No one really knows if it was doctored for sure or not. I'm not sure anyone cares either, because it's not like CNN/<insert media outlet> has never done any creative editing of their own. That concern there might as well be satire.
Some have speculated the choppy framerate may have been because of a conversion from 30fps (around that amount) video to a gif/gif-like format. The video that was released by the White House was the first one I watched and it did seem to be a very poor video. If they really pulled it from Alex Jones feed though, then that was just dumb. If they have access to the video, they should post original content.
There's very good reason for CNN to want to push this issue though of video doctoring, but it's not for the reasons most are suggesting it is. I don't think it has to do with partisanship at all.
As Alf has mentioned, there are many who are starting to prefer alternative sources to mainstream. There is a war between TV and social media/the internet for the "relevancy" crown as well. Online gets crazy views/clicks compared to TV now. It's a no-brainer that's where things are heading. Even Tucker Carlson (Fox) was recently interviewing with alternative media saying he was super jealous. Not only could they do whatever they wanted with their studio, but they had such an audience. Yes, they don't have the "footprint" of sattelite offices and such to cover for international events, etc... but I think it's no question, aside from local, Cable News is quickly becoming a thing of the past.
When I was watching the big networks before/post-2016, they did make it a regular point to pan all non-"mainstream" sources as suspect, potential fake news, "questionable", etc. Yes, that was usually right-wing, but they don't care about the right wing audience (Fox has them in the hole), so in downplaying it to be a left/right versus thing... what they're saying is, if you're like "one of us", then keep watching cable because we cater to you. Even though there are left-wing sources (Like The Young Turks). The demographics though favor right-wing media atm in terms of online. So CNN still has reasonble access to the female audience as well with their coverage of the Woman's March/feminism's goals, etc. So it's really just strategy I think more than partisanship.
Trump releases his updates on Twitter for example, and if you notice, many of the reporter's questions are about always about his
tweeting. That's because they know that's what people are talking about, so they create little story archs around his Twitter persona. Even if the story doesn't go beyond navel-gazing, which makes their punditry look sad, but it's terrible for business if all people just go straight to twitter for the "buzz" and don't check with TV media on their opinion of it. Cable News here is really dependent on Washington for their audience, so if the President and his ilk start relying more heavily on online to get their message out, then there's really no other reason to watch cable then.
That's why Fox is more than happy to cater him in terms of his schedule, his call-ins, his weird ranting style on their network, etc... yes, it seems a bit friendly, but we can certainly say that about MSNBC/CNN during Obama era anyway. So I think Cable News will always be in bed with Washington to some degree in order to maintain their relevancy... but yeah, that same tactic that helps preserve them, may eventually rid them of all authenticity, so I think it is a difficult line to toe with the rise of online competition...
Another CNN-related online video scandal some have probably forgotten by now...
CNN faces backlash over handling of doctored Trump video
https://www.cnbc.com/2017/07/06/cnn-...ump-video.html
https://www.cnbc.com/2017/07/06/cnn-...ump-video.html