[Post] Analysis on Features of DVD and DVD +

[Post] Analysis on Features of DVD and DVD +
DVD-Analysis of features with DVD +
DVD-R and DVD-RW is characterized by, because it is the official standards of the DVD forum, so the industry support strength, bottom thick, coupled with its own good compatibility design, make it better on DVD-ROM drives and DVDs. However, from the design of the disk, the addressing accuracy of LPP is very low (one ECCB [16 sectors] One LPP address, and cannot provide absolute physical address information, can only provide relative address information). Therefore, only limited random access capabilities can be achieved, which is a fatal weakness. Although in addition to writing (multi-segment writing), Background formatting, and other aspects, through the efforts of the day after tomorrow, we can be at the same level with the DVD + format, but the design of LPP brings irreparable damage, as a result, the confrontation with the DVD + format is gradually at a disadvantage.

DVD + R/RW is characterized by excellent physical design, coupled with powerful logic features, DVD + R/RW has capabilities above DVD-R/RW. That is to say, the DVD-R/RW can do, DVD + R/RW can be, but in turn is not the same. In addition, we have always been ahead of DVD in terms of speed improvement. We should all have some experience on this point. It can be seen that in the PC market, the DVD + RW format is already ahead of the DVD-RW format, which is not for no reason. Although, for some people, DVD + R/RW relative to DVD-R/RW there are still concerns about compatibility, but the emergence of booktype technology, as well as the old-fashioned DVD-ROM and DVD player gradually retired, this makes the compatibility of DVD + R/RW better and better in the industry. As for the jitter standard, DVD + (9%) is one percentage point higher than DVD-(8%), and it is not worth mentioning. It does not mean anything.

In fact, for normal PC users, selecting a DVD or DVD + is no problem, the advantage of DVD + is more obvious in the consumer electronics field (random addressing and lossless link capabilities of DVD + provide better editable capabilities ), both of them are competent for daily data storage and video storage.

However, in terms of comprehensive capabilities, the DVD + R/RW disc is obviously more powerful. If it is a demanding user, we recommend using a DVD + R/RW disc. Someone once said that DVD-R/RW is suitable for storing movies, because of good compatibility, DVD + R/RW is more suitable for storing data because of good performance. However, when you use a combination of DVD + R/RW and booktype, the compatibility advantage of DVD-R/RW may be lost. Therefore, I think that if you can modify the booktype, the DVD + R/RW format is a usable format. It should be pointed out that movies and so-called data can be regarded as "data", but it only involves the compatibility of playing a DVD player, therefore, it is futile to analyze who is more suitable for storing movies or data in the physical format. data is stored in ECCB units on DVD discs. The difference is only the logical architecture, but this is irrelevant to the disc format itself, and will be involved in the DVD-video and DVD-ROM application specifications.
What is book type?

Booktype is a term that has been gradually used by users with the popularity of DVD + R/RW in the market in recent years. To understand whether it is important or not, you must first understand its meaning.

Booktype originated from different standards of the DVD. The official organization of the DVD Forum released the corresponding specifications for each DVD standard. These specifications are called book type, similar to the red and orange books in the CD era. However, it is numbered by letters. The specific description is as follows:

Because DVD + R/RW is not the official standard of the DVD Forum, there is no corresponding book type in the specifications promulgated by the DVD forum, therefore, the compatibility with traditional DVD devices is not good (they are mostly designed according to the specifications of the DVD Forum, in the past one or two years, all new devices can correctly identify the DVD + R/RW disc type ). However, the 4-to-7 bits of 0th bytes in the physical format information of the control data area of the DVD disk in the import area are retained with the disc type parameter (named disk category ), when the disk is released, different values are set based on the disc type. For details, see the following table.

The structure (layers) of the DVD + R disc is expressed in 2nd and 5th bits of the physical format information.

It is reasonable that the book type of the disc cannot be modified, especially when it is used to burn the disc, because it involves the recognition of the disc by the drive, which affects related operations, for example, if it is identified as a DVD-ROM, it is impossible to write operations. However, what excludes DVD + R/RW is ?? Using ADIP technology, DVD + R/RW modulated the physical format information of the disc into the orbital jitter (see the detailed description of ADIP on this site ), in this way, you can modify the physical format information of the import area without affecting the recognition of the drive, and this is not possible for the DVD-R/RW (the physical format information of the DVD-R has only one copy, after modification can no longer append write, although the DVD-RW saves multiple physical format information copies, but the most critical, in the import control data area physical format information is solidified, cannot be changed ).

Therefore, related vendors have developed tools for modifying the DVD + R/RW disc type, this type of tool is mainly used to control the adjustment of a specific byte when writing a DVD recorder (so sometimes this type of tool is also called bitsetting), because it involves special write operations, therefore, this type of tool is usually customized for an optical drive and requires special firmware. Because the adjustment of booktype is to rewrite the specific location of related bytes, some such software is also called bitsetting.

Speaking of this, we will understand that booktype is currently specifically prepared for DVD + R/RW, although some software also supports modification to the DVD-R/RW, however, from the analysis above, we can see that DVD + R/RW has inherent advantages in this aspect. For devices older than the production date, changing the disc type of the DVD + R/RW to a DVD-ROM can significantly improve their compatibility, and for DVD devices that have been around for nearly a year or two, the support for DVD + R/RW is no longer a problem, so modifying the booktype is not important for such playing devices. However, for the DVD + r dl, it is still necessary to use booktype. Many machines may correctly recognize single-layer DVDs + R, but may not correctly recognize double-layer DVDs + r dl, this is why many big-name vendors that once dismissed booktype began to support the machine itself to support modifying the attribute function of DVD + r dl. So, is booktype useful to you? It depends on the user's usage habits and application environment. If you prefer to use a DVD + R/RW disc and are not at ease with the compatibility of your application environment, booktype is necessary.