Nice guide, although it seems that the description of each control is almost always followed by this sentence:

"This setting should only be changed in highly specialized production environments where there is a reason to do so."

The only two settings that don't have this statement are bitrate and DC coefficient.

For the dozens of other settings, other than bitrate and DC coefficient, the document contains no real information on what will actually happen if you try to change the defaults. For example, what would happen if -- just for grins -- I changed the I-Frame checkbox? Does everything get covered with purple polka dots? Beats me. This document sure doesn't tell me. I'm just as much in the dark as before.

Therefore, for those that don't want to read the document, as a public service, I think I can completely summarize the entire thirty-six pages as follows:

"Play around with Bitrate and DC Coefficient all you want, but don't touch any of the other controls."

I know a lot of work went into this "MPEG Encoding Overview", and I apologize to whomever wrote it for trashing their work, but it would be a LOT more useful if it told me what will happen when I change each setting.

John,

Your comments are well founded. However, users of TMPGEnc are faced with pretty much the same thing -- lots of controls and not much idea what the consequences of using them will be. Maybe we should just experiment.

-- seeker --

How do you log onto an ftp site. When I put the address in my browser, I get an error that the user is anonymous and can't log on.

short answer, get a real ftp client. :-)

almost as short, and more useful answer: ftp://dude:sweet@porker.sonicfoundry.com

I think the message is if it isn't broke, don't try to fix it. I know, I play the what if game a lot. If I see a drop down list or something I can check or uncheck, I'm tempted to mess with it just to see what happens.

For some to ask what happens if you do x, y or z is I think... about as foolish as some patient asking his surgeon the night before his open heart surgery to explain every possible variation in his technique and what complications may arise if he does option A verses option B or C.

While the MC MPEG-2 codec has many variables that can be adjusted, aside from bitrate and perhaps DC coefficient unless you ALREADY know what you're trying to accomplish before adjusting, you're probably already in over your head. What else to adjust if anything depends on the source file. Since the content can vary so much along with the target medium any specific advice in order to get useful information would probably require asking a whole laundy list of questions as to what you wanted to achieve.

For TMPGEnc
see Rui's guide
http://pwp.netcabo.pt/0165394101/TMPGEnc_Template.html

or

http://www.vcdhelp.com/tmpgencexplained.htm

It's supposed to be a manual and therefore to instruct. What else might its purpose be - a Keep Off sign?

We do know what we're trying to accomplish and that's get better quality (or use less space). What most of us don't know is how to tweak the encoder to achieve these ends. I think if each setting had had a "what's it for" paragraph, we might then have been able to decide whether to fiddle with it or not. As it is, an assumption has been made on the part of the author that the various terms and controls are already familiar to the reader. That's not so: some of us have difficulties walking and whistling at the same time <g> And for people who do know what all the terms mean; this guide isn't going to take them very much farther. Its aim rather falls between two targets.

I can't really see what the manual adds to the online Help. Then again, perhaps it wasn't intended to.


-Pete

The MPEG encoding guide seems to have disappeared from the ftp site.
Can one of you guys email it to me ?
How big is it ?


Thanks

Around 256K. I'll send you a copy if you want. But wouldn't you rather wait and see why it's been pulled??

I did not realize it, but the ftp site apparently allows users to delete files. I will lock this thing down today so nobody can delete (except me).

The guide is back up as of right now.

Can you email it to me at

beardie_the_dragon@hotmail.com

I suspect that somebody at SF deleted it by mistake and I am getting a bit desparate

Many thanks

got it !

thanks

For those wishing very wordy and highly technical data on MPEG-2 you can visit http://www.mpeg.org/MPEG which is referenced on the last page of the MPEG encoding guide, the topic of this thread. For example using the linked Google search engine entering GOP, a few hits down you will find some very meaty and highly technical discussion, same for I-frames, etc..

Those thinking any encoding guide no matter how complex is going to unlock "secrets" to convert crappy source files into sparkling, crisp DVD productions by just enterting a different value in one of the control paramaters are going to be very disappointed.

Like with real estate, the three most important things are LOCATION, LOCATION, LOCATION. In video rendering it is SOURCE FILE, SOURCE FILE, SOURCE FILE. Vegas Video comes with a rich set of filters that can really improve your work, rarely you may want to try a couple other things in VirtualDub or TEMPGE. Fiddling with encoding setting should be avoided almost always. The one real world exception may be to decrease the recommened bitrate if you have a few minutres more of video to try and squeeze onto a disc. Bumping up bitrates to max out will likely hurt, rather then help and you'll end up introducing problems for DVD players which may stubble because of it.

The MPEG-2 manual's goal from the start was to:

1) Provide some basic MPEG Q&A
2) Give a brief explanation of each custom control
3) Provide a reccomended setting for each control for SVCD and DVD
4) Give a why you should or shouldn't touch this control
5) Provide some links for further user investigation and support.
6) Provide 1-5 above in one document.
7) ...the doc will evolve over time as the encoder evolves.

As most of you know, there is no one setting that makes all footage look great at tiny bitrates. If there was, we would have exposed any controls at all. Same thing is true with filters in Vegas- there is no "make all video look perfect" filter/switch/setting. In either case, we provide presets that we have found work well, but if you are a knob-twister (like me) you can use the presets as a point of departure and go wild. Yes, it is time consuming and requires research- that's half the fun of the video experience.

True: There are many controls in the MC encoder that generally do not need to be adjusted for SVCD and DVD encoding. We could have trimmed the exposed controls way down and perhaps that would have cut down on the confusion... BUT: There are times when access to some of the "obscure" controls is needed. Some DVD authoring tools require specific file types (elementary streams, specific buffer sizes, delays, field order...) and most post production hardware has certain requirements (profile, color primary, transfer etc), so we do allow you to do make those adjustments if needed.

My suggested tweak order for DVD encoding is, in descending order of priority: bitrate, DC, quality, I/B frame frequency,field base to motion compensation. Pre-filtering the video in Vegas itself can also make a difference- color correction, media and other filters can improve the image quality. If you are experimenting, try changing ONE thing at a time, and keep careful notes. Love the result of a certain custom configuration? Save it as a template.

Don't forget: there is a back-door file size estimator in Vegas that works pretty well for MPEG (esp CBR). Make a time selection, go to Tools>burn CD> burn multimedia CD> and pick the format of your choice. Render loop region must be on for the calculator to be displayed-

We'll be setting up a "user suggested settings" list on sf.com, so if you come across a custom setting that works great for your purposes, please send it to DrDropout@sonicfoundry.com and we'll share your discoveries with the rest of the community.

Anyway, we hope some of you learned something from this guide; corrections, and additions are encouraged.

Seeker,

Count me as one of those self-taught TMPGEnc experts. I have a file that I keep on my computer where I have copied every little idea and trick that users have posted on various bulletin boards. In addition, I have performed dozens of experiments on short clips, changing just one paramater, rendering and then saving the results, burning a CD-RW with dozens of short test clips, and then playing them over and over on my big screen TV to look for differences. As a result of all this, I developed some settings for making SVCDs from video captured directly on DV tape from DirecTV broadcasts. I have also ripped a few DVDs.

The guy that wrote TMPGEnc doesn't speak English, so I didn't expect much of a manual. The people that write the Sonic Foundry stuff live in Wisconsin. I still spend my summers in Wisconsin, and while German is the main language in the area where I go, I think English still predominates elsewhere. I was therefore hoping for a somewhat more cogent manual.

Perhaps there will be a rev 2.

VonHosen,

Thanks for the link to this site:

Configuring TMPGEnc

Somehow I never saw this. This is the best guide I've come across for TMPGEnc. Most of the settings mirror those I've already discovered on my own, but he had one or two that are different and that I'm going to try. More important, he explained exactly what would happen if you change each control (which is my main complaint with the SF MPEG guide).

John

SonicEPM,

Thanks for the additional info, especially on the I/B Frame Frequency.

You give seven objectives for writing the document. Not to beat a dead horse, but my main problem is that the document failed to meet objective number two: "Give a brief explanation of each custom control." To adequately satisfy this objective, the manual should not only tell what the control IS, but in addition, what it DOES. What happens when I change this control? What circumstances would lead me to want to change this? What are the limits (e.g., can I have 200 B frames? Zero B frames?). B Frames is a perfect example of the problem with the document: I get a great description of what they are, and how they relate to I and P frames, but no information on when I would ever need to change them.

If some of these controls should never be changed under any circumstance whatsoever, then your engineers should remove the control.

JM- Thanks for the suggestions.

Diverging, slightly: Are you happy/unhappy with your Vegas MPEG-2 encodes?

Wow, brutal discussion. I agree that there are a number of settings that I would not explain, because you shouldn't touch them if you don't know what they are. The manual does help identify settings that may be called by a different jargon in other circles. That made the manual like the on-line help useful to the professional. Hiding the rarely used settings would negate its usefulness as a professional tool. Folks should remember that if they want idiot proof then they do not want a professional tool.

The order in which you set the priorities of tinkering is exactly what I use. In fact as I have always said, each scene will require a slightly (SMALL) tweak to look its best at the minimum bitrate. We can not do that right now with VV so using the generalized settings of bitrate first etc is the best approach. One setting that I had not caught before I read the manual leaves off the end sequence to assist with joining segments or scenes after encoding. Doubtful anyone in this forum will use that setting this week, but it should be exposed as it is for the occasion when we do encode on scene at a time.

There was one area that I thought might deserve a mention at some point, although it is not really an operational issue. That is the patent and royalty issues with using MPEG2 encoding. I doubt most folks in this user group understand that using MPEG2 encoding is subject to a royalty payment. They understand that as an encoder developer that you have to pay a royalty on each encoder sold, but they do not understand that a royalty is required for the encoded material as well. The producer is responsible for that. Now before everyone starts throwing things, here is a brief explaination. (this should not be considered legal advise and each producer should check with their attorney) In general, encodes done for personal use and given to family are not pursued for royalty. Encodes that are subject to royalty payment are ones that are burned to disc and sold. If you are doing a production run of replicated DVD's then use a liscenced replicator and they will add the minor royalty to your bill and process the payment required. If you are an event vidoegrapher and burning a few duplicated DVD's at a time on your -R or +R burners then you need to make the payments directly. Something folks should check into. Granted the patent holders and administrators have said that they are not hunting small duplicators like event videographers at the moment. They are working primarily with the big replicators. Since I consider my video to be intellectual property I am meticulous about paying other people for their intellectual property like patents. I therefore licsence my discs. (even thoguh I can't type or spell) Each producer needs to make their own choice, but most are not aware of the patents and royalties to begin with. Just my two cents worth.

K

The document, like the encoder itself as well as the parent app(s), will continue to evolve. JM and everybody else, keep that feedback coming.

SonicEPM

"Diverging, slightly: Are you happy/unhappy with your Vegas MPEG-2 encodes?"

Actually, I'm using VideoFactory (and recommending it to my local school district to replace Studio DV which I had previously recommended until it turned into a support nightmare -- but now it is I who diverge...).

I'm hoping to upgrade soon to Vegas, and would love to ditch TMPGEnc, not because it is a bad product, but because it is awkward to use and forces me to take a lot of extra steps to get where I want to go. However, I've been happier with TMPGEnc than I have been with the MPEG-2 SVCD encodes that I have been able to get with the MainConcept codec that comes with VideoFactory. I assume that this is the same codec that is included in Vegas, and if it is, then I would have to say that the quality of the encodes is significantly inferior to those that I get with TMPGEnc. This is true even when I use the default settings for both encoders.

I encode MPEG-2 to SVCD only from material that has been processed through my DV camera (Sony DCR-TRV11). Even using TMPGEnc, I have had poor results from native DV footage shot directly with the camera (in good lighting). I have had mixed results creating SVCDs from music videos from the VH1 Classic channel via DirecTV (I record directly onto my DV camera and then transfer to the computer via 1394). I can generally make pretty good SVCDs by using the Inverse Telecine feature in TMPGEnc when the video was originally shot on film. I have also created a few SVCDs from DVDs, just to see what it was like. Again, the Inverse Telecine is an absolute requirement to get quality results (the 3:2 pulldown completely trashes the encoder, so it must be eliminated).

When I encode from any of these sources using the MainConcept MPEG-2 encoder in VideoFactory instead of TMPGEnc, I get far more visual artifacts, and a sense that the results are not as sharp. The reason I read the MPEG Encoding Guide with such interest is that I wanted to find out if there was some setting(s) that could be tweaked to improve results. Since I am already encoding at the highest legal bitrate for SVCD, and since bitrate (and DC Coefficient) are the only two parameters that your guide says I can change, my conclusion is that I won't be able to achieve TMPGEnc quality using the MainConcept MPEG-2 encoder. This is too bad, because there are HUGE advantages to being able to encode from the VideoFactory/Vegas timeline, especially because it will eliminate the need to edit and join MPEG files in TMPGEnc (which almost always causes glitches).

Hope this helps you understand why I am critical of the guide, and where my issues with the VideoFactory/Vegas MPEG-2 encoder lie.

John

John

Speaking from experience with most of the [popular] encoders on the market, I can tell you categorically that the Vegas encoder is at least as good objectively; that is, tested by measuring the output, as any of them. Cinema Craft might be a pinch more efficient at choosing the lowest bitrate consistent with a particular quality because it makes that 'recce' pass before it starts to encode (I'm talking VBR all the time here).
However, in a real world environment, where you are playing a DVD on a stand-alone player and into a [PAL] TV, the subjective quality of Vegas/MC is better. I've burnt test DVDs and played them to people with good eyesight and no known mental aberrations <g> and asked them to pick their preferred version. Only I knew which version was which. Everybody, yes really everyone, picked Vegas!

Anyone reading my previous jottings will know that I am the first to start moaning if things aren't just so, but in this case - I have no significant complaints. That's not to say that the Vegas encoder is perfect, it isn't, but it's as good as it gets at the moment. Needless to say, while I do have Ligos, Tmpegenc, CCE, Ulead/GoMotion (Ligos?) and a partridge in a pear tree, I only use Vegas now.

Finally, remember that Vegas does have the advantage of frame serving uncompressed footage to its own encoder; the others must work with compressed AVIs.

-Pete

I note that your area of interest lies within VCD / SVCD. Whatever encoder I tried for these formats, I only experienced disappointment. They are all - inevitably - something of a compromise, and one I wasn't prepared to make.