Movies defragmenting before burning & playback artifacts

[zamar27]

I wonder if one needs to defragment .avi movie files before burning a folder with such files onto a DVD? Or, may be a burning app like ImageBurn actually defrags the file portion by portions in memory before burning these portions, or reads it from hard drive in the right sector sequence so that it's always burned defragmented regardless of the original on HD being fragmented? Any facts (not guessing) explaining the topic would be appreciated.

Also, after burning series of Divx 5 files onto a DVD, a light horizontal line periodically appears on TV screen during playback on a standalone DVD Player. The line divides the screen 1/3 to 2/3, its always in the same place, even if files are different (i.e. when playing a movie serial). The impression is, movie frames are glued in this place. Is it related to file fragmentation, or to incorrect decoding of DivX5 by my DVD Player, or errors in encoding during ripping the original movie from DVD? Any way to get rid of this line - it comes every 10-20 sec irregularly, stays for 5-10 sec then disappears, then appears all over again... No such line, when playing same DVD on PC.

[Case]

I wonder if one needs to defragment before burning

By default, ImgBurn would use both ISO 9660 level 1 and Joliet file systems for such a disc. ISO 9660 level 1 does not allow file fragmentation, thus such a disc would would only contain defragmented files.

a light horizontal line periodically appears on TV screen

This is not related to file fragmentation. Supposing a disc has file fragmentation, then it could be noticed as longer seek times, reading from various locations on the disc, perhaps freezing the image until the next data is processed.

[zamar27]

Thanks. So, where files defrag will be done - in RAM by ImageBurn just before burning read data to DVD? Or ImageBurn simply reads data from HD in the right sequence, so no defrag is required before burning? Just the app buffer size may fluctuate if the file is heavily fragmented, thus requiring heavy HD use to read sequentially?

[davexnet]

Are you talking about HDD fragmentation? Imgburn buffers the file in memory and that is used to feed the burner.
Assuming you have a recent PC with a fast hard drive, there shouldn't be any problems burning a disk
unless some other activity causes the drive to thrash when burning. But even then, you would see some
indication on Imgburn's burning screen, such as unable to keep the RAM or drive buffer filled.

[Case]

...simply reads data from HD in the right sequence

Yep.

Just the app buffer size may fluctuate if the file is heavily fragmented?

If the HD is not doing anything else, it should be able to keep up with ease, as HDs can read much faster than the optical drive can write, even with a heavily fragmented disk.