Buffer Under run

Gra · Post by **Gra** » Sun Sep 20, 2009 12:03 pm

Hi Guys
I tried to author a DVD (PAL-DV) video. It was two avi files (1x8gig & 1x5gig) and I set two-pass conversion as I wanted optimum quality. I knew it would take longer but after 1.5 hours, when it got to 99% of "recording disc", an error message popped up saying "buffer under run error, too many resources may be open" - how I laughed! (The disc plays the menu but not the movies.) My system has been configured following Steve's hardware profile, so only the bare minimum of resources are running. Is this a common occurrance for two pass conversion? (I authored without two pass conversion and in 16 mins it was completed).

mitchell65 · Post by **mitchell65** » Sun Sep 20, 2009 12:29 pm

Sorry did not mean to post here as I have no experience of working with such large files.

Post by **Ron P.** » Sun Sep 20, 2009 1:07 pm

Hi Gra,

Generally a Buffer Under-run is due to the buffer not maintaining enough data to the burner. When this happens the disc does not get burned properly. Most current burners however have Buffer under-run protection built in. This protection is to ensure that the buffer stays full. without it, the disc will not pause or stop and wait for more data. It must continue smoothly.

Wikipedia wrote:CD and DVD recording issues

Buffer underruns can cause serious problems during CD/DVD burning, because once the writing started, it cannot stop and resume flawlessly; thus the pause needed by the underrun can cause the data on the disc to become invalid. Since the buffer is generally being filled from a relatively slow source, such as a hard disk or another CD/DVD, a heavy CPU or memory load from other concurrent tasks can easily exhaust the capacity of a small buffer. Therefore, a technique called buffer underrun protection was implemented by various individual CD/DVD writer vendors, under various trademarks, such as Plextor BurnProof, Yamaha SafeBurn, JustLink or Seamless Link. With this technique, the laser is indeed able to stop writing for any amount of time and resume when the buffer is full again. The gap between successive writes is extremely small.

Due to the file sizes you mentioned, I'm suspecting that you're trying to burn a Dual Layer or BD disc, is this correct? Further they would not fit onto a Dual Layer, as it only holds 8.5gig. Unless these are DV files not MPEG-2, in which case we're talking about 1 hr of video. Could you clarify this?

Gra · Post by **Gra** » Sun Sep 20, 2009 5:34 pm

Hi Ron
Thanks. I imported the files in avi format to let MF convert them into mpg2. Should I have converted beore?

Post by **Ron P.** » Sun Sep 20, 2009 6:03 pm

There's nothing saying that you must, however you might have better luck.

Gra · Post by **Gra** » Mon Sep 21, 2009 10:10 am

Thanks Ron
I'm now having another problem, but I'll open a new thread.

trush44 · Post by **trush44** » Mon Oct 05, 2009 11:31 pm

Hey, I wanted to chime in here because I am currently experiencing the same Underrun issue.

I am burning DVD DL and have successfully burned 3 disks in 9 attempts. The 6 failed attempts were a result of the underrun error. My question is why is this only happening some of the time for the same exact project? These blank disks aren't cheap so any guidance on how to prevent this error would be greatly appreciated.

I am using a SH-S183L burner if that means anything to anyone.

sjj1805 · Post by **sjj1805** » Tue Oct 06, 2009 1:33 am

Try updating the firmware of your DVD burner:
DVD Burning / Playback issues

trush44 · Post by **trush44** » Tue Oct 06, 2009 2:07 pm

Thank you, Steve! Updating my firmware resolved my issue and I have burnt 5 disks in a row without any issue.

I had thought about upgrading the firmware before my post but didn't think it was a hardware issue since a feature of the SH-S183L is that it has "buffer under run free technology"...apparently not out of the box.

For anyone with the SH-S183L or other Samsung drive, use Firmware LiveUpdate (a.k.a. ODD Service) to get the latest firmware: http://www.samsungodd.com/eng/Firmware/FAQ/Faq.asp

sjj1805 · Post by **sjj1805** » Wed Oct 07, 2009 1:31 am

Glad your back in business.