Some Mainconcept MPEG Encoder questions.

[scott274]

I have recently been trying to create VCDs (PAL) out of some DAT files on my harddisk. The encoder used was TMPGenc 4.0 Xpress in the encoding step, but the problem was that the VCD when played in my VCD player had jerky video playback problem (slight stop & play and some distortion now and then). The VCD video quality was fine though here.

Then I switched to Mainconcept MPEG Encoder v1.05.01.00
During the encoding process, everything went fine except in the logs box of mainconcept I got this single line in red (possibly an error) in the end.
Frame 21825: Underflow possible!!!, bits_to_use=84152, in_picture=94616
But inspite of this, the VCD now when played in my VCD player didn't have any jerky video playback. But there was a lot of pixsation in the video ie. the VCD video quality had become noticably soft and bad.

So far I had kept all the advanced options in mainconcept as default. Now can something be done in MC so that not much video quality is lost & it doesn't become more soft after encoding (like in TMPGenc). For eg. enabling motion search pixel movement, changing other detailed and further advanced video settings etc. (With respect to VCD PAL in my case)

[setarip_old]

Hi!

1) You should download the updated v.1.1.1

2) After spending $460 ($368 on sale) for it, you should feel very comfortable in contacting the publisher to ask why this is happening

3) Aren't the .DAT files on your hard drive simply copies extracted from your original VCDs? If so, why don't you just duplicate the original VCDs?

[scott274]

You mean MainConcept Reference v1.1.1

Have you had any experience with it. Is its output video quality atleast as good as TMPGEnc.

Anyways, unless someone has any new ideas on my original post here is something a person on another board had suggested..


Just a wild guess: the default quantization matrix for the MainConcept encoder
compresses more than the default matrix for TMPGenc and CCE --- perhaps
this is the cause of the "surplus" macroblocking of your re-compressed videos.

MainConcept uses the matrix below:

08 16 19 22 26 27 29 34 16 16 17 19 20 21 22 23
16 16 22 24 27 29 34 37 16 16 18 20 21 22 23 24
19 22 26 27 29 34 34 38 17 18 19 21 22 23 24 25
22 22 26 27 29 34 37 40 19 20 21 22 23 24 25 27
22 26 27 29 32 35 40 48 20 21 22 23 24 25 27 29
26 27 29 32 35 40 48 58 21 22 23 24 25 27 29 31
26 27 29 34 38 46 56 69 22 23 24 25 27 29 31 33
27 29 35 38 46 56 69 83 23 24 25 27 29 31 33 35

CCE (http://www.videohelp.com/tools/Cinema_Craft_Encoder) and TMPGenc (http://www.videohelp.com/tools/TMPGEnc) normally use this one:

08 16 19 22 26 27 29 34 16 17 18 19 20 21 22 23
16 16 22 24 27 29 34 37 17 18 19 20 21 22 23 24
19 22 26 27 29 34 34 38 18 19 20 21 22 23 24 25
22 22 26 27 29 34 37 40 19 20 21 22 23 24 26 27
22 26 27 29 32 35 40 48 20 21 22 23 25 26 27 28
26 27 29 32 35 40 48 58 21 22 23 24 26 27 28 30
26 27 29 34 38 46 56 69 22 23 24 26 27 28 30 31
27 29 35 38 46 56 69 83 23 24 25 27 28 30 31 33

You will have to manually enter the numbers of the second sub-matrix
in the appropriate window of MainConcept.

I will as the same question here which i have asked him there right now..

OK will manually change numbers of the second sub-matrix in Mainconcept.
But will doing this only affect the video quality or frightfully other things as well. I mean like in TMPGEnc I experience the jerky video playback problem which is not so in Mainconcept. Changing the sub-matrix in Mainconcept won't introduce the same problem in it as in TMPGenc, will it? Your thoughts..

[setarip_old]

Again I'd ask you, since it would be so simple and logical:

Aren't the .DAT files on your hard drive simply copies extracted from your original VCDs? If so, why don't you just duplicate the original VCDs?

[scott274]

No setarip mate, you should have taken my word for it in OP that I have just the DAT files on my harddisk and don't have my original VCDs with me anymore. Otherwise as you said, it would have been as simple as a quick CD to CD copy in Nero.

So now my friend :) any ideas & tips on my original problem..

[dat720]

No setarip mate, you should have taken my word for it in OP that I have just the DAT files on my harddisk

And you should listen to him DAT files ARE the original VCD, all you have to do is re burn them with some support files, burn with nero and it should create these for you.

Goto this page for a explanation of VCD and it's file layout. (http://www.videohelp.com/vcd#struct)

Here is a quick VCD i made....

+---CDI
+---EXT
| LOT_X.VCD
| PSD_X.VCD
| SCANDATA.DAT
|
+---MPEGAV
| AVSEQ01.DAT
|
+---SEGMENT
\---VCD
ENTRIES.VCD
INFO.VCD
LOT.VCD
PSD.VCD


The easiest way to re burn your files would be to download VCDGear, use the dat -> mpeg option to demux your dat files to mpg files, then click the video-cd button and choose mpeg -> cue/bin[cd image], add your mpg files to the track list, then click start. This process does not re encode the video's.... so no quality drop. This will leave you with a cue/bin image that you simply burn with nero or imgburn.... this process took about 5 minutes including converting a 3 minute wmv to mpg for test purposes.

[scott274]

No actually copying VCD to VCD in Nero is not the same as making a VCD out of a extracted DAT file on the harddisk (atleast not most of the times). I did do that VCDgear, DAT -> Mpeg (with errors fix option) and then created a VCD image in it to burn to a CD-R. But when played in my VCD player, there was jerky video playback and the audio slowly went out of sync with the video. This most probably wouldn't have happened if I had the original VCDs and done a simple CD to CD copy in Nero. I had a discussion on this problem in VH forums (newbie section, Title: "[Help] Problems Creating VCDs") for more than a month now and still the mystery remains unravelled as to why this happens as far as VCDs are concerned.

This thread is just an extension of my main problem which brings us back to post 1.

[dat720]

The reason it is going out of sync is cos the fix mpg option removes video frames and not audio frames, even if the frames are not damaged it will remove them if it thinks they are....

Have you tried it without the fix option?

[scott274]

Hmm.. interesting point. you know during DAT to Mpeg conversion (with fix Mpeg option on) VCDgear gives a 1 error fixed and 2 padding notice. So according to you by 1 error fixed it actually removes a video frame or so (which it thinks is damaged) instead of fixing it. I hope i am reading you correctly.

Is the fix mpeg option in VCDgear completely useless and best kept unchecked. And do you think that this might be the reason why later on in the encoding step in Mainconcept I am getting that "Frame 21825: Underflow possible!!!..." error. Now i know you have suggested something completely different which doesn't involve encoding, but I just wanted your thoughts on this please.

[dat720]

To be honest i used to play with VCD about 10 years ago, as divx became popular i ditched VCD and have not created nor own any VCD's in the last 8 or so years, it is a dead format, quality is nasty and mpeg1 is a very inefficient codec, i plain don't use it!

In saying that i don't know if the fix mpg option is useless, it maybe useful if there are lots of errors in the stream, and i have never used mainconcept so i couldn't speculate on that.

[scott274]

No problem dat mate :) Thanks for atleast taking the time out for listening to me problem. you have been of much help so far. Have a few ideas to try out and lets hope my VCD problems are almost sorted out then.

I just wished someone could advise me about line filtering and motion search pixel movement including what values to input in it for best results..