identifying a codec

[SteveK]

Is there a way to identify what codec was used to compress a file if you don't know? I'm using xp Thanks
SteveK

[kitty]

Open in virtualdub. Get File Information will usually tell. If the audio is unknown 2000 or similar it is probably AC3

[mbellot]

I use a hex editor. Generally the codec info is somewhere in the first several hundred bytes.

I'm not sure Vdub can identify a codec unless its installed already and a codec that Vdub can actually use (there are a few that aren't compatible - notably ASF, by design).

Good luck

[SteveK]

Thanks for the replies. I am quite new at all of this and have much to learn. Mbellot, I do use virtual dub and it does have a hex editor in it. Now, I opened a file with the editor and had no clear concept of what I was looking at. I used the edit tab and did a search for "codec" of course, I didn't find anything. Will the editor actually name the codec being used, or do I have to know how to read something cryptic? Thanks again.
SteveK

[mbellot]

Steve:

Not really, you just have to poke around in the first several hundred bytes. If its an AVI (most other file formats are pretty self explanatory - MPG, MOV, RM, etc) then you will *typically* see something like "vidsdivx" or "vidsIV50" near the top of the file.

Obviously, the first example is DIVX. I believe the second is Intel Indeo V5.0... You may also find more info further down, like in DIVX 5.0 files. Shortly after the "vidsdivx" you will see "DX50".

Once you have identified the codec (or more likely the abbreviation the mfr used) its time to hit Google and see what you can see. If you don't get much from the web search try the newsgroups, they can sometimes be a great source of off the wall info.

I've never used the Vdub hex editor, so some (or all) of the above info may be completely worthless until you get a "real" hex editor. Check around, there are several good freeware editors.

Also, a little hacking (not the bad kind) knowledge would be very helpful, but that is usually only gotten the hard way.