when you convert with virtualdub it always sets .avi extension....

[Fking]

I'm using virtual dub to compress different kind of video files in WMV9 format, but it always saves the file with ".avi" for extension....yeah it compress them in the format you have choosen but the extension is always .avi

Could be this a problem and give unable to play errors on some systems...?

[rjc7394]

VDUB does not accept WMV files because they are copyrighted. If you try to open a WMV in VDUB you will get a message saying that. You can't even import a WMV using Avisynth if you want.

AVI (ie. XviD, DivX) is the most common, best and most efficient video format available. Most standalone DVD players use MPG format though.

[Fking]

the source format is not WMV but i'm compressing in WMV...
my point is that even when compressed in WMV the extension is still .avi

[BJ_M]

change it after....




btw = avi is NOT the best most efficient video format necessarily -- it is only a wrapper -- same as quicktime

[Fking]

can it make problems on some systems if it's wmv compression but with avi extension?

[BJ_M]

it plays - but gives a warning about the extension ... best bet is to not use vdub for wmv9 files since you can use windows encoder for exactly the same results (in this case)

[celtic_druid]

VirtualDub can only output avi (well also images I guess). As said, if you want wmv files, use a different encoder. Another reason against WMV9 VCM would be that it requires a registry tweek to enable bframes. Although if you have done that, then the quality should be the same.

[Fking]

well i'm used to virtual dub, especially when i have to add couple of effects

i guess everything will be ok, if i continue to use it for the wmv9 compression but just change the extension to .wvm once the file is done?

[BJ_M]

not really -- because it is not an wvm true file and media player keeps throwing out an error

[Fking]

not true wmv file?
why?

in virtual dub i'm using the same codec for compression as the one win media encoder uses?

[Cornucopia]

You need a little clarification on the terms "container" and "codec" with regard to file format.

In video, the file format is determined by the type of container (AVI, WMV, MOV, MPG, RM, MKV, etc).
The container "contains" (usually) video and audio streams.
Those streams are structured based on how they're compressed (or not).
Different compression technologies use different compressors & decompressors. (You usually need both to work with/edit clips, but end users can of course just have the decompressor)
These compressor / decompressor suites have been shortened to the term "codec". Examples of codecs are--DV, Xvid, HuffYUV, Cinepak, Sorenson, MPG2

Sometimes there's a ~1:1 correspondence between a cotainer and set of codecs--
MPG2 program streams only contain MPG1 or MPG2-type codec for video streams,
RM files only contain the various versions of RealMedia video,
ASF (aka WMV) files contain WMV7,8 & 9 video streams or Mpeg4v2,v3 streams

But with other containers (the more "general purpose" ones), you have wide choices in the type of codec--
AVI: DV, Xvid, DivX, HuffYUV, Indeo, WMV, Cinepak, Uncompressed, etc
QT (aka MOV): DV, MP4, Sorenson, ZygoVideo, Apple Video, Animation, Indeo, Cinepak, Uncompressed, etc.
MKV: Most anything

As you can see, it's possible to have a DV codec video stream in either AVI or MOV or MKV containers. Note that its also possible to have WMV9 codec video stream in either it's natural WMV/ASF container, or (un-usually) in AVI.

What you've got there is Vdub outputting an AVI (that's why the AVI file extension ), with a WMV9 video codec. You are not outputting a WMV file. Vdub CAN'T output WMV or anything else, except as AVI files and as frameserving.
It may be possible to pull the WMV9 video from its AVI container and plop it into a WMV container, but it would be much simpler to either output to DV/Lossless/Uncompressed AVI and then compress to WMV9 with Windows Media Encoder, or possibly to frameserve to WMEncoder (if it'll let you).

HTH,
Scott

[kschang]

Or think of it this way: container is the bottle, the encoded stream is the soda "syrup" in the bottle.

The syrup comes in different packages. Some packages you only add a little water, vs. a lot of carbonated water. (Decoding process). Different formula is the "codec". Bottle/Container is the AVI/WMV/MKV/OGM containers. They each have different connectors, you can't hook up one with the other, but a soda machine (media play) may have attachments for all of them, or some of them.

You can put any kind of soda, take out the appropriate amount of water, and put it in any sort of container, but the container will still be the container. Just because you put Coke in the container usually reserved for Pepsi doesn't make what's inside Pepsi. Just because you put WMV in an AVI container doesn't mean you generated WMV.

[Fking]

Sorry for getting back to this that late

Thank you all guys for the explanations
and especially, Cornucopia
I think I've never got that detailed and clear explanation in a forum till now
thank you very much!

[Fking]

What you've got there is Vdub outputting an AVI (that's why the AVI file extension ), with a WMV9 video codec. You are not outputting a WMV file. Vdub CAN'T output WMV or anything else, except as AVI files and as frameserving.
It may be possible to pull the WMV9 video from its AVI container and plop it into a WMV container, but it would be much simpler to either output to DV/Lossless/Uncompressed AVI and then compress to WMV9 with Windows Media Encoder, or possibly to frameserve to WMEncoder (if it'll let you).

HTH,
Scott

I was reading the thread again and have question about this part
so i'm using the wmv9 codec for the compression, but the file isn't wmv one wit just .avi extension (extension which allows the file to be wmv9 compressed) but what?

[kschang]

I know this is confusing, but bear with me.

In some files, the filetype IS the codec AND the extension. WMV9 is USUALLY of file extension WMV, codec WMV9, (Windows Media Video, rev. 9).

In OTHER files, there is no standard "file extension" or file layout. It can fit into ANY of the various "container" formats, such as AVI or MKV.

Think of it as a generic glass bottles vs. something distinctive, like a "Coke Bottle".

WMV is like a Coke bottle... You know it's got Coke inside.

Where as AVI is like a generic glass bottle: you have to know what's inside by a bit of looking and tasting.

[celtic_druid]

Well you might assume that a WMV file contains WMV, but that is like assuming that the Coke bottle contains only coke, when in fact I went and tipped half the coke out replacing it with bundy. Fact is that you can mux far more than wmv/wma streams to a wmv/asf file if you want. I can also store a wmv stream in say an mkv container.