6 Replies Latest reply: Jun 27, 2011 8:57 AM by cjd1234
Dave_E_P Level 1 (30 points)

I'm trying to edit 5 HD (1920x1080) clips (ProRes 422 LT) via Multicam but it keeps stopping/aborting.


Machine Specs :


MacPro - 8 Core (2.8Ghz)

ATI 5770


3x internal SATA as RAID 0


If I arrange the clips on a regular sequence using picture in picture (so I can see all 5 clips at the same time) everything seems to run fine but it's a pain to cut manually across all 5 tracks.


If I put these clips in to a Multicam sequence it runs for maybe 30 seconds then stops.   I can pick the angles all I want during that time, but every so often it just stops and the playhead jumps back several clips.


RT = Unlimited.

Quality and Frame Rate are currently set to Dynamic but I've also tried them on Medium/Half and Low/Quarter with no luck.



Any ideas what causes the Multicam to keep stopping?   Since I can play with picture-in-picture without any problems I was hoping this would also work in Multicam but it's not playing nicely

Mac 8 Core, 16GB, 30" + 23" Displays, 4x2TB HDDs + eSata for more!, Mac OS X (10.5.8), FCS 3, Aperture 3, Adobe CS3, MC Transport
  • RatVega™ Level 4 (2,000 points)

    Thing one: Is the Multiclip Playback option selected in the RT drop down menu?


    From your description, my first suspicion is that you may have a disk speed problem. The 30-second play is probably the amount of footage that can be fitted into the disk buffer.


    Five streams of 1080 footage in ProRes would require about something like 60-70 MB/sec continuous for playback. Even a fresh, empty SATA 2 drive would be breathing hard at that clip. There are several options to increase speed: internal or external RAID and SSD are the most practical. SATA 3 Drives are also an option. If you go external, make sure the solution can sustain twice the required transfer rate (there's more going on than just the transfer.)


    As for the PIP playing OK, I don't think that solution tries to display all the clips simultaneously in Viewer, so it probably requires less overhead.


    Hope this helps.

  • Dave_E_P Level 1 (30 points)

    RatVega™ wrote:

    Five streams of 1080 footage in ProRes would require about something like 60-70 MB/sec continuous for playback. Even a fresh, empty SATA 2 drive would be breathing hard at that clip.

    Thanks for the reply.  I really appreciate it ....




    If you read my first post you'll notice I'm running off an internal RAID 0 with THREE SATA drives feeding it.  If I run the BlackMagic speed test it says 238MB/s.    If it's hard disk speed then there's not much hope that I'll ever get this running at a rational price (e.g. replace 6TB of HDDs with SSD = broken bank).

  • RatVega™ Level 4 (2,000 points)

    DOH! I read your system specs, but from the trailer line...


    But it still sounds like a buffering issue. I'd be looking at differences in the sequences or in the playback scheme.


    (and I agree that SSDs are not an economical answer, but SATA3 is looking pretty good...)

  • cjd1234 Level 1 (5 points)

    The only time I've had a big problem is when I tried seven HDV streams.


    I cut it down to six streams and put the seventh on the Timeline in a PIP set-up like you did. It was more labor-intensive but it worked. (Just copy the properties of your clip before reducing to PIP so you can paste it back when you choose that shot. It's a huge time saver.)


    As a temporary solution, try cutting back one camera on the multclip and go PIP on the fifth. (That will be 20 percent less data on the multicam stream.) Go PIP with the clip you think you'll use the least. 

  • mark133 Level 1 (65 points)

    I'm blown away with the discovery of this technology at a commonly affordable price with my first iMac. I haven't come close to reaching fluency with everything that this system can do already. It seems almost unlimited. So I'm wondering, for what kind of project do you use 8 streams of video?

  • cjd1234 Level 1 (5 points)

    A concert or a musical would require several cameras. You could use a switcher, of course.