Using Movie Clips in PowerPoint Presentations: Part 1, Compatibility Issues

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1 Movie Clips in Presentation s Computers in Radiology Chun-Shan Yam 1 Jonathan Kruskal Michael Larson Yam C-S, Kruskal J, Larson M DOI: /AJR Received February 11, 2005; accepted after revision March 22, All authors: Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, WCC, Room 306, 330 Brookline Ave., Boston, MA Address correspondence to C.-S. Yam (csyam@caregroup.harvard.edu). AJR 2005;185: X/05/ American Roentgen Ray Society Using Movie Clips in Presentations: Part 1, Compatibility Issues OBJECTIVE. The purpose of this article is to discuss common compatibility issues relating to the use of movie clips in presentations. CONCLUSION. Our investigations found that successful display of movie clips in depends on the following three factors: movie file format, codec selection, and crossplatform compatibility. These factors primarily result from the rapid change in today s computer operating systems. Based on a compatibility study of common movie clips used in radiology presentations, a general guideline for preparing movie clips is presented. Also, a simple method is described for converting movie clips into compatible movie formats and reducing large movie clips to manageable file sizes to ensure smooth presentation. ith advancements in highspeed computing, multide- W tector scanning, and realtime image processing, many functional studies and protocols that could not be accomplished previously can now be routinely performed. For example, a full cardiac CT angiography study can be performed on a 64-MDCT scanner (Aquilion, Toshiba) in just 10 sec. Subsequently, nearly 1,000 images can be produced and transferred to an image processing workstation in less than 10 min. In addition to providing a swift and streamlined scanning workflow, most of today s image processing workstations, such as Advantage Windows (GE Healthcare), Vitrea (Vital Images), and InSight (Neo Imagery Technologies), are user-friendly. In all these workstations, 3D models can be rendered and displayed virtually in real time using state-of-the-art volume rendering algorithms with just a couple of mouse clicks. For example, a screenshot image of a volume-rendered cardiac model is shown in Figure 1. More important, users can easily capture these screenshot images and create movie clips that can be imported directly into (Microsoft). For many academic radiologists, creating movie clips for subsequent presentation has become part of the academic workflow. Depending on the application, a movie clip can be as simple as a series of axial images or as sophisticated as a fly-through cine loop of a virtual colonoscopy. Despite the ease and convenience of creating movie clips, however, there are still problems with using them in presentations. Many of these problems are the result of the rapid change in today s operating systems. The purpose of this article is to discuss these common issues and to provide a general guideline for successful presentation of movie clips in. Common Issues of Using Movie Clips in Codec Selection A codec (COmpressor and DECompressor) is a software algorithm used to compress and decompress digital videotape or audio files. The purpose of using a codec in movie clips is to reduce file size. This is especially important for today s multimedia applications over the Internet, where transmission of huge data files is a common bottleneck issue. Although using a codec can greatly reduce file size, the absence of a specific codec at the client computer will prevent the movie clip from displaying. For instance, some movie clips that can be displayed in older operating systems (e.g., Windows [Microsoft] NT, Windows 2000, and Macintosh OS 9.0 [Apple Computer]) will no longer function in the latest Windows XP version without the purchase and installation of an additional third-party codec, for example, Indeo codec (Ligos Systems) (Fig. 2) AJR:185, October 2005

2 Movie Clips in Presentations Fig. 1 Screen capture of 3D cardiac model generated at Insight workstation (Neo Imagery Technology) from series of 658 CT images obtained from 64-MDCT scanner (Aquilion, Toshiba). Scanning parameters are 120 kv, 0.5 mm, 80 ma, 200-msec temporal resolution, retrospective ECG-gating, and IV contrast material. Fig. 2 Screen capture of error message in 2002 (Windows XP Professional, both Microsoft) when displaying movie clip without proper codec. In this example, movie clip was saved in AVI (Audio Video Interleave) format and was inserted into previously using Ligos Indeo R4.4 codec. However, this codec is no longer available in Windows XP operating systems. Similar error messages will appear when any invalid movie clip attempts to display during presentation. Although this specific codec has been included with or is available for many Windows and Macintosh operating systems and is currently installed on more than 50 million PC and Macintosh desktops [1], Microsoft has decided not to include this codec in the latest Windows XP operating system. As a result of this decision, users must purchase and install the Indeo codec from Ligos Systems ($14.95) on each of the client computers for this particular type of movie to display [2, 3]. Although this example is specific to Windows XP and Ligos Systems, similar issues can also occur with other operating systems where a codec is used to compress movie clips. File Size To avoid the codec dependency issue, some of today s workstation manufacturers are cautious not to apply any data compression to their movie clips (or, at least, use uncompressed as the default movie format). The file size of uncompressed movie clips can be quite large. For example, the file size of a 20-sec movie clip with typical settings of 10 frames per second, uncompressed, red green blue color, and pixels is 150 MB. Generally, the file size (in bytes) of a typical uncompressed color movie clip can be calculated using the following formula: AJR:185, October

3 Size = (time in sec) (frames per sec) (image width) (image height) 3. Although most of today s portable storage media can be used to store large data files (e.g., 700-MB CD-R [CD-recordable] and 1-GB USB [universal serial bus] drives), using large movie clips in Power- Point will present problems such as system crashes or sluggish presentations, especially when a client computer is using a slow processor or does not have sufficient random access memory (RAM). At least 256 MB of RAM is generally necessary. Platform Compatibility Another frequently encountered issue is platform compatibility. Many movie clips created on the Windows platform are not compatible with Macintosh and vice versa. Although some movie formats claim to be cross-platform for both Windows and Macintosh [3], the true display capability in is still an ongoing issue. For example, the Apple QuickTime movies (.mov. or.qt) cannot be imported into in Windows XP unless a change is made to the Windows registry [3]. Similarly, MPEG-1 (Moving Picture Experts Group) is the only movie format supported by Power- Point on both Windows and Macintosh systems. Any higher version (i.e., MPEG-2, MPEG-3, or MPEG-4) cannot be used. Guideline for Preparing Movie Clips To ensure smooth presentation, simple precautions can and should be made when using movie clips in. For this purpose, we generated an array of sample movie clips using common movie formats and parameters. We examined the compatibility of each of these movies in different computer operating systems and versions. For practical reasons, we examined the movie formats that are commonly available in today s radiology environment from PACS and image processing workstations that is, QuickTime (Apple Computer), MPEG, and AVI (Audio Video Interleave). These common movie formats are generally cross-platform and compatible with common Web browsers, and they are also being used in many Web-based radiology presentations (e.g., the recommended movie formats for the Radiological Society of North America 2004 annual meeting at and the GE Scientific Movie Library at /video/medical/index.html). Nonetheless, the ability to display on the Internet does not necessarily ensure equivalent compatibility in. Tables 1 3 contain summaries of the results from a compatibility study of these three movie formats in different operating systems and Power- Point versions. Our study showed that Cinepak (Compression Technologies) and MPEG-1 are the most appropriate choices for presentations. Also, users can use our study results as a general guideline for movie conversions if necessary. For movie conversion, we suggest using a commercial software utility QuickTime Pro. Movie Conversion Using QuickTime Pro QuickTime Pro ($29.99; Apple Computer; is one of the most common software applications for digital movie editing. Unlike other professional TABLE 1: AVI a Format Results of b Compatibility Study Operating System Version Uncompressed Cinepak c Indeo d MS Video1 b Windows XP b 2003, 2002, 2000 Yes Yes No Yes Windows , 2002, 2000 Yes Yes Yes Yes Windows NT, , 1997 Yes Yes Yes Yes Macintosh OS X e 2004, v.x Yes Yes No Yes Macintosh OS , 1998 Yes Yes No Yes a Audio Video Interleave. c Compression Technologies. d Ligos Systems. e Apple Computer. TABLE 2: QuickTime a Format Results of b Compatibility Study Operating System Version Uncompressed Cinepak c Indeo d Sorenson e Windows XP b 2003, 2002, 2000 No Yes No No Windows , 2002, 2000 No Yes No No Windows NT, , 1997 No Yes No No Macintosh OS X a 2004, v.x Yes Yes No Yes Macintosh OS , 1998 Yes Yes No Yes a Apple Computer. c Compression Technologies. d Ligos Systems. e Sorenson. TABLE 3: MPEG a Format Results of b Compatibility Study a Operating System Version MPEG-1 MPEG-2 MPEG-4 Windows XP b 2003, 2002, 2000 Yes No No Windows , 2002, 2000 Yes No No Windows NT, , 1997 Yes No No Macintosh OS X c 2004, v.x Yes No No Macintosh OS , 1998 Yes No No a Moving Picture Experts Group. c Apple Computer AJR:185, October 2005

4 Movie Clips in Presentations Fig. 3 Screen captures of QuickTime Pro (Apple Computer) showing functions for importing movie clip. Top: Open Movie in New Player function and viewing detailed movie properties. Bottom: Get Movie Properties function. applications such as Premiere Pro ($699; Adobe Systems; and Xpress Pro ($1,699; Avid Technology; which are typically expensive and designed particularly for movie production, QuickTime Pro is cross-platform, low-cost, and user-friendly. QuickTime Pro is the professional version of the freeware Quick- Time Player. Unlike the freeware player, which can be used only for viewing movies, the professional version provides many other functions such as movie creation, conversion, editing, and scripting. To activate the professional version, a license key, which can be purchased online at the Apple Web site, is required. The software installation is straightforward for both Macintosh and Windows versions. Although there are many useful movie editing functions in Quick- Time Pro, in this article, we will only discuss the simple 2-step function for movie conversions. More detailed information for other functions can be found at the QuickTime Developers Web site [4]. For illustration, we will discuss the essential steps in converting a sample AVI movie clip from Indeo 4.4 to Cinepak codec, so that it will be compatible with many operating systems, including Windows XP. Step 1: Import Movie Clips In QuickTime Pro, select Open Movie in New Player function from the File dropdown menu to import an existing movie clip (Fig. 3). After importing, detailed information of the movie clip can be reviewed using the Get Movie Properties function from the Movie dropdown menu (Fig. 3). Step 2: Export Movie Clips Once a movie is imported, it can be saved in different formats using the Export function from the File dropdown menu in QuickTime Pro (Fig. 3). In the Save Exported window, select the movie format and then click the Option button for codec selection (Fig. 4). Although AVI and Cinepak are selected for this illustration, other movie formats and codecs can be used (see Tables 1 3). File Size Reduction As mentioned above, some movie clips obtained from workstations are uncompressed and large (> 100 MB). To reduce file size, these movies can be compressed using a -compatible movie format and/or codec based on our results presented in Tables 1 3. For illustration, we compared the file size of our sample AVI movie clip using different movie format and codec combinations (Table 4). Our study showed that movie compression can greatly reduce file size. For example, using Cinepak codec for both AVI and QuickTime formats can reduce the movie file to less than 10% of the original file size without causing significant resolution change. Alternatives and Limitations Although AVI, QuickTime, and MPEG are the most common movie files obtained from AJR:185, October

5 Fig. 4 Screen captures of QuickTime Pro (Apple Computer) showing process steps for converting movie format. In this example, codec of AVI (Audio Video Interleave) movie clip is converted from Indeo (Ligos Systems) to Cinepak (Compression Technologies). Current formats and codecs supported by QuickTime Pro are available at QuickTime Support Web site [5]. TABLE 4: Comparison of File Size Using Different Movie Format and Codec Settings Movie Format Codec File Size (MB) AVI a None 50 AVI Cinepak b 2.96 AVI MS Video 1 c 4.23 QuickTime d Cinepak 3.45 MPEG e MPEG Note Best image quality was used in codec settings for all these movies. a Audio Video Interleaved. b Compression Technologies. c Microsoft. d Apple Computer. e Moving Picture Experts Group. today s image processing workstations, other media files can also be used in, for example, animated GIF files, WMV files (Windows movie videotape, Microsoft), and Shockwave (Macromedia) files. However, it is not within the scope of this article to discuss the applications of these types of media files. Although we have discussed compatibility issues in this article (part 1), we have not yet described how to edit the contents of movie clips (e.g., brightness and contrast, cropping, masking, arrow drawing, and image rotation). In part 2, we will discuss a simple method for performing image processing on movie clips using common software such as Adobe Photoshop. Conclusion In this article we have discussed the pitfalls of compatibility and file size issues in using movie clips in and provided a general guideline for movie format and codec selections. We have also described a simple method for converting movie clips into compatible movie formats and reducing large movie clips to manageable file sizes. References 1. Ligos Systems Web site. Available at: 2. Ligos Systems Support Web site. Available at: Accessed July 8, Microsoft Support Web site. Available at: support.microsoft.com/default.aspx?scid=kb;enus; QuickTime Developer Web site. Available at: Accessed July 8, QuickTime Support Web site. Available at: AJR:185, October 2005