Edit (April 2024): Note that the So4 blacklist feature was removed in VEGAS Pro 21, as the newer mxcompoundplug became the default reader for AVC files. The feature is available in versions 15 to 20.
Short Version:
To solve sluggish playback of AVC files recorded by GoPro, DJI & Xiaomi Yi cameras in VEGAS Pro 15 build 361, move this file:
C:\Program Files\VEGAS\VEGAS Pro 15.0\FileIO Plug-Ins\so4compoundplug\so4_blacklist_vp15.xml
...to this folder:
C:\Program Files\VEGAS\VEGAS Pro 15.0\
Then restart VEGAS.
If it doesn't help, you almost certainly haven't lost anything.
This does not apply to HEVC files.
Long Version:
VEGAS Pro 15 has a new decoder, so4compoundplug.dll, that reads AVC and XAVC-S files. More details in this post.
Peculiarities in the structure of some AVC files, in particular those shot by GoPro, DJI & Xiaomi Yi cameras, mean that they currently perform poorly with this new decoder. Playback is sluggish and thumbnails build slowly. It is hoped that will be resolved in the future, but in the meantime a "blacklist" was hardcoded into VEGAS Pro 15 update 2 (Build 261) to force these formats to be decoded by the older compoundplug.dll, which enables them to play more smoothly.
In VEGAS Pro 15 update 5 (Build 361), this blacklist has been made into a separate xml file, C:\Program Files\VEGAS\VEGAS Pro 15.0\FileIO Plug-Ins\so4compoundplug\so4_blacklist_vp15.xml, containing this text:
<?xml version="1.0" encoding="utf-8"?> <filter_expr type="OR" comment="exclude IDR/I files where M = 1"> <video Title="DJI.AVC" /> <video Title="GoPro AVC" /> <video Title="XiaoYi AVC " /> </filter_expr>
Unfortunately this file is not being read in its default location. For it to be correctly read, it should be moved to C:\Program Files\VEGAS\VEGAS Pro 15.0\ and VEGAS restarted. It is intended to correct this in the next update/upgrade.
Note that AVC formats from these 3 camera brands will not be blacklisted if the Title attribute in the file's metadata is missing or does not match the description in the xml file. Others may play fine with so4compoundplug anyway.
Of course, you also have the option of completely disabling so4compoundplug.dll, but then you will lose native support for some formats such as iPhone/iPad AVC, Panasonic GH5 10-bit 422 AVC, and JVC YUV 4:2:2 AVC.
Blacklisting or Un-blacklisting Formats:
Now that the so4 blacklist has been made into a separate, editable file, it means that formats can be added or removed from it. THIS SHOULD BE DONE WITH GREAT CARE. You will probably need administrator privileges to edit the file, and you may need to copy it to a folder such as your Documents folder, edit it there, then copy it back over the original file.
There is probably no need to remove one of the 3 standard blacklisted formats, but to do so simply delete or comment out the appropriate line. Take a backup of the original file first in case you need to restore it.
To add a format to the blacklist, look for the Title or other differentiating metadata using MediaInfo on a representative file. Then add an extra line. As an example, here is a version of the file that blacklists XAVC-S (but not XAVC-L or XAVC Intra, which are decoded by mxfxavc.dll). This could be very useful for someone who is having trouble with playback or slow loading of XAVC-S files in VP15, but does not want to disable so4compoundplug completely and so lose the support for extra formats:
<?xml version="1.0" encoding="utf-8"?> <filter_expr type="OR" comment="exclude IDR/I files where M = 1"> <video Title="DJI.AVC" /> <video Title="GoPro AVC" /> <video Title="XiaoYi AVC " /> <!-- Formats below added by user --> <general Format="XAVC" /> </filter_expr>
It's a good idea to run the edited file with a tool like XML Lint or any other XML validator (e.g https://www.xmlvalidation.com/ ) to check the edits are safe.