So far, not impressed, is it me?

Caruso wrote on 3/21/2004, 4:49 PM
I took a 30 minute snippet from a concert I taped, edited, and have printed to both digi8 and SVHS tape. Those prints are as good as I can get, IMO. All color corrections, audio, FX, everything comes through as I planned it, no glitches of any kind anywhere.

I took that same editing effort and rendered to MPEG2 and assembled a DVD using DVDA.

In another recent thread, I questioned what sort of audio format I should use. Have tried AC3, WAV.

The audio was free of glitches when I used the WAV format, but had several interruptions when I used the AC3 format (I would have expected the opposite result).

After viewing the DVD and then my DV tape, I'd say the video on the DVD is more respectful than I had initially judged it, but there must be a dozen or so areas where artifacts ruin the picture - nothing major, mind you, just a digital blip in a dozen or so places - very annoying, and, for me, fatal to the usability of that particular DVD.

So, my questions: Am I missing something here? Is my experience representative of the state of the art in home DVD making?

Should I simply go back to tape until technology in this medium improves?

I remember in the days of Vegas Video 2.x and computers with more limited resources we suffered through similar though different inherent problems. Is that what I'm facing, or am I simply making some simple, correctible mistake in my process?

My setup is not earth shattering, but I would think more than adequate.

I run Vegas 4 on a 900 MHz machine with 384 megs of RAM. Plenty of inboard/outboard storage, burning via DVDA on a TDK 8x dual burner (model 840, I believe - it's newly purchased) to FujiFilm 4x DVD+RW discs.

Any critiques/advice welcome.

Caruso

Comments

johnmeyer wrote on 3/21/2004, 5:42 PM
I can still remember asking a Pinnacle rep at one of their seminars four years ago whether it was possible to make a DVD that was visibly indistinguishable from the original DV source material. I asked him during a break so he would feel free to be honest. His answer:

No way.

Encoding has gotten a little better since then, but the fact of the matter is that there is just a heck of a lot that has to go on to make MPEG2 video look good.

From both my own experience, plus reading hundreds of articles and posts, here are the things you must do to get close to the objective I stated to that rep:

1. Get your video clean. Ideally, Vegas or DVDA would provide noise reduction tools, both spatial and temporal, that could be applied prior to encoding. Unfortunately, they provide neither, certainly nothing that is specifically oriented towards pre-encoding processing. The goal is to reduce that "grainy" noise, especially that which is present in poorly lit video.

I received some advice on what another forum member uses to "clean" DV video prior to encoding, in this post:

2 hr DVD

2. Use VBR. In theory, at least, VBR should provide better quality. In practice, with the single-pass encoder currently included with DVDA and Vegas, I am not sure that this is true.

3. Use a separate MPEG2 encoder that offers more control. Most of the controls in the MainConcept MPEG2 encoder in Vegas are totally useless. If you read the documentation (both that which comes with Vegas, as well as the documentation for Mainconcept's standalone MPEG2 encoder) the instructions for each of these controls pretty much all say the same thing: don't touch these.

Kind of makes you wonder why they are there at all.

However, the standalone encoder does offer 4-5 controls that are not in the Vegas version, and which the documentation says you actually CAN change. Read this post for a description of my experience using this encoder and how I was able to improve quality beyond anything I could do with the encoder included in Vegas:

Mainconcept standalone MPEG encoder test results

4. Use a higher bitrate. Quite a few pretty knowledgeable people warn against using average bitrates much above 7.00 mbs because the error rate when older players read recordable DVDs is so much higher that they can't keep up with the higher bitrates AND do error correction. This results in stutters or stalls. Better media can help this. However, many players don't have this problem, and if you use only high-quality branded media, you may be able to use much higher bitrates. I routinely use 8.00 mbs average for video, with 9.5 mbs peak (when using AC3 stereo for audio).

Hope this helps!
BillyBoy wrote on 3/21/2004, 5:53 PM
Its the same siily "debate" that keeps popping up. Its simply silly to expect you can make a DVD on a home computer with MPEG-2 compression and a software encoder considering the Hollywood boys use equipment costing anywhere from 10 to 100 times more and there are using a totally different process and starting with the ORIGINAL film master.

DUH!

That all said you can make some very nice DVD's. Step back from the TV sir. Eight foot rule in effect. <wink>
wobblyboy wrote on 3/21/2004, 7:47 PM
If you are getting better results on VHS then something is really wrong. I have made both VHS tapes and DVD and DVD is better.
Caruso wrote on 3/21/2004, 9:43 PM
Johnmeyer, thanks for the info. I'm going to work over your suggestions in detail and see how much improvement I can achieve.

Billyboy, I said nothing about trying to emulate the "big boys." I will be quite happy to emulate the results I get on DV tape - clean, clear video & glitch free audio. My DV stuff doesn't rival Hollywood, either, but it's good enough that my clients are quite pleased. My results so far with DVD appear to be a step backwards in terms of quality, so, until I either solve my problems or until the state of home DVD making improves the quality possible, I'll be outputting and archiving to DV and DVD will remain a toy for me.

Wobbly, you apparently didn't read my question very closely, either.
I am comparing my current DVD results to results I get printing to DV and SVHS, not VHS - there is a big difference in quality between the two.

Given how much progress has been made in the personal NLE realm over the last four or five years, I don't think it silly at all to expect DVD's should equal DV tape in quality. But for some graininess and artifacts, my DVD's would be there already. I will sort this out (if it's achievable), but, until I do, I will rely on DV tape to save my pieces.

Thanks for the replies.

Caruso
PeterWright wrote on 3/21/2004, 11:27 PM
Caruso have you analysed what was happening in the frame when you noticed artifacts?

Often it's things like fast pans, fast motion, dissolves and other such times when MPEG2 has more problems, otherwise you should expect pretty good quality.

Also, try experimenting with different settings / bitrates. It is very possible to equal DV quality if you stay within the "rails".

I just finished a 104 minute project, and as this was too long for a DV tape, I used DVD to make a "Tapemaster" version which is used to make VHS dubs from. They look fine.
Caruso wrote on 3/22/2004, 6:36 AM
Peter:
I have done none of the analysis you suggest, but, will do so. If (when) I find some variable upon which to focus as the cause of my video glitches, what shall I do?

Be advised that the subject of this shoot is a classical concert - not much motion involved. The talent is simply standing in place singing a Schubert song cycle that covers some thirty minutes.

Nothing fancy.

Thanks for your reply. I'll review the segment for possible clues.

Caruso
PeterWright wrote on 3/22/2004, 5:33 PM
The range of things you can do is not great. Often reducing the average bitrate will help, as it gives the playback machine less decoding to do during these passages. Otherwise it's mainly a question of avoiding fast movement when shooting or dissolves/tricky effects when editing.

One other thing - how was the lighting - sometimes having large dark areas can produce unwanted artifacts - the low light areas can produce fizzy noise which the MPEG encoder has problems trying to deal with. Applying blur to such areas can smooth things a little.

Your material doesn't sound too demanding in this respect - I would have thought that Schubert would have come through smoothly. Wagner - now that's a different story ;)
bakerbud9 wrote on 3/23/2004, 5:05 PM

High frequency content is the fatal enemy of all video codecs. This is because visual information that changes gradually, like a clear blue sky, is full of redundant data and so is easy to compress. When the image content varies rapidly from pixel to pixel there is not much redundant data, and so the codec must work "harder" to compress the image. Nasty examples of this kind of high frequency content is "grainy" images shot in low light with lots of gain.

From a technical point, MPEG-2 is a "better" codec than DV because MPEG-2 uses 4:2:2 sampling and DV uses 4:1:1 sampling. This means that MPEG-2 stores about twice as much color resolution in the compressed data stream as DV.

But MPEG-2 also compresses data accross multiple frames of video, and this is both the strength and weakness of it. By compressing accross multiple video frames, MPEG-2 can typically encode higher-quality images at lower data rates than DV, which only compresses within individual frames. The downside to this, however, is that MPEG-2 is much more intolerant to high-frequency content than DV.

So check your footage. You said it was a concert. If it was shot in a dark concert hall, chances are there's lots of high-contrast, high-frequency content in it, maybe even some high-gain graininess. If this is true, one thing you can do is to blur your final video by a very small amount before encoding into MPEG-2. Blurring the video slightly will smooth out much of the high-frequency content and allow the MPEG-2 compression to work much better.

When I compress video into MPEG-1 for the web, I always blur the footage before compressing. The result is better looking video and much, much smaller file sizes.

-nate-
laffTrax wrote on 3/23/2004, 5:20 PM
My simple answer.

Try small tests. What I mean is - there are SO MANY different variables involved when rendering for DVD. Use a small video clip (the shorter the better, due to all the rendering tests you'll be doing, ie. 5sec) and make sure it has strong motion in it, like a camera pan. Render it, messing with all the different templates and settings - you'll be amazed at the different results you get. Document which settings produce crap results, and which produce quality. This is what i did and it helped me a LOT! I know it takes time but here's the thing....... This person says to do this.............that person says to do that.................. there's always conflicts of interest and different results due to all the different variables (including CPU specs). You're better off finding out firsthand what works best for you and your system.

Just my opinion.
farss wrote on 3/30/2004, 8:08 PM
Peter,
this is an area that gets very little attention, the PLAYBACK device. I've seen DVD content go from looking stunning to horrid just by changing the player. Despite what we might think not all DVD players are created equal and it seems very few of them meet the specs to the full limit.
pb wrote on 4/3/2004, 6:50 AM
I didn't notice anyone mention the 1.4 standalone's double pass encode feature. Perhaps my vision is failing as I approach 50 but I am sure that my DVDs are cleaner if the source MPEG2 is done double pass. Okay Bill, tell me what your cut on this is. BTW: I liked your comment vis-a-vis eight feet from source...

Peter
RichardHK wrote on 9/18/2004, 8:01 PM
Excuse me guys for dragging this thread back from the past.

I too have some annoying glitches that appear on one DVD that seems to be linked to the AC3 sound. The video scene is static, just a head shot and yellow jacket. Starts silent (background hiss had been dropped with Sound Forge), but at the exact point he starts talking, several small glitches appear in his jacket!!

Sound level is not high, but maybe the AC3 encoding (from Vegas) is being disturbed by the dynamic range? Or is it DVDA that is being disturbed?

Any comments? DVD otherwise is pristine, and close enough to original miniDV source to make user very happy. But those glitches right at the start only!! Used variety of encoding with same result. CBR 6,500 + AC3. VBR 6,000 2 pass. VBR 5,000 2 pass. DVDA 2.0a. Vegas 5.0b.

Richard
Hong Kong
RichardHK wrote on 9/18/2004, 8:14 PM
Sorry again... forgot to say I am using Procoder 2 to create the video material for DVDA. Using the DVD MPEG2 Program stream m2p video (no audio) setting. Mastering quality.

So many variables... no wonder this game is such fun/frustration! ;-)

Richard
Hong Kong