Why frameserve DVD's,Tmpeg can encode directly from VOB file

[wulf109]

You don't need to frameserve VOB files for Tmpeg,it will encode from them. Tmpeg contains all the tools needed for DVD conversion. Smartripper has the most flexible file sizing. In the case of TV episodes just set to rip each episode as one large file.
For movies set to rip as two equal size files. Each can then be converted to a CDR.
Some VOB's will open and encode directly,an example are the ST-TOS episodes. Some VOB files cannot,an example is ST-TNG episodes. They contain PTS pointers which confuse Tmpeg into thinking the file has ended long before it has. In this case open Mpeg Tools in Tmpeg and do a simple demux and then simple remux to create a new MPG file. That file contains the video and audio at DVD quality but without the PTS pointers. Tmpeg can now encode that MPG. Use the template of your choice the results will be far better than frameserving thru DVD2AVI or Flask.

[adam]

If your source is a pal dvd and your encoding in pal than I could understand skipping dvd2avi but with ntsc dvds its just not practical.

Almost all ntsc dvds store the movie as film and use RFF/TFF flags to telecine the video to ntsc in real time. This is a much more practical way of playing ntsc formatted disks since you are physically encoding %20 less frames (encode at 23.976 but it plays at 29.97fps) and thus free up
%20 more bitrate. This same technique can be used on vcds and svcds but your source needs to be kept at 23.976fps progressive. Dvd2avi's forced film can do this, and very quickly at that. Without dvd2avi and forced film you either have to inverse telecine (slow as hell and rarely perfect) or live with 29.97fps video (%20 lower quality and prone to interlacing artifacts.)

If TMPGenc is your encoder and you don't need forced film than you dont need dvd2avi. Otherwise dvd2avi is a crucial step in encoding. I don't know of any other program that can preserve the original framerate of the dvd the way it does. If your not using ntscfilm (23.976 w/ 3:2 pulldown so it plays at 29.97fps) than you are really missing out. It makes a huge difference in quality and actually makes the entire encoding process much easier.

[wulf109]

Yes I'm encoding NTSC. I have used DVD2AVI in it's forced setting. Then used Tmpeg's SVCD Film template to encode. The results are not as good as I get using the method I've described. The picture is sharper and has far better color and contrast than the forced film setting produces. Try my method you may be surprised. Frame serving,in my expierence,noticably degrades color and contrast.

[adam]

Actually that's not possible. Frameserving is exactly what its name implies. It simply serves the vobs into the encoder. Unless you specifically change any parameters such as the field order or color space then it is really no different than loading the vobs themselves. Frameserving itself has absolutely no effect on quality whatsoever.

Now if you use forced film correctly than it will literally free up %20 more bitrate. Depending on your encoding mode you will either get a theoretical %20 boost in quailty, or you can theoretically lower your filesize by %20 and still maintain the same relative quality.

Its no coincidence that nearly every commercial ntsc dvd made is encoded in ntscfilm. The quality gain you get from encoding in ntscfilm is real and is a mathmatical certainty. I would think that an extra %20 bitrate would make a noticable increase in quality, I know I can see it. But quality is relative so whether or not you notice any quality difference is up to you but its definitely there.

[Martyn1980]

Adam you sound an expert on this subject,

What DVD are better quality Pal or NTSC.

And if i download any NTSC films then they are 23.98 frames a second, and i used to leave them as that but when i use DVD2SVCD then it applies then 3:2 pulldown, is there any quality differences by doing this, my Pal DVD player plays 29.97 frames a second jerky when theres a pulldown so i usually just remultiplex again back to 23.98, is this normal.

[wulf109]

If I encode using the standard Tmpeg SVCD Film template and A/B the file done thru DVD2AVI forced film and my method I can see that my method produces far better resolution,color and contrast.
Theory is nice but real world results is what I'm concerned about.
Adam should at least try my method before declaring it impossible.

[adam]

Adam you sound an expert on this subject,

What DVD are better quality Pal or NTSC.

And if i download any NTSC films then they are 23.98 frames a second, and i used to leave them as that but when i use DVD2SVCD then it applies then 3:2 pulldown, is there any quality differences by doing this, my Pal DVD player plays 29.97 frames a second jerky when theres a pulldown so i usually just remultiplex again back to 23.98, is this normal.

Well the differences between pal and ntsc are really pretty subtle if both are authored correctly. Pal has a slightly higher resolution which at high bitrates is a plus and at lower bitrates (maybe svcd, definitely vcd) is actually a curse. Pal runs %3 faster than ntsc so there is something unnatural about the conversion to pal. Unlike ntsc where frames are added to increase the runtime, pal is actually just sped up. The movie physically runs faster so in some cases movement can appear jerky, though this is rare. There are additional problems with audio since speeding it up increases the pitch. Sometimes this sounds bad so often it is lowered in pitch to offset this, but this may be even more distracting. There are the odd cases where pal conversions really produce unfavorable results such as the pal version of the Wall. Just ask any true Pink Floyd and they'll tell you that you absolutely have to have the ntsc version. All in all, pal and ntsc are so close together that you will almost never be able to tell a difference between the two, at least as far as quality is concerned.

Vcds at 23.976fps are compliant. There is information in the file header that is supposed to tell your dvd player, hey I'm an ntscfilm vcd so telecine me. On most dvd players it works, if not on yours then there is nothing you can do but convert it to 29.97fps manually.

For svcds you must use the 3:2 pulldown if you encode at 23.976fps. Some dvd players actually autotelecine anything encoded at ntscfilm so the 3:2 pulldown is redundant but it does not hurt anything and it really has nothing to do with quality at all. The 3:2 pulldown tells the dvd player to do a telecine as the movie plays. Ntsc runs at 29.97fps only so either way the movie will play at this speed. If your dvd player telecines the movie properly, either because it does it automatically or because it recognizes the 3:2 pulldown, it will display the movie correctly. If it doesnt do a telecine and simply displays the movie at 29.97fps without adding the proper frames then you will know. The movement will be incredibly jerky and actually jump back a couple frames every couple of secs making the movie completely unwatchable.

I don't quite understand the rest of your question. The 3:2 pulldown cannot be used on 29.97fps material. Also I don't know how you can remultiplex 29.97fps material as 23.976fps. Can you clarify your question please?

[adam]

If I encode using the standard Tmpeg SVCD Film template and A/B the file done thru DVD2AVI forced film and my method I can see that my method produces far better resolution,color and contrast.
Theory is nice but real world results is what I'm concerned about.
Adam should at least try my method before declaring it impossible.

Who said I never tried your method? Also I never said your method was impossible, in fact I even noted instances where it would be viable. What I said was impossible was for there to be any quality differences between a file that was frameserved and a file that was loaded directly, assuming everything else equal and assuming you have not specifically made any changes in the frameserver. Like I said, frameserving simply serves the source to the encoder. The d2v file that dvd2avi creates simply says to TMPGenc, hey look here are 5 vob files, accept them as the video source. Theory is nice because it DICTATES what happens in real world situations. Frameserving doesn't change the source at all unless you specifically set it up to. Its not like this is a completely hypothetical or theoretical concept. Basically its analogous to encoding the vobs off your hard drive rather than off the dvd itself. Either way the source is still the same.

Perhaps there are other variables interfering with your comparison? Or perhaps your subjective judgement is just flawed like everyone else's. After all we are human.

[therick]

note to self-never disagree with adam-ever

No, really, I have done both ways and I am gonna go ahead and side with adam on this. I started using force film months ago and my svcds (or cvds I guess)have never looked better. The real reason I am posting this is for those of you reading who are doing Sat., VHS, and LD transfers and the capture force film equivalent-AVISynth and IVTC-that is, taking captures back to film and using pulldown there. The only reason I mention this is that the quality improvement I saw when using IVTC on my captures was far greater than the improvements that force film brought to my rips. That is a long two cents-

[adam]

Thanks therick. Yes your right using ntscfilm with more noisy sources such as captures will definitely result in a more noticable quality improvement simply because your source is less forgiving.

[wulf109]

Adam says that encoding in forced film produces a "theoretical"
20% saving in file size. To test that I took a 15 min VOB file and frameserved it with DVD2AVI in standard and in forced film mode. I then encoded the standard file using Tmpeg's standard un-modified SVCD template. I then encoded the forced film file using Tmpeg's standard un-modified SVCD Film template. I compared the file size of two resulting MPG files and they were excatly the same size,no 20% saving.
This is getting like another debate on another forum about CBR-CQ-VBR encoding. Each one has it's advocates. Video quality is very subjective. No one will ever convince me that not frame-serving produces better quality. And I suspect that no one will ever convince Adam that frame-serving is not the best method.

[Martyn1980]

Sorry Adam I should have made myself clearer, you have clarified some of my doubts and told me some stuff i didn't know, i understand the higher resolution can be a curse at low bitrates but in VCD there isnt that much of a difference is there.

90% of Divx DVD rips on P2P programs are NTSC 23.976fps, when i used Tmpeg i used this framreate directly with no problems, i then switched to CCE and started using DVD2SVCD, which executes a 3:2 Pulldown on NTSC material if is 23.976fps, the resulting Mpeg is 29.97fps, which played on my DVD player is jerky, not too bad just every 10 seconds it kind of stutters a little, i wondered what i was doing wrong and found the problem to be the pulldown, but you cant tell DVD2SVCD to not use the pulldown unless you convert to Pal, which i dont like doing as ive noticed it sounds speeded up at times, especially if you have watched the original a lot. So after DVD2SVCD you usually have a mpg, 2 mpv files and an mp2 file among other things, but this is the things im dealing with.
One of the mpv file is the encoded video one and the other is the pulldown encode video, i multiplex the audio with the original 23.976fps one because the Pulldown encoded one is jerky.

My DVD player is a Yukai cheapo thing but it is Multiregion and has a NTSC to Pal convertor, i also have a Toshiba SD210E but that is back in my mums house 400miles away, but its fussy about XSVCD anyway.

I hope this is more clear if not then i think i'll go back to school.

[therick]

@wulf109 - ok now we are getting somewhere-I see what you don't understand now. OK, you said you encoded both of the files (the 23.976fps and the 29.97 fps) with the standard SVCD template. I am going to assume that you did 2520 kbps CBR. Ok, here is what you don't understand-fps and seconds-you encoded at 2520 kilobits per second-per second...that means that if you had a file that was 10 fps it would be the same size as those that were 15fps, 16fps-because the bitrate doesn't care how many frames you have, only how long your video is. We all know that the 29.97fps and the 23.976fps run the same length, right? I think we should be able to agree on that much .

Now here is where you misunderstood the wise adam-

"Depending on your encoding mode you will either get a theoretical %20 boost in quailty, or you can theoretically lower your filesize by %20 and still maintain the same relative quality."

Now here I would have used bitrate-but your bitrate gives you your filesize, so I can see why he worded it as such. So what adam says is not that the resulting file size is different, but that you can lower your bitrate by %20 and keep the same relative quality.

Think about it this way-

you get 2520 kbits for 29.97 frames -> which gives you ~84 kbits/frame
you get 2520 kbits for 23.976 frames -> which gives you ~105 kbits/frame

that is the simplest way that I can say it.

And about the frameserving-well, don't get me started...

[adam]

Exactly as therick said, by using ntscfilm you have less total frames but the final playback is still the same. With less frames per sec the same amount of bitrate gets spread over less frames each second. Remember bitrate is allocated per sec, not per frame. At the same bitrate the ntscfilm encoded file will effectively have %20 more bitrate allocated to each frame than the ntsc encoded file. The filesize will be the same but the quality will not. If you can achieve %20 better quality at the same bitrate than it stands to reason that you can lower your bitrate by %20 and still maintain roughly the same quality. Thats where the smaller filesize comes from and thats exactly why I specifically stated that whether or not you get the quality boost or the size decrease depends on your encoding mode. If you encode in multipass vbr or cbr than the bits per sec are predetermined so you get better quality (same total bits, less total frames.) If you use 1-pass vbr than the encoder actually allocates less total bitrate, resulting in the same level of quality yet at a smaller filesize, (less total frames but equally less bitrate.) Yes quality is relative but the benefits of ntscfilm over ntsc are not. They can be quantitatively and mathmatically proven. Just do a web search on telecine and you will see why nearly every ntsc dvd released is encoded in ntscfilm. Here is a good place to start, http://www.doom9.org/synch.htm. Trust me its not a matter of opinion.

And sure anyone can convince me that frameserving isn't the best method. Dvd2avi is open source. Your welcome to analyze the source code and determine which bugs are somehow reducing sharpness and washing out the colors. I have analyzed the d2v file structure and there is nothing in dvd2avi which suggests that, at default settings, it does anything to the source other than create a link to it and the encoder.

If you believe that dvd2avi somehow degrades qualty than fine, chalk that up as a disadvantage of frameserving and factor that into your equation. Forced film is good, mysterious quality degragation is bad....its your call whether or not to use it. You specifically asked why anyone would need to frameserve when TMPGenc accepts the vobs directly. I gave you a perfectly valid answer, that dvd2avi's forced film provides better quality.

[adam]

Martyn1980 your post is perfectly clear now but I'm not sure what to tell you.

You see I cannot think of any reason why the 3:2 pulldown would be causing this problem, yet it appears that, that is the case.

Ntsc tv's run at 29.97fps period. Regardless of whether you use the 3:2 pulldown or not, if your file is encoded at 23.976fps it will be played back at 29.97fps. If you don't use the 3:2 pulldown than it will either be telecined or not telecined, depending on your dvd player, and I suppose the same can be said if you do use the 3:2 pulldown, though I have never heard of a dvd player which cannot properly interpret the pulldown flag. But if your dvd player does auto telecine 23.976fps material, which it seems it does, than I don't see how the 3:2 pulldown can hurt anything. If anything its just redundant and more than likely its ignored altogether.

The worst case scenario is that, with or without the pulldown flag, your dvd player doesn't telecine the video. If this happens the playback will be extremely jerky, much moreso than what you are experiencing. I don't think this is what you are experiencing because if you were then you would definitely know it.

My only suggestion is to play your 23.976fps w/ 3:2 pulldown mpg in a svcd compliant software dvd player like WinDVD. If the playback is still jerky like you are experiencing then there is something wrong with the way you are encoding your file. If it plays smoothly than the problem is indeed your dvd player and its inability to properly interpret the 3:2 pulldown flag. If this is the case then you have a decision to make. You can continue to make svcds without the pulldown flag and risk the chance of having an entire movie collection that is unplayable on any future dvd player you buy or you can live with this slight pause you describe until you upgrade your player.

Let me know if you get this sorted out.

[Martyn1980]

Thanks for the reply, thats what ive been thinking, i havn't tested these on any other players and its a concern that they wont work properly.

My DVD player is Pal so is my TV, but the DVD has a Pal to NTSC convertor.

Thanks again.

[adam]

Oh well in that case you have a third option, convert to pal. If your source is ntscfilm than this should not cause anymore quality loss than if you kept it at ntscfilm. Of course the resolution is another matter. If the source resolution is anything less than 480x576 than the image may look blurry when you convert to pal.

[Martyn1980]

I was thinking that, as i dont think i would notice the speed difference, but the resolution thing did concern me, im going to try it anyway, but is there anything wrong with having a 480x480 or 704x480 mpg running at 25fps, kinda like a hybrid Pal/Ntsc thing

[adam]

Yes mixing ntsc resolutions with pal framerate is very non-standard and will cause playback problems on many if not most dvd players. You'd be much better off just increasing the resolution. Its not ideal but in this case I think its the best option.