Avisynth Audio=True

Internal functions - Avisynth wiki

http://avisynth.nl/index.php/Internal_functions

DirectShowSource - Avisynth wiki

http://avisynth.nl/index.php/DirectShowSource

Using AviSynth 2.5 (page 6/15): Opening Sources ...

https://www.afterdawn.com/guides/archive/using_avisynth_page_6.cfm

This is controlled by the values for "video" and "audio", which both default to True. "pixel_type" works similarly to the same option in AviSource. In this case, however, if AviSynth asks for a colorspace the DirectShow filter used to decode the video can't supply, the default (DirectX) code converts it to the requested colorspace.

AviSource - AviSynth

https://avisynth.sinsixx.com/AviSource.html

AviFileSource(string filename [, ... ], [bool audio = true], [string pixel_type = YV12], [string fourCC]) WavSource(string filename [, ... ]) AviSource takes as argument one or more file name in quotes, and reads in the file(s) using either the Video-for-Windows "AVIFile" interface, or AviSynth's built-in OpenDML code (taken from VirtualDub). This filter can read any file for which there's an AVIFile …

Avisynth Crossfades - VideoHelp Forum

https://forum.videohelp.com/threads/355061-Avisynth-Crossfades

I do almost all of my video work in Avisynth but am frustrated by the fact that there appear to be no true audio crossfades available. For very simple work at quiet moments in an audio track, I can use the Dissolve() function with satisfactory results, but there are times when simply blending two streams linearly is not enough.

Amplify - Avisynth wiki

http://avisynth.nl/index.php/Amplify

Trim - Avisynth wiki

http://avisynth.nl/index.php/Trim