Audio Data Structures

The following data types are used by After Effects to describe audio data.

Structure	Description
PF_SoundFormat	Indicates whether the audio is in unsigned pulse code modulation (PCM), signed PCM, or floating point format.
PF_SoundSampleSize	Samples are in 1, 2, or 4 byte format.
PF_SoundChannels	Indicates whether the audio is mono or stereo.
PF_SoundFormatInfo	Contains the sampling rate, number of channels, sample size, and format of the audio to which it refers.
PF_SoundWorld	Use PF_SoundWorlds to represent audio. In addition to a PF_SoundFormatInfo, they contain the length of the audio, and a pointer to the actual audio data.

PF_SoundFormat, PF_SoundSampleSize, and PF_SoundChannels are all contained within a PF_SoundFormatInfo.

PF_SoundWorlds contain a PF_SoundFormatInfo, and further instance-specific information.