speedup, slowdown on ripped DVDs

[disturbed1]

GOP-
Group of pictures
I = Intra-Picture Coding, allow random access, for reference
P = Predictive coding, causal prediction only, can be referenced
B = Bi-directional coding, noncausal prediction, never referenced.
(Stolen from http://rcs.ee.washington.edu/CE/notes/sun_mpeg/sld005.htm)
MPEG1 NTSC standard max Distance between Intra frame=18 (15 for PAL I think).
(NO X here)VCD's should have a constant GOP, always IBBPBBPBBPBBPBB notice that's 15 letters, 1 I, 2 B's, then 1 P. I=1,P=4,B=2. You can add MAX!!! one more P frame, which in turn would add 2 more B frames, for a total distance of 18 frames between I frames. Some players (probaly all, don't really know) use this as a time code. Each GOP is ~.5 seconds as per MPEG1 Whitebook standard, (different than plain MPEG1 NTSC standard) 30x.5=15, 25x.5=~12, 23.976x.5=~12. For a GOP length of 12 use I=1,P=3,B=2. That's for a total complaint standard, most may get by with a max length of 18. I myself never do anything but total standard.
When you detect scene changes, the encoder will force Intra frames (key frames, frames with the most data allocated), and through off the constaint GOP allignment. This is OK for SVCD and DVD, but NEVER a MPEG1 VCD.
There is also an issue of TMPG muxing, there are certain headers, audio byte padding, and packet miss-allocation, and ever dreadfull 0bit Intra frame (how can a key frame have zero data?) that takes place. Those who are really interested should get a good MPEG Parser, or GOP analysizer (TECO makes one) to look at the encoded program streams.

(NO X here either)SVCD, as per Phillips SVCD authoring tool set; TOTAL MAX MUX RATE OF 2.6MBITS/SEC. That's 2376 video with 224 audio (27?? !?), that's if there is a total of only one MPEG2 clip, if your disc has more than one clip the standard DOES state max mux of 2.33MBITS/Sec. I have yet to run into any problems with FF/RW and Time Search on any SVCD encoded with TMPGenc, and burnt with Nero (Started with version 5.0.? and upgraded as avail). All I do is follow the spec.

As a side note, all my discs are only standard, FF/RW should always be constant (20 secs at a time, not 10, then 5, then 30......). I don't make (S)VCD's for just myself, all my disc's MUST play in ALL players. This wasn't in anyway ment to trash on X(S)VCD followers, but hopefully share usefull info.

Usefull links:
http://www.cdrinfo.com
http://www.mpeg.org
http://www.cselt.it/mpeg/
http://www.licensing.philips.com/cdsystems/cdsupervcd.html
http://rcs.ee.washington.edu/CE/notes/sun_mpeg/index.htm

<EDIT>
Becarefull of whose standard your reading. Even Phillips has released nonconforming info in a lot of their .pdf files. Always check the dates (bottom of last page) to make sure it is current. It seems like the spec would change every week when Phillips would release their weekly dev. docs.




<font size=-1>[ This Message was edited by: disturbed1 on 2001-07-02 05:11:09 ]</font>

[hitechjunkie]

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On 2001-06-28 18:15:47, hitechjunkie wrote:
duh!!

a GOP setting of I=1 P=5 B=5 is actually a GOP of 11 frames. a GOP setting of I=1 P=5 B=7 is then a GOP of 13 frames. TMPGEnc appears to encode two GOPs at a time.

damn higher level math!!


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boy was i totally confused here! i've been doing TOO much testing, changing, tweaking, etc. disturbed's right, though - don't mess with the GOP settings! keep the standard. changing it did absolutely nothing for the weird slowdowns/speedups i've been seeing. most users suggest keeping the GOP 12-15 frames in size, which is what disturbed also states above. one thing i did modify is the framerate. when encoding a VBR MPEG-1 XVCD from a 23.97fps progressive video source (DVD rip), i now use 24fps as my output framerate. so far, so good...

[hitechjunkie]

<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR size=1 color=black></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>when encoding a VBR MPEG-1 XVCD from a 23.97fps progressive video source (DVD rip), i now use 24fps as my output framerate. so far, so good...
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just wanted to add that the reason i went to a 24fps framerate was when attempting an encode with LSX, it complained about 23.97fps not being acceptable for an MPEG-1 encode, but accepted 24fps. i also remembered someone posting that 23.97fps was a problem but going to the full 29.97fps cleared it. figured it was worth a try going to 24fps from a 23.97fps source...

<font size=-1>[ This Message was edited by: hitechjunkie on 2001-07-02 13:54:30 ]</font>

[mijman]

Now HERE'S something interesting. To avoid this problem from ripped DVDs, I re-recorded ALL 22 episodes as AVIs, encoded with TMPGenc, burned them all, and STILL HAVE THIS PROBLEM!!!! Flabbergasted, I stuck it in the computer, and sent it to a known "trouble" spot, and guess what? It played FINE!!! The problem this whole time was my standalone player! AYE CARAMBA! I cannot BELIEVE how much time I wasted just by not cross-checking my discs! AAAAAAAUUUUUUGGGGGHHHHH!!!!!

But, on the plus side, the topic made for some enlightening reading...
my bad

[homerpez]

I STILL wanna know why my plain ol' normal VCD does this slowdown thing at 23.976, when VBR MPEG-1's at the same framerate work fine...

But, mijman, this is always how it goes, just usually one piece of the puzzle...

Maybe I'll try the repacketize thingy with M2 edit...

<font size=-1>[ This Message was edited by: homerpez on 2001-07-04 19:00:57 ]</font>

[hitechjunkie]

i'm beginning to see more and more posts on this phenomena. i'm beginning to think it's a problem with the later versions of TMPGEnc. i'm gonna go back to 12 and/or 12a and try an encode...

[ya_jai]

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On 2001-07-06 06:28:40, hitechjunkie wrote:
i'm beginning to see more and more posts on this phenomena. i'm beginning to think it's a problem with the later versions of TMPGEnc. i'm gonna go back to 12 and/or 12a and try an encode...
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I got this same problem with TMPGenc 12a. But just only one time that I encoded using NTSCfilm default template to encode at 23.976fps. Now I encode with 29fps for VCD and 23.976fps for SVCD with 3:2 pulldown and never see that speedup and slowdown ever again.

[hitechjunkie]

jeez - looks like i'll have to go back to 29.97fps on my VBR MPEG-1 XVCDs...

[homerpez]

Wait a sec... (here I am to pester again!)

#1 I CAN'T use 29.97 for VCD's, as when you rip a DVD, it can only look good by making progressive (from interlaced) frames, i.e. take your 29.97 and encode 23.976 from it... I'd have to give up entirely!

#2 This does NOT explain why one "standard" VCD has this slowdown-go-out-of-synch problem, when I have 4 or 5 that are "non-standard" that work great.

I'm getting really frustrated. Has nobody out there made PERFECT VCD's from PERFECT ENCODES that always work PERFECTLY?!?!?

(I guess not!)

[hitechjunkie]

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On 2001-07-06 17:36:51, homerpez wrote:
Wait a sec... (here I am to pester again!)

#1 I CAN'T use 29.97 for VCD's, as when you rip a DVD, it can only look good by making progressive (from interlaced) frames, i.e. take your 29.97 and encode 23.976 from it... I'd have to give up entirely!

#2 This does NOT explain why one "standard" VCD has this slowdown-go-out-of-synch problem, when I have 4 or 5 that are "non-standard" that work great.

I'm getting really frustrated. Has nobody out there made PERFECT VCD's from PERFECT ENCODES that always work PERFECTLY?!?!?

(I guess not!)
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i just did "Bedazzled", 23.97fps, 640x480, CQ_VBR 0-2300 CQ 95, which played back flawlessly. i still think it's a problem when using a lower max bitrate (< 1500) on 352x240 XVCDs...

[disturbed1]

Hi tech junkie,

All of my rips are done at Film specs. The main problem isn't just the GOP's, but also the muxer built in with TMPGenc, and the header sequence codes. It usually happens for me after a period of 7 minutes, after that it doesn't follow any set interval. Make sure if want to burn a test disc it's at least 10 minutes or so.

If you wanted to encode at the Film spec (352x240 23.976 @ 1150), follow the GOP suggestions above, encode only video in TMPGenc, run the .mpv through Mpeg sequence maker (available in the tools section) to put sequence codes on all headers. Doing that step also allows your files to be compliant with Philip's VCD 2.0 toolkit. Then do the audio with the proggie of choice and mux with either BBmpeg, or VCD toolkit muxer.

I've got about 40 rips done this way, and solved all speed/slow down problems. Perfect FF/RW, and goto function is right on.

[ahjay]

At long last I found someone with the same problem. I have an Apex 600A and have tried 4 different Firmware and still the problem but play a bad problem VCD in another brand DVD player or the PC and all is well !

Well I have moved away from using DVD2AVI/Tmpgenc as I have found the problem is clearly in TMPGes court. I even get the problem if converting AVI (DivX) to VCD with TMPGEnc. I use the standard PAL VCD template.

The solution I have found is to use FlaskMPEG 0.6 + unofficial 1.1 upgrade with the Panasonic Encoder 2.51 plugin. This gives me a perfect conversion from DVD to VCD everytime and plays without any of the video slowdown/speedup crap. And I still use TMPGEnc to cut my large mpg file in half to fit to 2 cd's

But I will give M2Edit a try.

[hitechjunkie]

ok, i'm still using dvd2avi/tmpgenc and just did "Mimic 2" but at the full 29.97fps, CQ_VBR 0-1350, CQ 70, audio 128kbps, 352x240 MPEG-1 and got all 82 minutes on one 74min disc. no slowdown/speedup problem, at all! so it appears it's related to using the 23.97fps vs. 29.97fps with lower bitrate VBR XVCDs.

as disturbed suggested, i'm gonna look at redoing some of my problem XVCDs using the tools he suggested.

[homerpez]

I really don't know if this is the problem... but I hope it works for you!

This still doesn't explain why the ONLY vcd I have trouble with is a "standard" CBR 1150 bitrate! I use lower VBR averages all the time, and since I SWITCHED to VBR, I NOW have no problems! And this is on the Apex 500W....

Whatever works, WORKS.

[LanceSteel]

Here is my deal. I'm trying to make a non-compliant SVCD (MPEG2) of Escape from NY. This film is (according to dvd2avi) about 99% film and 1% NTSC, 16:9 and 23.976 fps. I forced film-mode in dvd2avi and made the video and audio file. In tmpegenc h, I set the video resolution to 352x240, non-interlaced with a CBR of 2000 at 23.976 fps (no 3:2 pulldown and one with 3:2 pulldown.) Under the advanced tab, I selected 16:9 (NTSC) source video and a non-interlaced source type.

No matter what I do, the video will not play on my apex 500w. I've tried EVERYTHING in this thread (except the m2edit) and still I get, after about 5-6mins, slow/fast/jumpy video. Now I have been able to rip a movie that was 4:3 NTSC no problem. It seems that either if the video is 16:9 or the fps is 23.976 then it will not encode properly no matter what you do. Does anyone have any ideas about this? Should I not be doing MPEG2 compression but Mpeg1 instead? Should I use a different encoder?

Thanks for any help!

[homerpez]

Is your SOURCE video 16:9, or is your OUTPUT 16:9?

Remember that the target OUTPUT MUST be 4:3, all the time. It will place black along the top and bottom, and resize your 16:9 movie into it.

SVCD and VCD are both 4:3 aspect only.

Just set your output to 4:3 at that res, and under "Advanced" have the 16:9 checked. HINT: if you peek under something like "Source range", it won't look right. But when you encode, it should.

[LanceSteel]

The source is 16:9 and I set the output to 4:3. The picture looks fine (no squished picture) except after about 5mins of playing, the video speeds up and slows down (just like what everyone in this thread is experiencing. Like I said before, I think it has something to do with either the 16:9 aspect ratio or the 23.976 framerate. I followed the advanced SVCD guide on this website as well.

[disturbed1]

you'll get jumps like that when playing 23.976fps MPGE2 files on some standalones.

How to fix....
Demux your MPEG2 (TMPG mpeg tools, demux)
obtain BBmpeg18 make sure its 18
obtain Pulldown.exe
drag n drop you .m2v file over pulldown.exe
open BBmpeg hit start, goto settings, load pulldown.m2v into video stream, and your demuxed .mp2 file into audio.

Under program stream settings select SVCD, and set mux rate to 0. Set mux rate to 0. Make sure mux rate is set to 0.
Click ok, click encode. Reburn.

Even though you did 3:2 pulldown with TMPG, still try this with your 23.976fps clip. TMPG doesn't know how to mux correctly.

<font size=-1>[ This Message was edited by: disturbed1 on 2001-07-20 11:25:11 ]</font>

[homerpez]

Question on another setting (bbMPEG)...

When I used VBR, it offers me the option to "synch headers", which I do. And that works.

It also offers to remux based on AVGbitrate, or by MAX bitrate. When I pick "MAX" (which would be 2500k), it works fine. When I choose "AVG", it brings up all sorts of errors, and the end file won't open.

What is this? Something related?

I just want to make absolutely sure I'm not screwing things up (new to the bbMPEG remux method, always just did TMPGEnc before) Thanks!

[disturbed1]

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On 2001-07-20 13:12:18, homerpez wrote:
It also offers to remux based on AVGbitrate, or by MAX bitrate. When I pick "MAX" (which would be 2500k), it works fine. When I choose "AVG", it brings up all sorts of errors, and the end file won't open.
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Never had that happen, but I've only chosen AVG like once or twice, I too always use max.

When Average is selected, BB scans the mpeg, and set bitrate flag according to the calculated average bitrate it finds.

Max, finds max bitrate, and flag mpeg at that setting.

You should check out BBmpeg's help files, they offer a wealth of great knowldge.

[homerpez]

Well, I guess so long as using "MAX" doesn't effect anything, I'll just use that, since it works...

Maybe because my bitrate MIN and MAX were so far apart? (0, 2500k/sec)...

No, that's not it, I remember it did find the average and it ended up exactly what I put in TMPGEnc...

Like I say, whatever works, WORKS.

[homerpez]

OK. Need a bit of advice here...

As I said, I use (or useD), 0 for MIN, ***AVG, 2500MAX (now 2400)...

I ran across one movie which I think suffers from this "Throttling" problem, where it goes from no motion to fluid fast motion, and there is about 2-3 seconds of slow motion, then it speeds up to normal rate again.

Now, this isn't fatal or anything, but I still wanna fix it. I think the solution is to raise my MIN bitrate just a little, so it's not dropping totally down to 0.

BUT... I want to have my AVG bitrate, for whatever movie, remain the same! And... since I heard TMPGEnc deviates a bit when you raise the MIN above 0, so you don't know how big the end file will be...

Does anyone have a calculator to tell how much MIN bitrate would be TOO much for TMPGEnc? Or should I just struggle to get the CCE method working?...

[ya_jai]

Hi guys, I just ripped short clips Proof of life DVD at 23.976 fps used Sefy's NTSCfilm template. I did change some setting like, use CQ instead of CQ_VBR, use 2 pass max 1650 avg 1150, use CQ_VBR max 1100 min 1100 CQ100. All played fine in my APEX (no speedup slowdown), but the clips are only 7-8 minutes long. I will finish the whole movie and test in a few days, and post the result here.

[ya_jai]

Hi guys, I just finished ripping VCD at 23.976 fps with CQ_VBR and 2 pass VBR (doesnt matter what bitrate I use). The result, play perfectly from beginning to the end. BUT..IF, whenever I use FF/RW function, VCD gets out of sync for a few second. Or if I use stop and Resume button, picture jerk a little bit. This does not happen with VCD rip at 29.97 fps.

[geoff]

To the disturbed1 ... you truly are a resource on this. Please help me ...

What exact settings should I use in TMPGEnc (I'm using 12i) to get a truly VCD2.0-compliant file ? I'm loading the NSTC VCD template, but apparently I should then unlock and tweak a few things. Can you please just spell it out for me ?
Or ... suggest an encoder that produces as good an image result and actually produces a VCD standard file.

many thanks.
(my email: gfawcett@fastx.com)


[quote]
On 2001-07-02 05:02:08, disturbed1 wrote:
GOP-
Group of pictures
I = Intra-Picture Coding, allow random access, for reference
P = Predictive coding, causal prediction only, can be referenced
B = Bi-directional coding, noncausal prediction, never referenced.... (won't include the whole thing)