Sequence header

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Always dealing with the entry point stuff, i've read that, in order to make it work, the Mpeg file *must* have the sequence header before every GOP. Ligos LSX 3 does that, but it accept only AVI input. Xing Encoder 2.20 has a option to put SH before every GOP, but in its VCD mode this isn't set, so there's the need to create another profile with the appropriate settings. I don't know if this one works. Panasonic encoder has no option for SH.

The problem is, if i have a Mpeg source, coming from a hardware board, or a good Panasonic encoding, and want e.p. for my vcd??

In both cases the input file is a Mpeg one, which isn't accepted by LSX.

Possible answers: - Feed the Mpeg system file into Flask 0.58 (http://go.to/ultraflask) and use the LSX plugin to re-encode the file with the SH before every GOP option. There's a way to minimize the damage - aka re-encoding process, which can lower down the final quality of the mpeg file? For example, identical settings for input and output, so the encode engine does nothing but a mux? - demux the MPEG file into .mpv and .mpa and then feed it into Xing Encoder 2.20 with the option "SH before every GOP". Will it work?

What do you think, something of these can work?

-- Jean-Luc Picard (jl.picard@startrekmail.com), May 03, 2000

Answers

I am assuming you are capturing hign bitrate MPEG with an onboard encoder like ATI. The you are down sampeling them to VCD?

The problem with just re-muxing. SH are points in the stream that can be completly cut out of the file without ill effects. SH also help to improve the quality of damaged MPEG's giving them another jumping off point if a segment is fubar. I dont believe that you can just add them in ( I am not a stream guru tho ), but I may be wrong.

They are not always necessary, but sometimes they are handy.

Other prograrams to try are

bbMPEG ReMpeg

LSX 3.0 can accept MPEG source with a little trick.

Open the Mpeg in VirtualDub 1.3c and start the frameserver ( proxy avi ). Then open that avi in lsx. The nice thing is you can use all the wonderfull virtualdub filters to do cleanup / corrections of brigntness, intensity, hue, saturation, contrast / Noise filtering.... before it gets to LSX.

Personally I have been doing all captures in MJPEG ( Pic Video SW ) and filtering / leveling / ... export directly to bbMPEG or LSX. works like a charm, capturing created huge files tho ( ~8GB hr )

-- Eric (eric@snowmoon.com), May 03, 2000.


I'm capturing with a Adaptec VideOh, so the only possible output is MPEG. Doing it at max. bitrate then making it VCD-ready with Panasonic deliver a very good result, looks great even on a 32" TV. So, no AVI stuff (laptop doesn't have PCI or AGP slots).

Think i can try the VirtualDub+LSX3 encoder to check out if everything works.

-- Jean-Luc Picard (jl.picard@startrekmail.com), May 04, 2000.


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