bbMPEG screws up SVCD aspect

[brett]

I have several DVD players and several SVCD's. Perhaps I'm completely wrong, but I have a theory that I'm surprised hasn't been said anywhere that I can find.

bbMPEG screws up SVCD streams!

All my SVCD's made in I-Author and TMPGEnc work beautifully on all DVD players, but when I use DVD2SVCD, the stream is cocked up and displays the wrong aspect on my Pioneer.

There are several sites which talk about strangeness with Pioneer DVD players. You will see many people complaining about Pioneers giving a squished picture. This is apparently because of the Sequence Display Extension. According to the MPEG-2 spec, decoders are allowed to ignore the Sequence Display Extension. Most players do not allow anamorphic SVCD's. They simply resize the picture to fit the screen. Well, Pioneer do read the SDE, and when the SDE is encoded wrong, the aspect will look wrong on Pioneer players even though it plays correctly on most standalones. The program FIX12C is supposed to fix it, but I can't get it working (http://www.geocities.com/eby_vdo/).

bbMPEG correctly makes VCD streams, but my player doesn't really like the "header trick," and it plays very choppy.

The only fix I can come up with is to demux/remux in TMPGEnc, then the SVCD's work on all players. This makes DVD2SVCD much less useful, since it can only mux with bbMPEG.

Does anybody know of a way to make a proper SVCD stream with DVD2SVCD? I've tried a lot of monkeying around with the bbMPEG advanced settings, but nothing changes the Sequence Display Extensions.

[EXCLAMATION MARK EDITED OUT]

[r6d2]

Originally posted by brett
Does anybody know of a way to make a proper SVCD stream with DVD2SVCD?
@brett, you may have found something very interesting, but I'm clueless. I have created several SVCDs and have never found your problem. I have not tried them on a player that supports the anamorphic flag, though.

If you could post your settings someone may compare them to his own and try to find a solution.

Also, I recall a post from jsoto about the infamous flag. You may find useful do some search on jsoto's posts.

[brett]

Thanks for the reply.

I think now that my theory is completely wrong. I've been trying so many different things over the past week, I think I got confused for awhile about having my player set for 16:9 output. The only thing I've seen about Pioneer players squishing SVCD output relates to the SDE info, and I was assuming that had something to do with it. I went back, though, and found that all my SVCD's behave the same way. It's pretty strange; it seems to be acting as though all SVCD's have the 16:9 flag set. If my player is setup for 4:3 letterbox, the picture is extremely squished vertically. If my player is setup for 4:3 pan/scan, the left/right sides are chopped off. If my player is setup for 16:9 output, the screen looks normal (on a 4:3 TV).

So, all my SVCD's show up squished vertically (letterboxing bars are huge). They display properly when I have my DVD player set for a 16:9 TV, but seeing as I have a standard TV, this makes regular DVD's show up stretched vertically.

Regular VCD's, however, show up properly no matter what. Any resolution, any bitrate, MPEG-1 or MPEG-2 -- it will display fine on my Pioneer as long as it's mux'd as a VCD.

So, I just have to build the disc image as a VCD in vcdxbuild. I can even leave the bbMPEG settings and everything else like a regular SVCD as long as vcdxbuild thinks it's VCD 2.0.

But then I run into another problem, which is something I've also seen popping up on the forums a couple times. When my player thinks it's playing a VCD, it wants 44.1k audio, and if you encode with 48k audio, it will be out of pitch (voices sound lower).

So, right now it looks like my Pioneer DV-260 has two properly-supported options:

1) encode as XVCD with 44.1k audio (with any resolution)
2) encode as anamorphic SVCD (with any resolution)

Converting to 44.1k never comes out too well. What I'd like to do is have 352x480 MPEG-2 streams with 48K audio so that I can burn DVD-R's without reconverting (I already have a ton of DVD-R's, and at this point there aren't many movies left that I want to waste a buck on).

This will work out fine, except DVD2SVCD doesn't support 4:3 sources encoded as anamorphic. I suppose I'll have to manually do the Avisynth script if I run into that situation.

[ralphthedog]

Same experience here with a couple of Pioneer DVD players (DV-266,466), seems to be more of a pioneer problem than a SVCD flaw.

I spent some time fiddling with mpeg streams, flags etc. a while back with no luck.

If these players are set for 16:9 screen they seem to play SVCD's OK (on 4:3 TV's anyway), so it might be annoying to have to switch screen settings if you want to play DVD or SVCD, but it could be worse I guess.

Could it just be a bug in the player firmware?

[r6d2]

Originally posted by brett
This will work out fine, except DVD2SVCD doesn't support 4:3 sources encoded as anamorphic.
This is the AviSynth Script generated by DVD2SVCD for a 4:3 source (Clear and Present Danger) and anamorphic output selected:

LoadPlugin("C:\ARCHIV~1\DVD2SVCD\AVISYN~1.5PL\Mpeg2dec\MPEG2D~1.DLL")
mpeg2source("...\Source\DVD2AV~1.D2V")
BilinearResize(480,480)
Import("...\Video\ResampleAudio.avs")
ResampleAudio(44100)

As you can see, it is identical to the one generated by selecting 4:3 output for a 4:3 source. The reason for this is that 16:9 (anamorphic) DVDs (or SVCDs if supported) are stretched horizontaly by the player. So the concept of DVD2SVCD for anamorphic output is "leave the source as-is".

Selecting 16:9 output also changes the AR of the output stream, so if you use anamorphic output in DVD2SVCD, players which recognize the flag will stretch horizontally.

However (IMHO), it makes little sense to encode in "really" anamorphic mode a 4:3 source, because DVD2SVCD would have to stretch vertically the source, creating information which is not in there and hence increasing not the quality whatsoever.

Unless of course you keep the height and shrink horizontally instead (undoing what the player will do), in which case you'll be saving some bitrate, but I doubt you'll retain all quality. It may be interesting to try, though.

To do all this you must create the AVS yourself, as you mentioned.

[brett]

Yeah, I understand it's a little silly to encode a 4:3 source as 16:9, but I might as well since my player (along with my GF's Pioneer) forces any SVCD into 16:9. I rarely see 4:3 DVD's anyway.