maximum length of home burned DVD

[keithm]

What is the maximum length of a DVD created on a pc based burner? I would like to transfer 6 X 30 mins vhs episodes to dvd at full screen size (at reasonable quality). Can this be done?

[Dr Mordrid]

Depends on the bitrate. If you use a lower bitrate then you can fit more on the DVD.

Don't forget, however, that you will also have to take into account the space taken up by overhead (directory structure etc.) and whatever menu authoring you add to the mix.

Dr. Mordrid

[Brian Ellis]

Yes, it's possible. When trying to shoehorn a large size in, I recommend using a CBR, rather than a VBR. This is because you can calculate the bitrate precisely and this would avoid the nasty surprise of rendering a 3 hour project to find it's a few Mb too big to fit. Using the MSP Create feature for a PAL DVD, I found that a 2 hour 20 minute 720 x 576, 48 ksample sound, project (that I've just finished) would fit comfortably with a 3800 CBR, leaving enough for the overheads. For 3 hours, I would suggest 3800 * 140 / 180 = a tad under 3000 CBR (3000 would probably be OK). At 3000, the quality is still considerably better than VHS. As you're in PALland, these figures work but may need adjustment for NTSC.

I'll make one reservation about what I say above. I believe the sound quality is possibly unaffected by the bitrate, just the video. If this is so, then the function may not be strictly linear or, if it is, may be offset from zero (i.e., a zero bitrate would not give an infinite video length). This means that very long videos may require a disproportionally slow bitrate. If so, the optimum may require to be calculated with a slightly more complex formula which can be determined empirically, known as trial and error

I aim for an mpg file of about 3.9 Gb.

[keithm]

Does anyone know of a good bitrate calculator for DVD production?

[dZeus]

however, when maximizing the amount of time to fit on one DVD, CBR is a huge waste of space (thus valuable extra time). When in doubt about the projected file size, it's better to take a slightly lower average bitrate for VBR, as that will provide smaller total filesize, and must better quality image than the CBR stream with a slightly higher video bitrate.

[wkulecz]

Audio does matter!

The lame MyDVD or DVDiT! bundled with many burners can only do PCM audio! This means ~1.2GB of your 4.36GB two hour disk is taken up buy the audio.

Ulead DVD MF has bugs, but is workable and uses "layer2 audio" which is like MP3 but different. 224Kbps stereo audio works well for me. I have no trouble getting 2hrs encoded using MSP6.51a VBR 5000 Kpbs with 224 Kbps stereo layer two audio with simple menus and 10-18 "chapters" on a DVD+R.

DVD+R seems to hold closer to the advertised 4.7GB than does DVD-R which is really 4.36 GB -- if your image says 4.37GB in windows explorer it won't fit onto DVD-R!

All is not perfect, the MPEG.now encoder in MSP6.51a seems to create "pulsating artifacts" in bright scenes in original DV footage -- I've seen it myself. But I don't seem to see it in DV captures of stuff recorded on SVHS tape from my cable TV.

--wally.

[Brian Ellis]

dZeus

Yes and no! With CBR, you know EXACTLY where you stand. With VBR, you are at the mercy of the subject matter. If you have a lot of still scenes, yes, you can fit more in per Gb but, conversely, if you have a lot of movement (e.g., panning, racing cars going by, etc.), then you will need more Gb to maintain a given quality level. Then there is no way you can forecast the needs until after the event. CBR is adequate for most items, even if it does waste space.

[wkulecz]

In my test encoding with MSP 6 and 6.5 it seem VBR is "constrained" to average about the same rate. I saw minimal difference in file sizes between 5000 VBR and 5000 CBR

[keithm]

Were you using the Ligos or Mpeg.Now (yuk) codec

[keithm]

I just wondered what DVD burners people use? Is the pioneer compatible with most stand alone players? I think the pioneer is dvd-r

[Brian Ellis]

Keith

If you use CBR PAL, the figures above will help you calculate, based on the length of the file in hours. With VBR, there is less accuracy in calculation because you cannot judge the scene content. Perhaps use 10% less if you subjectively judge the average movement (including camera shake!) to be somewhat above average or vice versa. I use VBR only for DVDs of < ~60 minutes, where I want max quality, set at 7500.

For the anecdote, wifey has discovered I can copy protected commercial VHS tapes onto DVD and has asked me to do the major ones in her collection, some of them quite old, as she realises that tapes have a finite life. The 2 h 20 m project above is one such, Oliver! (film version). I've just finished it on a Verbatim disc and it seems glitch-free and well synched. The capture was a single DV AVI file 29 Gb long, via the Canopus ADVC-100, at 720 x 576. The only editing I did was to eliminate the publicity at start and finish and add a 5 sec black leader and trailer, before and after the start and end credits resp. Making the menu in MF was a wee bittie laborious, as the intro to each of the 13 songs, which she wanted on the menu, was before the actual scene started, so the thumbnail was often not relevant. I hate doing it, but I had to change 11 of the thumbnails.

I must say that doing this kind of copying, which took me 2 days, including the rendering of the mpg file, which took nearly 9 hours alone, allows you to appreciate much more of the subtleties of the film's subject matter, especially during the slow motion during the rendering, such as the kids' expressions during the Food, Glorious Food scene or the choreography of Fagin's gang. I found a lot more in it than a casual viewing would give!

Sorry for the OT bit!

[wkulecz]

I've done CBR vs VBR in both Ligos and MPEG.now for DVD+R.

I think if you calculate a 10% "cushion" on the size when uisng VBR you'll be OK most of the time. I sure made lots of encoding that didn't fit on DVD-R until I figured out that Sonic MyDVD expands the audio to ~650MB/hr since it only supports PCM, and the disks are 4.36GB *not* 4.7GB so a DVD image file that is 4.38 GB in explorer will not fit a DVD-R!

For most of what I've been doing -- catching up on things recorded from cableTV on SVHS tape and capturing as DV with ADVC-100 for encoding to NTSC-DVD, I find MPEG.now looks better to me. This source material doen't seem to trigger the pulsating artifacts I see from DV original in high contrast scenes -- I've been saying high brightness scenes but after further testing it seems one needs a certain amount of blown out highlights (as in backlighting) and some very dark parts in the image as well.
MPEG.now generally seems significantly faster too.

I plan on trying TMPGEnc soon.

None of these tools are close to perfect, I've found a workflow that is good enough to be worthwhile for what I'm doing now. Clearly its still not good enough yet for some things I've planned.

--wally.

[Rob100]

I have the Pioneer DVR-104 and have had no problems with playback on either of my standalones. See the following link for my "experience"...

http://forums.murc.ws/showthread.php?s=&threadid=35029

As for bit rates, this is what works well for me...

Okay a standard single layered DVD-R disc has can hold 4700000000 bytes.

This divided by 1024 (3x) gives us GB, which is 4.37GB. You can actualy squeeze as a little more on (4706074624 bytes, 2297888 sectors * 2048), but not all programs will allow you to create an image this big.

Now decide on your audio bitrate and lets say 224 kbps. So that's 224000 bits per second.

So supposing you project was 120 mins long, then this is 7200 seconds.

Now let's set a "reserve" to allow for menu's, and other "overheads". Lets say 50MB, so 50 x 1000 x 1000 (yes I know I'm using 1000 and not 1024, but it works for me).

So 4700000000 - 50000000 = 4650000000 bytes

Audio will take up approx 7200*(224000/8) = 201600000 bytes (the /8 is because 8 bits = 1 byte)

So... 4650000000 less 201600000 = 4448400000 bytes for video

So ((8*4448400000)/7200)/1024 gives us an average bit rate of 4826 kbps. You may find some encoders work on 1000 rather than 1024.

Anyway, there are probably flaws or mathmatical errors in this, but it's worked for me so far very well...

Rob.

[paulw]

I haven't seen anyone here mention CQ Constant Quality.

I did some quick tests here with a 30 second file in PAL DVD setting with TMPGE and default settings.. The results were.

CBR 27.8Meg
VBR 25.38Meg
CQ 9.79Meg.

From looking at these files on my PC I could see no difference between CBR and CQ in quality

[BrianP]

The bitrate calculations give me a headache. I try to stuff as much on a disc at the highest quality as possible, and if it doesn't fit, I notch down the bitrates. Having a dedicated PC for encoding helps, YMMV.

Example: I'm putting HBO's Six Feet Under episodes on DVD. I'm sure they will sell them eventually, but it's been a good exercise in learning.

The first DVD I made has the first two episodes on it. Ep1 is 60 minutes long. Ep2 is about 50. I encoded both at 2-pass VBR, 8000 max, 6000 avg. I also included a couple minor other things on the disc like a short intro, scene selection menus, and the show open.

It wouldn't fit at these bitrates. I forget the exact file size of the disc image, but it was around 4,500,000MB. Note that's the disc image, not the actual data that would be burned on the disc. There's a difference, and I suspect the disc image is larger by some amount because it has instructional directions for the burning program. Probably not a lot, but some.

Anyway I re-encoded the 60min episode using 2-pass VBR with 7000 max, 5000 avg. The file size of the m2v file decreased by 200MB. This time it all fit.

I am using a Pioneer DVR-A04 with Prassi, ReelDVD and TMPGEnc. I've been burning generic discs and have had with no problems viewing on my Pioneer 343. The last five minutes look as good as the first five. This with stock from cdrecordable.com (now out of business) and the dark purple Ritek discs sold by supermediastore.com.

Tip: get a RW disc or two! This is a huge Q&A helper. I've found a bunch of errors in menus or general quality that I could fix before having actually spent a DVD-R disc.

edit: One big thing to note is that ReelDVD has AC3 encoding. This obviously goes a long way in allowing better video bitrates.