Best way to convert saved MPEG2 to DivX

[DrWorm]

What is the best way to convert the MPEG2 video files to DivX format? I don't have a DVD burner, just a CDRW but I'd like to archive some of my favorite shows. I tried using Virtual Dub but the resulting file sizes for a 30 min show are about 200 megs and they looked awful. Ideally, I'd like to get them down to about 50-100 megs. I have downloaded DivX tv shows before that were a small size but they looked pretty good and definately good enough to watch in a small window. I dont care too much about quality because I'm probably just going to watch them in a small window while I work. Is there a better program to use? If not, what settings should I use with Virtual Dub to make them smaller and to increase the quality? Thanks.

[SHS]

There only two option Vidomi Encoder or Dr. DivX

[Xleon]

The best method is DVDx v2 or (at a push) Vidomi
DVDx is a fantastic freeware program that can convert VOB and MPG files to almost any codec you have installed. I regularly use it to convert to DivX and XVid.

Get these from www.doom9.org

[rrussell]

Can you use any of these programs automatically?

That is, can I create a batch file to run every night at midnight to run through all of the day's MPG files and compress them to AVI with minimal or no intervention by me?

All of my attempts to do this sort of thing in the past have met with miserable failure.

[falchulk]

There are many converter programs, not just 2. I have at least 4 at home I tested when I ripped all of my dvd's to my HD and converted them. I found the best small size/acceptable quality was 352 x 240 @ 780 kbs with light pre processing. If you cut commercials, a 30 min show ends up being about 126 megs.

I should say that its barely acceptable though. I found that the only settings I could really stand for everyday use would put the file size up near the equivalent mpeg 2 file. I started using 702x480 @4000kbs with light preprocessing and keyframes every 90 seconds. This makes for a great picture but a file size of 1.6 gigs.

I used showshifter for 4 or 5 months before coming over to sage recently. Divx is its main recording format. Unfortunately, I am not satisfied with the quality of the picture. Divx is great with a DVD because its a noiseless format. Tv inherently is noisy. You files end up being larger because of this and the picture worse. To compensate, you have to up the bit rate just so the noise appears as it did on the live broadcast instead of smearing into the detail information. Most people can tolerate the slight pixilation but I am not one of them.

[rrussell]

Originally posted by falchulk
Divx is great with a DVD because its a noiseless format. Tv inherently is noisy. You files end up being larger because of this and the picture worse. To compensate, you have to up the bit rate just so the noise appears as it did on the live broadcast instead of smearing into the detail information. Most people can tolerate the slight pixilation but I am not one of them.

Innnnteresting, I did not know this. Maybe I'm chasing a holy grail, then, because the times I did get a show converted, it wa grainier than I could stand - but it sounds like this is inherent in the codec, based on the noisy source.

Food for thought. Thanks.

[Xleon]

A few helpful hints:

Always go for 2 passes or more. It obviously takes twice as long, but the quality is MUCH better than one pass.

On DVDx, use the TAP resize functions as apposed to the others as this is a two-pass resize against the others which are one pass. Again, this slows down the encoding again.

On my 2.4Ghz Athlon, I get 17fps while encoding with all settings at maximum.

You should be looking at a bit rate no lower than 900Kbs.
If you have a 1/4 size output (328 x 288) you can get away with 900Kbs. If you go for the full 704 x 576 (giving one PAL example), you will need to use more bits.

As for the audio, you might as leave that at 48Khz. There is no reason to resample down to 44.1Khz as all soundcards today can handle 48Khz.

The new XVID codec has lots of new, exciting additions to increase the quality. You will just have to experiment and find out what works for you, but bear in mind that if you have a Sigma Designs XCard, if you enable some of the specialised settings, it may no longer play through the Xcard.

DVD is not completely noiseless. I've seen some very bad transfers and satellite TV is getting much better than it used to be.

The extra pixelation from TV grabs can be almost removed by increasing the bit-rate and applying some of the noise-removing filters and other advanced DivX / XVID encoding options. If you have a ProVideo card, you could also adjust the pre-filtering before it encodes it to MPEG.

[Xleon]

I should say that its barely acceptable though. I found that the only settings I could really stand for everyday use would put the file size up near the equivalent mpeg 2 file. I started using 702x480 @4000kbs with light preprocessing and keyframes every 90 seconds. This makes for a great picture but a file size of 1.6 gigs.

I think that's a bit overkill. DivX at that quality is hardly worth the effort of converting from the original MPEG. If you sit watching DivX encoded material a few inches from the screen, then a very high-bitrate is good.

If you sit a normal distance away from the TV, the small artifacts will tend to 'blend' away and if the player is very good (XCard), then it does a lot of output processing to remove them even further. It's not much different than watching the original MPEG from Sky for example with those artifacts. If the original had MPEG artifacts, then it's bound to affect the final compressed file.

[falchulk]

I did not say that I converted to that. I recorded straight to that via showshifter to get the quality that I currently have with mpeg 2 and sage. I also stated that increasing the bitrate will help pixelation. I have never had much luck with 2 pass. It seems to always look worse then 1 pass. I also think I menttoned pre processing. DVD is noiseless. It may have artifacts but they are not the same as noise.

[Xleon]

Sorry falchulk, I miss-read your post.
I've been up for 36 hours so far, so I'll blame it on that ;-)

[jmeeks]

If your having that much noise, have you looked into improving your source signal?

[falchulk]

Its not "so much noise". Its just that the lower the bitrate, the more the noise bleeds into the detail elements. I may just have a sensitive eye, but it bugs me. Every TV signal has some amount of noise content. As I said, convert a clean DVD to divx of equal res ,bit rate
and length of a recorded tv program. Want to take bets on which one is smaller?