The VideoLAN Forums

why are people using the WMV codec?
is it good (for window's users)?
is it better than other codecs in ANY way?
who is using the WMV codec?

why are some mp3 players supporting wmv but not ogg?


//simon

wmv3 actually does a good job concening video compression ... (but it isn't as good as h264.)

i dont like it for a number of reasons.

Its not the actual playback (although buffering does tend to annoy) its generaly pretty good in terms of quality to filesize in certain cases.

The headaches occur when your looking to edit and acheive audio that actualy syncs to the video.

Take a normal run of the mill progresive mpeg, you start of with an I-Frame (this renders the entire scene[ie takes a lot of space], then you layer on P-Frames and B-Frames (layer sections of the bits that move) in a simmilar way that oldskool animation was drawn you get a detailed background and then layer on acitate with the parts that actualy move.

So frame 1 (an I-Frame)
then frame 2(P-Frame)
frame 3(anoter P-Frame)
Frame 4 (a B-Frame)
and so forth till you wind up with IPPBPPBPPIPPBPPB.....
This way EVERY FRAME is in an ordered and sane sequence.

WMV isnt sane however, instead of rendering every frame it does a pass and drops all simmilar frames, so you might end up with frame 17 shown 12 times because its a static part of film and instead of having 12 frames you only need to add a delay on 1 frame.

This is great for anime where not a lot of movement occurs (although ive noticed a lot of chroma bleeding especialy with brighter reds) in certain encodes.

For the end user theres no real difference a smaller filesize to quality ratio and it all plays hunky dory.

The insinity really kicks off when you need to edit or if your looking to convert something from WMV to say MPEG-2 (to compile a DVD)

First off WMV is a Microsoft product (im not even going there) and is therefore open to an insane ammount of editing/copywrite restrictions, so actualy converting it to another format to begin with is an uphill struggle, theres plenty of tools to allow you to acheive it but your favorite ones (ie the ones you use most and know inside and out) never seem to allow you to work with the format.

Once you find a way to convert it you wind up with a video stream that will ALWAYS (dear god ive tried everything on the face of the earth) wind up a different length from the original source.

So you get handed a video stream of 2:37:23 in length and an audio stream of 2:49:12.
Or vice versa, fact is they seldom match and on the rare occasions they do... they go out of sync as the streams progress.

MUXING NIGHTMARES!!!

That being said if you dont need to edit anything then theyre bearable, ive seen a few wmv encodes that have been outstanding (which only makes things worse because you seriously contemplate opening the can of worms to get it on a DVD)

People still insist on encoding stuff with it however.
And to be honest idd rather have a .wmv than a .rm any day.

Any1 have any clips encoded with h264 codec that i can try and play and see what it looks like??????? -- Im assuming VLC will play those easily.........

Merci

>>>WMV isnt sane however, instead of rendering every frame it does a pass and drops all simmilar frames, so you might end up with frame 17 shown 12 times because its a static part of film and instead of having 12 frames you only need to add a delay on 1 frame. <<<

I had a situation where we needed to chop up 60 secs of WMV into 10 sec chunks. I wonder if thats why we had some many problems with it...
I havent tries getting our capture cards to dump into any other format than wmv.. i'll have to give it a try...

Any1 have any clips encoded with h264 codec that i can try and play and see what it looks like??????? -- Im assuming VLC will play those easily.........

Merci

You might want to have a look at Apple's website about HD content and H.264. It features a number of very high quality samples. Anyway, H.264 can be scalled to even mobile phones, so you don't need such a fast computer for all H.264-encoded videos, though I don't have an URL for that at my fingertips.

why are some mp3 players supporting wmv but not ogg?

Because WMA is DRM friendly and a lot of majors feels better if they could restrict and control the way the user use they protected content.

does someone got idea where i can find wmv9 encoded streams with B-Frames........ mailto:act302us@yahoo.com

Personally I just hate WMV (and WMA) because they're proprietary, riddled with crazy patents and copyrights, and chock full of DRM. (Also, the software designed to play it - WMP - is bloat city.) It really does bug me when people post videos on the web and all I see is WMV, WMV, WMV. Does VLC for Linux have any WMV support at all? Does anything?

You can use windows codecs for wmv under linux if you compile with --enable-dmo --enable-loader. Of course that will only work with intel 32bit binaries.