing I forgot. Try setting windows to show all hidden files just incase the dat file is hidden.

open any folder and hit Tools/Folder Options/View and select show hidden files and folders.

[plomon]

#1-Make sure you're not pre-filtering for only *.mpg in your browse/open dialogs.

#2-You should either find AVSEQ##.DAT or MUSIC##.DAT files in MPEGAV folder, and/or you should find ITEM####.DAT files in the SEGMENT folder, just as adam said.

#3-Try ISOBuster. Somebody may have change the files attributes to hidden. ISOBuster should be able to see them though, and extract/convert from M2F2 sectors to raw mpg.

Scott

thank u so much cornucopia. u'r idea worked like fire. i used isobuster, and it showed me all the hidden parts of the VCD which i wasn't able to see all these days using any of the other softwares. here's a screenshot of how isobuster showed the contents of the VCD:



And, another point is that the Track 02 that your seeing in the above picture is not from the main folder - 'Session 1', but, it belongs to the folder Track 02. Look at the screenshot below to get the point exactly:



I extracted Track 02(of main Track 02) into a folder as MPEG file. Now, things are going fine. the movie s playing. But, still i don't understand what is this "tracks on CD" stuff all about. if u see the screenshot above, there are two tracks Track01 and Track02 belonging to Session 1(to the left in picture), in which

Track01 has all the folders that a common VCD would have. This is the folder which opened in windows explorer as soon as i put in the VCD into the drive. this looks like a misguiding track, as it doesn't have any data.

Track 02, again has it's own tracks - Track01 and Track 02(to the right in picture). Now, between these two, Track02 has the actual movie data.

I've some very basic questions on this kind of file structure on a VCD:

1.) Firstly, what is this "Session 1" folder on the VCD, and why does it contains the tracks in it.
2.) Why is Track 01 created if it doesn't have any content in it - i mean all the folders(although they look similar to VCDs which open on a computer) are absolutely empty except the VCD folder ?
3.) Why are there again two tracks in Track 02 ?
4.) How can I relate the main tracks - Track 01 and Track 02, and what's the use of storing movies in the form of tracks like this ?
5.) What is the software used to created VCDs in this manner ?

[Cornucopia]

I'm glad ISOBuster worked for you! Now, on to your questions...

1. "Session 1" isn't a folder, it's a recording session on that recordable discs. All recordable discs record in sessions. Either 1 session only, in the case of Disc-At-Once recording, or 1-or-more sessions, in the case of Session-At-Once or Track-At-Once Recording (won't even go into packet writing here). All [written] and [closed] sessions contain 1 or more tracks.

2. Track 1 does have content on it, just not content you're interested in. All [valid] VCD's must have the VCD folder (and appropriate files), should have the MPEGAV, EXT and CDI folders and files, may have the SEGMENT folder and files, occasionally might have the KARAOKE and CDDA (or AUDIO) folders and files. When you want the video, you go looking for the ITEM####.DAT files in the SEGMENT folder (if any) or the AVSEQ##.DAT files (aka MUSIC##.DAT files) in the MPEGAV folder. Yet, in truth, the MPEGAV files really aren't files--they're pointers (kinda like shortcuts/aliases) that point to the "non-file" media tracks of Track 2 and beyond. If your computer isn't reading the 2nd tracks right, I could see where you wouldn't find much on track 1.

3. This is where your disc is non-standard. You should never have a m2f2 media track (normally MPG video) that also has enough of a filesystem on it to point itself to 1 or more tracks. This is probably the reason most apps (VCDGear, etc) couldn't read it right. You should just see Track1 with the files and folders, and all Tracks 2 and up also coming from the root of Session1--a "track within a track" isn't really valid.

4. You've got to remember that until DVD came along (and even after that where you've got JPEG/MP3 reading drives) all media disc players read by tracks & indexes, hard-coded pointers, and or minutes/seconds/frames and that's it. No "files" as a computer would expect.

5. If you want to see what app originally authored this disc, you should be able to see it by opening up ISOBuster's sector viewer (right click on track1) and going to sector 16. About 1/2 way down on the hex readout on the right, you should see the app name. But that doesn't necessarilly mean that that app is the one that munged this up--could have been tweaked by hand (hex/cdmage/etc.)

Scott