Tip of the day: enabling closed GOP's in MPEG.now

[Dr Mordrid]

When encoding MPEG video the pictures are grouped into GOP's....Groups Of Pictures. These GOP's can be open or closed, depending on how the encoder is set up.

First some definitions:

A "closed GOP" does not reference pictures from the previous GOP. As such when a "closed GOP" MPEG is loaded into a stream properties analyzer like BitRate Viewer its GOP properties show "closed" on all GOP's.

An "open GOP" does reference pictures in the immediately previous GOP. When an "open GOP" MPEG is loaded into a stream properties analyzer its GOP properties show "closed" for the first GOP (ther is no previous GOP to reference) and "open" for all the rest.

This becomes a problem because some authoring programs, Reel DVD for one, prefer the use of "closed GOP" MPEG's. The rub is that Uleads MPEG.now programs default to open GOP's in their MainConcept encoder engines. This post will address how to set MSPro 6.51a/6.52/7 to use closed GOP's.

First you have to turn on the MPEG Advance menu. You do this by browsing to;

C:\documents and settings\all users\application data\ulead systems\ulead mediastudio pro\7.0\ (or ....\6.5\ in earlier MPEG.now enabled builds)

and opening the "MSP.ini" file in notepad. You may have to set Explorer to show hidden files to see MSP.ini.

Under the [VIODRIVER] heading in MSP.ini add "Advance=1" to the end of the list so it looks like this;

[VIODRIVER]
UleadVideoPlay=1
UleadVideoDecoder=1
UleadAudioPlay=1
UleadAudioDecoder=1
UseOnlineMuxing=1
MotionEstimate=20
PlayAC3=1
DecodeAC3=1
UleadAC3Encode=1
Advance=1

Now save MSP.ini back out and start MSPro.

The next time you go to render an MPEG go into the Compression tab, enter the newly visible "Advance" menu and browse to its "Video Settings" tab. On the lower left is a box labeled "GOP Structure".

One of the selections in this box is "Closed GOP every". Its default value looks ghosted, but it isn't. You can change it with the up/down buttons.

The default "Closed GOP every" setting of "0" results in open GOP's.

Changing "Closed GOP every" to a value of "1" results in closed GOP's.

As you may notice the Advance menu reveals a whole bunch of new settings to play with, but most people should stick to the basics until they do some reading up on MPEG parameters. One of the more useful settings is in the Basics tab. Here you can set the MPEG "Video encoder quality" slider, which defaults to 35.

Upping this to 40-45 enhances your output quality considerably at low bitrates at the cost of longer renders. I use 45 quite a bit to fit 2 hours of video on a DVD-R at just 4600 kbps.

Dr. Mordrid

[AmSci]

Thanks. The same ini trick can be added to DVD Workshop to unlock a large number of advanced features.

[Dr Mordrid]

DVD MovieFactory as well.

Dr. Mordrid

[bitz4brainz]

Good Grief! Like magic! Sheez, I might be able to use this software after all. I was ready to give up.

Are you saying that MPEG.now is really the MainConcept encoder????

In hopes that you (or anybody) monitor your thread, I will tell you my problem"

I am transferring some movies from my laserdisc collection so I can retire the LDs. As far as I know, some of these movies are not available on DVD and may never be. For example, the original Star Wars films (before Lucas messed with them). I am capturing the films through a Sony DV camcorder.

I bought Ulead MF2 (and Pinaccle Expression, which was unsatisfactory). I also have DVDIt Lite (came with Premiere), and Easy CD/DVD comes with a lame little DVD Builder. To learn the thing, I did a film completely through MF2, and while the encoding wasn't very good, it was acceptable for that project. But for Star Wars I wanted the best possible quality. So I spent a couple weeks learning and doing tests with TMPGenc. After much trial and error I figured out how to do this (everything else defaulted):
-- specified film source (reverses the telecine)
-- specified 16:9 (and asked TMPGEnc to crop top and bottom).
-- specified High Quality Motion
-- specified 8000 Mb/sec CBR. (I plan to split across two DVDs)

When played through Power DVD, the resulting encodings (.mpg) look fabulous! Even the 16:9 workes. It also plays well through WMP 9, which letterboxes. No skips or artifacts. To be safe I also did an M2V encoding, and pulled the PCM audio track directly off the DV capture file as a WAV.

So now I author it with MF2, supposedly without reencoding, just a remux. Now it skips and burps! Esp at scene changes and during movement. Sometimes the skipping is as often as twice a second. What could possibly have happened on the way to becoming a VOB?

I tried to use Pinnacle Expression and the package blew up. I tried DVDIt, but it won't accept 16:9. I finally tried that little lame-o DVD Builder in the Roxio package...and it works! But DVD Builder can't do chapters, scene menus, etc. I downloaded the demo of DVD Workshop (1.2) and it does the same thing as MF2. And worse, there's a bug where WS doesn't count frames properly in the previewer and thinks the clip is 48 minutes vs 60 minutes. (It probably forgets to allow for pulldown.)

First, I'm wondering if this closed/open GOP thingie you were talking about might be the problem.

Second, if I can figure out what I am doing wrong, I'd like to use TMPGEnc (with its built-in cropper) and MF2 for authoring (I'd probably even buy Workshop).

In the alternative, if I can figure out how to use these MainConcept (?) settings to accomplish the same things and the encodings are better, I'd be willing to do that. But then I guess I have to pre-crop and stretch the film first, a step I'd hoped to avoid.)

Thanks for any suggestions you can offer...

[DSE]

I had no idea this was in MovieFactory as well. Thanks for the tip.

[Dr Mordrid]

Yes: Uleads MPEG.NOW is the MainConcept MPEG encoder and in the Advance menu all the good settings are there...even some you probably shouldn't play with

By editing their various products *.ini's the Advanced menu can be used to gain access to the full feature set. The same plugin SDK was used in Premiere 6.5.

These *.ini's are named thusly for each product;

msp.ini = MediaStudio Pro
dvdmf.ini = DVD MovieFactory
dvdws.ini = DVD Workshop

All found in the Documents and Settings\All Users\Applications data\Ulead Systems\.... folders.

The first thing I'd do if having a problem is download and install any patches you haven't already applied. Ulead often includes bug fixes not documented in the patches page.

After that: for long program lengths on a single disk I usually encode to 4000-4500 kbps using an MPEG quality of 80-90 in DVDWS or 40-45 in DVDMF. Splitting across two disks I'd probably keep the quality settings but up the bitrate to 6000-8000.

Dropping the motion search value in the "Advanced/Advanced Video Settings" menu to 4-6 lenthens encoding, but is very helpful with DV video or motion content. Most MPEG.now enabled programs default this to 8, which IMO is a couple notches too high.

Dr. Mordrid

[Carl West]

Just a note that Video Studio 7 has it also

UVS.ini and its lovely

Thanks Doc

[bitz4brainz]

Thanks for the info, Doc! You ARE good! The more I find out the more interesting the stuff gets.

TMPGenc is producing closed GOPs, and forcing an I on scene changes. From what I read, that shouldn't be the problem for the Ulead authoring packages, so I'm still looking for the answer to that prob where MF and WS cause stuttering on a perfectly fine encode.

Thinking out loud. I read on another site that at higher bitrates (I'm using 8Mb) it might be a good idea to dispense with B frames. What do you think? TMPGenc seems to have been encoding with 1 I, 5 P, 2 B. This movie has a lot of action, a lot of scene changes.

[bitz4brainz]

PS, I'd like to switch to MainConcept / MPEG.now but it would mean a a major strategy shift and still more tools. TMPGenc takes care of cropping, resizing, and IVTC for me. It seems to be better documented since so many people use it.

[Dr Mordrid]

TMPGEnc and the Ulead packages work well together here too, but MC delivers the goods too when you get yourself wrapped around it more and VirtualDUB can do most anything TMPGEnc's filters can do, and then some. It's also faster than TMPGEnc.

Also: most any encoder that can load an *.avi will work nicely from your editors timeline when you use a videoserver (no exporting a HDD file before encoding) to pass the timeline directly to 'em. Videoservers are an excellent tool.

Now for some weirdness: you can frameserve MSPro's (or Premiere's or Vegas Video's) timeline directly to VirtualDUB for processing then use VirtualDUB's internal frameserver to serve an external encoder

This lets you do what TMPGEnc can do in terms of processing the video during the encoding process. Daisy-chaining looks kinda weird when it's running and it takes a bit of learning to get the moves right, but once you know how it's a snap & very useful.

There are two videoservers out there now that matter: VideoTool.net's VideoServer and PluginPak.

VideoServer runs $25 USD, has more features & settings and comes with other software that is very useful (Link2, an "input server" for one). It can also be copied into most other Ulead video programs (VideoStudio, Cool3D and even GIF Animator ).

PluginPak is a basic no-frills videoserver that is freeware. NO idea yet if it can be "transferred" to other Ulead proggies to enable frameserving in them yet.

Dr. Mordrid

[Patrick]

Ummmm.....

Doc, when I do a search on the web for PluginPak all I get are references to Netscape. Would you happen to have a link for PluginPak?

[Dr Mordrid]

Frameserver: http://www.debugmode.com/pluginpac/frameserver.php

Forum: http://www.debugmode.com/forums/forumdisplay.php?fid=26

PS: PluginPak has cropping controls.

Dr. Mordrid

[Patrick]

I see the problem

Ah, it's PluginPac and not PluginPak. Thanks for the links, Doc.

[Flying dutchman]

@bitsforbrainz:

Try the freeware IfoEdit (version 0.95 or higher). This is a program for manipulating IFO/Vob files but it is also a primitive DVD authoring program.

If you demux your mpg file (or render it into separate audio/video streams), you can use IfoEdit to multiplex it into a DVD-compatible set of VOB and IFO files. No additional software needed, except a program to burn the files.

[bitz4brainz]

Dutchman,

I've considered ifoedit but can I then get the VOB files into an authoring package and do chapters and menus? If not, then Roxio's DVD builder does vanilla DVDs, and it works.

bitz