Divx puzzler

[turner3d]

I have been trying to figure out how to downsample the video files in the Xbox version of "The Guy Game". These files have a .top extension, but all I've been able to find out about them is that they are supposedly DivX.

Not only will they not play in any player when renamed to .avi, no program I've tried on it (Gspot, aFree, AVIToolbox, abcAVI Tag Editor, AVIcodec) has been able to extract a single piece of any kind of info other than file size.

Here's what I found by studying the .TOP vid files in a hex editor:

first 4 bytes: TOPH
first 4320 (10DFh) bytes of all the vids are identical except for:
4 bytes @ 0020h
2 bytes @ 003Ch
4 bytes @ 0040h
3 bytes @ 0078h

structure from 10E0h on:
• MARF - 4 char literal marking start of data chunk
• 2 bytes defining distance til next MARF
• 26 bytes of 0s
• DDIV (always 32 bytes after MARF) - 4 char literal marking start of video subchunk
• 2 bytes defining distance til next DDUA
• vid data
• DDUA - 4 char literal marking start of audio subchunk
• 2 bytes defining distance til next MARF
• audio data

rinse, lather, repeat

Notes:
• 2-byte distances are always LSB, MSB format
• "vorbis" appears twice in the first 165 bytes suggesting ,so it's probably safe to say that's how the audio is compressed
• there is a definite header for each vid, but it has no similarities to the standard RIFF header of DivX encoded AVIs.

Does any of this sound familiar to anybody?

[yoda313]

try www.xbox-scene.com

They have tons of xbox related information and can probably steer you in the right direction.

[turner3d]

I've already searched there - no go... also in the DivX forums at afterdawn. Nobody seems to have any clue about this format.

[yoda313]

Have you tried opening them with any program? Can virtualdub open it? You might try copying the file and renaming the extension to .avi. You might get lucky and have a program recognize.

Plus you could try the beta version of gspot and see if it can open the file for the video specs.

[turner3d]

I've tried changing the extension from .top to .avi, .mpg, .mov... no go in virtualdub or a number of other programs.

The first 4 chars when viewed in a hex editor are TOPH instead of RIFF, and nothing else in the rest of the file comes even close to standard layout defined in the MSDN reference, and no program I've tried on it (Gspot, aFree, AVIToolbox, abcAVI Tag Editor, AVIcodec) has been able to extract a single piece of any kind of info.