Premiere Pro CC 2014 Multicam Playback Dropping Frames Like Crazy
Hello all, long time lurker, first time poster,
I just finished a short mutlicam project, a musician demo with 6 separate angles and 1 music track. Footage was shot on Blackmagic 4K prores HQ. I transcoded to 1080p Prores LT for the sake of multicamming and sent the flattened version to DaVinci for the final output.
I spent the first few hours of the project though struggling with Premiere getting like 5fps while in multicam mode. I could play in real time for maybe a few seconds before it would start dropping frames, and it became unusable a second or two after that.
I called Adobe and went through the basic troubleshooting tests, deleting preferences, checking the disk with disk utility, and only got a minor improvement in the time it took to sh*t the bed. The Adobe tech concluded that it was my hard drive speed after moving the proxies to my internal SSD and having no drop frames at all.
I contacted drobo and the tech there has been giving me the runaround about what will actually fix the problem. I updated my dashboard firmware, again checked the drive with disk utility (fine both times) and they have recommended I get an mSATA card to get more speed.
I also tried shutting down and starting my computer right before trying playing, unplugging my second monitor, and disabling/enabling a few settings in premiere per some suggestions on similar Creative Cow threads I found. No success.
Thankfully this project was very small, only 1:44 and each clip was only about that long it all fit on my internal fine, but this is VERY rarely the case. I can't fit whole projects on my internal if I want to do multicam in the future. Below are my system specs. Can anyone shed any light on this?
According to my calculations the max bitrate for prores LT is around 147 so 18.375 MB/S. 6 streams of this would mean 110.25 MB/s. When doing speed tests with the blackmagic app of my drobo I get around 170 MB/s read. So this should of course saturate a lot of that but not all of it. Why am I seeing such terrible performance? (also when I play the clips in VLC the bitrate stream says around 80000 kb/s which is no where near the max you should see from prores LT)
Perhaps my math or understanding is way off
Late 2013 Mac Pro
3.5 GHz 6 core
daul AMD FirePro D500s
Hard drive specs:
Drobo Mini with 4 1TB HGST Travelstar 7200 RPM 2.5" HDDs no mSATA drive
connected via Thunderbolt
No clue on the spec side of the equipment but I've had some serious playback issues with my multicam sequence as well.
36 minutes long, Canon C300 MXF files, 4 camera angles. The way I've been working around the stuttering has been to lower the resolution of playback a little bit and double check to make sure none of the multicam sequences are also open in the source window. Oddly enough if I closed files in the source panel playback dramatically improved.
Hope this helps until a better answer is offered.
Yes, just close the source panel first. That will free up gfx performance. Are you using CUDA? Some trouble with those lately. Best to turn it off.
How big are the source files? Are they in the same place (is that an internal drive or an external)?
You are using a 1080p proxy, what type? Should be AVC-50, Pro-res proxy, or the like, and take up no more than a few (2-6) gigs per hour of video each.
I've had performance issues like this in the past, so I've learned to deal with them. With more than 4 angles, you can do some simple things to enable your system to handle the multiple inputs. First, spread them across physical devices (i.e., place them on separate esata, usb, thunderbolt, firewire drives) so that they can all be queued faster. Second, if the performance lags, set the playback res to 1\4. If you are still having trouble, clean your cache files. Still bad after this means you need more ram\better gfx processor\faster interfaces. Finally, if this won't run the multi cam script, try just doing your own playback (scrub through using the mouse or the arrow keys) and place edits with the blade, the click the right side clip and select the camera you wish to change to. You can also multi cam your audio. Alt+rightclick on the audio and enable multi cam. Make sure all audio is on in the original sequence and all cameras. Make sure your single audio track is attached to a camera track by matching number. In the nest, you can dupe the audio track, for each cam or audio mix you have in the original sequence, then alt+rightclick the audio track, and select a camera for each one, and have your multi cam monitor switch audio and video as you please at each blade mark.
As an aside to my last... ...Conventional hdd's have a bandwidth max of 6gb\s, but that's in a perfect spin world (doesn't exist). Most actually get about 30-40 with a single operation requesting info. SSD's get more like 0.5gbps though they are rated much higher with straight line reads. The problem with LT while editing is that it needs 50-75mbps. You're only getting half that, and probably less if you store other info on the drives. Try an esata raid. You might even do okay with a usb based raid (max of 480mbps but you'd be able to play the video back). Try it with a RAID with three or four drives, and the drives don't need to be big, just big enough to make the space you'd need. I'd go with prores proxy while editing and prores LT on output only. Use the offline and relink procedure to swap files in project panel. The renders will come out perfect if you export your media to prores LT for your output step and then compress that.