Minimum mpeg2 settings for dvd

[JonH]

I have three types of video I want to put on dvds. I want to create mpeg2 files for burning the dvds that maintain the highest quality of the source.
My first type of video is from my digital camcorder. No problem here. But I also want to convert mpeg2 files that were used to make svcds and vhs tape converted to dv using Canopus.
I assume I should use a lower bit rate on the these. How low can I go and still maintain the quality of the source and still have the dvd playable in most players? Are there other settings to be concerned with?
Thanks.
Jon

[mits]

Well, i assume that you have VHS material converted to DV which means that is 720*576 (in the pal world). In that case i wouldn't go lower than 6500 or 7000 kbps in CBR Personally i use 7000-8000kbps when the duration of my clips can easily fit on a dvd.

[JonH]

Thanks, Mits. Acutally I'm trying to put 2 hours worth of mpeg files on a dvd. These files are SVCD compliant. I'm tried to lower the bit rate to 4000. I have a $70 Apex dvd player and it won't play it but my dvd player on my computer will. Wondering if it might be the audio -- I'm using lpmc.
Jon

[Brian Ellis]

There is absolutely no point, for most applications, in exceeding 6000 CBR for DV footage and much less where the original came in from VHS. Similarly, as Dr. M has pointed out in another thread, there is no point in going higher than 192 kbit/s for AC-3 stereo. In both these cases, there is no perceptible improvement in the quality of the viewed DVD.

Jon, you are probably right: NTSC DVDs have AC-3 as the standard audio system. Cannot really help, as I'm in PAL land.

[JonH]

Well, it looks like my problem is with my Apex player. Originally bought it to play SVCDs which it did fine.
I went to an appliance store and the dvds I burned work fine on all of the players I tried.
Jon

[mits]

Brian,
i don't want to argue (i know the theory about the resolution of (s)VHS and the frame size) but in various tests that i have made (using wife and friends as a jury) the verdict was that with higher bitrate the picture looked better on a tv screen (less mosquito artifacts and less pixelation on fast movement scenes). When i use half/D1 resolution i usually encode between 4500 and 6000 CBR. Comparing half/D1 with D1 the latter still looks a bit sharper.

[JonH]

When you guys are talking about CBR I assume you are referring to constant bit rate rather than VBR which would be variable bit rate. Why wouldn't you always use variable bit rate? I'm really showing my ignorance now.
Thanks.
Jon

[mits]

Jon,
CBR takes at least half the time to encode, but with VBR (especially with 2 pass) you can put more video on your disc and have better output quality. For example if you encode with CCE (cinema craft encoder) with 2 pass VBR it will take you 3 times the time that you would need with CBR (one pass for creating the vaf file and 2 more passes for the encoding). If encoding time is no problem (i.e. overnight encoding) then i believe that 2 pass VBR yields better results than CBR.

[Brian Ellis]

If you use, e.g., CBR 6000, you have a constant very good quality. For short DVDs, this is what I always recommend. If you use CBR 4000, you will have a constant reasonably good quality, but less than at 6000, bit you can fit almost two hours onto a DVD (depending on your sound encoding, the complexity of your menus, subtitles and how many audio tracks you have). If you use VBR with an average of 4000, you will be able to fit exactly the same onto your DVD, but the relatively static scenes, where there is little difference between successive frames, it is possible to encode them at, say, 3000, which will allow the fast-moving scenes to be encoded at, say, 5000. As it is the latter scenes that show the most artifacts, the apparent overall quality is improved, because the poorer quality in the static scenes is not so noticeable. IOW, it is movement that is the principle cause for apparent deterioration in quality with low bitrates and VBR is a compromise which favours the best encoding where there is movement, at the cost of a poorer quality in static scenes, which is less noticeable.

It should be noted that a noisy picture, such as from analogue tapes or a received signal with poor reception (speckling in flat colours) is treated with VBR in the same way as if the noise were movement. There is therefore no advantage in using VBR under these conditions, as it will simply try to push the bitrate uniformly upwards. Noise filters are generally ineffective under these conditions, so I always recommend CBR for these conditions, even when filtered.

Generally speaking, I use CBR about 80% of the time and always for DVDs of <75 minutes, at 6000. It doesn't necessarily fill the disc, but this is no disadvantage.

[DarrenD]

Brian

With such a detailed answer can I ask a question?

I have lots of VHS tapes, Hi-8 tapes and growing Mini-DV tapes of my kids growing up. I am nearly at the point of burning my first DVD+R and would be interested in optimal settings.

My current project was recorded on Hi-8, captured using AVI_IO at 704x576. I am not particularly worried about fitting as much on a DVD as possible since I have over 50 hours on VHS anyway so I know I will end up with a fair stack of DVDs in the end.

I currently encoded at VBR 9000-8100-192 (max-avg-min) using MSPro 7 VE DVD version with AC-3 at 428K (can't remember but it is the maximum value). I used this setting as it is probably the limit (9000, for some reason MSPro forces avg to be 8100 even though I reduced it to 6000). My theory is that this should give me the best quality at the expense of DVD running time. However, watching one hour of kids footage can be a long time!

Am I simply wasting running time with such high settings (I just read about your reference to Dr. Mordrid's 192K AC-3 limit)? I too am in PAL land and am curious to know whether AC-3 is better than MPEG-2 Audio. If I create an AC-3 DVD+RW my player plays it fine and PowerDVD says it is Dolby Digital. If I create an MPEG-2 Audio DVD+RW my player also plays it fine and PowerDVD says it is MPEG-2 Audio. Will I get compatability problems with AC-3 on other people's DVD players (but my DVDs are for home use and I guess all new players should handle AC-3).

Then...

my VHS tapes will be captured (one day!) through my Canon MV600i (analog to DV converter). Current thoughts are at 352x576 and then encode to CBR6000?

Your help will be appreciated