Table of Contents
Advertisement
AUDIO EDITOR: CHAPTER TWO
325
Quantizing a waveform
When you record audio data, you need to indicate the sample size, or the
number of bits used to store the resulting file. This can be either 8-bit or
16-bit. The more bits the better the quality of the recording, but the
greater the size of the audio file. If you need to reduce file size, but still
want to maintain a good level of quality, you can quantize the file by
clicking Effect: Quantize. This command opens a dialog box which
allows you to specify the number of bits allocated to the file, 1-7 for 8-bit
files and 1-15 for 16-bit files. Often, a small reduction in the number of
bits is all you need to bring the file size down while at the same time
maintaining audible quality. (If you reduce the number of bits too much,
you will 'clip' the sound, thereby producing noticeable distortion.)
Working with silence
From a computer's perspective, silence is amplitude point 0 in a waveform
(the baseline). Silence is useful in audio editing, particularly for what it
isn't rather than what it does. For example, silence is responsible for
adding and removing time to an audio file, and timing is perhaps one of the
most important aspects of any audio sequence. For example, the sound of
a door opening must be timed to occur after the sound of the key entering
the lock. Also, if you are creating a video project you will have events
occurring at specific times and these all require an audio track that
complements those times.
If you want to add silence to a waveform, click Edit: Insert Silence.
This opens the Insert Silence dialog box where you can enter the time
range you want to add in minutes, seconds, and milliseconds (M:S:ms).
Once you click OK, the silence is added to the waveform at the cursor's
position, increasing the length of the audio file accordingly. To remove
silence, click Edit: Trim Silence. In the Trim Silence dialog box that
opens, you can specify to remove all silent areas in the file or just those
matching a specified duration, measured in M:S:ms.
Advertisement
Table of Contents
