INTEROFFICE MEMORANDUM

Transcription

1 INTEROFFICE MEMORANDUM TO: Professor K. LaGrandeur FROM: SUBJECT: Audience Analysis for Project 4 DATE: 12/7/04 PURPOSE: The purpose of this memo is to present an audience analysis of the person(s) that would read the research report which was created as a project for this class. The goal of the project was to analyze the effectiveness of a recent technical innovation. The topic chosen was the DVD+RW format recorder. AUDIENCE DESCRIPTION: When writing this report, I imagined that two types of readers would be interested in it. The first type consists of people that are interested in consumer electronics and/or computers, and how they work. The second type is made up of people that actually want to buy a DVD recordable drive, but don t know what to look for, or aren t sure what type they want. This type of reader will be more likely to read the full report, whereas the first type will probably only read parts of it. HOW THE AUDIENCE DESCRIPTION AFFECTED THE RESEARCH REPORT: The report was targeted towards both types of readers. In the introduction, I stated the conditions to be investigated that would determine the effectiveness of the drive. This informed the first audience type of what they could learn by reading the report. It also stated the criteria that the second type of reader should consider before making a purchase. The performance factors of the results section contains several technical descriptions, and highlights some of the things that make the drive unique. This section should be most interesting to the first type of reader, and is longer for that purpose. However, the length and content of this section emphasizes to the second type of reader that there are large technological differences between the popular DVD recorder types, and that performance is an important consideration. The remainder of the results section is mostly targeted towards the readers who are looking to buy a DVD recorder. They can learn the features available for the different formats, and determine which type is more compatible for the application they plan to use the recorder for. In addition, they can obtain an idea of which format type is currently the most popular. Finally, in the conclusion, the second paragraph suggests which type of drive(s) to consider for which DVD application, which should help the type two reader to decide what type they should buy.

2 RESEARCH ON THE EFFECTIVENESS OF THE DVD+RW FORMAT REWRITABLE DVD DRIVE Prepared for: K. LaGrandeur, Professor New York Institute of Technology Prepared by:, Student New York Institute of Technology December 12, 2004

3 2 Table Of Contents Executive Summary 3 Introduction 3 Research Methods 4 Results 4 1. Performance Factors 4 2. User Functionality 8 3. Consumer Acceptance 9 Conclusions 10 Glossary 12 Bibliography 13

4 3 Executive Summary In the DVD recorder market, the most sought-after recorders have good performance, useful features, and are known to the consumer. Several writing formats exist for DVD recorders, of which the two most popular are DVD+RW and DVD-RW. This report examines the DVD+RW format drive and its usefulness for DVD applications. The data presented in the research results leads to the conclusion that the DVD+RW drive is capable of handling all DVD functions, and that it is generally an improvement over other formats. Introduction This report details the results of my research on the effectiveness of the DVD+RW format rewritable DVD drive. The research was conducted by consulting manufacturer s publications, technical reports, product reviews, and internet articles. DVDs, or Digital Video Discs, are used to store large amounts of data, such as movies, which tend to have huge file sizes. In addition, they are used for file backup on PCs, which usually consists of storing a large amount of small files. Because DVDs hold such a large amount of data (typically 4.7 GB), the reading and writing times are very important. When writing to any type of disc, the format in which the data is written can affect both the speed at which the disc is written or read, and the functionality of the disc once it is used. With some formats of DVD recording, it can take almost as long to write a small file to a disc as to write a very large file. The access time needed to find a file on a DVD can also be fairly long. The DVD+RW format was made from the desire to decrease the writing time for smaller files, and also to reduce the necessary access time. This format was first created in 1997 by Philips and other members of the DVD+RW alliance, but wasn t available until it was modified to its current version in 2001 (Wikipedia, n.d.). To determine the effectiveness of the DVD+RW format drive, it must be evaluated in terms

5 of performance (disc writing speed, access time, etc.), user functionality, and consumer acceptance. This evaluation cannot be done without a comparison to drives with other formats. There are five main formats used in DVD writing, including DVD+R, DVD-R, DVD+RW, DVD-RW, and DVD-RAM. Of the five, only three formats can use rewritable discs, DVD-RW, DVD-RAM, and DVD+RW. DVD-RAM discs are useful for data storage, but cannot be played in regular DVD players, therefore the comparison focuses mainly on the DVD+RW and the DVD-RW formats. 4 Research Methods In order to evaluate the effectiveness of the DVD+RW drive, the following research methods were employed. 1. To learn about the DVD+RW format and how the drive works, I went to the website of the format s creator, the DVD+RW Alliance. 2. To find performance factors of the DVD+RW drive and other format drives, internet articles and technical reports were reviewed. 3. To appraise the user functionality of the DVD+RW drive and other format drives, I consulted technical reports and manufacturer publications. 4. To measure consumer acceptance of the DVD+RW drive and other format drives, I looked for sales data in technical publications and internet articles, and product reviews. Results This section contains the findings of the research I conducted. First, I provide information regarding the performance of this drive. Then I discuss user functionality, and later, consumer acceptance of the drive. In each section, to consider the effectiveness of the drive, the features are compared to those of its main competitor, the DVD-RW format drive. 1. Performance Factors To analyze the performance of a rewritable DVD drive, the major factors involved

6 5 include the write speed and access time (or read speed). These factors are affected by the technology used when writing or reading a DVD. When performing reading or writing operations, computer drives regularly access random areas of the disc, frequently changing to a different radius. DVD+RW drives can operate in CAV (Constant Angular Velocity) mode, where the disc rotates at a constant speed, and data is written faster at the outer edge than at the inner diameter. No wait time is necessary for the disc to change speeds when moving from one radius to another (Royal, 1999). DVD+RW drives can also operate in the traditional CLV (Constant Angular Velocity) mode that is used in DVD-RW format drives. To further reduce disc writing and reading times, the DVD+RW drive uses a technology called linkless editing. Data is written to DVDs in a single spiral shaped groove that starts at the center of the disc and extends outwards. This spiral is not ideal, but has a slightly sinusoidal deviation, which is called wobble, as seen in Figure 1. DVD Note that the groove is not an ideal spiral, but shifts up and down in a sinusoidal shape, called wobble. Data Groove Figure 1. Illustration of Wobble (Adapted from Understanding, p. 8, n.d.) The distance between these sinusoidal shifts determines the wobble frequency. The higher the wobble frequency, the closer together these shifts are. Data is stored on DVDs in blocks called ECC blocks. For rewritable DVDs, there exist places on the disk between some ECC blocks where writing has stopped and started again, which creates block segments. A high wobble

7 frequency allows the writing mechanism to be extremely accurate, so that the space between the block segments is very small. Linkless editing uses a very high wobble frequency to read from one segment of ECC blocks to the next without any additional linking strategies. In addition, each individual ECC block can be rewritten one at a time (Understanding, n.d.). The DVD+RW drive also eliminates the need for finalization when writing a disc. Finalization is a step in the recording process where the writing session is closed and formatting information is written to the DVD to make it readable. This step takes about the same length of time whether the amount of data written is small or large. When creating a DVD, the disc is formatted in the background (while the drive is not reading or writing). This data can be read right away. New data can be added to the disc at any time, and the formatting will pause until the drive is idle again. As an alternate to the DVD+RW drive, the DVD-RW drive reads and writes in CLV (Constant Linear Velocity) mode, where the disc spins faster when the laser is near the center, and slower when the laser is near the outer diameter. Data is written at a constant speed. When switching from one radius to another, the drive must wait for the disc rotation to increase or decrease to the proper speed before reading or writing (Royal, 1999). To handle spaces between ECC block segments, the DVD-RW drive uses a writing method called packet writing. This is a linking strategy where the spaces are included in special ECC blocks called link blocks. When an ECC block needs to be rewritten, the drive reads all of the ECC Blocks between the two Link Blocks surrounding the ECC block that is to be rewritten. Then the drive rewrites all of the ECC Blocks plus parts of the Link Blocks back onto the disc (Understanding, 1999). In early DVD-RW drives, discs required finalization and formatting before they could be read. This process could take an hour or longer for each DVD, but recent updates such as the quick format feature have significantly reduced the formatting time to only one minute. The 6

8 7 quick format feature writes temporary format information at the beginning and end of a writing session, and replaces the temporary information with final formatting information once the recording process is complete (Pioneer, 2002). Table I contains a comparison of write times of various DVD drives for the DVD+RW and DVD-RW formats. The times listed show the total time required to format a disc and write 1.18 GB of data to it. The DVD-RW times of the first three drives are from before the quick format feature was available. The last three drives are Dual format drives, which can use both DVD+RW and DVD-RW formatting. Table I. Comparison of Write Times for Various DVD Drives (Jacobi, 2002) DVD Drive DVD+RW Write Time (min:sec) DVD-RW Write Time (min:sec) CenDyne CD N/A 122:02 LaCie D2 DVD-RW U&I N/A 101:14 Pioneer DVR-A04 N/A 106:17 HP DVD Writer Dvd200i 13:27 N/A Ikebana DVD+RW/+R 7:46 N/A Memorex DVD+RW+R Internal ReWriteable Drive 7:33 N/A Pacific Digital DVD BurnerPlus U :29 N/A Philips DVDRW228 7:30 N/A Sony DRU-500A 7:48 23:29 Pioneer DVR-A06 * 22:57 28:22 Plextor PX-708A * 14:35 29:41 * (Marianna, 2003) Table II provides data on the reading speed (access time) for several DVD drives when using the DVD+RW and DVD-RW formats. Table II. Comparison of Access Times for Various DVD Drives DVD Drive DVD+RW Reading Speed (Higher is Better) DVD-RW Reading Speed (Higher is Better) TEAC DV-W50D * Memorex Dual-X1 * Ricoh MP5240A-DP ** Aopen DRW4410 ** * (4x DVD±RW Roundup Vol.1, 2003) ** (4x DVD±RW Roundup Vol.2, 2003)

9 8 2. User Functionality Among the factors that define the user functionality of a DVD recorder are the compatibility of the DVDs it writes with other DVD recorders and players, as well as the functions it can perform. The main uses for a DVD recorder are to record DVD movies, to play DVDs, and for file backup on computers. In addition, they are used to make and play CDs. Both the DVD+RW and the DVD-RW drives perform these functions. Many of the other features a DVD recorder contains may vary depending on the model, such as the software used for writing, and the available input/output connections. However some functions depend on which format is used. Table III and IV highlight some of these functions. Due to the large number of technical terms used in these tables, definitions are provided in the glossary. Table III. Comparison of Basic Functions for DVD+RW and DVD-RW Drives (Case, 2002) Function DVD+RW DVD-RW Maximum recording speed 4X 4X Uses VBR recording Yes Yes * Drag-and-Drop enabled Yes No Uses Defect Management Yes No Supported by DVD-RAM Recorders No Yes * Added in 2003 Table IV. Comparison of Video Related Functions for DVD+RW and DVD-RW Formats Feature DVD+RW DVD-RW Compatible mode (Comparison, n.d.) DVD-RW Non-compatible mode Divide title afterwards (manual making of titles) Yes No No Manually add chapters afterwards Yes No Yes Hide chapters / create playlist Yes No Yes Partial overwrite old recordings Yes No No Add new recordings to a (compatible!) disc Erase old recordings Yes - always Yes - any title No (only on unfinalized incompatible discs) Only last title (on unfinalized incompatible discs) Finalising time Not needed, always immediately compatible 5-15 minutes 5-60 minutes 5) Automatically updated picture menus Yes - Updated after each recording No n/a Edit recordings on same disc using PC Yes No n/a Picture quality Variable Bit Rate - always Constant Bit Rate (VBR on some models 6) ) Variable Bit Rate Recording time (per side) (Similar to EP, SP, and LP on a VCR) Time needed to change recording mode, or re-use finalized disc 1-4 or 1-6 hours 1) 1 and 2 hours only (1-6 on some models 6) ) Yes Yes 1-6 hours Not required 1 minute 1 minute 1) Recording modes vary between DVD+RW video recorder models. 6) As implemented in Pioneer's 2003 models. 5) In order to meet Video Recording Mode specifications.! not the same as compatible mode

10 9 Compatibility information for the DVD+RW and DVD-RW formats is provided in Table V. Table V. Compatibility of DVD+RW and DVD-RW Formats (Taylor, 2004) Compatible with: DVD+RW DVD-RW DVD-ROM disc reads reads DVD-R disc * reads reads, writes DVD-RW disc usually reads reads, writes DVD-RAM disc doesn't read doesn't read DVD+RW disc reads, writes usually reads DVD+R disc reads, may write usually reads * Modified slightly from author s content for simplicity 3. Consumer Acceptance Consumer Acceptance can be defined in terms of product sales and the cost of the DVD recorders, as well as the cost of the DVD discs. (For DVD recorder and disc costs, a lower price is obviously better, which will result in greater consumer acceptance.) Figure 2 shows both past and predicted sales data for DVD+R/RW recorders and DVD Dual drives (drives that can use both the DVD+RW and the DVD-RW formats). DVD+R/RW Shipments (All devices) 2003 Digital Tech Consulting Figure 2. Sales Data for DVD Dual and DVD+R/RW Drives (Digital, 2003) Figure 3 shows the percentage of shipments by format for the DVD Dual, DVD-R/RW, and DVD+R/RW Drives.

11 10 DVD Recordable Shipments by Format (PC and CE products) 2003 Digital Tech Consulting Figure 3. Sales Data for DVD Dual, DVD-R/RW, and DVD+R/RW Drives (Digital, 2003) Pricing for DVD recorders varies greatly depending on the brand and the features provided, but they are roughly the same for DVD+RW and DVD-RW drives of similar quantity. Table VI provides current pricing information for some DVD+RW and DVD-RW media (DVD discs). Table VI. Current Prices for DVD+RW and DVD-RW Media (Media, n.d.) Media Type Total Price Price Per Disc Ridata DVD+RW Media, 4x rewrite speed, 4.7GB, 25-pack Spindle $17 $0.68 Ridata DVD-RW Media, 4x rewrite speed, 4.7GB, 25-pack Spindle $18 $0.72 Memorex DVD-RW Media, 2x write speed, 4.7GB capacity, 10-pack in Jewel Cases $19 $1.90 Memorex DVD+RW Media, 4.7GB, 4x write speed, 10-pack with standard jewel cases $16 $1.60 Conclusions From the results of the research, it is clear that the DVD+RW format drive is highly effective as a quality DVD recorder. The technologies it employs, such as linkless editing and

12 CAV operation mode, enable it to write and read a DVD quickly. The features available with the DVD+RW format set it apart from other formats, such as drag-and-drop capability, which simplifies the copying of files to and from a DVD. This format also allows for advanced video editing features as seen in Table IV, some of which can be used even after the DVD has been recorded. It is compatible with most other types of DVD players and recorders, but is less compatible than its main competition, the DVD-RW format drive. This may change however, if the format becomes more popular, as predicted by Digital Tech Consulting in Figure 3. The DVD+RW drive shows signs of increasing consumer acceptance. In 2002, the DVD-RW drive had much higher sales than the DVD+RW drive, but the situation reversed the following year, as more consumers became familiar with the DVD+RW format. Figure 3 projects that this trend will continue. The cost of the drive has decreased greatly since it was first introduced, and should continue to decrease, as is the case with most electronic products. When compared to the DVD-RW drive, the DVD+RW drive is usually slightly faster and has more available features. However, supporters of the DVD-RW format have updated their technology to include many features that were unavailable originally, which makes the competition between the two formats closer. In choosing which format to purchase when buying a new DVD drive, a consumer should consider the application they will most use it for. If the drive will be used mainly for computer backup, DVD+RW or DVD-RAM should be used. DVD- RAM discs can be rewritten many more times than DVD+RW discs, but they can only be used for backup purposes, since they are enclosed in a case that cannot be played in any other type of DVD drive (Verbatim, n.d.). If a consumer wants to record DVDs that will be the most compatible with existing DVD players, the DVD-RW format should be considered. The best solution to compatibility however, may be to purchase a Dual Format DVD recorder, so that both DVD+RW and DVD-RW discs can be used, although these are more expensive than single format drives. 11

13 12 Glossary Chapters - A marker that can be placed anywhere on a DVD, so that the point can be easily found from the menu during playback. Compatible mode (Also called "Video Mode") - An operating mode of a DVD-RW recorder where a disc is created that can be played on a normal DVD-Video player, but none of the basic features of DVD recorders are accessible, such as making chapter stops, overwriting recordings, or adding a recording once the disc has been "finalized" (Comparison, n.d.). Defect management - A system that handles minor errors on a DVD when reading it, to prevent reading errors and drive hangups. Divide title - A DVD video feature that allows titles to be added to various sections of a DVD. As an example, if several TV shows were recorded on a DVD, titles could be added to each of them that would show up on the index as individual recordings when the DVD was played (Comparison, n.d.). Drag-and-drop - A feature of the DVD+RW format that allows easy file backup and copying on computers. Files can be copied directly between a computer and a DVD without the need for DVD burning (writing) software. (This software is required to write anything to a DVD for other formats, and to write DVD movies for the DVD+RW format.) DVD+RW Alliance - A group of electronics manufacturers who support the DVD+RW format. Its main members include Dell, HP, Mitsubish/Verbatim, Philips, Ricoh, Sony, Thomson, and Yamaha. GB - Gigabyte, or 2 30 bytes. A byte is the basic storage unit of computers and other electronic equipment. A byte contains eight bits, each of which can have a value of 0 or 1. MB - Megabyte, or 2 20 bytes. There are 1024 MB in a GB. Non-Compatible mode (Also called Video Recording mode ) - An operating mode of a DVD- RW recorder that enables a disc to be recorded with more video features. Discs recorded in this mode must be played on DVD players with extra functions in order to use these features (Comparison, n.d.). Playlist - A list that is entered by the user that allows some sections of a DVD to be viewed while other sections will be automatically skipped during playback. VBR (Variable Bit Rate) recording - A recording method that uses more memory for scenes with a lot of detail, and less memory for scenes with less detail or little activity. This allows for better image quality than if all scenes were recorded at a CBR, or constant bit rate (Comparison, n.d.).

14 13 Bibliography 4x DVD+RW Roundup Vol.1 (Teac DV-W50D & Memorex Dual-X1). (2003, November 19). (Page 6). Retrieved December 5, 2004, from Specific.aspx?ArticleId=8428&PageId=5 4x DVD+RW Roundup Vol.2 (AOpen DRW4410 & Ricoh MP5240A). (2003, October 15). (Page 6). Retrieved December 5, 2004, from Specific.aspx?ArticleId=8285&PageId=5 Case, Loyd. (2002, April 23). DVD+RW vs DVD-RW: The Key Differences. In DVD+RW Drives: Ready for Primetime? (Sect. 3). Retrieved November 14, 2004, from Comparison with DVD-R/-RW Video Recorders. (n.d.). Retrieved December 5, 2004, from Digital Tech Consulting. (2003, August 8). The Role of DVD+RW in the Computer and Consumer Electronics Industries. Retrieved November 14, 2004, from Jacobi, Jon L. (2002, December). DVD Burners Hit Prime Time (Sect 9). PC World. Retrieved December 5, 2004, from 0,aid,105848,pg,9,00.asp Marianna, Roland. (2003, November 21). Plextor PX-708A DVD±R/±RW Recorder Goes 8X. Retrieved December 5, 2004, from index.html Media. (n.d.). Retrieved December 5, 2004, from categories_major.asp?pid=214 Pioneer Corporation. (2002). Technical Information. Retrieved December 5, 2004, from Royal Philips Electronics. (1999). DVD+ReWritable: How it works. Netherlands: Royal Philips Electronics. Taylor, Jim. (2004, November 11). DVD Frequently Asked Questions (and Answers) (Sect. 4.3). Retrieved December 5, 2004, from Verbatim Corporation. (n.d.). CD, DV: Applications, Not Standards, Are the Issue. Retrieved November 14, 2004, from wp.cfm?wpid=1135 Understanding the Design of the DVD+RW and DVD+R Disc Format. (n.d.). Retrieved December 5, 2004, from DVDRW_Physical_Format_Explanation.pdf Wikipedia. (2004, November 28). DVD plus RW. Retrieved December 5, 2004, from

15 This page contains the peer edit I received from Sean. Suggestions for Dan Overall I think that this was a very well written research paper. The main suggestion I have is that perhaps you should rethink your audience. The average consumer does would not understand certain portions of your report. I liked the use of graphics and tables to portray comparison information. One other thing is the paper focused a lot on comparisons. Introduction The introduction was very good, but a few things were left out. You did not mention the sources of your information. Everything else was covered. You did a good job of giving background information and explaining the subject of the report. Results The graphs and tables in this section definitely helped illustrate what you were trying to get across. My suggestion is that there should have been a little more explanation to go with the graphs and diagrams. I think that you relied too much on the reader understanding these graphs though. Conclusion You did a good job of wrapping up the report in this section. Your recommendations were very clear. This page contains the peer edit I received from Alla. Alla Peer Edit Suggestions for Dan For the Audience Analysis Memo: I particularly liked the breakdown of how the audience affected your formatting. It was helpful that you described your potential reader and what would be of specific interest to them. For the Research Paper: I have one single suggestion for you, but otherwise there is really nothing I would change as far as the main information, organization, and writing style.

16 1. In your introduction, the last two sentences: DVD-RAM, and DVD+RW. DVD-RAM discs are useful for data storage, but cannot be played in regular DVD players. *Therefore, the comparison focuses mainly on the DVD+RW and the DVD-RW formats. *I would use a colon instead of a period I think you did a phenomenal job on your project. You really knew what you were talking about, discussed everything very coherently and organized your information well. It was great that you were able to include graphs and diagrams that were very relevant and helped a reader to understand what you were discussing at a particular point in your report. As a whole, the report seemed to flow and I feel that there was no unnecessary data. As someone that purchases this type of innovation, I feel better prepared the next time I need to make a decision as to which company to purchase from and what to look for in my analysis. PROF. LAGRANDEUR TECHNICAL WRITING RESPONSE SHEET: TECHNICAL REPORT KEY: 3=PRETTY GOOD; 2=O.K.; 1=NEEDS WORK I. CONTENT 3 II. ORGANIZATION of presentation is clear 3 III. FORMATTING of document is proper 3 IV. GRAMMAR A.) Word order is clear 3 B.) Word choices are clear and well-considered 3 C.) Punctuation 3 V. GRADE: A