Subtitles of the Movie

To round off this chapter on audio, we will explore the various audio settings that are available in Adobe Captivate. First let's take a look at how you can access the audio settings. Whilst there are many ways of calling the settings dialog box, the simplest is just to choose Audio followed by Settings. Let's start with the simple stuff in this dialog, the first of which is specifying which device you want to use to record your audio, known as the input device. Although many of you may just have one audio input, if you do have a more-advanced audio setup, then you'll be able to choose the device you want to use from this menu. Next, we have the encoding bit rate. Bit rate refers to the speed at which the bit stream, the compressed audio data will travel. Now, if you recall, Adobe Captivate always converts your audio to MP3. With MP3, the bit rate the data is encoded at is in kilobits per second or how many bits per second. By default, Captivate uses an encoding bit rate of 96 kilobits per second, which will result in a near-CD quality bit rate. However, if you are creating courses for CD, then you can choose 128 kilobits per second or CD bit rate. On top of that, if you prefer a lower bit rate, then you can choose 64, which is FM radio and for advanced users, Captivate also includes a custom bit rate and you can mov the slider either to the right or to the left to specify your desired bit rate. In this case I'm going to go back to near-CD bit rate. Next, we have encoding frequency. The encoding frequency is the sampling rate of the audio. In a nutshell, the higher the frequency, the better the quality of the published audio file. As you would probably expect, increasing the frequency will result in the audio file size also being increased. In most cases, unless you're using high-quality audio files such as music where a higher encoding rate might be useful, you should be able to get away with the default frequency, which is what Captivate uses to record and store all audio files. The encoding speed is the speed at which Captivate's encoder converts from WAV to MP3 format. In general, a higher encoding speed might reduce the quality of the output file. Choosing a higher encoding speed in some cases might increase the speed that the project is published at.