I use both flavors of Sony XAVC long GOP UHD files at 100Mbp/s. However, I have always noticed that Vegas handles H.264 in an .MP4 container much, MUCH better than it does in an .MXF container. Why is this the case? Is the .MXF container "that" much harder to unpack? Does the .MXF container cause "that" much overhead? Or, is it something that Vegas is not doing correctly? I have also noticed that Premiere handles .MP4 better than .MXF too. However, it's differences are not as dramatic as Vegas. Even VLC player struggles with .MXF far more that it does with a similar UHD file inside .MP4.
We know the H.264 CODEC is virtually identicle inside the two container types. I know the Sony H.264 CODEC in the .MXF version only has one small MPEG tool activated that the .MP4 version does not. (off the top of my head, I cant remember that mode type but it's very small)
Can anybody shed light on this problem? I'd LOVE to see Vegas finally improve Sony XAVC-L playback (long GOP h.264 in .MXF)