During installation you'll be prompted to select which components should be installed. Given the total size of all components (4MB) you should make sure everything is installed.
Offline Configuration
Most settings in AC3Filter can be set before you ever use it. Although the exact settings you use will vary based on your computer and attached speakers, but shouldn't vary much from one source to another. If you run into source files that require some different settings you can adjust them on the fly, which we'll cover in the last section of the guide. You can get to the configuration options (Properties dialog) from the AC3Filter folder on the Start Menu.
Main
As the name suggests, the Main tab contains the main settings for AC3Filter. If you're sending AC3Filter's output to a surround sound equipped home theater receiver you only need to set the Output Format to AS IS (No Change) and PCM 16bit (for standard Dolby Digital or DTS) and check the Use SPDIF checkbox. This will bypass AC3Filter's internal processing and send the original signal through your S/PDIF connection.
Unchecking the Use SPDIF box will allow you to adjust the output via AC3Filter's Mixer. Using the slider bars, you can adjust both Gain (volume increase or decrease) and DRC (dynamic range compression that reduces the difference in volume between very loud and very quiet sounds). For output using the Mixer the output format should be set to match your soundcard or home theater receiver's configuration.
Gains
The Gains tab gives you access to detailed settings for each channel. If you don't experience any playback issues that need correction you shouldn't ever need to worry about these settings. If you want to use the Mixer all the relevant settings are here.
Gains
The various Gain sliders adjust the volume of individual channels, groups of channels, or all channels. Increasing the Gain of properly mixed and encoded surround sound will usually result in lower quality, but poor quality DVDs or DTV broadcasts may benefit from these adjustments. If, like the majority of people, you don't have speakers that are all perfectly designed to work with each other or in your viewing space you may find adjustments to individual channels helpful. However, if your home theater receiver has similar features they should be used instead.
DRC
Dynamic Range Compression, or DRC, reduces the difference between very loud and very quiet sounds in an audio stream, making it possible to play a movie with loud explosions and quiet dialog without the viewer having to adjust the volume for one or the other. It's generally unsuitable for music.
The most important setting on the SPDIF tab is SPDIF Passthrough. If you have a Dolby Digital, DTS, or MPEG Audio decoder in your receiver, checking the appropriate box ensures the signal will be passed through untouched by AC3Filter.
AC3 Encoder
AC3Filter can re-encode MPEG Audio or DTS streams to Dolby Digital (AC-3), which can then be sent across your S/PDIF connection to a home theater receiver. If you have 6 analog surround connections between your computer and receiver you shouldn't need to use this option.
System
The System tab allows you to configure which audio formats AC3Filter will be set to decode, as well as the decoder merit. In DirectShow, the filter with the highest merit is used by most applications. If AC3Filter is set to a lower merit than another decoder, such as ffvfw or a Dolby Digital decoder installed with DVD player software, it may not be used at all.
Tray Icon
Enabling the tray icon will allow you to make changes to AC3Filter settings during playback so you don't have to guess at the exact settings you need during Offline Configuration.
AC3Filter is designed to compensate for jitter, which is the cause of some audio synchronization problems. If the audio plays either slightly behind or ahead of the video you can sometimes use the Time Shift slider to get them into sync with each other. This is best done during playback so you can be sure the adjustment is correct.
Changing Settings During Playback
While most configuration should be done ahead of time based on your computer and speaker configuration, some adjustments are best made while a file is being played in order to fine tune them. The last section of this guide will show you how to do that once you've enabled the tray icon in AC3Filter's System settings.
S/PDIF, also referred to as SPDIF, is a data link and physical specification for transmitting digital audio streams. S/PDIF signals may be sent across coaxial or optical (TOSLINK) cables. It stands for Sony/Phillips Digital Interconnect Format.... (Read More)
Jitter comes in many forms, but the one common factor between them is a failure to deliver data in a timely fashion for realtime decoding, such as CD or DVD playback. Jitter is perhaps most famously used to refer to dropouts in audio CDs when one or more samples are difficult for the CD drive or player to read and must be skipped.... (Read More)
