BBMPEG and simple multiplexing??

[rdad]

Hi guys, quick question regarding bbmpeg. I read somewhere that to make a svcd that can be time-seek/fast-foward/rewind in most dvd players without sync problems, I should add timestamps to the frames.

I simple-demux a mpeg2 file with tmpgenc and now I am ready to re-mux using bbmpeg. I selected "add SVCD scan offset" but I am not sure which option to use for "timestamp". Which option should I choose? The 3 choices are:

1) Time stamp all frames
2) Time stamp I and P frames
3) Time stamp I frames?

Anybody know what those options mean? And which should I choose to solve the problem I mentioned?

Also, in the mux section of bbmpeg it has a option "VBR". Should I select or de-select this option if all I want to do is a simple mux. I don't want to loose any video quality from the original mpeg2 file. I only want to format it to a svcd mpg2.

Any help would be truly appreciated. Thanks in advance.

-r

[jan_hut]

I could be wrong but I think the standard for SVCD would be CBR so don't check VBR.

[adam]

To multiplex a svcd you should simply select SVCD under program stream type. Time stamps should be left at that default, all frames.

There are various other things that you might have to change to cater to your specific dvd player but these should only be changed if sync problems persist.

First off you will probably get buffer underruns or overruns. These are caused by spikes in your bitrate and for the most part are harmless. If you seem to lose sync at certain parts of your movie, however, change the force mux rate to 0. This actually just lets bbmpeg pick an appropriate level and should eliminate any underruns or overruns, but like I said this probably won't be necessary.

If you still have sync problems try unchecking "ADD SVCD scan offsets" and unchecking "Allign Sequence Headers."

What versions of bbmpeg are you using and under what tab do you see the vbr and cbr options? I have no such options in my version and I don't see how you could possibly set these as output options since multiplexing has nothing to do with bitrate allocation. I would assume that this option would simply be asking for the nature of your video stream so if you encoded in vbr you would set it to vbr and vice versa, but like I said, I'm not familiar with this option.

[rdad]

Thanks for the reply guys. I think I got it now. Sorry I took so long to reply. Been away for a week.

Adam, I am using version 1.24 beta 13. (The actual name of the file is "AVI2MPG2.exe").

My question has to do with the following section of the program:



The following pic shows the default options that the program selects when someone chooses "SVCD". Why is "VBR" selected?

Again, if I have a mpeg2 file copied off a svcd CD. And I simple de-mux it with tmpgenc. When i am ready to (simple) re-mux it with bbmpeg, should i select the VBR option?. (I DO NOT want to do any conversin/encoding to the original mpg file. I only want to re-mux it). Also, if I only select the VBR option if the original source was encoded with VBR... how do I check to see if a mpg file is originally VBR? It seems to me that all mpg2 files always move up and down in bit rate during viewing. Is there a program that can tell me if a file is VBR or sure? Thanks in advance for any input.

-rdad

[kinneera]

VBR is correct for SVCDs, although it is perfectly within spec to encode a CBR SVCD. If you're not sure what your source is, run the bitrate viewer on it that can be found in the tools section.