Buffer Underrun Error

[robitala]

Trying to burn a (7.46GB) iDVD disk image to a 4.3GB DVD.

 

Toast Titanium 7.0.2 gets to Writing Lead-in/Preparing then returns Buffer Underrun Error.

Prevention is checked in Recorder settings. Message says to try a slower burn speed,

but I've gone done to the slowest write speed (2X) with the same result.

 

A Toast .img of the iDVD .img gives same error.

 

Any ideas?

[freshburn]

tsantee is right, iDVD uses PCM audio. If you have an image that is 7.46GB, the audio alone could be 3-4GB depending on the length of the film. My guess is that you have about 3 hours of video. That would make the audio about 2GB. The video can only be compressed so much. If you have more video that 3 hours it may just not fit.

 

When saving as a disc image, Toast will prompt to save as a single layer or dual layer. Are you selecting single layer?

[robitala]

How long is the iDVD movie?

Close to the limit - 3:58/238mins(iMovie), 3:59(iDVD).

 

Something you might try is mounting the iDVD image file and dragging the VIDEO_TS to the Toast Video window with DVD video from VIDEO_TS selected as the format. Save as a disc image and see if the size still is 5.02 GB.

Yeah, still makes a 5.02 GB.

 

I presume you're doing it this way because you want to make use of iDVD's menus.

Correct. But seems I can’t with this length of movie. I wonder what the limit is? I’ve managed 2:20 on one project.

 

Dropping the .mov from iMovie produces a 3.98 .toast disk image, though Toast indicated it would be 3.73 GB (85%). The result is not satisfactory because I have to reduce the bit rate to the minimum to fit it to a single-layer.

 

It’ll have to be two seperate burns which gets better quality anyway.

 

 

tsantee is right, iDVD uses PCM audio. If you have an image that is 7.46GB, the audio alone could be 3-4GB depending on the length of the film. My guess is that you have about 3 hours of video. That would make the audio about 2GB. The video can only be compressed so much. If you have more video that 3 hours it may just not fit.

 

When saving as a disc image, Toast will prompt to save as a single layer or dual layer. Are you selecting single layer?

Yes. Seems iDVD using PCM audio is the problem here. Didn’t think that it would be file size when Toast can compress 9.4 GB from other sources.

[tsantee]

It seems to me you have two options.

One is to forgo the iDVD menus and let Toast make a DL-sized disc image file and then use Toast's fit-to-DVD to burn that to a single-layer DVD. This way you get the AC3 audio instead of PCM.

 

The other option is to split the movie into two parts and use iDVD to make two discs.

[freshburn]

This is just me, but I would just use Toast to burn the disc in the first place How long do you spend watching the menu, plus you have to waste so much time setting it up? I would use Dolby audio and set the bit rate to about 4Mbps with motion estimation set to high and Half PEL on.

 

You will get much better quality with Toast at these settings and it will fit on a single layer DVD without re-compression.

 

Or you could just burn a DL disc. Unless something changed in iDVD that I don't know about, a DL image can't be created without a DL drive so that means you should have one. Unless you are making a large # of copies.

[robitala]

It seems to me you have two options.

One is to forgo the iDVD menus and let Toast make a DL-sized disc image file and then use Toast's fit-to-DVD to burn that to a single-layer DVD. This way you get the AC3 audio instead of PCM.

 

The other option is to split the movie into two parts and use iDVD to make two discs.

So do you think I will get better quality if instead of immediately compressing the .mov to a 3.98 GB disk image, I make a DL disk image and then compress to fit SL media?

 

This is just me, but I would just use Toast to burn the disc in the first place How long do you spend watching the menu, plus you have to waste so much time setting it up? I would use Dolby audio and set the bit rate to about 4Mbps with motion estimation set to high and Half PEL on.

 

You will get much better quality with Toast at these settings and it will fit on a single layer DVD without re-compression.

 

Or you could just burn a DL disc. Unless something changed in iDVD that I don't know about, a DL image can't be created without a DL drive so that means you should have one. Unless you are making a large # of copies.

Not sure what you mean "burn the disk in the first place"...burn straight from what? Thanks for settings I hadn't seen anything about those options in the Toast manual.

[tsantee]

So do you think I will get better quality if instead of immediately compressing the .mov to a 3.98 GB disk image, I make a DL disk image and then compress to fit SL media?

I didn't think Toast 7's encoder would fit a 4-hour movie to a single-layer disc. That would be a very low bit rate (averaging about 2.3 mbps for the video if the audio is at 192 kbps). I do see, though, that the custom encoder settings allows an average bit rate as low as 2.0 mbps.

 

With Toast 7's new MPEG encoder it might be better to do the full compression at once; freshburn knows that much better than I. But my instinct tells me it could be better to do the DL disc image followed by the fit-to-DVD "requantization" in your situation. I haven't ever created a 4-hour DVD from iMovie so I'm just guessing here.

[freshburn]

If one goes to DVD DL in iDVD, the bit rate will be at 3.5 Mbps anyway, and you have PCM audio. After it goes through Toast to requantization, then you will have a bit rate of 2-2.5Mbps.

 

If you just use Toast, you can get up to 5 hours of video on a single layer disc. I would set audio to 128kbps and the video at about 2.5Mbps. If you use a motion estimation of best and Half PEL on you will get good quality. If you don't use a high motion estimation and Half PEL, the quality won't be good.

[tsantee]

I wonder if something went to sleep during the compression stage. Try choosing Save as Disc Image rather than clicking the burn button. When Toast has completed creating the 4.38 GB image file, choose it to burn your DVD.

[dvr108]

Trying to burn a (7.46GB) iDVD disk image to a 4.3GB DVD.

 

Toast Titanium 7.0.2 gets to Writing Lead-in/Preparing then returns Buffer Underrun Error.

Prevention is checked in Recorder settings. Message says to try a slower burn speed,

but I've gone done to the slowest write speed (2X) with the same result.

 

A Toast .img of the iDVD .img gives same error.

 

Any ideas?

 

I went looking for help with pretty much the same problem and your post was exactly what I was going to write!

 

Here are my specifics:

 

Mac G4/533DP, OS-X latest, Toast 7.0.2, Popcorn 1.0.3, Pioneer DVR-108, drive firmware recently updated to official 1.20 from 1.12.

 

In my case, I have been using this setup (minus the firmware update) for some time to successfully write data and video DVDs. I did some limited writing of iDVD disc images as well; I do that more on other machines.

 

Tonight I tried to write an unlocked VIDEO_TS folder to a Memorex 16x DVD-R using Popcorn (compressing first). Got the buffer underrun error, which is not normal. Same error with Toast, at various write speeds (6x, 8x, 12x, 16x), straight from the VIDEO_TS folder as well as from a Toast disc image.

 

Last night I successfully wrote a VIDEO_TS folder via Popcorn to a DVD-RW with no problem. And minutes ago I wrote 2 CD-Rs with no problem.

 

So at this point I'm thinking the Memorex media is funky, though before the firmware upgrade they too wrote fine.

 

I will try a data DVD on this setup and report back. I will also try to get different DVD-R media (I have some in the office) and will try again on the G4 in a few days.

 

Bottom line: iDVD is not involved with my buffer underrun problem, which seems to be the same problem robitala is having.

 

PS: I too am getting oversized disc images from Toast 7 on this machine. The disc image I wrote from the VIDEO_TS folder (with compression settings on and single layer disc chosen) was 4.89 gigs.

[robitala]

I have now trashed the iDVD DL disk image and its resulting .toast requantisation to single layer. I have also trashed the .toast DL disk image and its requantisation to single layer as tsantee suggested. Little difference in picture quality; both methods are blotchy or pixelated.

 

When you say use Toast...what should I throw into Toast? I have been using the .mov.

[robitala]

I wonder if something went to sleep during the compression stage. Try choosing Save as Disc Image rather than clicking the burn button. When Toast has completed creating the 4.38 GB image file, choose it to burn your DVD.

Nothing went to sleep as far as I can tell. That was the second iDVD .img and second .toast image (both redone from iDVD project). And as occured before .toast disk image returns the same error. Toast actually created a 5.02GB disk image.

 

Now, what am I supposed to do when after mounting either disk image, DVD Player opens, asking if I want to view the DVD from the previous position or the beginning?

 

P.S. have all the previous posts gone for good, or is the search function not up yet?

 

Thanks for your reply, here's me thinking you were part of Roxio.

[freshburn]

Just the the MOV directly in Toast.

[tsantee]

Nothing went to sleep as far as I can tell. That was the second iDVD .img and second .toast image (both redone from iDVD project). And as occured before .toast disk image returns the same error. Toast actually created a 5.02GB disk image.

 

Now, what am I supposed to do when after mounting either disk image, DVD Player opens, asking if I want to view the DVD from the previous position or the beginning?

 

P.S. have all the previous posts gone for good, or is the search function not up yet?

 

Thanks for your reply, here's me thinking you were part of Roxio.

You may need freshburn's help here because I'm not sure if there are issues with compressing iDVD DL disc image with Toast. I'm curious about the 5.02 GB image file Toast created. Maybe that is due to iDVD using uncompressed PCM audio which Toast cannot compress. It could be the video compression was at the maximum but the size of the audio still made it too big for a single-layer disc. How long is the iDVD movie?

 

Something you might try is mounting the iDVD image file and dragging the VIDEO_TS to the Toast Video window with DVD video from VIDEO_TS selected as the format. Save as a disc image and see if the size still is 5.02 GB. I presume you're doing it this way because you want to make use of iDVD's menus.

 

Obviously something is going to go wrong writing to a 4.38 GB disc when the file size is 5.02 GB. I think buffer underrun isn't what the real problem is here.

 

Don't worry that DVD Player opens when the image file is mounted. Just quit DVD Player. You can also disable that auto opening by changing the settings in the CDs and DVDs panel of System Preferences.