Vegas pro will not show video for avi with mp4v fourcc codec? I have a few avi videos that are encoded with the mp4v fourcc codec. I have Sony Vegas Pro 8 and it will not open the video part. It will bring the files into the file manager, but when I drag them into the project timeline they only show the audio track as if there is no video track at all. There is no error message at all.

I would like to be able to resolve this without converting the files.
I resolved this issue by installing VLC. Apparently VLC has some necessary codecs that Vegas Pro uses.

After installing VLC I was able to import the video and use it normally with no hindrances. 



After some time, this issue cropped up on a different computer. Installing/reinstalling VLC did not work.

I installed AVI Codec Pack Pro v2.4.0 from Softpedia and the issue was resolved. 

If Softpedia no longer has the file available by the time you are reading this, the file was titled "avi.codec.pack.pro.v2.4.0.setup.exe" and was 16.7MB (17,538,685 bytes). A google search at the time of update yields other sources for download, but some are concerned with malware imbedded in it. I haven't noticed any malware with the softpedia download.