I have recently purchased Jaksta for Windows, and am running the latest version (126.96.36.199). I am having a problem recording BBC iPlayer videos. I was pleased that they were detected, and the full files were downloaded. However, although the file plays on the Jaksta Player, Windows Media Player and also on Quicktime on the Mac, I only have audio - the video screen is black. Streaming the videos through the browser (Edge) shows normal videio. When I inspect the file, it shows that the MP4 file consists of H.264 video and the appropriate bitrate, and AAC audio. I don't know what could be causing this problem, and would be grateful for any help that you can offer.
Your video player will need to support H.264 video and AAC audio if that is what you have downloaded. Otherwise convert it to the codecs you require for your player.
VLC is the best player out there: https://www.videolan.org/vlc/index.html
Depends what the H.264 profile is that is used and what the player supports.
VLC is your best bet to play anything. WMP and QuickTime are extremely limited as players.