What is wrong with this MPEG-1 file?

[koozmusic]

I recently came across a rare copy of the MPEG version of Return to Zork for Mac. This game was bundled with an MPEG decoder card and required it to run. To my surprise, it seems all 358 of the FMV sequences in the game are just sitting on the root of the disc as .MPG files, free to peruse at will.

A large majority (316 out of 358) of these play without issue, for the most part. MPC-HC seems to handle them fine, while VLC will present a glitchy second or two at the beginning of some clips. However, 42 of them appear to be garbled and stuttering. Again MPC-HC handles these better than VLC, but no player that I've tried can seem to play them fully correctly.

It seems like maybe there is something wrong with the header, the pack order, or maybe some encoding issue that the original hardware decoder had no trouble coping with?

I have attempted to use basically all forum-recommended MPEG stream fixing tools and editors, and after thoroughly exhaustive googling to no avail I thought someone here might be willing/able to assist.

I've attached two small files as an example of both working and non-working clips.

[Baldrick]

I tried reconvert with it Xmedia Recode but still same video errors.

And the old tmpgenc wont read the video tracks.

[DB83]

That 'broken' file does not have a frame-rate. So,yes, it appears on the surface to be a header issue. Someone with the knowledge could, possibly, use a hex-editor and edit the header but even that might not 'fix' the issue.

More than likely the actual program, with the decoder card, loads these as stubs and then decodes them properly

[koozmusic]

That 'broken' file does not have a frame-rate. So,yes, it appears on the surface to be a header issue. Someone with the knowledge could, possibly, use a hex-editor and edit the header but even that might not 'fix' the issue.

I noticed that as well. I actually did attempt this by following this page as a guide, but it didn't seem to make a difference.

Even the files that play properly seem to lack a frame rate, for whatever reason, despite them playing at their intended 30fps.

EDIT: okay, never mind. I must have been only looking at broken ones. I see they are actually set for 29.97fps.

[DB83]

Possibly a proprietory format that requires the game .exe (or whatever) + decoder to actually run them similar these days to DVRs which only play the recorded files direct - transfer them as-is outside and they are un-playable.

[koozmusic]

Well, I do have the game CD, but unfortunately none of the hardware to actually run it; and I don't know anything about disassembly to try and figure out what it needs... It seems so close to being right, though. It doesn't really look like its scrambled.

On another note though, your previous post (and my subsequent realization that I hadn't thoroughly looked at the metadata for each type of file) made me realize I should take a closer look. It looks like there is actually a lot of disparity between them.



I'll have to see if I can get some more of these properties carried over to the unplayable file.

[DB83]

Very odd. The playable one does not have a GOP structure (which it really should)

Another possibility. Some form of copy-protection is underway so there is something else on the CD to help them play.

The time-code is an odd one and that may hold the key.

[aedipuss]

i played with the sequence header a bit and made it the same as the playable one.

[DB83]

^^ It's actually worse

[aedipuss]

plays the same here. both the broken one and the transplanted header version play with artifacts in vlc.

[mazinz]

For sake of argument here are two links that go into a bit more detail about the special hardware card used to play this game

http://www.vogons.org/viewtopic.php?t=37363&p=328920

And

http://www.forcedperfect.net/hardware/cards/applempegmediasystem/

Interesting since the bottom makes mention of a "QuickTime MPEG format

[DB83]

plays the same here. both the broken one and the transplanted header version play with artifacts in vlc.

Maybe I did not get passed the first few seconds but I saw much more disturbance - the lady was surrounded by pixels whereas when I played the original this morning I just saw a little interference.

But after reading the above links there is more than meets the eye. This double-pixels may have something to do with it - 320*240 playing as 640*480 - whereas our players just play it as 320*240.

I thought quicktime players always played mpeg but there appears to be an extra codec level here..

[johns0]

The FBOW05XX_broken file plays in mpc-hc with a few artifacts at 12fps.

[DB83]

Sometimes an old clip needs an old program.

Went in to my archives and found a c2007(2002-2006) version of Media Player Classic(Unicode build) v6.4.9.0 (Gabest)

Played the clip smoothly without a single artefact.

[El Heggunte]

Sometimes an old clip needs an old program.

Or more probably, a broken file needs a fault-tolerant player

Went in to my archives and found a c2007(2002-2006) version of Media Player Classic(Unicode build) v6.4.9.0 (Gabest)

Played the clip smoothly without a single artefact.

[DB83]

But are the clips actually broken ?

The link shows this game was issued with that card - not the card with the game (an important difference in my book). So the game is designed to show off the card.

If they did not play with the card then, yes, they are broken. There can be no guarantees for other playback. And was this form of the game actually released on it's own ?

[poisondeathray]

Probably the clips are fine. I think it's more likely that nobody cares about full mpeg1 support. Microsoft's own decoder can play it back correctly, and MS isn't exactly known for "fault tolerant" playback; they just tend to keep legacy things around longer (quartz.dll in a directshow graph, and that was dated Jun 15 2014 in a Windows 8 build). You can probably setup a custom filter in your chosen media player to use MS instead for mepg1 media. (for example, in MPCHC, you would right click , options => external filters => add filter => MPEG Video Decoder (this is MS's own decoder quartz.dll and ships with all Windoze builds) , set the merit to "prefer". Make sure mediatypes are set to MPEG1 only (otherwise you will use it for other MPEG types) , push apply

[El Heggunte]

FWIW......

MPlayer plays the playable MPG fine. As for the broken one, it returns the following warnings:

[mpeg1video @ 01384940]ac-tex damaged at 16 12
[mpeg1video @ 01384940]end mismatch left=679 149A62
[mpeg1video @ 01384940]end mismatch left=222 4A4451
[mpeg1video @ 01384940]Warning MVs not available
[mpeg1video @ 01384940]concealing 60 DC, 60 AC, 60 MV errors in B frame
[mpeg1video @ 01384940]slice mismatch
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]ac-tex damaged at 0 7
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]ac-tex damaged at 19 8
[mpeg1video @ 01384940]skip with previntra
[mpeg1video @ 01384940]ac-tex damaged at 15 10
[mpeg1video @ 01384940]end mismatch left=1619 6197B0
[mpeg1video @ 01384940]end mismatch left=30 124BAC
[mpeg1video @ 01384940]Warning MVs not available
[mpeg1video @ 01384940]concealing 220 DC, 220 AC, 220 MV errors in B frame
[VD_FFMPEG] DRI failure.
[mpeg1video @ 01384940]ac-tex damaged at 16 3
[mpeg1video @ 01384940]invalid mb type in P Frame at 17 9
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]invalid mb type in P Frame at 0 14
[mpeg1video @ 01384940]Warning MVs not available
[mpeg1video @ 01384940]concealing 80 DC, 80 AC, 80 MV errors in P frame
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]slice mismatch
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]skip with previntra
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]ac-tex damaged at 10 12
[mpeg1video @ 01384940]end mismatch left=45 134D49
[mpeg1video @ 01384940]Warning MVs not available
[mpeg1video @ 01384940]concealing 220 DC, 220 AC, 220 MV errors in B frame
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]skip with previntra
[mpeg1video @ 01384940]invalid mb type in B Frame at 9 5
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]skip with previntra
[mpeg1video @ 01384940]skip with previntra
[mpeg1video @ 01384940]invalid cbp -1 at 1 13
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]skip with previntra
[mpeg1video @ 01384940]invalid mb type in B Frame at 17 14
[mpeg1video @ 01384940]Warning MVs not available
[mpeg1video @ 01384940]concealing 240 DC, 240 AC, 240 MV errors in B frame
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]invalid cbp -1 at 10 5
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]ac-tex damaged at 11 7
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]slice mismatch
[mpeg1video @ 01384940]ac-tex damaged at 9 10
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]end mismatch left=7614 780214
[mpeg1video @ 01384940]invalid cbp 0 at 11 13
[mpeg1video @ 01384940]Warning MVs not available
[mpeg1video @ 01384940]concealing 240 DC, 240 AC, 240 MV errors in P frame
[mpeg1video @ 01384940]ac-tex damaged at 9 2
[mpeg1video @ 01384940]ac-tex damaged at 1 4
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]skip with previntra
[mpeg1video @ 01384940]invalid mb type in B Frame at 11 9
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]skip with previntra
[mpeg1video @ 01384940]end mismatch left=3979 2C20E0
[mpeg1video @ 01384940]ac-tex damaged at 3 13
[mpeg1video @ 01384940]end mismatch left=1903 2F1B43
[mpeg1video @ 01384940]Warning MVs not available
[mpeg1video @ 01384940]concealing 260 DC, 260 AC, 260 MV errors in B frame
[mpeg1video @ 01384940]ac-tex damaged at 11 2
[mpeg1video @ 01384940]slice mismatch
[mpeg1video @ 01384940]invalid mb type in P Frame at 3 4
[mpeg1video @ 01384940]ac-tex damaged at 11 5
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]invalid cbp 0 at 7 8
[mpeg1video @ 01384940]invalid mb type in P Frame at 17 11
[mpeg1video @ 01384940]ac-tex damaged at 13 10
[mpeg1video @ 01384940]invalid cbp -1 at 3 11
[mpeg1video @ 01384940]invalid mb type in P Frame at 14 13
[mpeg1video @ 01384940]end mismatch left=3234 798EED
[mpeg1video @ 01384940]ac-tex damaged at 19 14
[mpeg1video @ 01384940]Warning MVs not available
[mpeg1video @ 01384940]concealing 280 DC, 280 AC, 280 MV errors in P frame
[mpeg1video @ 01384940]ac-tex damaged at 10 2
[mpeg1video @ 01384940]invalid cbp 0 at 6 4
[mpeg1video @ 01384940]invalid mb type in B Frame at 15 4
[mpeg1video @ 01384940]invalid mb type in B Frame at 1 6
[mpeg1video @ 01384940]slice mismatch
[mpeg1video @ 01384940]slice mismatch
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]invalid cbp -1 at 3 11
[mpeg1video @ 01384940]ac-tex damaged at 19 13
[mpeg1video @ 01384940]invalid mb type in B Frame at 6 14
[mpeg1video @ 01384940]skip with previntra
[mpeg1video @ 01384940]Warning MVs not available
[mpeg1video @ 01384940]concealing 260 DC, 260 AC, 260 MV errors in B frame
[mpeg1video @ 01384940]ac-tex damaged at 9 2
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]invalid cbp -1 at 8 4
[mpeg1video @ 01384940]ac-tex damaged at 13 7
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]slice mismatch
[mpeg1video @ 01384940]ac-tex damaged at 14 12
[mpeg1video @ 01384940]ac-tex damaged at 3 11
[mpeg1video @ 01384940]invalid cbp -1 at 4 12
[mpeg1video @ 01384940]skip with previntra
[mpeg1video @ 01384940]invalid cbp 0 at 9 14
[mpeg1video @ 01384940]Warning MVs not available
[mpeg1video @ 01384940]concealing 226 DC, 226 AC, 226 MV errors in B frame
[mpeg1video @ 01384940]invalid mb type in B Frame at 14 2
[mpeg1video @ 01384940]slice mismatch
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]skip with previntra
[mpeg1video @ 01384940]invalid mb type in B Frame at 1 8
[mpeg1video @ 01384940]invalid cbp -1 at 9 8
[mpeg1video @ 01384940]invalid mb type in B Frame at 11 10
[mpeg1video @ 01384940]ac-tex damaged at 14 11
[mpeg1video @ 01384940]skip with previntra
[mpeg1video @ 01384940]ac-tex damaged at 5 13
[mpeg1video @ 01384940]end mismatch left=496 422072
[mpeg1video @ 01384940]Warning MVs not available
[mpeg1video @ 01384940]concealing 280 DC, 280 AC, 280 MV errors in B frame
[mpeg1video @ 01384940]slice mismatch
[mpeg1video @ 01384940]slice mismatch
[mpeg1video @ 01384940]invalid cbp 0 at 5 4
[mpeg1video @ 01384940]skip with previntra
[mpeg1video @ 01384940]skip with previntra
[mpeg1video @ 01384940]ac-tex damaged at 10 8
[mpeg1video @ 01384940]skip with previntra
[mpeg1video @ 01384940]ac-tex damaged at 3 12
[mpeg1video @ 01384940]ac-tex damaged at 5 12
[mpeg1video @ 01384940]invalid mb type in B Frame at 9 14
[mpeg1video @ 01384940]end mismatch left=242 3FF6A0
[mpeg1video @ 01384940]Warning MVs not available
[mpeg1video @ 01384940]concealing 244 DC, 244 AC, 244 MV errors in B frame
[mpeg1video @ 01384940]slice mismatch
[mpeg1video @ 01384940]invalid mb type in P Frame at 17 2
[mpeg1video @ 01384940]invalid mb type in P Frame at 18 3
[mpeg1video @ 01384940]invalid mb type in P Frame at 5 5
[mpeg1video @ 01384940]ac-tex damaged at 16 6
[mpeg1video @ 01384940]ac-tex damaged at 5 6
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]ac-tex damaged at 4 14
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]ac-tex damaged at 4 12
[mpeg1video @ 01384940]invalid cbp -1 at 5 13
[mpeg1video @ 01384940]end mismatch left=1248 2DFFC
[mpeg1video @ 01384940]Warning MVs not available
[mpeg1video @ 01384940]concealing 280 DC, 280 AC, 280 MV errors in P frame
[mpeg1video @ 01384940]slice mismatch
[mpeg1video @ 01384940]invalid mb type in B Frame at 15 3
[mpeg1video @ 01384940]ac-tex damaged at 5 4
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]ac-tex damaged at 11 8
[mpeg1video @ 01384940]invalid cbp -1 at 17 8
[mpeg1video @ 01384940]invalid cbp 0 at 6 10
[mpeg1video @ 01384940]invalid cbp -1 at 15 10
[mpeg1video @ 01384940]invalid cbp -1 at 2 13
[mpeg1video @ 01384940]invalid mb type in B Frame at 9 13
[mpeg1video @ 01384940]end mismatch left=343 79F02
[mpeg1video @ 01384940]Warning MVs not available
[mpeg1video @ 01384940]concealing 240 DC, 240 AC, 240 MV errors in B frame
[mpeg1video @ 01384940]invalid cbp 0 at 10 5
[mpeg1video @ 01384940]skip with previntra
[mpeg1video @ 01384940]invalid cbp -1 at 13 6
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]slice mismatch
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]invalid mb type in B Frame at 11 12
[mpeg1video @ 01384940]skip with previntra
[mpeg1video @ 01384940]end mismatch left=171 6ECC20
[mpeg1video @ 01384940]Warning MVs not available
[mpeg1video @ 01384940]concealing 220 DC, 220 AC, 220 MV errors in B frame
[mpeg1video @ 01384940]invalid mb type in B Frame at 0 5
[mpeg1video @ 01384940]invalid mb type in B Frame at 18 5
[mpeg1video @ 01384940]invalid cbp -1 at 11 7
[mpeg1video @ 01384940]invalid mb type in B Frame at 12 8
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]invalid cbp 0 at 9 10
[mpeg1video @ 01384940]invalid mb type in B Frame at 7 14
[mpeg1video @ 01384940]invalid cbp -1 at 7 14
[mpeg1video @ 01384940]Warning MVs not available
[mpeg1video @ 01384940]concealing 181 DC, 181 AC, 181 MV errors in B frame
[mpeg1video @ 01384940]ac-tex damaged at 11 2
[mpeg1video @ 01384940]invalid mb type in P Frame at 9 10
[mpeg1video @ 01384940]ac-tex damaged at 9 9
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]invalid mb type in P Frame at 11 13
[mpeg1video @ 01384940]ac-tex damaged at 4 14
[mpeg1video @ 01384940]Warning MVs not available
[mpeg1video @ 01384940]concealing 220 DC, 220 AC, 220 MV errors in P frame
[mpeg1video @ 01384940]ac-tex damaged at 13 7
[mpeg1video @ 01384940]invalid mb type in B Frame at 2 9
[mpeg1video @ 01384940]invalid cbp -1 at 16 10
[mpeg1video @ 01384940]invalid cbp 0 at 14 11
[mpeg1video @ 01384940]skip with previntra
[mpeg1video @ 01384940]invalid mb type in B Frame at 3 14
[mpeg1video @ 01384940]ac-tex damaged at 11 14
[mpeg1video @ 01384940]Warning MVs not available
[mpeg1video @ 01384940]concealing 161 DC, 161 AC, 161 MV errors in B frame
[mpeg1video @ 01384940]ac-tex damaged at 5 8
[mpeg1video @ 01384940]slice mismatch
[mpeg1video @ 01384940]slice mismatch
[mpeg1video @ 01384940]skip with previntra
[mpeg1video @ 01384940]slice mismatch
[mpeg1video @ 01384940]slice mismatch
[mpeg1video @ 01384940]ac-tex damaged at 12 14
[mpeg1video @ 01384940]Warning MVs not available
[mpeg1video @ 01384940]concealing 140 DC, 140 AC, 140 MV errors in B frame
[mpeg1video @ 01384940]invalid mb type in P Frame at 5 6
[mpeg1video @ 01384940]slice mismatch
[mpeg1video @ 01384940]invalid cbp -1 at 15 10
[mpeg1video @ 01384940]invalid cbp -1 at 13 9
[mpeg1video @ 01384940]slice mismatch
[mpeg1video @ 01384940]ac-tex damaged at 0 12
[mpeg1video @ 01384940]ac-tex damaged at 0 13
[mpeg1video @ 01384940]end mismatch left=2975 5FFD4C
[mpeg1video @ 01384940]ac-tex damaged at 7 14
[mpeg1video @ 01384940]Warning MVs not available
[mpeg1video @ 01384940]concealing 180 DC, 180 AC, 180 MV errors in P frame
[mpeg1video @ 01384940]invalid cbp 0 at 1 10
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]invalid mb type in B Frame at 7 12
[mpeg1video @ 01384940]ac-tex damaged at 17 12
[mpeg1video @ 01384940]slice mismatch
[mpeg1video @ 01384940]ac-tex damaged at 13 14
[mpeg1video @ 01384940]Warning MVs not available
[mpeg1video @ 01384940]concealing 140 DC, 140 AC, 140 MV errors in B frame
[mpeg1video @ 01384940]invalid mb type in B Frame at 19 8
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]skip with previntra
[mpeg1video @ 01384940]skip with previntra
[mpeg1video @ 01384940]invalid cbp 0 at 3 13
[mpeg1video @ 01384940]end mismatch left=139 3A55B6
[mpeg1video @ 01384940]Warning MVs not available
[mpeg1video @ 01384940]concealing 140 DC, 140 AC, 140 MV errors in B frame
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]ac-tex damaged at 1 4
[mpeg1video @ 01384940]ac-tex damaged at 18 5
[mpeg1video @ 01384940]ac-tex damaged at 0 6
[mpeg1video @ 01384940]slice mismatch
[mpeg1video @ 01384940]skip with previntra
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]slice mismatch
[mpeg1video @ 01384940]invalid cbp 0 at 12 13
[mpeg1video @ 01384940]invalid cbp 0 at 3 13
[mpeg1video @ 01384940]end mismatch left=11 690
[mpeg1video @ 01384940]Warning MVs not available
[mpeg1video @ 01384940]concealing 260 DC, 260 AC, 260 MV errors in B frame
[mpeg1video @ 01384940]ac-tex damaged at 13 2
[mpeg1video @ 01384940]ac-tex damaged at 1 3
[mpeg1video @ 01384940]ac-tex damaged at 9 5
[mpeg1video @ 01384940]slice mismatch
[mpeg1video @ 01384940]invalid cbp -1 at 14 7
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]ac-tex damaged at 7 8
[mpeg1video @ 01384940]ac-tex damaged at 8 9
[mpeg1video @ 01384940]invalid cbp 0 at 9 10
[mpeg1video @ 01384940]skip with previntra
[mpeg1video @ 01384940]skip with previntra
[mpeg1video @ 01384940]end mismatch left=662 40AC05
[mpeg1video @ 01384940]invalid cbp -1 at 12 14
[mpeg1video @ 01384940]Warning MVs not available
[mpeg1video @ 01384940]concealing 280 DC, 280 AC, 280 MV errors in B frame
[mpeg1video @ 01384940]invalid mb type in P Frame at 11 2
[mpeg1video @ 01384940]invalid mb type in P Frame at 5 4
[mpeg1video @ 01384940]slice mismatch
[mpeg1video @ 01384940]ac-tex damaged at 16 4
[mpeg1video @ 01384940]invalid cbp 0 at 9 6
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]ac-tex damaged at 5 7
[mpeg1video @ 01384940]ac-tex damaged at 11 8
[mpeg1video @ 01384940]ac-tex damaged at 1 10
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]invalid mb type in P Frame at 15 11
[mpeg1video @ 01384940]ac-tex damaged at 13 12
[mpeg1video @ 01384940]ac-tex damaged at 3 13
[mpeg1video @ 01384940]end mismatch left=1456 21075F
[mpeg1video @ 01384940]Warning MVs not available
[mpeg1video @ 01384940]concealing 280 DC, 280 AC, 280 MV errors in P frame
[mpeg1video @ 01384940]invalid cbp -1 at 14 2
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]ac-tex damaged at 17 4
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]skip with previntra
[mpeg1video @ 01384940]skip with previntra
[mpeg1video @ 01384940]ac-tex damaged at 3 9
[mpeg1video @ 01384940]skip with previntra
[mpeg1video @ 01384940]invalid mb type in B Frame at 18 10
[mpeg1video @ 01384940]invalid cbp -1 at 4 12
[mpeg1video @ 01384940]ac-tex damaged at 19 12
[mpeg1video @ 01384940]end mismatch left=377 599A0C
[mpeg1video @ 01384940]Warning MVs not available
[mpeg1video @ 01384940]concealing 260 DC, 260 AC, 260 MV errors in B frame
[mpeg1video @ 01384940]invalid cbp -1 at 2 4
[mpeg1video @ 01384940]invalid mb type in B Frame at 14 3
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]ac-tex damaged at 7 5
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]invalid cbp -1 at 7 9
[mpeg1video @ 01384940]ac-tex damaged at 12 9
[mpeg1video @ 01384940]invalid cbp -1 at 16 12
[mpeg1video @ 01384940]mb incr damaged
[mpeg1video @ 01384940]ac-tex damaged at 13 12
[mpeg1video @ 01384940]ac-tex damaged at 6 13
[mpeg1video @ 01384940]ac-tex damaged at 2 14
[mpeg1video @ 01384940]Warning MVs not available
[mpeg1video @ 01384940]concealing 260 DC, 260 AC, 260 MV errors in B frame

<SNIP>

Exiting... (End of file)

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[DB83]

I would be more worried if it did not play the 'playable' file 'just fine'

Someone may be able to translate all those error messages but it is more likely that, as pdr states, modern players have little concern for legacy formats such as full mpeg1 support.

I well remember those VCDs and if you copied the main video file to your HDD and renamed it to mpg it played but not so smoothly. Seems that something similar is happening here.

[koozmusic]

Sometimes an old clip needs an old program.

Went in to my archives and found a c2007(2002-2006) version of Media Player Classic(Unicode build) v6.4.9.0 (Gabest)

Played the clip smoothly without a single artefact.

Wow, thats awesome. Thanks for all your help, guys! What a great community

But are the clips actually broken ?

The link shows this game was issued with that card - not the card with the game (an important difference in my book). So the game is designed to show off the card.

If they did not play with the card then, yes, they are broken. There can be no guarantees for other playback. And was this form of the game actually released on it's own ?

There are two MPEG versions of the game, both bundled directly with an add-on decoder card. This one is for Mac. The other one is for DOS and was included with the Sigma Designs ReelMagic MPEG card.

[jagabo]

MPCHC plays both files properly using Windows' built in MPEG 1 decoder (quartz.dll). Just disable MPCHC's internal MPEG1 decoder (and any other DirectShow MPEG1 decoders you might have installed). And of course WMP plays it with that decoder too.

I have a a bunch of old games (in their original boxes, etc.) on a shelf in my office -- the PC version of Return To Zork is among them. Unfortunately, when I opened the box there was no disc inside.

[El Heggunte]

That 'broken' file does not have a frame-rate.
...
...
...
The playable one does not have a GOP structure

For me at least, it's very difficult to believe that those flaws are not flaws at all.
Until proven otherwise, I serious doubt the MPEG-1 specs do not require the stream headers to inform about the frame-rate and the GOP structure.