code: def decode_to_pipe(
      infile,
      fmt="f32le",
      sample_rate=None,
      num_channels=1,
      channel=None,
      skip=None,
      max_len=None,
      buf_size=-1,
      cmd="ffmpeg",
      replaygain_mode=None,
      replaygain_preamp=0.0,
  ):
      """
      Decode the given audio and return a file-like object for reading the
      samples, as well as a process object.
  
      Parameters
      ----------
      infile : str
          Name of the audio sound file to decode.
      fmt : {'f32le', 's16le'}, optional
          Format of the samples:
          - 'f32le' for float32, little-endian,
          - 's16le' for signed 16-bit int, little-endian.
      sample_rate : int, optional
          Sample rate to re-sample the signal to (if set) [Hz].
      num_channels : int, optional
          Number of channels to reduce the signal to.
          If 'None', return the signal with its original channels,
          or whatever is selected by `channel`.
      channel : int, optional
          When reducing a signal to `num_channels` of 1, use this channel,
          or 'None' to return the average across all channels.
      skip : float, optional
          Number of seconds to skip at beginning of file.
      max_len : float, optional
          Maximum length in seconds to decode.
      buf_size : int, optional
          Size of buffer for the file-like object:
          - '-1' means OS default (default),
          - '0' means unbuffered,
          - '1' means line-buffered, any other value is the buffer size in bytes.
      cmd : {'ffmpeg','avconv'}, optional
          Decoding command (defaults to ffmpeg, alternatively supports avconv).
      replaygain_mode : {None, 'track','album'}, optional
          Specify the ReplayGain volume-levelling mode (None to disable).
      replaygain_preamp : float, optional
          ReplayGain preamp volume change level (in dB).
  
      Returns
      -------
      pipe : file-like object
          File-like object for reading the decoded samples.
      proc : process object
          Process object for the decoding process.
  
      Notes
      -----
      To stop decoding the file, call close() on the returned file-like object,
      then call wait() on the returned process object.
  
      """
      # check input file type
      if not isinstance(infile, (string_types, file_types, Signal)):
          raise ValueError(
              "only file names, file objects or Signal instances "
              "are supported as `infile`, not %s." % infile
          )
      # Note: closing the file-like object only stops decoding because ffmpeg
      #       reacts on that. A cleaner solution would be calling proc.terminate
      #       explicitly, but this is only available in Python 2.6+. proc.wait
      #       needs to be called in any case.
      call = _ffmpeg_call(
          infile,
          "pipe:1",
          fmt,
          sample_rate,
          num_channels,
          channel,
          skip,
          max_len,
          cmd,
          replaygain_mode=replaygain_mode,
          replaygain_preamp=replaygain_preamp,
      )
      # redirect stdout to a pipe and buffer as requested
      if isinstance(infile, (Signal, file_types)):
          proc = subprocess.Popen(
              call,
              stdin=subprocess.PIPE,
              stdout=subprocess.PIPE,
              bufsize=buf_size,
          )
      else:
          proc = subprocess.Popen(
              call, stdout=subprocess.PIPE, bufsize=buf_size
          )
      return proc.stdout, proc
  
imports: from __future__ import absolute_import, division, print_function
  import errno
  import os
  import subprocess
  import sys
  import tempfile
  import numpy
  from ..audio.signal import Signal
  from ..utils import string_types, file_types
label_desc: Use image node_id 4 for calling a global function with example usage: decode_to_pipe(infile, fmt, sample_rate, num_channels, channel, skip, max_len, buf_size, cmd, replaygain_mode, replaygain_preamp) and returns: proc,  proc