Buffer Underrun???

[MCD]

Can someone please explain what buffer underun is and how to diagnose it. Here is my problem: I have successfully made about 30 perfect dvds so far. The very first one I ever tried to make I was burning with the authoring sw. I used dvdit, and moviefactory. The results were identical. 50 mins into the movie, the screen started skipping, freezing, and blinking on stand alone sony player. After many coasters, I started burning the folders with nero. That worked perfectly. I enabled buffer underun and all was well. So from then on, it has been nero ever since with perfect luck. Nero was awesome. Until 2 days ago!!! Coaster after coaster after coaster and still can’t figure out what is going on. I am using the exact same processes for encoding (tmpg) authoring with spruce. But the same thing now is happening as the first dvd I made. Skipping, freezing, blinking colors 50 mins into the movie. I don’t get it, I havn’t changed anything. Still using the same MEDIA , Memorex which has been flawless so I know my player likes that brand. So my question is am I experiencing “buffer underun” with nero now even though I still have it enabled? Please give me some suggestions. By the way I have encoded this movie 3 times with different bitrates, and no change. I also scanned the avi for errors which found none. Today I plan to try burning in dvd-rom udf mode as headstate has suggested in another post.

[hardwork12]

Buffer underrun as far as I know is this:

There is a data buffer that the burner uses to keep the stream of data to the burner flowing without interruption. If the buffer becomes empty the burner can not continue to write so this causes the buffer underrun error (empty buffer).

The "Burn Proof" works if the device supports It unfortunately I do not have a DVD burner so I can't answer if you have "buffer underrun" protection. I would assume that if Nero gives you this choice then maybe you have it just not sure. "burn proof" is a technology that allows for the buffer to go to zero and then pause the write function in a way that it can restart when the buffer has enough data again to burn and it resumes correctly.

maybe you have some new applications running or you are leaving some web pages open or something that can put demand on the system. If so close all applications and windows and run the burn that way.

Just some thought.

[Nelson37]

SFAIK, if buffer underrun occurs you will get an error message to that effect, and your disk will be completely unplayable. I think you have some other problem, try a media change and clean both burner and player. Also check for ANY software running in backround.

[MCD]

Thanks for responding. I’m not sure what is going on. As far as to many background applications running, I hit the end it all proggie to close all those programs. There is nothing at all running. I guess I could try different media, but like I said before I have had great luck with Memorex in the past, so I know the media is compatible with my player. I did try playing the disc in my cpu. It plays smooth with no skipping at all, BUT it quits and windvd shuts down before the movie is over. However, if I just watch the vobs from the video_ts file not on the disc but from my folder on the desktop, it plays fine. So it definitely seems like a burning issue. Hopefully when I try burning as dvd-rom udf it will work. If not, maybe a different burning application is in order. Maybe prassi primo, or vob instant. Anybody have better luck with these as apposed to nero?

[SLK001]

Your problem is most likely your media (Memorex ain't all that grand - and only 1X, too). If they carry a warrantee, I would definately exercise it.

Buffer underrun is when your recorder buffer runs out of data to write to the disk (since DVD's are almost always written in DISK AT ONCE mode, this is very bad news). Next time this happens in NERO, check the NERO LOG file that it always asks you if you want to print, save or discard. See if there were any buffer underruns (this shouldn't happen on any modern, relatively fast machine, unless you are trying to encode in parallel). Just make sure that you don't have any background programs requiring a lot of CPU time or a lot of disk access.

Next time you burn, try killing all background processes, start the burn, then walk away until it is done. If you still have the bad results, then your media is crap (I'm putting my money on bad Memorex media).

[MCD]

Thanks for the info SLK. I will look at the log you mentioned. It just seems so weird cause that’s all I ever have used is Memorex( mainly because that is all I can find in stores around here). I got a whole rack of movies on Memorex that are perfect, but it is possible I got a bad batch I suppose. As for the background applications, I know this isn’t a problem since I used enditall to kill those programs. My cpu has plenty of horsepower.( 2.8 1556 RAM) although I am not real sold on this Matashita burner. Boy I wish it burned rw lol. This is getting expensive, and frustrating!

[MCD]

Well after 2 coasters and a massive headache, I finally got it to play all the way through the whole movie without a problem. I still used the crap Memorex media but I burned it in 1.02 UDF mode in Nero. Worked perfectly, so hopefully that will cure any future problems. Got 2 Memorex blanks left, then I’m done with those. Picked up some Verbatim blanks, probably not the best but worth a shot.

[SLK001]

I use Verbatim disks almost exclusively. I also construct my DVDs to use all of the disk (last night I burned a 4,694,944,723 byte disk). These disks have never failed me - no pixelization, jerky video or picture stuttering - all symptoms of crappy media. You can get a 15 pack spindle of Verbatims for about $45 everyday at BestBuy (and they are 2X).

[MCD]

Thats good to know that you have good luck with those, hopefully I will to. I do have a question which is probably a little dumb but I just noticed you mentioned 2x. I saw this on the package of the discs and I am wondering if they will work even though my burner only burns 1x? Boy I hope so or I just blew 12 bucks!

[SLK001]

Max burn speed is 2X. No problem burning at 1X.

[Greg12]

Nero automatically uses Power Burn (Sony's version of Burn Proof) on DVD's and has a checkbox for CD's.


From what I can gather, when the buffer becomes critical, the burner slows way way way way down, which gives the buffer time to recharge.