What's the best workflow for creating a long DVD using V5 / DVDA2?

smhontz wrote on 4/29/2004, 5:07 AM
I'm creating a DVD for my son's fifth grade class to commemorate their outdoor camping trip. At this point, it looks like it will be 1 hour to 1 1/2 hours worth of stuff. The DVD will have various movies, deleted scenes, photo galleries, etc. so it should be a lot of fun for them. And, they're going to sell the DVDs as a fund-raiser, so I want to make sure it's top-notch.

Since it will be so long, I'm wondering about the best way to work with V5 and DVDA2. Should I just render everything to AVI, put it into DVDA2 and let it figure out how best to compress everything? Or should I use V5 to render all the pieces to MPG2 and then put it into DVDA? I've never made a DVD this long before and I'm worried that it's not all going to fit.

Comments

Spot|DSE wrote on 4/29/2004, 6:36 AM
Were it me doing it, I'd either;
a. Render entire project to m2v (DVDA Video stream) and AC3, then import those two files to DVDA. Author from there.
b. Render each "chapter" as a separate m2v and AC3, and author from there.
You can also render to avi from Vegas and then let DVDA do all the work, but that's really a slower process in the end, and you stand to lose a little quality, but it's not significant.
Render the m2v's with an average bitrate of 6Mbps, and you should be happy with the results. Do a few short render tests of high motion and low motion areas to see what works best. If you've got 90 mins of footage, then you'll almost surely not want to be rendering at 8Mbps anyway. That's cutting it pretty close on time.

riredale wrote on 4/29/2004, 8:43 AM
I don't know that much about DVDA, but I can tell you a fairly traditional way of doing a project such as this.

(1) Complete your individual sections of the entire project (main movie, outtakes, still photo montage, etc.). Save them to DV avi on your disk and also save them to DV tape as a backup.

(2) Look over the entire project, and calculate how many minutes of video you have. Then use the formula B=600/t (B: total bitrate, t:time in minutes) to figure out the average bitrate for the DVD. For 90 minutes of video, you'd be shooting for about 6.7Mb/sec.

(3) I assume you will be using AC3 for audio, which eats up .2Mb/sec. That leaves an average video bitrate of 6.5Mb/sec.

(4) Again, since I don't know much about DVDA, I don't know whether it is better to do the MPEG2 encoding in Vegas, or let DVDA do it. I assume the MainConcept encoder is the same in both programs, but I don't know if you will get the same level of quality from both instances.

(5) You build your menus, import the video to DVDA, and build the final product. I assume DVDA lets you decide whether to burn immediately, or just build a VIDEO_TS folder that you can use to burn multiple DVD disks either from within DVDA or from any burning program such as Nero.

I've come to the conclusion that it takes me about one month of pretty serious work for each hour of finished video. But it's fun.
Express wrote on 4/29/2004, 9:21 AM
I've only done PCM stuff before, AC3 is new to me.

Because the audio is in a different file, Is it easy to get the AC3 out of sync with the Video?

Anything to watch out for, or ensure that a particular action or procedure is followed?

If time is not a consideration - will two pass VBR be the very best? (being a long run time on the disc a high CBR will not do)

Also, if I bring it into DVDA 2, and let it encode - I have not found a way to specify CBR/VBR.
Is that option available within DVDA (2 pass also)?

Thanks,

Chris
Mandk wrote on 4/29/2004, 9:33 AM
Spot's recommendation of 6Mbps should definately be followed.

If the end result will be distributed to a wide variety of households in your 5th grade class the lower bit rate should produce better compatibility among players. I did a few videos this year for the local high school marching band. First go round I wanted the quality as high as possible and did bit rate at about 8Mbps. A combination of bad media and this bit rate resulted in a number of disappointed customers and returns. Lowering the bit rate to 5 or 6 and using reliable media. No more problems.

Good luck with the project, sounds like fun.
Spot|DSE wrote on 4/29/2004, 9:41 AM
AC3 won't be out of sync unless you use the Render Selected Region, and select a different region than what you used during the video render process.
2pass is only of real benefit on fast moving vid, as opposed to headshots or more static information with lots of redundant frames.
I've not rendered AVI to MPEG in the new version of DVDA, I'm only working with elementary streams, so can't comment on quality there.
DVDA is always VBR, it has no CBR option. If you want CBR, render in Vegas.
smhontz wrote on 5/3/2004, 5:13 PM
I'm a little confused. I start with the DVDA Video Stream template, and, looking at the various bit rates, I see Max of 8,000,000, Avg of 6,000,000 and Min of 192,000. If I render a 1 minute segment as a test using this template, I get a file that's 42.82 MB. If I change the settings to Max of 6,000,000, Avg 6,000,000 and Min of 192,000, I get a file that's 41.40 MB - a savings of just over 3%.

It's that what you are suggesting I do? (Just change the Max from 8,000,000 to 6,000,000).) Or am I mistaken?
TVCmike wrote on 5/3/2004, 5:32 PM
The AVERAGE bitrate is what you want to change from 8,000,000 to 6,000,000, not the maximum or minimum.

You could also consider placing the original photos in a separate directory on the DVD and/or create a photo gallery of them instead of embedding them in a program stream.
riredale wrote on 5/3/2004, 5:53 PM
Smhontz:

Think about it for a second.

If you tell the encoder that you want a min of 192, max of 8,000, and an avg of 6,000, then the encoder can look over the whole project and decide that some parts really need the full bitrate while other parts can get by with less.

If you instead tell the encoder that you want a min of 192, a max of 6,000, and an avg of 6,000, then you're telling it that, no matter what, don't go above 6,000, but it's okay to go lower if desired. But in the same breath you're saying you want the whole project to average 6,000. The encoder will probably mutter something under its breath and just do the project at 6,000, because if it goes under 6,000 for some parts, that implies it would have to go over 6,000 for other parts in order to make sure the whole thing averages 6,000. But you've already told it that it can't go above 6,000.

I guess if I were an encoder I would retaliate by throwing a Blue Screen Of Death.

Seriously, leave the max high and the min low and just worry about the average bitrate. I've done some DVDs (using a different encoder, but the principle is the same) that ran over 2 hours, which means the average bitrate had to be around 4.5Mb/sec, and the results were very satisfactory.
smhontz wrote on 5/3/2004, 9:02 PM
Well, that's exactly what I'm getting at. Spot said to set the AVERAGE bitrate to 6,000,000 - but that's exactly what the default template was set to to begin with - MAX 8, AVG 6, Min 192K. So I don't see how I can change it to 6,000,000 when it's already set there. I don't see how I can follow the advice when it doesn't make sense. So, I was wondering if either a) he meant I should change the MAX because it was 8 and I should make it 6 or if maybe b) I should set the AVG to something less than the default of 6 - maybe 5 or something.

So, to be precise, and to make sure I'm not being a moron, exactly what MAX-AVG-MIN values are you recommending that I use for a 90 minute video? DVDA-2 said it was too big to fit when I used the default NTSC DVD template set to 8 - 6 - 192.

Thanks for the help.
TVCmike wrote on 5/3/2004, 10:22 PM
So, to be precise, and to make sure I'm not being a moron, exactly what MAX-AVG-MIN values are you recommending that I use for a 90 minute video? DVDA-2 said it was too big to fit when I used the default NTSC DVD template set to 8 - 6 - 192.

The rule of thumb is that 600 divided by the number of minutes of video will give you the average bitrate in megabits per second (which you then multiply by 1,000,000 and put in the boxes). This assumes that you'll use 192kbps AC-3 stereo audio encoding for the DVD and that there's no extra material. 6,000,000 bits per second will give you 100 minutes of video, from which you'll need to lop of about a second for every 775kBYTES of additional data like slideshows, raw pictures and other data on the DVD, menu background music, and so on. I think your confusion with the bitrate is a result of not realizing what was originally in the dialog boxes. On that note, you should turn on field based motion compensation and two-pass encoding, and setting the DC coefficient to 10 bit in the advanced settings.

As we're discussing workflow, I'd like to advise you on a few things that'll make the quality of your DVD even better. Learn your camera's features inside and out, paying particular attention to the exposure, white balance and focus settings. Knowing these in advance will significantly help your picture quality and, therefore, your DVD quality. Generally speaking, scenes with high/random motion, that are dark or low contrast, or have elements like smoke or fire will appear to have more block noise in MPEG-2 than scenes without these attributes. Being a camping trip, you probably won't be able to avoid filming fire and smoke, but the noise at a reasonably high bitrate should be minimal if it's noticeable at all. Also consider using a tripod or monopod wherever possible to steady your shots. Don't rely on your post production process to alleviate the major flaws because you won't be happy with the results.

Finally, I'm assuming you're using a DV camera and DV source material. If you're capturing any type of analog source material, I highly recommend borrowing a time base corrector for capturing it through a DV bridge to ensure your capture is clean and steady.