DVD to XVID Resolution

[chris98007]

Hello all. I am taking some of my DVDs and converting them to xvid through autogk

When i want to watch them i run them through CCE and convert to mpeg2 to watch on my tivo. They question i have is what resolution should i use?

I have tried a min setting of 720 which gave me good results. I have also let it run on auto which gave me a 640 i think. Since i have no restriciton on trying to play it on a divx dvd player what should i choose?

The other option is to set AutoGk to auto, then use CCE to resize to whatever i want. I have looked all over for some info and i just need to decide then run with it.

Please help!

[chris98007]

so nobody has any suggestions or ever come across this?

[Baldrick]

Have you tried vob2mpg? no reencoding cause a dvd is already in mpeg2 format. Or does the tivo require some special mpeg format(resolution or something)?

[chris98007]

no tivo just needs mpeg2. however i want to store them on my hard drive. so i am going dvd to xvid back to mpeg. if i left them in mpeg i would need lots of large hard drives for all my movies.

[steveryan]

Your last post doesn't make any sense. Surely if you're converting back then you're not saving any space anyway? You also lose a lot of quality.

[Baldrick]

Probably wants them in mpeg2 in lower file size / quality. But you willl lose more quality if you convert to xvid and then to mpeg2 again, convert directly to mpeg2 using for example dvd rebuilder or dvd shrink and then convert them using vob2mpg.

[chris98007]

ok i guess i am not being clear enough. I want to take a dvd a put it into xvid format for storage. Then lets say on a certain night i want to watch it. I dump it into cce and covert and save it to mpeg2 format on my tivo.

The reason to go to xvid is just for storage. I do this with all my DVD's both movie and TV.

[chris98007]

i guess i will ask a question. If i want to take an episode of 24 that i have on dvd, about 45 min, and convert it down to a 350-400mg file. what would i do?
I have always gone to xvid becasue going from dvd 1.9gig file to xvid 350mg file then back to mpeg 1.1g for viewing gives me the least quality loss.

[Baldrick]

Going directly to mpeg is much better, you can use DVD-Rebuilder together with CCE. It will output a DVD but you can easily make it into a mpg file.

[chris98007]

i understand how to do it, what i am wondering is file comparisons. It would rather have everything in mpeg2 if the file size was similar. From everything i have done and read, to get mpeg2 quality up to mpeg4 the file size is much larger.

[FulciLives]

I have a suggestion.

autoGK has an option to make a MPEG-4 file (XivD or DivX) that is "friendly" to stand alone MPEG-4 capable DVD players.

SO ...

Why not back-up your DVD discs and TV captures etc. using that option and then instead of trying to convert back to MPEG-1/MPEG-2 for playback via your TIVO just buy a MPEG-4 capable DVD player.

This way you can play the MPEG-4 back-ups directly on the player. Granted this means you would have to burn them to a CD or DVD but discs are cheap these days and in the end this will save a lot of time VS having to convert something from MPEG-4 to MPEG-1/MPEG2 for playback via the TIVO.

All you need is a decent MPEG-4 capable DVD player. A great option that is also inexpensive is the Philips DVP-5140 which can be bought at WALMART for approximately $50 US Dollars.

So basically you would be doing what you do now (back-up to XviD) but then burn the XviD files to a CD or DVD then just play back the CD/DVD on the Philips DVP-5140 when you want to watch something.

Granted this means spending $50 and the cost of the discs but this really gives you more choice (can watch whatever you want when you want without converting to MPEG-1/MPEG-2 first) and will save a lot of time in the long run (yeah you will have to burn everything to a CD/DVD but once that is done ... there you go).

Other than the $50 for the Philips DVP-5140 the only other complaint I can maybe see you having is the storage concerns of the discs. Well if you burn to a DVD instead of a CD that will cut down on discs (vs burning only to CD) and you can always buy one of those FOLDERS/BINDERS that have "pages" that hold usually 4 discs per page (or 8 total with 4 on each side). That is a good way of cutting down on storage space (vs putting each disc in a jewel case of some sort).

I realize that my suggestion may not be what you are looking for but since you are already going through the autoGK process of making a MPEG-4 back-up of a DVD ... well it only seems logical to make them stand alone friendly (simple with autoGK) and play them back on a MPEG-4 capable DVD player ala the Philips DVP-5140.

Another suggestion ... buy the Philips DVP-5960 which is the "big brother" of the Philips DVP-5140. Sure the DVP-5960 is a bit more ($20 to $30 more) but it has a USB port which allows you to connect a USB device. This way if you have an external USB HDD you can store your MPEG-4 files on it and then just plug it into the DVP-5960 ... thus saving you from burning all those CD/DVD discs. Two problems though ... one a HDD does not last forever so you should eventually burn the MPEG-4 files off to CD/DVD anyways and two the USB port on the Philips DVP-5960 can be a bit ummm temperamental and does not work with all USB devices. In fact there is a whole thread here covering that USB computability issue.

So for me the Philips DVP-5140 is the better solution (and just burn everything to a CD/DVD disc).

In short it just seems "crazy" to back-up a DVD to MPEG-4 and then re-encode to MPEG-1/MPEG-2 when you want to watch it. I mean that just is not a functional system ... at least not in any way/shape/form relating to convenience nor quality.

- John "FulciLives" Coleman

[chris98007]

Well i guess it is based on my thoughts that everything will go digital. I am tied to mpeg2 becasue of tivo. I believe that most of us would like to sit down at any tv in the house and choose a movie stored on our hd.

I know there are other media players on the market that play xvid they are just not mainstream yet.

I think that xvid/divx/mpeg4 will make this a more reality in the future.

Thanks for the post though

[manono]

I know there are other media players on the market that play xvid they are just not mainstream yet.

I and hundreds of people around here might disagree with you on that one. Go to Wal-Mart (mainstream enough for you?) and check out the DVD/MPEG-4 players they stock.

And count me in as another one that thinks what you're doing is silly and a waste of time.

[chris98007]

ok lets not all get upset. its just my personal opinion. I think that the divx players are great and produce great quality. For me though it is a waste of time to do. I have the dvds and the dvd players.

What i am wanting to do is go disk-less. So i can store all my dvds in a box in the garage.

Getting back on topic.....i guess i am heading in a direction that most dont. Thats cool, i have no problem with that.

[chris98007]

manono, lets be clear...

What i ment was meda extenders, ie mediamvp or netgears or linksys media lounges. not divx disk players.

Media extenders that play xvid/divx/mpeg4 files.

[FulciLives]

I just had my 2nd HDD die on me the other day. It was a Maxtor (yeah I know make fun of me) from 2002. Back in 2003 I had another Maxtor (yeah make more fun of me) that at that time was a few years old that also died. Yes I know Maxtor is shit. I've had PC/DOS/WIN type computers since 1990 and the only two HDD failures I have had have been Maxtor drives.

Anyways the most recent one that died was no big deal really in that it was only an 80GB drive and it mostly had some crap on it that was no big loss but I had just very recently spent a LONG time making autoGK XviD back-ups of the entire FIRST SEASON box set of CARNIVALE and I lost all of that work (which was easy enough to do but took a lot of time).

Luckily I have the DVD discs still but what a pain-in-the-ass to do that ALL over again.

My point? If you don't back shit up from a HDD you will loose it eventually.

Since you are making MPEG-4 back-ups anyways just burn them to CD/DVD and be done with it i.e., purchase a MPEG-4 capable DVD player.

The whole TIVO networked thing is just making your life a lot harder than it need be.

- John "FulciLives" Coleman

[chris98007]

that is true for the time being becuase i have this extra of converting to mpeg. I do believe that once media servers/extenders are more popular it will make life easier. Again just my belief.

Yeah it is true that you have back up and mirror and raid the drives. I am simply running out of room to put the dvds in my house.

So i see this is not a popular subject here. thats ok. I was just wondering if anyone had ideas on resolution.

[FulciLives]

Well if you are making a MPEG-4 back-up only to then convert it back to MPEG-1/MPEG-2 then you might as well not fuss with any cropping or resizing. Just leave it 720x480 which is what all NTSC DVD discs use (at least those that you purchase). Same thing for your captures ... just leave it in the original resolution.

The idea is that you want to minimize any resizing or at least not do it twice. If you resize to make the MPEG-4 then you have to resize again to make the MPEG-1/MPEG-2 file. So it's best not to resize from original to MPEG-4. If you want to resize when going from MPEG-4 back to MPEG-1/MPEG-2 then that would be OK. For instance to save space you might decide to encode at Half D1 MPEG-2 instead of Full D1 MPEG-2 etc.

I'm not sure if autoGK will allow you to make a MPEG-4 without doing any cropping/resizing. You may have to do the encoding "manually" using VirtualDubMod. This might be better anyways as you can just do a single pass XviD with a high quantizer number (like 1 or 2 with 1 being best quality wise but 2 might be a better choice in that the quality should still be very good but with a smaller file size).

- John "FulciLives" Coleman

[jagabo]

You may have to do the encoding "manually" using VirtualDubMod. This might be better anyways as you can just do a single pass XviD with a high quantizer number (like 1 or 2 with 1 being best quality wise but 2 might be a better choice in that the quality should still be very good but with a smaller file size).

With a full D1 frame and a quantizer of 1 the Xvid file will likely be larger than the MPEG2 file. At Q=2 it will be a little smaller than the source but the image quality will still be nearly identical. To get a 45 minute TV episode down to 350 MB with a full D1 frame size will require a Q around 5. There will be noticable macroblocking. That is why people use smaller frame sizes when they want that much compression.

[FulciLives]

You may have to do the encoding "manually" using VirtualDubMod. This might be better anyways as you can just do a single pass XviD with a high quantizer number (like 1 or 2 with 1 being best quality wise but 2 might be a better choice in that the quality should still be very good but with a smaller file size).

With a full D1 frame and a quantizer of 1 the Xvid file will likely be larger than the MPEG2 file. At Q=2 it will be a little smaller than the source. To get a 45 minute TV episode down to 350 MB with a full D1 frame size will require a Q around 5. There will be noticable macroblocking. That is why people use smaller frame sizes when they want that much compression.

Well can you force or trick autoGK into doing no cropping/resizing? If so then that would probably be best as you can allow autoGK to do it's thing in regards to 2-pass encoding.

- John "FulciLives" Coleman

[jagabo]

Well can you force or trick autoGK into doing no cropping/resizing? If so then that would probably be best as you can allow autoGK to do it's thing in regards to 2-pass encoding.

Even if you do that, a 45 minute video in 350 MB will have a lot of macroblocking. When a 2-pass VBR encode and a single pass CQ encode end up with similar file sizes the quality is similar.

[FulciLives]

When a 2-pass VBR encode and a single pass CQ encode end up with similar file sizes the quality is similar.

I'm confused LOL

Wouldn't a 2-pass VBR give better quality when the bitrate is a "low" or at least not a "high" bitrate? ... or am I confusing CQ encoding with fixed bitrate CBR type encoding?

- John "FulciLives" Coleman

[Scorpion King]

A 704x480 uncompressed avi --> Xvid
using quantizer 2.00 came out 4,036Kbps
using quantizer 1.00 came out 10,114Kbps

[jagabo]

Wouldn't a 2-pass VBR give better quality when the bitrate is a "low" or at least not a "high" bitrate? ... or am I confusing CQ encoding with fixed bitrate CBR type encoding?

Yes, you are confusing Contant Quantizer with Constant Bitrate. Constant Quantizer is a variable bitrate encoding, essentially each frame with the same quality. The reason to use 2-pass VBR rather than CQ isn't quality, it's go get a known file size. With CQ you know what the quality will be but you don't know the final file size until your done. With 2-pass VBR you know what the file size will be but you don't know the exact quality.

A 704x480 uncompressed avi --> Xvid
using quantizer 2.00 came out 4,036Kbps
using quantizer 1.00 came out 10,114Kbps

Of course it will vary with the video being compressed. A completely black movie will compress to very low bitrates even at Q=1 (I just ran a test -- it came out to 17 kbps). A bright, high motion, video may come out several tens of thousands of kbps. I have a short video of between channel static encoded with XVID at Q=2. It's about 90,000 kbps.

[chris98007]

When i let autogk run on auto setting for resolution. It gives me a xvid file of 640x380. I can tell it to keep a 720 width and it automaticly sets the height to like 410. File looks good. My question was should i go with the auto or set it to a width of 720.

Here is my procedure. dvd to xvid = 380mg file. Then if i want to watch it, i dump it into CCE and keep the resolution so it does not resize it. CCE takes about 10-15 minutes to convert it to a mpeg2 file usually around 900 to 1gig file size. Then i am done.

I know it seems weird to take a vob/mpeg and got to xvid then back to mpeg. However it comes down to the difference of 4 shows that equal 1.5 gigs in xvid or 4 shows that equal 4 gigs or so. I would be so happy to either have a good quality mpeg2 file that is under 800megs or some kind of transcoder to make it all automatic.

[FulciLives]

When i let autogk run on auto setting for resolution. It gives me a xvid file of 640x380. I can tell it to keep a 720 width and it automaticly sets the height to like 410. File looks good. My question was should i go with the auto or set it to a width of 720.

Here is my procedure. dvd to xvid = 380mg file. Then if i want to watch it, i dump it into CCE and keep the resolution so it does not resize it. CCE takes about 10-15 minutes to convert it to a mpeg2 file usually around 900 to 1gig file size. Then i am done.

I know it seems weird to take a vob/mpeg and got to xvid then back to mpeg. However it comes down to the difference of 4 shows that equal 1.5 gigs in xvid or 4 shows that equal 4 gigs or so. I would be so happy to either have a good quality mpeg2 file that is under 800megs or some kind of transcoder to make it all automatic.

What you may not realize is that DVD MPEG-2 uses "non-square" pixels but MPEG-4 uses "square" pixels. So when you go from DVD MPEG-2 to MPEG-4 and use something like autoGK it will resize to account for this difference. For instance 720x480 is "Full Screen" for DVD MPEG-2 but for MPEG-4 you would use 640x480 (traditionally) or 720x540 (not that common but it can be used).

Anyways that is how you get a "proper" aspect ratio with MPEG-4 but since you are just making the MPEG-4 to temporarily "store" the DVD and therefor not actually watch or view the MPEG-4 ... well then ... that is why I said NOT to change the resolution (nor do any cropping).

For instance. If you have a source that autoGK makes 640x380 or will make 720x410 and the source is the same ... well think about it. In this case if you take the source and leave it "as is" resolution wise but cut the black ... then see what is left ... you will find that the resolution is not 640x380 nor 720x410 but probably something like 720x380.

So either way you are resizing. Unless you don't and encode the AVI at the EXACT same resolution (with no cropping) as per the original.

Which means that using autoGK is probably out-of-the-window as I can't figure out how to use it and make it NOT crop/resize. However you can easily do a MPEG-4 encoding yourself (through VirtualDub) without doing a crop/resize but then you don't have the nice nifty autoGK interface. However setting up a MPEG-4 encode that way (through VirtualDub) is not all that difficult BUT if you need help then you can still use autoGK to "set-up" the files and the AviSynth file then stop autoGK when it starts to encode ... then use the AviSynth file yourself in VirtualDub (after removing the parts about cropping/resizing).

- John "FulciLives" Coleman

[jagabo]

The larger the frame size, the more bitrate you need to keep the image from degrading into macroblocks.

The smaller you make the frame, the lower the bitrate you need to encode it. but the less clear it will be when blown up to full screen on playback.

Autogk tries to be smart about its encoding. It looks at the nature of your source, and the bitrate you're requesting, then adjust the frame to a size that it thinks will give an acceptably small amount of macroblocks, while maintaining the correct aspect ratio. You can override its recommended image size but you will get more (using a larger frame) or less (using a smaller frame) macroblocks.

[chris98007]

yeah i have used vdub to make encodes. They seem to come out the same as autogk since autogk uses vdub. The only advangte i have using vdub really is to set my own resolution size.

However i do not blow up the image when i go from xvid to mpeg. I leave the res size the same in cce. So if the xvid file is 640x380, then that is what the mpeg is.

I have taken long looks at the 640X380, 720X410 and the 720X380. They all seem to look the same. I was thinking that the 640 would look the best bucause i am shrinking the res down so the bitrate is concentrated in a smaller area. However i am having a hard time seeing a difference thought i know there should be one.

Maybe it is just that CCE is that good at encoding. I am not sure.

[FulciLives]

yeah i have used vdub to make encodes. They seem to come out the same as autogk since autogk uses vdub. The only advangte i have using vdub really is to set my own resolution size.

However i do not blow up the image when i go from xvid to mpeg. I leave the res size the same in cce. So if the xvid file is 640x380, then that is what the mpeg is.

That makes no sense. Since MPEG-4 uses square pixels (and you are encoding it that way if you use autoGK) then you can't use the exact same square pixel MPEG-4 resolution when you go back to MPEG-2 for TV viewing as that will give you an aspect ratio error!

So if the MPEG-4 is 640x380 then you need to encode it as 704x380 (with black padding around that to make it 720x480 total) and if you don't do that then you will not get a proper aspect ratio.

- John "FulciLives" Coleman

[jagabo]

Since MPEG-4 uses square pixels (and you are encoding it that way if you use autoGK) then you can't use the exact same square pixel MPEG-4 resolution when you go back to MPEG-2 for TV viewing as that will give you an aspect ratio error!

So if the MPEG-4 is 640x380 then you need to encode it as 704x380 (with black padding around that to make it 720x480 total) and if you don't do that then you will not get a proper aspect ratio.

Maybe he's not converting to MPEG2 for DVD. In his first post he said he was using his Tivo to play the MPEG2 files.