VFL Format

VFL ("Versatile File List") is a textual format specially adjusted for listing audio/video files. It's a plain-text format where each line contains exactly one file name enclosed in quotation marks. File names are optionally followed by additional parameters separated by the pipe ("|") character.

Example 1: A simple VFL containing 5 media files; the last one uses absolute path:


Example 2: Files can have additional parameters:


File Names

When a file name in the list includes a drive letter or folder, that media file must be located exactly at the specified position. This can create problems if files are placed on removable media (CD-ROM) or network, because other computers may have differently mapped drive letters to them. If the VFL file is in the same folder with the media files then media files can be listed without the drive or folder. Image sequences can be open by specifying the first image and vLen > 1.


If a line starts with the "#" character the remaining text in the line is ignored. The comment marker must be the FIRST character in the line. If any spaces or tabs are preceding the comment marker, that line is NOT considered a comment.


A file name may be followed by additional parameters in no particular order. Some parameters have two versions: starting with "v" for video or with "a" for audio. This version of VFL supports the following parameters:

  • vIn=nnnn - Defines the start of video selection, in pictures, to process just a part of the video. If nothing is specified, first frame = 1.
  • vLen=nnnn - Sets the length of the video selection, in pictures. If the source is image sequence, you can open it by setting the length > 1.
  • vFps=nn.nn - Overrides the frame rate of a video or image sequence.
  • aIn=nnnn - Sets the audio in-point. Audio is processed from the specified sample on. Default value is 1.
  • aLen=nnnn - Sets the length of the audio selection, in samples.