How to compress mpeg2 files?

[blade]

What I'm trying to do is put some football games on one DVD. I recorded them using powervcr II and each game is 6 to 7.5gb, split into 600mb files. I tried vidomi but for some reason when compressing mpeg2 files from powervcr using vidomi, the sound is always not in sync. So I need something else.

I found a tmpgenc version that makes mpeg2 files into DVD files, but doesn't compress them (I don't think), so I have to use 2 DVD's. Any ideas?


Also, anyone know how to delete a large file? I made one game into a 4gb file using vidomi. The sound is still way off and it won't let me delete it. Tried safe mode, same thing.

[Busby]

Originally posted by blade
Also, anyone know how to delete a large file? I made one game into a 4gb file using vidomi. The sound is still way off and it won't let me delete it. Tried safe mode, same thing.

Command prompt baby! It works!

MPEG2 by nature is uncompressed so unless you lower the bitrate you're probably SOL. Try doing custom options in TMPGEnc and lowering the vdeo bitrate.

Do you want it one long continuous film or short multiple ones to make a menu system? If you want just a long one, take TMPGEnc and merge the files then try to compress that down. If the other, uses percentages in the TMPGEnc wizard that add up to around 100%.

[FlyingPenguin]

Actually MPEG2 IS compressed by nature - it's a compression codec. However there are various compressors and bitrates.

I've noticed that the cheaper software uses low compression to overcome quality issues in poorer compressors, or to speed up the compression (when you record something on the fly in a DVR for instance you usually can't compress as much as you can in a render unless you have a VERY fast system).

For example, MyDVD and NeoDVD have their own built in MPEG2 compressor but it's poor quality and generally only gets 1 hour on a DVD (2 hour is normal compression).

That's why I ALWAYS capture to AVI and then use a high quality MPEG compressor to create the MPEG2 file for the DVD burn. I use Vegas Video 4, but that's a professional commercial video editor.

Most compressors will compress an AVI to an MPEG2 without a problem, but they often won't recompress an MPEG2 to a higher compression or lower bitrate. Vegas will, don't know about others.

I THINK Ulead Video Studio (version 6 or later) should re-compress an MPEG2. Not sure though.

No matter what, you won't get more than 2 hours on a DVD with standard MPEG2 DVD settings. If your compressor will allow you to set a custom bitrate though, you can halve it and get 4 hours on a DVD while probably reducing the quality to the equivalent of a VHS 6 hour recording if that doesn't matter to you.

I know you can get 8 hours on a DVD but the quality is horrible (worse than VCD).

[blade]

No, I want good quality. I just assumed it could be done on a DVD with good quality. So it looks like 2 DVD's is it then. I'm new at this but one good thing about the files being split into 600mb files is when using tmpg to make them into DVD files, it sperates each in the menu.

I'd be happy if I could encode the games to divx. But each time I try the sound is off.


What's the command to delete a file at tghe command prompt? Isn't is something like d\del newfolder\game.mpeg



*I'm trying this at the D prompt. Del \pvcrwork\NFC Title Game.avi

With and without the slash, each time it says 'cannot find title'.

[FlyingPenguin]

I'd be happy if I could encode the games to divx. But each time I try the sound is off.

Same here

I've never had any luck encoding anything RELIABLY in Divx. I just want a simple one button solution, no fiddling with settings and having to repair out of sync audio.

DOS command prompt delete is:

DEL C:\path\filename.mpeg

Unless you're in the same folder as the file you need the full path WITH the drive letter.

[blade]

Vidomi makes great xvid/divx backups from dvd movies. Sound is perfect and vidomi is very easy to use. Just needs a few simple settings at first, then add the files, select the output and go. Only thing to change is the size of the disk, and how many. I can help with what settinsg to use at first if you wish to try it. It really is simple and sound is synced.

But vidomi can't properly encode sound from powervcr files.


My path is D:\pvcrwork\NFC Title Game.avi

I've tried deleting that from the c prompt, and from the d prompt, and even from d:\>pvcrwork and still says can't find the file. Or does it need to be done during a boot and not going to the command prompt in windows?

[Busby]

Quotes. If the filename has spaces it requires quiotes.

so for you it'd be del "D:\pvcrwork\NFC Title Game.avi"



FP: I thought MPEG2 was considered to be uncompressed due to the fact it is like the highest quality available (I know there is better quality like HDTV) but MPEG2 is pretty good. Shows what I get for thinking

[Executioner]

I thought mpeg2 was also uncompressed. The encoding gives you the compression depending on the codec you use.

Encoding is the process of changing data from one form into another according to a set of rules specifiec by a codec. The data is usually a file containing audio, video or still image. Often the encoding is done to make a file compatible with specific hardware (such as a DVD Player) or to compress or reduce the space the data occupies.

MPEG2: An encoding standard designed as an extension of the MPEG-1 international standard for digital compression of audio and video signals. MPEG-1 was designed to code progressively scanned video at bit rates up to about 1.5 Mbit/s for applications such as CD-i. MPEG-2 is directed at broadcast formats at higher data rates; it provides increased support for efficiently coding interlaced video, supports a wide range of bit rates and provides for multichannel surround sound coding such as PCM, Dolby Digital, DTS and MPEG audio.

[rogue]

MPEG2 is definitely a lossy compression codec. Encoding is just a general term when you take one format and transform it into another..ie Blade's football games are encoded in MPEG2 from their original video signal.

[blade]

Thank you Busby. That did the trick.

[BillyGoat]

blade, for encoding dvd mpeg2's thst are high quality and lower bitrate
i use canopus procoder-

settings

var bit rate
min bitrate 4500
max bitrate 6500
vbr 2 pass- its worth the extra time

This works great for all my home videos - should work for your needs i would think

[blade]

Sorry to bring this back up, but FP I found how to correct the sound sync problem. I was recording in mpeg files, when I select record as DV files (powervcr has 3, I chose best quality), then vidomi has the sound perfect in sync, or when encoding to a DVD too.

[canton_kid]

I found a tmpgenc version that makes mpeg2 files into DVD files, but doesn't compress them (I don't think), so I have to use 2 DVD's. Any ideas?

If your making a DVD from the files it's pretty simple!

Use Tmpgenc DVD Author to create the DVD up to about 9gigs, then use DVD Shrink to compress the files to fit one disk. You should have great results that way. I have done it many times!!
Also preview the files with Power DVD or something before burning to check the quality. About the only thing I have found was some artifacts in large mostly black areas and that was after alot of heavy shrinking!

Actually you can author the over size dvd with any program you like, long as it lets you make large DVDs. Tmpgenc DVD author will give you a warning you exceeded the 4.7 disk size, ignore it and create the dvd files anyway. Be aware though there is not a seperate warning if you if you exceed 9gigs which is the actual limit. Course that might be changed now in newer versions since dual layer burners have come around. I haven't upgraded to any newer versions for quite awhile now, everything works great for me so why bother?

Since I may buy a new burner soon geuss I need to look at whats new for software supporting Dual Layer.

[FlyingPenguin]

I have a follow up too. I've been wanting to record some stuff of mine on DVD and been wanting to fit more than 1 1/2 - 2 hrs on a DVD. Quality is not a major issue since these recordings are poor quality to start with.

Found out that the DVD authoring program I use (DVD Architect by Sonic Foundry) has a compression feature that allows you to squeeze up to 5 hours on a DVD with some trade-off in quality.

Once you setup your project with all the videos you want (even if it tells you it's too large to fit) you bring down the File menu and select "Optimize DVD". There's a slidet hat lets you adjust the bit rate. As you adjust the slider it tells you exactly how large the project is and whether it fits on a DVD. Just crank it down until it fits.

This already helped with a 2 hour VHS I dubbed to DVD for a friend. It wouldn't fit on a single DVD until I tried this trick. Quality loss was unnoticable compressing it down from a 6.4Mb project size to fit on a DVD.

[canton_kid]

Yep, it's all about bit rates.

Another thing that helps fit more to a disk with better quality is to use 352X480 (half D1) resolution instead of full D1, (740X480 I think) when you capture. Basically most broadcast stations and All VHS tapes are closer to 352x480 resolution anyway. By useing a higher resolution than what you are recording you are just adding extra data you don't need anyway for the same video quality.

Record in the resolution closet to the source your recording without going over it. Half D1 one is a valid DVD resolution and unless your doing DV camcorder stuff I dought you will often get much better source anyway.
Half the resolution only needs half or less the bits to maintain equal quality. Full D1 needs much more bit rate to maintain the same quality as a Half D1! So if you capture most sources in D1 what you are doing is adding data that is not present in the first place (higher than source resolution) and to maintain decent quality you require far more bits per second to display the extra uneeded resolution you added.

Half D1 at 4,000 - 6,000 gives very good quality about equal to VHS and SVHS and provides much more time on a disk.
Full D1 needs much more bits per second, 6,000-8,000 to equal the above quality and that cuts down your disk time for recording.

Problem with many one click programs is they give you a choice of presets like High med low qualities and High is full D1 High bits and gives you about an hour on a disk. Then Med is like D1 6,000bits and is crappy but gives 90 minutes to 2 hours, then low they jump down to maybe Half D1 2,000 bits and give you 6 hours of not worth watching junk.

I have made several very good 3 hour or longer DVDs, very hard to tell the differance in the source or my disk. Titanic 2 tape set on one disk, Lord of the rings 1 and 2 on one disk each. Gonna try putting all 3 Lord of the Rings on 1 dual layer disk soon, first I have to buy the 3rd DVD. Got so burned out on 1 and 2 I never bought 3 yet. Never even saw it yet either.