Calculate Amplitude Envelope for Audio Segment

Calculates the amplitude envelope for a specified segment of an audio file.

Usage

amp_env(
  segment_row,
  wav_dir = NULL,
  msmooth = NULL,
  amp_normalize = c("none", "peak", "rms"),
  plot = FALSE
)

Arguments

segment_row

A row from either find_motif output or segment class in SAP object

wav_dir

Optional path to WAV files directory (default: NULL)

msmooth

Numeric vector of length 2 for envelope smoothing:

• First value: Window length in number of points

• Second value: Overlap between windows (percentage)

If NULL, no smoothing is applied

amp_normalize

Waveform amplitude normalization before envelope extraction: one of "none", "peak", or "rms" (default: "none")

plot

Logical, whether to plot the envelope (default: FALSE)

Value

A numeric vector containing the amplitude envelope values

Details

The function processes audio segments with the following steps:

• Validates input segment data

• Constructs correct file path

• Reads specified portion of audio file

• Calculates amplitude envelope

• Optionally smooths and normalizes the envelope

See also

find_motif for creating segment data

Examples

if (FALSE) { # \dontrun{
# Basic envelope calculation
env <- amp_env(segments[1, ], wav_dir = "path/to/wavs")

# With smoothing and normalization
env <- amp_env(segments[1, ],
  wav_dir = "path/to/wavs",
  msmooth = c(256, 50)
)

# With waveform peak normalization
env <- amp_env(segments[1, ],
  wav_dir = "path/to/wavs",
  msmooth = c(256, 50),
  amp_normalize = "peak"
)

# With waveform RMS normalization
env <- amp_env(segments[1, ],
  wav_dir = "path/to/wavs",
  msmooth = c(256, 50),
  amp_normalize = "rms"
)

# With plot
env <- amp_env(segments[1, ],
  wav_dir = "path/to/wavs",
  msmooth = c(256, 50),
  plot = TRUE
)
} # }