Purpose: after spending several days reading hundreds of posts and guides here at cdfreaks, I thought it would be helpful to compile the basics I learned and create a simple guide from a newbie’s perspective with the purpose of getting others up and running quickly:
To reliably scan DVD burn quality you will need a DVD writer that scans consistently. Lite-On is known for scanning well. Recent Samsung 182 to 184, 202, and 203 drives, Plextor, BenQ, and NEC writers also scan. Lite-On and BenQ drives are often sold under different brand names and models - a google search for any drive model and “Lite-On” or “BenQ” can be used to check. Older BenQ drives that scan are 1620, 1640 and 1650.
Run CDSpeed, insert a burned DVD and click on the Disc Quality tab. Notice the media ID (MID) in the upper right. This is a code for the actual type of media that you have. Brand names may vary between MIDs. By scanning different types of media you can get an idea of what works best with your writer and at what burn speeds.
Under Settings choose 4x. If you have a BenQ drive choose 8x scan speed. Then click Start to begin the scan. When finished, click the disk button in the upper right corner to save an image of your scan. When naming the file it’s a good idea to include the MID, brand, type, and speed you burned at along with drive model and firmware in order to make future comparisons, i.e;
Example of a very good burn.
- Test your writer to see if it consistently scans by performing at least five scans with the same disc. Make sure to save the image of each scan. When done, compare the PI Error (PI) and PI Failure (PIF) totals between the scans. Figure out the percentage of spread by taking the lowest and highest PI numbers, subtracting them, and then dividing again by the highest PI, i.e;
13252 - 12405 / 13252 = 6%. Do the same for PIF; 115 -107 / 115 = 7%.
(these results are from an actual scans from a Lite-On SHW-16H5S here)
Also look at the scan graphs to make sure they all look similar, showing the same pattern. If your writer does not scan consistently, then scans will not be very useful for getting an idea of burn quality.
If your writer does not scan consistently you may try updating your firmware. Updating firmware will usually result in better burns and make your drive compatible with more media. Check the manufacturer’s website for your drive or The Firmware Page.
A good DVD burn should have PI levels lower than 280 and PIF levels under 4. Discs with much higher levels can still be readable, but may have more problems playing and may degrade faster. PO Failures should always be 0. Even one PO Failure can make a disk unreadable. Different drives, media, firmware, and burn speeds can all result in different quality burns.
In general if a Quality Scan is good, a disc is good. But, since PI scanning only measures error correction, it does not determine whether or not a DVD can actually be read well. To get a better idea of this, the drive needs to actually read the disc. This can be done with a Transfer Rate Test (TRT). In CDSpeed click on the Benchmark tab and then go to menu Run Test>Transfer Rate. A good result is a nice smooth curve. If there are any dips in the curve, they usually represent areas on the DVD that the drive had trouble reading and as a result had to drop to a lower read speed. Example of a good TRT:
Transfer Rate Test
- DVDs can degrade over time with exposure and wear. Save some of your scan images for each type of media you burn and mark the disc so that you can test the same disc again in the future to see if it has suffered any degradation.
To see comparison scanning of different types of writers and learn more details about Quality Scans, see this cdfreaks article here: