Ryzen r7 1700, and even the upcoming R5 1600 should both handily beat a 7700k in video rendering/other workstation tasks, yes the 7700k has higher clock speeds for similar ipc, but in applications that use multiple threads the 6 real cores and 12 threads (50% more than 7700k) of r5-1600 or the 8 real cores and 16 threads (100% more than 7700k) of the r7 1700 will take the cake.
Overclocked to the limit, so lets say 5Ghz the 7700k should have a roughly 1Ghz clock speed advantage, and with similar ipc (instructions per clock) a single core on the i7 will be roughly 20% faster than ryzen. Which is why it does better in games than ryzen. However workstation tasks like editing tend to use more cores than games do. So having 50% more cores in something like the r5 1600 will result in an overall advantage over the i7 of about 20%. And having 100% more cores in the r7 1700 will result in an advantage of 60% over the i7.
Lets recap
In games, which are generally limited to 4 cores the ryzen cpus theoretically should be 20% behind intel.
However in video editing, rendering, etc the Ryzen R5-1600 should be about 20% faster than an i7 and the R7-1700 should be about 60% faster than the i7.
In short, for editing you should pick ryzen all day long. For gaming intel is faster, but it must be noted, that difference is usually the difference between 130fps and 100fps. So unless your running a 144 hertz monitor you won't see a difference.