Newbie DVD Capacity Confusion

[Sam Houchins II]

I'm wanting to put a 1 hr., 56 min. movie on DVD. It's mp2 captured size (captured via ATI AIW 7500) is 2.52 GB (720x480, 8Mb/s). When I ran it through Vegas 4, I added chapter markers and rendered it as DVD NTSC template to avoid rendering when burning. Now it's 5.14 GB!!!
Then I opened it up in DVD Architect 1, but when I clicked on optimize DVD, it tells me it's 148% the size of the 3.95GB media, including main menu and scene selection.
1) How do they get a 2+ hr. movie with bloopers and commentary, and fancy menus and alternate languages and subscript on a single commercial DVD?
2) Why did my 2.52 GB captured file balloon up to 5.14 GB when "rendered?"
3) Why is DVD Arch telling me I'm working with 3.95 instead of 4.7 GB media?
4) Why does the box encasing the 10 pk. of Memorex DVD+R's list 6 different modes on the side ranging from HQ (1hr.) to SEP (8hrs.) recording capabilities?
ARRGH!
Thanks for the insight. :-)

[Rob Lohman]

I can't answer all your questions, but I might some.

First. Commercial DVD's can hold much more data (around 9.5
gb) due to the fact they are dual layer discs (most of the time).
Also they are using high quality mpeg2 encoders that allow them
to optimize (by hand if needed) certain parts. This makes sure
the bit allocation is optimal accross the disc and at a lower bitrate.

Your movie probably increased in size due to the following:

1. your capture is probably NOT DVD compliant MPEG2. So it
needs to be re-encoded

2. audio needs to be encoded into a DVD compliant stream

When you rendered, what settings did you use? This will determine
how large your final file will be.

You can never get more then 4.5 GB on a 4.7 GB media. Also
there is a media around 4.0 GB so are you sure you aren't
using that one??

Why is your source in MPEG2? This means you are going from
a heavily compressed source and heavily compress it again in
the same format. Never good. If you captured something with
the ATI card it is probably better to keep it in MJPEG. If you have
a DV camera keep it in DV.

[Sam Houchins II]

I hate not understanding the answer... :-)
Well, the choice I selected from ATI capture said:
"Use this setting to capture high quality video which can be used for DVD authoring: MPEG-2; 720x480,NTSC (525), 8.00 Mbit/sec; Audio 44.1 Khz, 16bit, Stereo"

I notice now it says '"can be used for DVD authoring." I naively thought this was the correct format. Anyone want to explain from scratch what the format choices should be from analog thru capture, editing/rendering, and authoring to DVD?

It sounds so simple on the packaging. What in the world's going on here?

When I rendered in Vegas, I chose "DVD NTSC Template," described as, "Audio: 224 Kbps, 48,000 Hz, Layer 2
Video: 29.97 fps, 720x480; Use this setting to create an MPEG-2 file with an NTSC DVD-compliant video stream, and an MPEG layer 2 audio stream."

DVD Architect says that when run through a Vegas DVD template first, re-rendering is not necessary.

The rendering & capturing settings sound the same to me, so why rendering doubles the file size, I don't know.

The reason I opted to capture in Mpeg2 is another issue. I originally tried to capture using Vegas in avi2, 720x480. My understanding was that 13 GB=1 hr. Having 50+ GB available on the drive, I thought that translated into nearly 4 hrs. video capture. I only got 49mins. I still don't understand that one!

I found ATI's capture program would do mp2 directly (a good thing I thought, since the final DVD format would be mp2), and as it turned out created a nice, 2.52 GB file, which I thought would drop quite nicely into a 4.7 GB disc.

I'm apparently dazed and confused because I'm expecting something (promoted by the packaging) that's not there, and continue to misinterpret the software's prompts. Can anyone set me straight? I'm not sure how basic you have to start in your explanation.
Thanks.

[Edward Troxel]

Render it in Vegas again but this time change the Average Bitrate to a smaller value. The default setting works for between 1 and 1.5 hours.

Try reading the article on DVD authroring in the Vegas Tips Tricks and Scripts newsletter at http://www.jetdv.com/tts and use the chart to find an appropriate bitrate for 2 hours.

[Walter Matlock]

<<<-- Originally posted by Sam Houchins II : I hate not When I rendered in Vegas, I chose "DVD NTSC Template," described as, "Audio: 224 Kbps, 48,000 Hz, Layer 2
Video: 29.97 fps, 720x480; Use this setting to create an MPEG-2 file with an NTSC DVD-compliant video stream, and an MPEG layer 2 audio stream." -->>>


Im not sure what actually caused you video to almost double in size when you rendered it, but one thing that may be contributing to it is the audio stream. Many DVD authoring packages use Uncompressed PCM audio when they create the DVD. PCM audio is huge. Im not familiar with the DVD Architect product so I can't say if this is the case, but if it's possible I would recommend rendering to elemental streams, then converting the audio stream to AC3 format which is significantly smaller.

See http://www.dvdrhelp.com/ for information on how to do this, and many other nifty tidbits of information.

[Peter Moore]

Whatever you rendered it to the first time around (that created a 2.5 GB file) wasn't MPEG2 at 8 Mbps, I can promise you that. That much video at 8 Mbps would take up about 8 GB, I think.

What happened was DVD Architect re-rendered your video to make it DVD compliant.

If you're using DVD Architect, make sure to select the DVD Architect template in Vegas, NOT NTSC DVD. In fact, the NTSC DVD template is basically unusable. If you want to use another porgram besides DVD Architect, you need to go into the advanced settings and make sure to separate the video and audio streams.

At any rate, to fit onto a DVD-R you should render 2 hours of footage at about 4.5 Mbps VBR. That'll do it with the right amount of space for a 2-ch PCM or 6-ch AC3 soundtrack.

As for fitting movies onto disks, like Rob said most all commercial titles are DVD-9s and so they can encode at 6 Mbps or higher and still fit on the disk. Sometimes these are called "superbit" or erroneously called high definition disks; nowadays virtually all movies are like this. For your purposes, you want to just use 4.5 Mbps.

As for the times listed on the DVD-R box, that's all just marketing. There's no such thing as SP/LP etc. at least not as far as software like Vegas is concerned. The bottom line is your bitrate, and again, 4.5 is decent quality for standard televisions. It won't look quite as good as a commercial DVD, but then again, no video footage ever will, so it doesn't really matter.

[Rob Lohman]

Let's get back to the beginning.

1. capture

You chose to capture in MPEG2 because the file would otherwise
get too large. This probably happened because you were capturing
in UNCOMPRESSED. You need to select either DV or MJPEG if
possible. If that is not possible then go back to your mpeg2 if
that looks good. Keep in mind that editing is nearly impossible
with mpeg2

2. vegas rendering

Why did you load the file up in Vegas instead of directly putting
it in DVD Architect? MPEG2 is an OUTPUT format not an editing
format (although with some mpeg editors you can do some form
of mpeg editing).

3. settings

As other people have pointed out to you, there is not ONE
setting for each and everything. Rendering and capturing
requires tinkering and using the correct settings to get the
results you want. It isn't a "black box" so to speak.

MPEG2 encoding can be done in two ways. Constant bitrate (CBR)
and Variable bitrate (VBR). In the first one each frame gets the
exact same amount of bits to use. Whether it is a completely
black frame or a frame with much detail in it. The second allocates
bits to a frame where it needs them most while respecting the
average bitrate you set and doesn't go over the maximum you
specify.

In the last case a black scene can use far less bits to encode and
thus free up precious space for a completed one where you
have a wideshot of a nice landscape with trees and such.

Try to see if DVD architect accepts your captured MPEG2 file,
otherwise you will definitely need to look into "settings" for
your mpeg encoder.

[Sam Houchins II]

Thanks, gentlemen. I'll try putting these points into practice today. I very much appreciate the input :-)

[Sam Houchins II]

re: capture size... ok, I think I know where I went wrong here.
The 13 GB/hr rate that I've heard was in context using the Firestore 1 hard disc recording device. It stores one hour in 13 GB. I overlooked that DV from the camera is 5:1 compression (I think that's right). The transfer from Firestore to Vegas (avi2) is straight, no compression, but it was wrong to overlook that it was originally compressed in DV recording. The benefit of firewire and Vegas is that there's no further compression. However for capture, using Vegas directly results in NO compression, hence ~49 mins. avi2 capture in 50GB. So, you were right, Rob. Kinda "duh" now that I see it.
Also, re: DVD Arch. talking as if I had a 3.9 GB disc, I changed a setting somewhere that set the default to 4.7 instead.

I used the formulas and table that Ed referred to to reset the average bit rate for rendering in Vegas to 4.85 Mbps (darned close to Peter's gut instinct of 4.5 Mbps) to achieve a 4.19GB DVD. I actually cheated on the formula a little to be sure I skirted under Rob's warning of 4.5GB size. From the resultant file size, it looks like I could've trusted the formula completely and been safe. The resultant DVD was exceptional quality on the boob tube (much better than on the monitor where it was merely acceptable.) I even butchered the sound somewhat trying to fix it, but again, playing through the boob tube it was hardly noticeable. I learned alot about noise reduction, though.

Speaking of noise reduction, I've heard and read some about Sound Forge and the Noise Reduction plug-in... pretty impressive. I almost ordered it last night, then I remembered Wave Edit from Nero that came bundled for free with one of the Nero pkgs. which came bundled with one of my optical drives (it may have even been Nero Express.) Anyway, I think I had to dig for it in the Nero files (back when I originally found it for converting old, favorite audio cassettes). It has a noise reduction ability in it. I took a small sample of the noise during a should-be silent point, did a noise reduction analysis, and it came up with a wave form formula to apply whenever I wanted to remove that ID'd noise, even the thru whole track at once if I wanted. I was VERY pleased to find that for free, dormant in my computer. I copied these steps from Spotted Eagle in his DVD tutorial re: Vegas when he mentioned noise reduction as a plug in. Same technique, just free :-)

In DVD Architect, I could have achieved the same bit rate adjustment result using a slider adjustment that predicts file size (now that I understand what it's doing) when it "optimizes". However, I would have had to take the original captured file to DVD Arch for rendering without the opportunity to edit it other than simple trimming. Unfortunately, the sound track needed attention in the beginning and I felt it was easier in Vegas to apply chapter points (it'll do it auto every 5mins default or whatever you want.) Those chapt. pts. can be saved with the project to be there to create a scene selection menu in DVD Architect. In DVD Arch, you have to set the chapter points manually, which would be worth it if that's all the tinkering I needed to do, but it wasn't in this case.

That's the good news...I successfully got nearly 2hrs. of movie onto a DVD+R of enjoyable quality thanks to y'alls (yeah, I'm in VA, I'm licensed to use y'all in oral and textual conversation) precision diagnostic skills and appreciated help :-)

Now for the complaints and residual issues:

It's normally great that Vegas does not alter the original file. However, when all I want to do is tweak the first 10 mins. of audio and auto add some chapter points, it sucks that those changes only take effect through a 2-1/2 hr rendering procedure instead of just a quick alter of the original file. Maybe that's related to Rob's point about the difficulty of editing mpeg2, in addition the the fact that Vegas' work is nondestructive and as such is only a project; it doesn't really exist until it creates a whole new file.

I pondered and read up on what Walter pointed out about the sound's file size and format, and what Peter said about separating the sound and video files. In Vegas, I seperated the sound file from the video, edited the sound file in Nero's Wave Edit, and converted to ac3 back in Vegas. It was interesting that Vegas did not support ac3 format for importing into a project, but it would render a sound file out. WOW! A 1.2GB wav file knocked down to a 163MB ac3 file. Very impressive. HOWEVER... when I put it all back together in DVD Arch, for some reason and somehow, it turned the ac3 file into a file the same size as the video file. Instead of a 163 MB ac3 file and a 4.2GB vid file, it rendered two 4.2GB files = 8.4GB!!! Oddly, it did not fit on the 4.7GB disc ;-) Note, I was applying the new bit rate to the vid at this point. This is a great mystery. I thought the plan was sensible, but the result was totally alien. I ended up having to render the mp2 vid file and the edited wav sound file together in Vegas, outputting as a DVD NTSC template = "Audio: 224 Kbps, 48,000 Hz, Layer 2
Video: 29.97 fps, 720x480; Use this setting to create an MPEG-2 file with an NTSC DVD-compliant video stream, and an MPEG layer 2 audio stream."
(no other applicable option, Peter), but then DVD Arch had to render the resultant mp2 audio into ac3 when it got its hands on it. Rediculous. Anybody see where I went wrong?

After all that, as I said I had a wonderful quality DVD movie. Oh, did I mention that half way through the movie, it locked up and froze in the stand alone DVD player in the living room? It had a couple of jitters and skips leading up to it, and then freeze frame, no response. The first time, I ejected / restarted / returned to scene, everything was ok, then 15-20 mins later again, no recovery that time. I checked it on the comp dvd player, same scenes plus another 10 mins., no apparent probs. I'll try running a laser cleaning cd through the stand alone tomorrow. It's an Apex 3 disc carousel, purchased Christmas 2001. It also displayed extreme pixelation with Spotted Eagle's training DVD with any movement, while the same disc played great in comp. I don't have such probs with "factory" DVDs except an occasional, intermittent stray pixel every 30th disc or so. On the one hand I won't be surprised if my DVD stand alone player isn't up to the technology, but I'm not looking forward to bride and groom having similar probs with their player and movie.
Note: this is not a wed vid, I'm practicing by recording from vid source through ATI card (which will lead to VHS tape conversions)before I've got someone waiting on me for their once in a lifetime memories vid that locks up in the middle of their vows :-0.

Thanks everyone for your help, I've been hard at it applying your suggestions. I'd love any follow up comments, and appreciate your time and interest in applying your experience.

re: my Memorex box listing SEP (8hr) to HQ (1hr), Panasonic's web site lists their 1-6 hr recording times as being 1.7Mbps - 10Mbps. I wonder what 1.7Mbps looks like? How low can you go and still be pleased on the boob tube?

[Sam Houchins II]

Wanting to investigate further, I tried to duplicate the scenario in DVD Arch creating a DVD with a video only stream rendered from Vegas (using DVD Arch vid stream template), coupled with its seperately Vegas rendered ac3 soundtrack file. The problem had been that it resulted in two 4GB files instead of a 4GB and a 160MB file. For whatever reason, it worked fine this morning, combining sound and vid into 4.2GB disc. in a speedy 17mins.
Also, when I played the 1st DVD on the set top last night, it played all the way through, no hiccups. I haven't even run the cleaner through the player yet.
Note to self: never render or test DVD's on Thurs...?

[Rob Lohman]

Glad it all worked out. It should just combine the video and AC3
as it did on your last test. Lets hope it stays that way. Keep in
mind that self burned DVD's can have the problems on playback
you described. The players, burners and media just haven't
worked long enough with eachother to garantuee good playback
(or recording).

Good luck!