Google Video Files (.gvi), and latterly its .avi files, are modified Audio Video Interleave (.avi) files that have an extra list containing the FourCC "goog" immediately following the header. The list can be removed with a hex editor to avoid playback issues with various video players. The video is encoded in MPEG-4 ASP alongside an MP3 audio stream. MPEG-4 video players can render .gvi Google Video Files without format conversion (after changing the extension from .gvi to .avi, although this method of just renaming the file extension does not work with videos purchased with DRM to inhibit unauthorized copying. Among other software VirtualDub is able to read .gvi files and allows the user to convert them into different formats of choice. There are also privately developed software solutions, such as GVideo Fix, that can convert them to .avi format without recompression. MEncoder with "-oac copy -ovc copy" as parameters also suffices.