3 hour DVD ??

[maverick]

Hi. I have several old VHS videos, that exceed 2 hours and I want to transfer to DVD. I captured them already to my computer, but now I they need to be reencoded to fit. Most of them have already degraded in quality. My question was... what would you suggest (video settings etc.) that can fit around 2.5 - 3 hours of video on a 4.7GB DVD? I just want to preserve them as best as possible, but since they have already degraded, they will never look perfect, so I don't mind a little quality drop, but as less as possible.
By the way, I am using TMPGEncoder.

Thanks for your help!

[Anonymous65]

352x480 resolution with a CBR of 3Mb/sec will give you about 3 hours on a DVD. If you want to use VBR, then make sure you use noice reduction to lower the bit rate.

[adam]

Assuming 192kbits for audio (my suggestion) you will get 2.5hrs of content to fit with a bitrate of about 3380kbits. For 3 hours you looking at a bitrate of about 2775kbits. This came straight out of a bitrate calculator which you can download in the tools section.

As for resolution, I'd use 352x480. You probably won't get much benefit using anything higher with a VHS source and these bitrates are too low anyway. The resulting quality should be pretty darn close to your captured video quality.

[lordsmurf]

Huh?
A bitrate of about 3420k and 256k audio will yield a DVD of just under 3 hours. Something like 2900k will be more than 3 hours. I use these settings often, as I work with many 3-4 hour prjects. I'm also using VBR, max 4000k usually.

[stone1721]

I always capture at a high bit rate ,encode my files ,then use dvd shrink to size the file.It always works great for me.Good luck

[adam]

Lordsmurf your numbers are closer then mine. I just realized that Fit2disk is somehow not clearing out old calculations, so its inflating the filesize. But after reinstalling I can tell that your numbers are still high.

At 256kbits audio, 3 hours of content would use about 3140kbits. Now THAT number I am sure of

[FulciLives]

Lordsmurf your numbers are closer then mine. I just realized that Fit2disk is somehow not clearing out old calculations, so its inflating the filesize. But after reinstalling I can tell that your numbers are still high.

At 256kbits audio, 3 hours of content would use about 3140kbits. Now THAT number I am sure of

To be on the safe side (leave room for authoring) I am getting about a 3100kbps video bitrate for 3 hours ... assuming a 256kbps 2.0 AC-3/MP3 audio track.

I would do a 2-pass or multi-pass VBR with a MIN of 1500kbps an AVG of 3100kbps and a MAX of 5000kbps

Also use Half D1 resolution ... 352x480 NTSC or 352x576 PAL

- John "FulciLives" Coleman

[maverick]

Thanks to all for your quick response !
I'm off to bed now, but I will give it a try by the weekend and see the results.

Many thanks!

[solarfox]

I always capture at a high bit rate ,encode my files ,then use dvd shrink to size the file.

Why don't you just encode at the bit rate that will make the video fit on the disc to begin with? DVDShrink doesn't have some magic ability to reduce the size of your high-bitrate file without altering the quality, you know; if you're already going to spend a couple of hours (or more!) encoding the MPEG to start with, it seems like you'd save yourself a lot of time and effort getting it right the first time...

[FulciLives]

I always capture at a high bit rate ,encode my files ,then use dvd shrink to size the file.

Why don't you just encode at the bit rate that will make the video fit on the disc to begin with? DVDShrink doesn't have some magic ability to reduce the size of your high-bitrate file without altering the quality, you know; if you're already going to spend a couple of hours (or more!) encoding the MPEG to start with, it seems like you'd save yourself a lot of time and effort getting it right the first time...

I agree that it makes no sense to MAX out the bitrate on an encoding only to use a transcoder like DVDShrink to make it fit.

That is a very poor way of doing things!

- John "FulciLives" Coleman

[maverick]

Good question solarfox.... and I have sort of a good answer
I have a sony computer (RZ series) that has what sony calls a "giga pocket" capture card. This capture card is a sony propietary card, and most software doesn't recognized it. (If I knew this before hand, probably I would not have buyed it, but anyway....) It works with windows media center, but if I record using the media center, I end up with this file in .dvr-ms format. I tried several ways of converting this to .mpg (after all, it is an mpg with some wrapper) but I always ended up with sync problems.

I finally found a program that recognizes the capture card, but I can only capture using the best setting. Actually I have to double check on that, but last time I tried to change setting, I didn't found any option.
So that's my story
BTW, if anyone has a Sony RZ computer and knows of a good program for capturing mpeg's, let me know!

[FulciLives]

BTW, if anyone has a Sony RZ computer and knows of a good program for capturing mpeg's, let me know!

You should have a free PCI slot in that SONY VAIO computer so I suggest you buy a cheap PCI type capture card.

If you want to capture straight to MPEG with such a card then I suggest one with the Philips chipset such as the Asus TV tuner card (which you can get for around $50.00). I suggest the Philips chipset because you won't get an A/R error using that ... many BT based capture cards will give you an A/R error if you capture straight to MPEG.

As capture cards go $50.00 is about as cheap as you can go and the Philips chipset is a very good one.

- John "FulciLives" Coleman

P.S.
Here is a link to the Asus TV capture card:
LICK HERE FOR THE LINK

[maverick]

Thanks for the suggestion FulciLives. For now I can do pretty much what I need with the Vaio, but I'm thinking that is a good choice for my other computer. I will do a couple of searches of the Asus tv capture card, check reviews, and probably I'll end up buying one.... maybe 2 if they work good

PS. another downside with the vaio is that it only has 1 free PCI slot of the 3 it comes with. Right now it's still free, but as soon as I decide to add a card, I'm stuck there with no more free space. I'm planning on adding a second video card and get a second monitor for editing with 2 monitors... that should make things alot easier! Need to start saving cash!

[lordsmurf]

Lordsmurf your numbers are closer then mine. I just realized that Fit2disk is somehow not clearing out old calculations, so its inflating the filesize. But after reinstalling I can tell that your numbers are still high.
At 256kbits audio, 3 hours of content would use about 3140kbits. Now THAT number I am sure of

Well, those are my default settings in varying templates system-wide. Work just fine for almost 2 years now.

[adam]

I don't know what to say except that possibly your encoders are not adhering to the bitrate you set. If you do the math it is impossible to fit 3 hrs of content on a single-sided DVD-r using those settings.

[handyguy]

Another alternative we talk about is using a dvd recorder instead. Panasonics can get 12 hours per disk, but you should stay with 4 hours, which is LP mode.

[lordsmurf]

I don't know what to say except that possibly your encoders are not adhering to the bitrate you set. If you do the math it is impossible to fit 3 hrs of content on a single-sided DVD-r using those settings.

Well, 2 hours is about 5500.
And 4 hours is 2500.

[adam]

Lordsmurf your numbers are getting further off the mark. Just use a bitrate calculator. Still assuming 256kbit audio, you can only use a bitrate of 4862kbits and still fit 2hrs onto a DVD5. And once again, to fit 3 hrs of content on a dvd-5 you'd need to use right around 3100kbits.

[lordsmurf]

These are VBR average bitrates, and I've been using these settings for two years now, without fault. Whether it be ATI AIW, TMPGENC, PROCODER, MC, JVC, APEX, LITEON, etc. Those are the specs, and those times are my results.

Only once have I gone over, and on that disc, I lowered the audio to 192k AC3 2/0, and then it fit fine. Was just a couple dozen MB too large for the DVD.

Your calculator must only go to 4000MB or something, I don't know.

[midnightsun]

hmmm let's fire up some math:

4700000000 bytes=37.6x10^9 bits

37.6x10^9bits/(3x3600s)= 3481481bits/s

if you use 256kb/s audio you're left with:

3481-256= 3225kb/s for video+overhead

This is done assuming kb=1000bytes as I think most (all?) mpeg encoders do.

This of course disregarding the athoring process.

EDITED: typed 37.2 instead of 37.6 but the math was OK regardless.

[adam]

Lordsmurf, like I already said, your actual results may be differing from your input settings. But you cannot argue with math.

[solarfox]

A bitrate calculator works by a simple mathematical calculation: Take the total capacity of the media, and divide by the total amount of time, in second, of programme which the user wishes the media to hold. Then, subtract the user's intended audio bitrate from that result, and what's left is the maximum allowable bitrate for the video portion of the stream.

This calculation, by its very nature, assumes constant bit-rate encoding. If Lordsmurf is using VBR encoding, then the calculation no longer holds, because there's no longer a fixed correlation between the size of the file and the length of the video contained. With VBR encoding, a bitrate calculator can only provide you with a useful ballpark figure -- i.e. if it tells you that 4000Kbps CBR is the maximum you can use to get your intended program onto the disc, then you can probably push that to somewhere in the 4500 - 5000Kbps range if you use VBR, depending on how clean your source is and how good the encoder is.

[ZippyP.]

With VBR encoding, a bitrate calculator can only provide you with a useful ballpark figure...

It depends on what type of VBR you are talking about, but you would use the calculated bitrate as the average bitrate in a 2-pass (or more) VBR encode. Now some encoders are better at hitting the average than others and that can give some discrepancy, but the final output size should be pretty close. Certainly much closer than just a ballpark figure.

[adam]

This calculation, by its very nature, assumes constant bit-rate encoding.

Of course it doesn't. Do the math. If the bitrate stays at 4000kbits every second then isn't its average bitrate 4000kbits too? Just like the VBR encode?

solarfox you need to read up a bit more on VBR encoding. A file encoded in VBR with an average bitrate of 4000kbits will be identical in size to a file encoded with a constant bitrate of 4000kbits...every single time. It does not matter whether bitrate is constant or fluctates every GOP, you can still calculate the average bitrate used and this is what determines filesize.

A properly coded bitrate calculator never gives you a ballpark figure. It tells you the exact average number bits that can be used every second to achieve the specified filesize. This applies equally to both CBR and VBR encoding and never varies by source quality or encoding mode. Now whether you can get the encoder to output a file with such an average is another matter. I have yet to find any encoder which cannot achieve the exact average bitrate specified in multipass encoding. I always encode in multipass VBR using CCE and I always calculate my bitrate in advance with Fit2Disk. My filesize is always the exact target size that I calculate (load final DVD into IFOEdit and check filesize...it reports 0 bytes remaining, meaning that I am within 1MB.) Its a trivial thing to do.

If you are using 1-pass encoding modes obviously its going to be difficult to control your bitrate, and you will almost surely get a file with an average different then desired, but this has no bearing on how you calculate the average bitrate needed to fit X amount of content in Y amount of space. Its a mathmatical formula and there is nothing ballpark about it.

[midnightsun]

I thought this was straightforward but still somebody felt like challenging the algebra.

Well, basically what Adam said ^^^. If you use CBR that is your value, if you use VBR evidently it's the average bitrate you set when you encode.

Not a lot to mess around is there?

[solarfox]

I'll thank you not to condescend to me like some newbie who barely knows which side of the disc to record on, thank you very much.

It has never been my experience that the final size of a VBR-encoded MPEG can be accurately predicted by a bitrate calculator. Usually, my encodes will come out anywhere from 10 - 20% smaller than the calculator would predict -- and as this has been a fairly consistent phenomenon for every project I've authored, I felt fairly confident in stating it as an observed fact.

I will amend my initial statement by allowing that it may depend on exactly what tools and settings you're using, but you'll forgive me if I'm loathe to disregard empirical evidence just because it contradicts your theory. :P

[adam]

Sorry, I did not mean to offend...I just don't understand where the confusion is coming from. I am horrible at math and this just seems elementary to me. We are of course all still learning but I can't say I have ever heard of anyone having these kinds of problems before. If your filesize is varying from the calculated filesize, then naturally you are calculating it wrong. What bitrate calculator do you use? When you say its off do you mean the elementary video stream is off or the final program stream is off? Because maybe you just aren't taking the overhead into consideration. Under no circumstance should you ever be more then 10mb's off.

Solarfox, this is not theory. Filesize is a result of the number of bits every second multiplied by the number of seconds. If you know the running time of your video then you can calculate down to the exact bit what its filesize will be at any given average bitrate. There is no reason to rely on mere empirical evidence, it is math. The numbers can be calculated with 100% accuracy and I am quite certain that the majority of people on this board do it regularly.

If you haven't already, give FitCD a try. There is no reason why you shouldn't be able to hit your target size within a few MB's everytime.

[jimmalenko]

children, children, ever think that your bitrate calculators might not be hitting the same target size ? I used videohelp's bitrate calculator and found the Adam was 14kbps off in one of his calculations. Did you hear me making a song and dance about it ? No.

I think there's something in that for all of us, don't you ?

[adam]

I think there's something in that for all of us, don't you ?

Not really. Assuming the poster took all of our advice to heart...if Lordsmurf had not corrected my original numbers then his DVD would have been significantly undersized. If I had not corrected Lordsmurf's numbers then his DVD would not have fit on his media, and he would have had to start over.

When it comes to squeezing every bit (pun intended) out of your media then you have to be accurate, and since it is fairly simple math, there is no reason why you can't be. Anyway, he got his answer. If he encodes with 2-pass VBR with an average of about 3100kbits then his movie should just fit on a DVD5.

[jimmalenko]

I think there's something in that for all of us, don't you ?

Not really. Assuming the poster took all of our advice to heart...if Lordsmurf had not corrected my original numbers then his DVD would have been significantly undersized. If I had not corrected Lordsmurf's numbers then his DVD would not have fit on his media, and he would have had to start over.

When it comes to squeezing every bit (pun intended) out of your media then you have to be accurate, and since it is fairly simple math, there is no reason why you can't be. Anyway, he got his answer. If he encodes with 2-pass VBR with an average of about 3100kbits then his movie should just fit on a DVD5.

So that's why you took half a page over semantics ?

anyway ...

here's my calcs using VideoHelp.com's Bitrate Calculator: