I'm having trouble working with video files from my R5. Previously, I shot a lot of videos with a Canon EOS R and I usually had C.Log enabled. I don't think I ever tried shooting a 4K video with my R. I never had any problems playing/editing that footage in Resolve v16 (or any other video player). I know the R generated H.264 video and my R5 generates H.265. I tried working with the R5 files in v16 and since it didn't work, upgraded to v17.2. It still doesn't work.
I am running a Windows 10 MSI GS73VR 6RF laptop that has an Intel i7-6700HQ CPU, both integrated Intel graphics, and an NVidia GeForce GTX 1060 graphics processor, and 32Gb of RAM. BTW, normally I have no trouble playing and viewing 4K video with my laptop. It has a 17.3" 4K screen.
I shot 2 video files with my Canon EOS R5. The settings for my first video were 4K-U 23.98fps ALL-I. The second video was shot in 1080P (FHD), 29.97fps ALL-I. Both were shot with C.Log enabled. When I try playing these video files with the VLC media player, the 4K video plays jerky (it shows stills periodically) but the audio sounds normal. The 1080p files play just fine.
In Resolve v17.2, I tried adding both of the R5's MP4 files to a project. It seems like Resolve treats them like audio-only files. It shows only the audio waveform and no video frames. Clicking on the play button only plays the audio.
I downloaded the latest H.265 Windows 10 codecs from the Microsoft store and it still isn't working.
Someone in the Blackmagic (Resolve's developer) forum said the free version of Resolve can't decode 10-bit HEVC h.265 files. It wasn't clear if this also applied to the Studio (paid) version. He said I probably need to transcode the files to a 10-bit intermediate format because my system isn't going to have an easy time of it, playing 4K H.265. Someone else reiterated this by saying, "There is nothing on your system that can hardware decode HEVC 4.2.2. IIRC all the C.Log files are 4.2.2."
Note: HEVC (H.265) and H.264 are codecs. 4:2:0 and 4:2:2 are chroma subsamplings. And things like C.Log and Rec709 are gamma/gamuts. All completely independent of each other. Thus, the following info will specifically be in terms of the codec only (won't matter the chroma, gamut, etc.)
For playback, most modern computers should be OK with H.265. Dedicated hardware would be a must though for encoding. For this reason, I avoid exporting final projects to H.265 even on my 18-core iMac Pro. Since encoding is all done in software and takes way too long. My next Mac will have dedicated H.265 hardware.
Now then, for an NLE, it will not only will be decoding H.265 for playback while you edit, but will need to apply effects, etc. And if you have multiple streams playing at once, that could bog things down. Here, a hardware-based codec would definitely help with playback (decode) as well.
If you have the option, I would suggest capturing future footage in H.264 until you have better software and/or hardware solutions. For existing H.265 footage, unfortunately transcoding may be your only option.
you're right greggp, I had just encountered this problem and googled for the answer on this question. indeed r5 doesn't film in H.264. Does it happen with the premiere pro as well? I don't have this issue I'm just interested what works and what doesn't. I'm actually just starting my path of filming and editing videos so I am like a child who asks a lot of questions!) Last 2 months I was editing videos using https://www.fastreel.com/video-maker.html so now I think I should move to such software as DaVinci and so on. What do you think?