Store brand and generic brands of DVD media
I periodically get email from the members of the group who have lost a lot of work as a result of using some no-name brand media. Evidentally, the recordings were made with poor quality and so they were not playable on a PC. DVD players are sometimes a little more forgiving since they will skip bad blocks and you may never even notice what's going on if the problems are confined to single frames of video. It may just be a minor annoyance. However, computer drives look to see that all the data is being recovered and will generate an error if they notice that some of the data is missing.
Each media vendor uses unique formulations that need to be tuned on each drive so that they have an optimized 'write strategy' for each and every type of media. There is actually a lookup table in the drive's firmware. This is one of the reasons it's so important to stick with known brand names since they will generally use only media from reputable manufacturers which are likely to have been tested with each drive. Also, that's why the firmware updates for DVD drives need to be done periodically so that the tables to identify new media types and write strategies are kept up-to-date. This is especially true with the higher speed media since it wasn't even invented when the early DVD writers began shipping. No-name and discount brands of media most likely have NOT been tested with your DVD drive and thus they have to use a 'generic' write strategy which is rarely successful in producing a good quality disk. On any given disk, there are thousands of 'soft' errors, which is normal since there is a method of dealing with them called ECC (error correcting code). If the media is poorly written, then the soft errors may become so numerous that even the ECC can't recover the data.
One of the metrics besides soft errors that can be used to determine disk quality is the 'jitter', which measures the consistency of the bit lengths as they are written to the media. Typically this number needs to be below around 10% to be considered good enough to guarantee playback on most DVD players and DVD drives. If it gets up into the 15% range, then data loss is almost certain. Optimizing a write strategy requires finding a method to reduce jitter for each formulation of media on a particular drive. It takes a lot of work on the part of the drive manufacturer.
If you find that you cannot read back some recorded DVD media on a particular drive, there is a utility called NeroCDSpeed which on certain drives supports the commands to measure jitter. Unfortunately, none of the drives in the HP DVD Movie Writers support this command, but you can still perform a surface scan with the CDSpeed utility to see how much of the disk can be read. If you see that the amount of unrecoverable data is low, perhaps just a few blocks, it may be possible to read it back in a different DVD drive. If you can recover all the data, it would be a good idea to write it to another disk, because the write quality may have been poor on the original recording.
Other possibilities in having difficulty in recovering data may be that the optics inside the drive have become covered with dust or other contamination such as smoke particles. Also, if the disk is contaminated with dust or fingerprints, you may be able to clean it to make it readable again. Use only soapy water and a soft cloth so that you don't scratch the disk's surface. If you can't read the data back on one drive, try several more if you can to determine if the problem is related to the drive or the media.
Always stick with name brand media and if you're uncertain about the brand of media then before you write to it with Showbiz, you should use that media to store data with RecordNow with the 'verify' option set to make sure it can recover the data. If you are having trouble with a particular type of media, you can find out who the original manufacturer is with a utility called DVD Identifier. You should see a manufacturer such as CMC, MKM, Taiyo Yuden, Ritek, MBI, Prodisc, or Ricoh. Please note, this is not the brand name on the outside of the disk (such as Maxell, Verbatim, HP, etc.) . If the media is not manufactured by one of the companies in that list, then there's a good chance you're going to have problems with it.
The utilities mentioned above (NeroCDSpeed and DVD Identifier) can be found with a Google search or on this web page:
If you want to read more about media, there's a FAQ here:
It has some errors in it, but overall it's pretty good.
Return to the HP DVD Movie Writer FAQ