lowest bitrate to re-encode without loosing dvd quality?

[krazyscotsman]

I read that a lot of dvds are encoded at say 5mb/s and up sometimes for security reasons. I'm wondering how low I can set the bitrate on these movies without loosing the dvd quality. I don't want the video to become choppy, to loose picture quality, or become pixelated. Thanks for your suggestions.
Scotsman

[crahak]

Oh my god. This already feels like one of these will-get-long thread It will depend on many factors. First being what _YOU_ see as DVD quality (I know people ripping VHS tapes to VCD directly with ms movie editor and call it DVD quality LOL), also, it will change with every movie, as some are more easily compressible than others. You sure can read everyone's comments, but it sounds like you have to do some testing. Also, we do not know what media you want to use (CD or DVD). You want "real" DVD quality? Rempeg them and burn them to DVD's after ripping the languages and stuff you don't want I would say, and you'll have the best possible. Again, you might have been thinking of something completely different. Good luck

[medievil]

The Backups I make usually span the 2mb to 3mb range. I use CCE 1 pass with 0 min and 9800 max. I also rip them using Snartripper, then I use DVD2AVI and create a D2v file. I don't decode audio as it's easier to just demux it and keep the Ac3. You also want to force fime if it's feasable. Makes for better looking encode as well as the bit rate not being wasted on the extra frames. After encoding use pulldown.exe to change the frame rate back to 29.97 (Ntsc) this also has the added effect of re- "weaving" the video so players won't use the crappy "bob" method.
Final version with Ac3 audio usually end up running about 3gb and look exactly like the original (Minus the menus) on both PC and TV.

[shynomi]

Definetely do some testing if you're talking about dvd r's then if your burner supports /rw than just use those for testing if it's to your standards for "dvd quality" then burn it to dvd r. That would be my plan.
good luck!

[bugster]

Lets assume you are ripping the DVD, discarding all the extras, subtitles and unwanted audio channels, leaving just the main movie, one audio track and a simple menu structure. If this still will not fit onto one DVD-r then you have to re-encode using your favourite method. Then the best quality you will get is by using the highest possible bitrate that will still fit the movie onto one DVD-r. Use a bitrate calculator to find this value (there sre several listed in the tool section), encode, author and burn!

[SingSing]

The solution is most likely in VBR.
I am currently doing it at 1500min, 2000 average, and 2520 max.

[Niceone]

seems very low bitrate there, might as well be doing svcd no dvd, cartoons/animation require less bitrate whilst films with lots of dark scenes need quite a high bitrate.

I personally would never go below 3000k if i wanted it to actually look like dvd quality, and thats with a few passes

Btw, always do at least 2 passes, 1st pass on its own to create video information file, you can select the Q level you desire for decent quality and see how big that turns out, used the advanced feature in CCE to then work out how far away you are from your desired file size and itll show you the scenes that havent got enough bitrate which will give you an indication on how the film will turn out

You can also redistribute the bitrate to certain areas that need it there too

then you can do another pass (at least) for your actual result

Hope thats some help

[eatin sammiches for lunch]

u need to look at the CCE encoding guide using the robshot method on doom9.org

it is very good in trying to optimize your transcode for size and quality

and like it was mentioned before by other posters in this thread u should use mulitpass settings and i usually try not to go below 3000 avg bitrate (with a 9000 max)

[_fester_]

I use TMPGEnc Plus, and when trasncoding larger DVDs usually I use Automatic VBR method, with 6000 max and 2000 min bitrates, quality setting at 75%. This usually gets me a file that is the same size(or nearly) as the estimate given from TMPGenc's wizard. If the movie is a very high bitrate or is unusually long(like say, Gladiator), you're obviously gonna have to adjust the settings to make it fit on 1 DVD.

IMHO, bitrates less than 4000 show a fairly noticeable loss of quality, maybe equal to a VHS tape.

hope this helps

_fester_

rotting in the corner

[Roy Batty]

_fester_
I have made successful dvd-9 transfers following the digital-forums.com guide, which goes through the Decrypter > DVD2AVI > TMPG Plus > Spruce DVD Maestro route.

The only complaint I have is that the size reduction from the original Decrypter VIDEO_TS folder to the remuxed VIDEO_TS is pretty big. If anything it is reduced more than it needs to be. For example I just did Terminator SE which was 5.8GB raw and compressed right down to 2.8GB after the re-encode/maestro compile. On playback of fast motion scenes with bright colour palettes some block artifacts are visible.

What manual calculation do you use for calculating bitrate to end up with a DVD fileset that comes out at about 4.2GB? I only require the English audio stream and I usually discard all extras, angles etc and only work on the main movie files.

More to the point, where do I set up parameters within TMPG Plus to use the highest bitrate I can to reach the "safe" 4.2GB limit?

Cheers

Roy

[Faceman101]

You can use 352x480 as your res and use a SVCD bitrate or slightly higher to keep your quality. If you try such low bitrates on DVD material and keeping it at 720x480 you're going to have pixelation in motion scenes.

*EDIT*

@ _fester_

my post was more towards the original poster and some responces, your responce is a very valid method. it was more towards sing sing and the original poster.

Personally I never go below 4000 b.c I do CBR for speed reasons. For LotR I bit the bullet and did a 2 pass with CCE.

[_fester_]

Faceman, I don't agree.

Roy, I use the exact same software. As for your problem, my solution is to use the CQ_VBR encoding with a 75 % quality rate, This produces(usually) a file similar to what the project estimate is. They way to be able to get the project estimate is to first change the settings at the bottom of the screen, then save the file. Go to file menu, use Project Wizard and load the file you just saved. Its a handy kind of bitrate calculator that kinda works. I realize that the amount of space its going to say is the max(that is, your max bitrate setting). If the encoder can save the data at any lower bitrate, it will, and you will save space on the file.

The reason that you are having files that dont fill up what the maximum file size should be is that the source movies are lower average bitrates (like 4000-6000), or are able to be encoded efficiently(low action). Terminator''s case is probably that it is a lower bitrate original, because its kinda of an older movie. You can use the freeware tool BitrateViewer to open a VOB file and get these important facts before you encode: The average bitrate, the quantize level(how compressed the movie already is) and the DCT precision factor. These numbers can be used in TMPEnc for a quicker and better transcode.

Hope I actually solved something with that narrative.

_fester_

[Poplar]

The "Sweet Spot" of MPEG-2 MP@ML at D1 is usually over 4Mbit/s, under which artifacts become non-transparent. If you are quality freak, you should not go under this. But if the source is excellent, you can get away with 3Mbit/s, perhaps. If you are doing film, you can save 25% bitrate or space with IVTC, which is another factor you should consider.

[vitualis]

I think anyone reading up to this point of the thread should have a read of crahak's post (the second one) for some perspective...

It ultimately depends on your personal definition of "DVD quality".

Regards.

[medievil]

seems very low bitrate there, might as well be doing svcd no dvd, cartoons/animation require less bitrate whilst films with lots of dark scenes need quite a high bitrate.

I personally would never go below 3000k if i wanted it to actually look like dvd quality, and thats with a few passes

Btw, always do at least 2 passes, 1st pass on its own to create video information file, you can select the Q level you desire for decent quality and see how big that turns out, used the advanced feature in CCE to then work out how far away you are from your desired file size and itll show you the scenes that havent got enough bitrate which will give you an indication on how the film will turn out

You can also redistribute the bitrate to certain areas that need it there too

then you can do another pass (at least) for your actual result

Hope thats some help

I disagree, 2 pass on DVD rips is a waste of time. 0 min, 9800 max and a Q of 50 will yield DVD quality. DVD rips have no noise and therefor don't need 2 passes to balance out. The only use for 2 (or more) passes is for noisey sources that have a lot of trash moving in the background (Those movenments eat bits)

[medievil]

I use TMPGEnc Plus, and when trasncoding larger DVDs usually I use Automatic VBR method, with 6000 max and 2000 min bitrates, quality setting at 75%. This usually gets me a file that is the same size(or nearly) as the estimate given from TMPGenc's wizard. If the movie is a very high bitrate or is unusually long(like say, Gladiator), you're obviously gonna have to adjust the settings to make it fit on 1 DVD.

IMHO, bitrates less than 4000 show a fairly noticeable loss of quality, maybe equal to a VHS tape.

hope this helps

_fester_

rotting in the corner

I disagree. I did a backup of Lord of the rings (3 hours) it wnded up being 3.5gb and looks EXACTLY like th original. I used CCE 1 pass vbr with a min of 0 and a max of 9800mbs. The movie is letterbox.
as you can see I am not limiting the maximum bitrate, I did give it the full 9800 and it does peak out at that when needed. , but the parts tahat are under 3000k Show no artifacts. It does indeed look exactly like the original. If I had server space I would upload a sample to prove my point.

[ItsMe]

I agree more or less with medievil. I usually use min 1000 and max 8000 and choose the average depending on the length of the film I am backing up. Even with average bitrates between 2500 and 3500 I get stunning results. maybe not 'exactly' the same as the original but pretty close and certainly much better than (s)vhs.

I am using a Vidac VMagic card to trancode which graphically dispays the current bitrate, minumum bitrate, average bitrate and maximum bitrate during trancoding. By watching this along with the preview window I can see which scenes are taking up bandwidth, and which are not. Some scens go as low as 900 without much loss in quality. This leaves loads of bandwith over for scenes that need more bandwidth.