User Guide to the QTW.INI INTRODUCTION As was previously mentioned, QuickTime for Windows achieves its perfor- mance advantage by checking your hardware configuration, and if it recog- nizes the video card's chipset as one that can be optimized, it attempts direct hardware access. As an end user, it is relatively easy to open your QTW.INI file and gets some important information from it. From the Program Manager, select "Run" from the File menu. In the command line, simply type, "QTW.INI". Notepad should open up with your copy of the QTW.INI file. The top section contains most of the information we need. It may look something like this: [QuickTime for Windows] VHDW Component=Base Apple VHDW Component Video Hardware=8-bit palettized pixels; S3 801 or 805 internal hardware support Implementation=Full [Video] PreferredComponent=C:\WINDOWS\SYSTEM\QTVHDW.QTC Lets examine each line of the .INI file, and see what significance it has on the overall performance of QuickTime. The first line, [QuickTime for Windows], is a section header whose information directly indicates QuickTime's hardware support options. The second line, VHDW Component= Base AppleVHDW Component, indicates that QuickTime is using a standard base level hardware support component in order to write directly to the hardware. The next line, Video Hardware=8-bit palettized pixels; S3 801 or 805 internal hardware, is very important in regards to performance. If this line has information in it, it means that QuickTime has recognized the video hardware. In this case, QuickTime has recognized this chipset as being either a S3 801 or 805 chipset. It will achieve the highest quality performance for the PC's video bus. For example, if you have direct hardware support, but have an ISA card, you will get the maximum performance allowable for the data transfer bandwidth of an ISA card. If you have a supported VLB card, you should get the very best video playback performance. The next line of the file indicates that all QuickTime options are installed and available. This line should always say "Full". The next section is the Video section. The line directly under it will specify the path to the component that QuickTime is using in order to write directly to the video frame buffers. Make sure never to delete this file, or QuickTime will have to resort to GDI level performance. Now lets look at a file from a machine that does not offer direct hardware support. [QuickTime for Windows] Implementation=Full VHDW Component=None Video Hardware=Not directly supported As you can see, quite a bit of information is left out here. You will notice that no VHDW component is specified, and the Video Hardware section indicated that it is not directly supported. There is also no [Video] section in this document. Not having direct hardware support does not necessarily mean bad performance though. If you have a machine without direct hardware support, but you have a VLB card, you will not see optimal performance, but the high data transfer rate of the card should yield good performance. If however, you have an non-optimized chipset, and it is also and ISA card, you will notice some performance degradation due to the data bus bottleneck. A section near the end of the file may also have some important significance. Let's take a look: [Override] oldVersion=38 This section lets you know that you have an older version of QuickTime on your drive. Generally, it's not good to have older versions of QuickTime around. The qtold.dll checks for older versions of QuickTime on your drive whenever QuickTime is initialized. If it finds one, it adds a digit to this counter. Whenever old Version gets to a multiple of ten, a warning message appears after QuickTime is initialized that advises the user of the older version. To determine if you have an older version floating around, set this number to one that ends in 9, and launch the Movie Player. If you got the warning dialogue, you have an older version on your drive. The best way to get rid of older versions of QuickTime is to run the latest QuickTime installer. It automatically searches for older version, and gives you the option of getting rid of them. TROUBLESHOOTING While the QTW .Ini file's main purpose is to record and track your machine's hardware specifications, there are some other uses for it that can help increase performance for machines experiencing playback problems. As was previously mentioned, the Video section of the .ini file controls the preferred playback driver for the video data tracks. If you have supported hardware, the information in this section should have a path statement to the preferred QuickTime component that will be used to provide direct hardware access. If you don't have supported hardware, and you are experiencing playback problems with video, a simple edit in this section will help solve performance problems. If you have a PCI video card, QuickTime 2.0 does not currently have supported drivers to optimize access to the hardware. If you have a PCI card, you may be experiencing some playback performance problems. Adding the following lines to the QTW .INI file may help alleviate those issues. Here are the lines to add. You should not already have a [Video] section and should add these lines [Video] Optimize=Driver That's it. Save and close the .ini file and the next time you launch QuickTime you should see some performance gains. If you have some other video card and your performance is not what you would expect for the hardware, try the above solution. If that still does not do the job, try this modification to the file instead: [Video] Optimize=BMP You should remember to save and close the file and relaunch QuickTime to examine the results.