View Full Version : GOP too long

11th June 2004, 05:55
Attempting to convert an SVCD to a DVD-R format. I used TMPG to merge the mpg files, demux them, and finally I used TMPG dvd authoring to try and generate the vobs. When I add the files to TMPG DVD authoring program, I get an error that the GOP is too long. Since I only used the mpeg tools in TMPG and I don't see any GOP menu on the mpeg tools section, do I have to reencode the entire file using the main layout?

Another question: I followed the guide to convert SVCD to dvd without exception. But why can't you simply merge the mpegs into a single mpg file then reencode them using tmpg. Tmpg gives you the option to downsample to 48khz and does everything else the guide mentions. I suspect it would be a lot slower but is it an option? The reason I ask is I have tried 2 movies using the guide and neither have turned out right. When I am previewing the clips in the DVD authoring stage they all have green interference dancing around the right part of the screen. Thanks in advance for any info you can provide!

Oh one more thing: How can you standardize an SVCD mpg file to play on windows media player? I have read that if they aren't within certain specifications then they will not play. The ones I have play on say PowerDVD but I really would like to use WindowsMedia Player. I have the necessary codecs and sometimes they start but play for a few seconds and give an unexplained error.

EDIT: I tried to reencode with TMPG the SVCD mpg files to fix the GOP but when I use the wizard or the main menu it says "Failed to open or unsupported file type". So I guess it's not possible to reencode mpeg-2 files with tmpg?

11th June 2004, 13:29
Yes, you have to re-encode to shorten the GOPs to DVD standard. You can use DGMPGDec to decode the SVCD MPG file and serve it to TMPGE using an Avisynth script. If you use TMPGE 3, you'll need to convert to YUY2 at the end of your script because it apparently will not open AVS files that deliver YV12.


11th June 2004, 18:55
Awesome thanks a lot Neuron. I didn't realize it but I already had this program packaged inside DVD2AVI. I'm just a little overwhelmed right now at the sheer volume of different programs that I need to use and am trying hard to get up to speed. I found some guides bundled with dvd2avi that I will read and if I have any more question's I'll post em here. Thanks again!

Here is my new thought process:
Merge the 3 SVCD video mpg's into one using TMPGE
Use DGMP to reencode to a d2v file (this will fix the GOP hdr)
Write an AVISynth script to convert to YUY2 (I don't know much about any other filters so I will stay away from them for now)
Load this new file (d2v?) into TMPGE and DeMux the video and audio
Convert Audio to 48000
Author the dvd using TMPGE
Burn the VOBS using TMPGE dvd writer utility

EDIT: What is TMPGE 3? Is this the version? I am using version 2.5, do I need to upgrade to version 3?

11th June 2004, 23:00
Just finish a 2 hour encode without success. I assumed that TMPGE would take care of the GOP but it didn't. I've figured out how to find the GOP menu but am not sure how to correctly configure them. It is set for 1 5 2 now, but I'm not exactly sure if that is what I encoded it to the first time. Also, do I need to encode it in interlace mode if the source is progressive and I'm watching it on my NTSC television? Actually, when I viewed the merged mpg's in DGIndex it said progressive, but after I get the .d2v file and preview it, now it says it's interlaced. So which mode should I use?

Video Dude
14th June 2004, 02:19
If your source is interlaced, encode it as interlaced.

If your source is progressive, encoded it at 23.97 frames per second. Then you have to add pulldown flags. You have two options:
(Option 1) When you encode as progressive, select "pulldown on playback". TMPGEnc will automatically add the pulldown flags. This is the easiest way. You have to unlock the template in order to select "pulldown on playback".
(Option 2) Encode the video and audio separately. Then use a program called pulldown.exe and run the video file through it. This will create a new video file with pulldown flags. Then mux the video and audio together.

For the GOP:
I would use the GOP that is the TMPGEnc SVCD template.
That is 1 5 2, as you posted.

TMPGEnc 3.0 is the new version. If you have 2.5 working, stay with that.

14th June 2004, 05:19
I was successful at fixing the GOP length problem, but I have a few more questions. I forgot to mention that my source is PAL and progressive. Do I still encode it at 23.97 fps and add pulldown flags? If I understand everything I've read in the last week doing what you said should convert my PAL source to an NTSC source (which is another thing I was trying to do).

Now when you say pulldown flags you mean telecine right? The guide says it's a 2:3 pulldown to convert FILM to NTSC. What I don't understand is where the 2:3 ratio comes from. Shouldn't it be 4:5? Sorry for my ignorance I'm a complete beginner at this stuff but trying to get up to speed.

Do all DVD players support "pulldown on playback"?

Video Dude
14th June 2004, 05:50
Now when you say pulldown flags you mean telecine right?
All NTSC televisions can only output one frame rate which is 29.97.
Television show DVD's are interlaced and usually filmed at 29.97 fps, so nothing extra has to be down when encoding. However, Hollywood films and some animation is produced with a 24 fps. If you output 24 fps to a NTSC television it will look jerky in motion. To solve this problem, special pulldown flags are added to the video to tell the player to repeat some frames to make it 29.97. But the video is still 23.97, only the player repeats frames making it 29.97. All hardware standalone dvd players and software dvd players support the pulldown flag.

If your source is progressive PAL, you need to convert it to progressive NTSC which is 23.976 with an NTSC resolution. You will then need to add the pulldown flags. (Search the forum for "pulldown.exe" and you will get more details about it.)

I have never converted PAL to NTSC so I can't help you with that. There are many topics on this forum that discuss it.

14th June 2004, 11:10
Ah, us aussies are lucky :)

More good reasons that the world should convert to PAL @ 25 fps ;)

Being a PAL user I never have to muck around with pulldown, telecining etc, which is a good thing cos the whole topic leaves me for dead!

14th June 2004, 13:01
Thx a lot for your patience video dude. I think I'm gonna take the easy way out and buy a new dvd player or just play them with my laptop using an svideo out to the tv. But I still wanna try to convert at least one just to say that I did it. :)

23rd June 2004, 21:08
I don't think it's worth upgrading to v3.
When the pros on most related boards upgrade, then that's the time. They haven't, probably wisely I might add.

23rd June 2004, 21:26
Sorry I'm not following.. Can you explain what V3 is?

Video Dude
23rd June 2004, 21:45
cweb is referring to TMPGEnc 3.0

I would agree and use TMPGEnc 2.5 for now.