Interesting...

[oo7tushar]

Hi all,
This being my first post I thought that I'd write something informative. First off, how many people are watching the Olympics? Exciting init? (sorry if I'm posting common knowledge)

2nd, lots of people have been asking about playing the wmv's on your DVD player. Well, most DVD players support the mpeg1 format aka VCD. Mpeg2 is SVCD (super VCD) and is the format the DVDs are encoded in (to the best of my knowledge).
Continuing: Since mpeg2 is such "high quality" you only get 30 to 45 minutes onto a CD. Thus it's like getting a couple of Family Guy Episodes onto CD.

VCD on the other hand can hold a lot more. Of course, the downfall is reduced quality. There's a lot of CD burning programs that will convert your wmv's or avi's into mpeg format for you (Nero for one) but they do a very poor job of converting. Nero also burns to mpeg2 but the plugin runs into all sorts of ownership issues so they charge you for the use of it.

Ok, so how to make better quality VCDs? Convert the files to mpeg on your own. The best program to do this is TMpeg encoder (I won't post the link here as I don't want to run into some linking to illegal material copying software blah blah blah (ala DeCSS) but you can do a search on google or yahoo and find it). Of course, I've been having trouble converting the wmvs with it.

What's the problem? Well, MS has encoded the WMV files in such a format that you can't extract the audio stream when you convert from certain file types. Also, if you want to edit wmvs you'll have to use VirtualDub 1.3c or earlier (MS told the author to remove that editing "feature").

Ok, more info: you can't just drop your WMV files into VirtualDub. You can encode in Mpeg4 format (str8 in SnapStream) or you can export to WMV 7 (or 8) then get Windows Media Encoder (from MS, it's free (as in b33r)), convert to Mpeg4, then import into VirtualDub, convert to divx then convert to mpeg-1 (with tmpeg), then burn it onto a CD (in proper VCD format, check vcdhelp.com or vcd-help.com, I've umm...forgotten ;-)

That should get you good quality. Unfortuneatly the process takes a long long time but the results are worth it as you get good clean picture and sound. That's a good free way to convert (if your burning software is also freeware).

Of course, I'm expecting newer versions of SnapStream to export to mpg right away. The downside is that a more powerful machine may be required, I've got a P4 (aka P$) and encoding at higher bitrates take up more CPU power than I'm willing to allow.

Hope you've enjoyed this read and I've answered many questions.

[Rob]

oo7,

Got a question for you. I have the option to record to WMV7/8 and MPEG4-v3 or -ISO. Do the MPEG4 options record the stream into a WMV file format, somewhat fibbing to you about the encoding vs. file format?

-Rob

[oo7tushar]

The WMV file format is just a wrapper, how the information is actually stored (like AVI). The actual encoder type is stored in the file format.
If you have any option then I suggest encoding in WMV7. I have found that encoding to MPEG takes up almost 100% CPU whereas WMV7 only uses 30%.

More on file wrappers: if you have an WMV/ASF wrapper then you don't need the whole file to play the start.
With AVI you need the whole file as the "headers" are stored at the very end. Thus, Windows uses the extensions to find out where to look for the encoder type.

I am not 100% sure about this but I think ASF tools can take a wmv file and convert it into AVI which will then let you use tmped to put it into mpeg 2 or 1. I know for sure it will do the avi part but I cant remember about the sound as mentioned earlier. I will have a go tomorow and post the results either way ASF tools is great for trimming wmv into smaller files to put on cd if you just want to play them on the pc.

[Rob]

Actually, on my box in custom Near-VHS, 800KB/s, WMV7 uses around 60% CPU while MPEG4 uses around 30% for the same options but just different encoding, so for me when doing very high bitrate encoding MPEG4-v3 or -ISO is less CPU intensive.


I use 800kb total for 350MB 1hr = 2hr per 80min CD.

-Rob

[oo7tushar]

(reply to the AsfTool bit)
AsfTools can be very time consuming for chopping videos up. Also, it does convert to AVI but I've found that it doesn't do a very good job (in terms of usability and stability) as VirtualDub does.

About chopping WMV's up. Each day I have 8 gigs of video to chop up, that amounts to about 12 hours to search through. Doing that through Asftools would take 6 hours. A much faster method is to use AsfCut (which Asftools uses to chop the WMV up).

The method is simple: Go through your video and write down on a piece of paper the following:
1. in seconds, the start time where you want to start chopping.
2. in seconds, the duration of the clip.

You should have a list of numbers after you've gone through and taken out bits you don't want (like commercials and yakity yak). The next step is to make a batch file with the following format:

asfcut -i inputfile.wmv -o part1.wmv -start start_time -dur duration
asfcut -i inputfile.wmv -o part2.wmv -start start_time -dur duration
and so on...
this process will take at most 2 hours (for 12 hours of video).

Then you double click on the batch file (remember to give it a .bat extension) walk away for 20 to 30 minutes and when you come back it'll be all done. You can even put them into seperate directories if you want (nicely organizes 6 different Olympics events).

I've found that to be a good way. Since they have wmv players for Linux now I don't convert it to divx as that takes too long and I WMV is pretty high quality.

oo7
Quack

Originally posted by oo7tushar:
The method is simple: Go through your video and write down on a piece of paper the following:
1. in seconds, the start time where you want to start chopping.
2. in seconds, the duration of the clip.

ASFCut works great but the 'duration' part it's looking for makes it a little more difficult to use than it should be.

Having purchased Snapstream at about the same time I started teaching myself Perl I decided I might as well make my first project something that could 'automate' that task a bit.

It's definitely a work in progress but does the job, and since I'm a stickler for getting those commercial breaks out at EXACTLY the right 10th of a second it eliminates the need for manual calculations. (My latest revision will also let you view all of the extracted segment sections and make any changes if necessary, so if you notice a segment that runs long you can easily make a change.)

What I do is load up the clip in Windows Movie Maker, and then note down the beginning and end of each segment into my program. The program then outputs 'segs#.txt' files containing the start and duration information that can be fed into asfcut. (The actual splitting part is still a manual process and I'll probably be adding that functionality at some point, but like you said if you just build a batch file even that can be pretty easily automated.) Then, once all the segments are yanked out you can use asfcut to put them back together and within a few minutes have a nicely edited, commercial free show waiting for you.

Anyway, if anyone is interested I'd be happy to share. Keep in mind, it's perl so you're either going to have to have perl on your system or convert it to an executable if you want it to run. Of course, (insert legal stuff) I take no responsibility for anything that might happen to your system if you decide to use the program etc.