Header Trick, What is really going on?

[edsmith77]

Good Afternoon to All,
Problem: My standalone DVD player does not play SVCD (or any variant thereof). However, it will play DVDs and VCD and XVCDs without any problem. Question: How do I get my DVD player to play SVCDs in spite of its not wanting to play them.?
I remember reading about remuxing an svcd as a vcd and that usually fools the player into thinking it is a vcd and voila. Thus, I followed the guide on the left by loading up the SVCD into tmpgenc and multiplexed as vcd. Voila, poof etc. it did not work. However, being the obstinate one I am I demultiplexed the SVCD file into its audio and video files and then remultiplexed them as a standard xVCD in tmpgenc. Surprise, surprise, that worked, so long as the video was 352x480. When the video was 480x480 no fooling around would get it to play. The DVD player would play the disc but the screen was totally black and sans sound.

My question to the experts is what really happened behind the scenes that caused the svcd modified header trick to xvcd to work?

Ed

[DJRumpy]

Your player can handle 352x480 since it's a valid DVD resolution (half D1). 480x480 is an SVCD resolution only. If your standalone's chipset doesn't support SVCD, you chances are usually better for the header trick to work. I'd guess your players chipset simply doesn't like the SVCD playback resolution, but it doesn't mind CVD (352x480).

[MOVIEGEEK]

Not many NTSC DVD players support 480x480 because it was sanctioned by the Chinese gov. as an alternative to DVD patents.If your DVD player plays (X)VCD then make a 720x480 MPEG-1 384mp2 profile(do a test on a CD-R/W first for compatibility),they look and sound better than 352x480 224mp2 and you won't lose any quality if and when you get a DVD writer.This is done of course using "MPEG-1 VCD(non-standard)" in TMPGEnc.

[kitty]

For various stream and format types certain information is put into the encoding of the movie. The Header trick writes "VCD" or "MPEG1" in the file even though it may be XVCD or even MPEG2. The player will read this, say "ok, I can play this" if the player is VCD capable then get to the content and if the trick works, it reads other info on the start of decoding to actually play it correctly. Gets around some players not wanting to support SVCD and other formats (and possibly paying royalties for using certain patented formatting methods).

[edsmith77]

DJRumpy, MovieGeek, and Kitty,
Thanks for the information. As always expert and on the mark. After a little fooling around (with the computer, that is), I did manage to make the VCD header trick work. Errr that is SORTA work.
The player will actuall recognize the mpeg2 stream and play it as mpeg1. However, here is the SORTA part, the video and audio are both extremely jerky. Not jerky in a random sense, but jerky in a sinusodial sense on about 1 second intervals. Hmmmm. How to explain this better. The audio increases in volume then decreases, then increases, etc. This happens on approximately 1 second centers. The video matches this same repeating pattern but motion is smooth when the video is normal and becomes very jerky when the audio is loosing volume.
Since this is a very repeatable pattern it would, to me, seem to indicate some type of encoding problem or bit rate problem. The original was encoded to strict svcd standards (even the 480x480, which was totally surprising to me that it actually showed something other than a black screen). In general, the only change was to multiplex (via tmpgenc) to again vcd standard and reburn as vcd 2.0 with vcdeasy.
In the past, I have created xvcd's with bit rates as high as 8000 which seems to say that I am not exceeding the bit rate capacity of the player.
Maybe there is some other parameter that I have not adjusted that needs to be reset.
In numerous other posts, most of the suggestions to correct jerky video was to demux and remux and even to burn at a lower speed.
I have already tried those suggestions and that is how I came to be where I am today.
Now only, if, there was something that I am overlooking or some other steps.
Any ideas.

Ed
Any idea's on how to

[DJRumpy]

It doesn't sound like a media/burn speed problem, as the problem cycles at a normal rate. You may just have to accept the fact that your player won't work with the VCD header trick. I finally just went out and bough a new player that supports all the formats and media. Well worth the purchase. I'd be curious as to what the MPEG reports when loaded into MPEGProperties (Find it in the TOOLS section). Specifically the framerate, and bitrate. I'm curious as to how the header affects these reported properties.

[energy80s]

If your DVD player plays (X)VCD then make a 720x480 MPEG-1 384mp2 profile(do a test on a CD-R/W first for compatibility),they look and sound better than 352x480 224mp2 and you won't lose any quality if and when you get a DVD writer.This is done of course using "MPEG-1 VCD(non-standard)" in TMPGEnc.

Don't use MPEG1 at 720 x 480 as DVD authoring software won't recognise it. MPEG1 video has to be at basic VCD frame sizes for a straight transfer onto DVDR. Oh and run the sound at 48k too.