Common Audio Formats settings in Compressor
Four built-in settings in Compressor use the Common Audio Formats transcoding format: AIFF File (Audio Interchange File Format), CAF File (Apple Core Audio Format), FLAC File (Free Lossless Audio Codec), and WAVE File (Waveform Audio File Format).
Note: You can also create custom settings that use the Common Audio Formats transcoding format. However, the built-in settings (in the Settings pane) analyze your source media and assign optimal properties to ensure the best possible transcoding results.
The properties of built-in and custom settings that use this transcoding format are located in the General inspector and Audio inspector (described below).
Displays the setting name and transcoding format, as well as an estimated output file size. When you add a setting to a job or change the setting’s properties, this summary is automatically updated.
Name: Displays the name of the setting.
Description: Displays the description of the setting.
Extension: Displays the extension of the output file (.aiff, .caf, .flac, or .wav).
Tip: To output a file with a different extension, change the value in the “File type” pop-up menu, described below.
Allow job segmenting: This checkbox is dimmed because job segmenting is not available for settings that output only an audio file.
Default location: Choose an item from the pop-up menu to set the default save location for transcoded files.
File type: Choose a file type from the pop-up menu (AIFF, CAF, FLAC, or WAVE).
This area contains one property:
Set duration to: Sets the processing algorithm used to adjust the frame rate during transcoding. Select either of the following options:
[Percentage] of source: Modifies the output clip’s speed by a percentage of the source clip’s speed. Enter a value in the percentage field or choose a preset value from the adjacent pop-up menu (with a down arrow).
[Total duration]: Sets the duration of the clip. Enter a timecode duration in the field or click the arrows to increase or decrease the time.
For more information, see Retime video and audio using Compressor.
Channel layout: Use this pop-up menu to manually set the type of audio channel layout. For more information about audio channel layouts, including the surround sound channel layout, see Audio channel layouts in Compressor.
Sample rate: Use this pop-up menu to set the number of times per second that music waveforms (samples) are captured digitally. The higher the sample rate, the higher the audio quality and the larger the file size.
Sample size: Use this pop-up menu to manually set the sample size of the audio signal.
Format: Use this pop-up menu to set the format of the audio output.
Quality: Use this pop-up menu to select the quality of the audio output.
Bit rate: Use this pop-up menu to set the bit rate for the encoded audio.
Bit rate strategy: Use this pop-up menu to select the strategy used to encode the audio. There are four options:
Constant bit rate: Uses the value set in “Bit rate” to determine the bit rate for the encoded audio.
Average bit rate: Uses the value set in “Bit rate” to determine the target average bit rate for the encoded audio. This option provides a more consistent bit rate than variable bit rate.
Variable bit rate constrained: Uses the value set in “Bit rate” to determine the maximum bit rate for the encoded audio.
Variable bit rate: Encodes the audio using a variable bit rate determined by Compressor.
Compression: Use this pop-up menu to manually set the amount of compression the FLAC encoder uses to encode the audio signal. This setting is only available for FLAC file types.
For a list of available audio effects and instructions on how to add an audio effect to a setting, see Add and remove effects in Compressor.