Wrong FourCC Code?

[DrinkOrDie]

I have an AVI that appears to be tagged with the wrong fourCC Code.

I first searched the forum and other sources before posting but didn't really find any conclusive information.

The closest related thread I could find is here:

http://forum.digital-digest.com/showthread.php?s=&threadid=34718&highlight=fourCC

So, I was thinking setarip would probably be able to shed some light on this.

I've included the virtualdubmod file info screenshot which highlights what I'm talking about. The file opens just fine using Divx player but I have trouble when it comes to editing or converting the file, and it really doesn't look all that great.

I've never ran into a file encoded with one codec, yet the fourCC says another. Any thoughts on this?

[setarip]

Somebody messed with the header and altered one of the TWO references to the codec used.

Load the .AVI into a hex editor. Within the first 13 "lines" (0000 to C000, if I remember correctly, you should find TWO references to the code. Write down the EXACT text of each (Capitals and Lower case are important!). Change the second one to duplicate the first one and save.

If, after that, anything seems wrong in the file's behaviour, reverse the procedure - and change BOTH to what the second one was ORIGINALLY.

[Soulhunter]

But that XviD is used for decompression does not mean its a XviD file...

Your decoder settings decide which decompressor is used for a 4CC !!!




Bye

[UncasMS]

Somebody messed with the header and altered one of the TWO references to the codec used.

says who??

the screenshot doesn't


btw, soulhunter has given all necessary information and instead of messing with a hexeditor better use abcavi tag editor

installing FFDSHOW should solve any decoding problems

[setarip]

To DrinkOrDie

Since I am readily able to replicate what your VirtualDubMOD "File Information" screen shot shows, by simply altering the header information, I'd be curious to know whether the file header of your file actually showed two different FOURCC codes, as I speculated...

[Soulhunter]

Uhm, where does it show 2 different 4CCs...

The "DX50" is the 4CC for DivX5, and "XviD" is simply the decompressor that is used !!!

Here is what I get after loading one of this official movie trailers from the DivX website...

As I dont even have DivX installed atm, the XviD decoder is used for DivX decompression !!!


Bye

[setarip]

To Soulhunter

"where does it show 2 different 4CCs"


As I stated earlier in this thread, load the .AVI into a hex editor. Within the first 13 "lines" (0000 to C000, if I remember correctly), you should find TWO references to the code.

[UncasMS]

and as we said, the screenshot does NOT show any such thing ^_~

[DrinkOrDie]

OK, soulhunter says:

"Your decoder settings decide which decompressor is used for a 4CC !!!"

I reply: I understand the concept. If that is so, then what I don't understand is why my XVID decoder would be used to decode files with a "DX50" fourCC code. Shouldn't a DX50 coded file be left to my divx decoder?

Up until now, everything has been pretty normal. I think I should clarify that I have Divx 3 files that playback using the Divx 3 codec. I also have Divx 4 which plays back any divx file encoded with divx above version 3.

With all due respect UncasMS, I don't have any trouble decoding the file and I have followed advice before that told me to get ffdshow and had more problems after doing so.

I tried getting ffdshow long ago for playing back Xvid files and had nothing but problems. I can't clarify what the problems were(encoding/decoding headaches), but they were solved by getting rid of ffdshow and installing an Xvid codec.

I wish my codec list provided more details about the xvid I installed but it doesn't. Here's a screenshot that gives a better picture of my codec environment. Maybe that'll help.

OK, well, it's not letting me post attachments. dunno why. frack!

Thanks everyone.

[setarip]

To DrinkOrDie

Did you have an opportunity to examine the header of the file with a hex editor? If so, as I requested of you earlier, I'd be curious to know whether the file header of your file actually showed two different FOURCC codes, as I speculated...

[Soulhunter]

Originally posted by DrinkOrDie

...why my XVID decoder would be used to decode files with a "DX50" fourCC code.

Shouldn't a DX50 coded file be left to my divx decoder?

Well, not if the XviD decoder is told to decode DX50 4CC's...

Guess you have to give the DivX decoder a higher merit than XviD's !?!



You can use ZoomPlayer's filter manager to do this !!!

Btw, for picture hosting you can use this site...


Bye

[DrinkOrDie]

Well setarip, I wish I could lay the question to rest but I don't have the file any more. I deleted it shortly after I started this thread. It was a movie I wanted to check out before buying the DVD. I got the DVD and discarded the file. I tried to get the file again just to find out about the header, but I can't connect to "the network". Probably something to do with that court thing that started today in Australia.

I wasn't so much trying to solve a problem or fix a particular file as I was just trying to figure out why a file would show a fourCC of DX50 yet decode with Xvid. Thanks to everyone that answered my posts, particularly soulhunters last post, I think I accomplished that much.

After writing the above paragraph I went ahead and downloaded a trailer from the DivX site which has the DX50 FourCC. And behold, there it is again. Xvid is being used as the decompressor. I guess I just didn't notice before because I haven't aquired many DX50 files. I mostly aquire or create Divx 3 and 4 files, and they use the appropriate decompressor when I open them or check the files properties.

This new DX50 file (alexander.avi) won't even play correctly in windows media player, as it is using the Xvid decompressor. It looks all blocky and scrambled. The DivX player plays it back fine even though DivX 4.12 is the newest DivX codec I have. I can't help thinking that this has much to do with the problems I had with ffdshow, prompting me to get rid of it and install the Xvid 4 codec instead. That was back when I first wanted to play an Xvid file.

Having said all that, I think soulhunter has pinpointed the cause and I think I should get the DX50 encoded files to playback using DivX 4.12 instead of Xvid. Can I do that through windows xp or do I need a 3rd party tool?

[Soulhunter]

Im not even sure if the DivX4 decoder is able to decode DivX5 files !?!

Afaik DivX was only MPEG4 SP while DivX5 and XviD is MPEG4 ASP...

Guess DivX4 cant decode content with B-Frames, GMC or QPel !!!


Bye

[Soulhunter]

Originally posted by DrinkOrDie
The DivX player plays it back fine even though DivX 4.12 is the newest DivX codec I have.

Ok, I have some more questions now...

- Have you tried to uninstall DivX4 ???

- Have you tried a different player ???

- Have you tried to install DivX5 ???


Bye

[DrinkOrDie]

First thing that comes to mind is...

"say what?" I don't think I understand anything beyond

" Im not even sure if the DivX4 decoder is able to decode DivX5 files"

I see that a few answers to a simple question has turned up more questions. I love it when that happens. That's how I've learned so much.

What I mean is, I've been asking myself 3 questions for every answer in this thread.

When I playback this DX50 file(from the divx website) in windows media player, it doesn't playback correctly. Looks all scrambled. Windows media player file properties says "DivX decoder filter" as the video compression. Makes sense since this is a divx file. but it looks horrible.

When I play the DX50 file using DivX player, it looks great. Is Divx player using DivX 4.12 codec to decode the file since I don't have DivX 5 codec? If Divx player is not using 4.12 codec, how is it decoding the file? Is it the Divx decoder filter? If so, why is windows media player having trouble using the filter?

Windows file properties claims Xvid compression for the file, yet windows media player file properties says "DivX decoder filter"

Why?

Furthermore, I am prompted to ask another question I've been asking for years now, but still don't understand:

What's the difference between a filter and a codec? I thought I knew. I went through this when I got rid of ffdshow. I got rid of it as a way to playback Xvid files because I had so many problems with it. I then installed Xvid codec version 4 which I still have.

I'm so confused.