Whats wrong with Windows WMV?

venomhed wrote on 7/4/2002, 11:41 AM
Good morning.

After completing and rendering my Bowie Live video I made two versions. One a Divx 5.02 at 1000 bitrate, MP3 at 160 and also a Windows WMV at 1mb bitrate and the audio at 160wma.

Now i hear alot of people griping about Video for Windows (wmv?).

Here is what I have concluded.
1. The Divx 5.02 looks fine, the audio is "chimey" or "glassy" sounding. The file is 934 mbs big.
2. The Windows WMV looks fine as well, I really can't tell the difference between Divx 5.02 and WMV so no complaints. The audio is fine, sounds good and that is important due to this being a concert. The file is only 718mbs!

To me the Windows WMV is superior. Performance wise I can skip to any part of the video and there is no sync problems. It instantly goes to the spot, no delay, bam it plays. Divx will delay a bit and the video will go through a fast forward state to catch up to the audio.

So why do people not like Windows WMV? Does this file type not play on macs? It streams which is cool? You can copy it, overall im very happy with it but will have to render it again and make it below 700mb.

Oh and one last thing. Why is audio and or video allowed to be bigger than 700mbs on a burnt cd? Im gonna try this 713mb file on an erasable cd to see if it makes it on there. Maybe this was just something I heard once.

Thanks again all.

Comments

venomhed wrote on 7/4/2002, 11:43 AM
Correction on the file sizes.

Divx was 934mbs
WMV was 739mbs

Cheesehole wrote on 7/5/2002, 1:56 AM
I like WMV, especially with the WM8 player. it's not as good with the older 6.4 player, but still very good. I wish there were more audio codecs to choose from. narration doesn't sound so good to me using either ACELP or WMA v8.
JavaNut wrote on 7/5/2002, 3:13 AM

I don't have a problem with WMV either. The problem I have is with VV3 using WMV. Have you experienced VERY long delays when using a WMV in your project?

When I capture a 25Mbps in WMV format using Microsoft Movie Maker, and then bring it into VV3, after it plays for a few secs and then I hit stop my processor spikes and stays that way for about 30 to 45 secs. Every single time!

I thought it might be an oddity like when it builds the audio peaks for the first time, but it does this over and over again. For the life of me I can't understand why?

Has anyone else experienced this?
SonyEPM wrote on 7/5/2002, 9:07 AM
java, others: I encourage you to capture to .avi, preferably DV .avi, if at all possible. WM can be used as a source format in a pinch, but it is not all that reliable, especially if it wasn't generated by Vegas in the first place. Performance comapared to DV is lame, and since WM always gets recompressed (even in a cuts only project), quality will suffer.

WM is best used as a destination format, rather than a source format. Same thing with MPEG.
Chienworks wrote on 7/5/2002, 10:30 AM
JavaNut, this is a pure guess, but i'm assuming that Vegas can't make use of the .wmv file directly. It has to decompress on the fly in order to display on the preview screen. It probably decompresses sections to DV until it's filled available memory (probably only a few seconds worth). Once you scroll beyond the section it's decompressed, it has to dump that section and decompress where you are now. Not very efficient at all, but that's not really Vegas' fault.
JavaNut wrote on 7/5/2002, 11:03 AM

SonicEPM,

I captured the WMV file at 25Mpbs uncompressed, and to prove that this was uncompressed, I captured the exact same footage in VidCap using the AVI DV format and overlayed the track with a difference and difference squared, amplified the contrast, and there was ABSOLUTELY NO DIFFERENCE. Not even a blip! Also note that the file sizes were identical.

While I recognize capturing a compressed WMV file would be subject to loss and generation issues, the uncompressed one was not. Yet, VV3 still had problems with this format, and I am not sure why. Do you have any ideas?

JavaNut wrote on 7/5/2002, 11:14 AM

Chien,

I answered this in SonicEPM's reply, though, in addition I have another question. I am considering taking all of my tapes and converting them to DVD, because I am concerned with the life of the magnetic media for archive purposes.

So far, I have done this archiving only with my VHS tapes and I recognize that quality of the VHS isn't great so I can get away with going to DVD, but now you have me wondering about my higher quality DV tapes.

Since there are no blue-laser drives and media yet, archiving uncompressed AVI on a semi-permanent media is not yet practical. What do you recommend?


Regards,
JavaNut

P.S. As an FYI, I am using a Philips DVD-RW985 set top DVD Recorder to transfer my analog and DV sources to DVD, and it does a pretty good job, it also keeps my computer from getting tied up for hours doing the capturing, rendering and then burning.

Chienworks wrote on 7/5/2002, 1:50 PM
25Mbps must be compressed somewhat. Uncompressed would be more like 150Mbps. Note that DV is also compressed. I'm curious though, if the file size is the same, then why use WMV? It's proprietary. DV is used by everyone and is a much more universal format.

I'm not too concerned about tape life. I've got piles of old VHS tapes from 15 to 20 years ago that are still fine. I would assume that digital tape formats will last better. For that matter, i'm not convinced that compact disc media is any less fragile.
2me2u wrote on 7/5/2002, 3:29 PM
If you want to put a file larger than 700mb, you have to enable your over burn, if your software has that, I use nero and I was able to squeeze a 730mg file on to a single cd, so it is possible. If you have other burning questions check out this site
www.vcdhelp.com
JavaNut wrote on 7/5/2002, 7:30 PM
Chien,

Yes DV is compressed 4:2:2 or 4:2:1 depending. For completely uncompressed video capture, it is around 40MBps (or only 316Mbps!) from the formula:

720 Pixels wide
480 Pixels high
32 Bits of color depth
11,059,200 Bits per frame
8 Bits/Byte
1,382,400 Bytes/Frame
30 Frames/Sec
41,472,000 Bytes/Sec
1,048,576 Bytes per megabyte
================================================
40 Megabytes per second = (316 Mbps) No prob!


Anyway (sorry, you got me curious), the main reason for using WMV, or why I was investigating it, is because VV3 will not capture from my camcorder, but MS Movie will do it just fine. I borrowed a friends for the time being, but when I have to give it back, I am still stuck. I have not figured out why yet.

As far as aging tapes, I used to work as a tape operator for the mainframes, and when we would get some 20 or 25 year old tapes, we would have to clean the heads because the magnetic coating was coming off. In some cases, while transferring these tapes, we would encounter source tapes with absolutely no coating on them whatsoever (absolutely clear). Ever since then, I don't put a lot of faith in magnetic media.

Keep in mind also, that these tapes are stored in a highly controlled environments, unlike the DV tapes that we all (at least I) have.

Cheesehole wrote on 7/6/2002, 1:10 AM
>>>Yes DV is compressed 4:2:2 or 4:2:1 depending. For completely uncompressed video capture, it is around 40MBps (or only 316Mbps!)

fyi: DV NTSC is 4:1:1 and DV PAL is 4:2:0
in either case the chroma is sampled once for every four luma samples.