I tried DVD-ISO burn compilation to burn some files which finished with warnings on data verification
#34 SectorVerify 11 File Cdrdrv.cpp, Line 11816
Sector 1080125 on disc has different content to source
D:\VIDEO_TS\VTS_01_3.VOB
SectorVerify 11 File Cdrdrv.cpp, Line 11816
Sector 1332468 on disc has different content to source
D:\VIDEO_TS\VTS_01_3.VOB
How much information am i losing here?
Since it's a video, and only two sectors in total, not much. However, if it were up to me, I would re-burn the image to a different disk. Write errors do occur depending on the quality of the media (1 in 10 for cheap discs, 1 in 100 for quality ones). If that was text, encrypted data, or other data, I would not risk it.
For your information, a sector on a DVD is only 2048 bytes, or 2 kilobytes. Since the verification only tells you the sectors do not match, but doesn't tell you which bytes are different, then assume that the whole 2 kB is different (it could only be a single bit that doesn't match, but you don't know).
However, let's put that into perspective. You have two bad sectors (so 4 kB total) on a DVD with a capacity of just over 4 GB. So, let's make things simple (and assume 1 kB = 1000 bytes), and assume that your DVD has 4 GB of data, which equals 4,000 MB, which equals 4,000,000 kB. So, you lost 1/1000000 of your data.
For a 2 hour video, this would equate to 0.0072 seconds, or 7.2 ms of lost information (assuming a constant bit rate). If your movie is at 30 frames per second, then in total you only lost 0.216 of a single frame in total. So for both of those bad sectors, you lost 1/10 of the video information for a single frame - and that's a worst-case scenario.
You can easily see why a few corrupted sectors really doesn't matter for video information. If we're talking about raw text, however, and you just lost two sectors, that could be very detrimental. If 1 character takes up a single byte, then you just lost 4000 characters of text - and that is almost always a big deal.
