Render Previews Size and Aspect Ratio

Question

We are currently editing several projects that have an odd editing dimension but a standard output dimension.  These videos are for a live event with rows of four projection screens set somewhat tightly together.  From a production standpoint, we wanted to have content flow freely across all four screens.  We prefer not to have to visualize this, so we set up a "Desktop" mode, square pixel sequence within a project with a dimension of 2560 x 540.  The 2560 dimension is because most of the footage is from the Panasonic P2 camera (HVX200P).  This camera shoots video at a rectangular pixel dimension of 1280 x 1080.  The pixel aspect ratio is 1.5.  So 1.5 times 1280 = 1920, the final output square pixel dimension. In this case the final output WOULD be 1920 x 2 or 3840 x 540 high. 3840 divided by 4 = 960 x 540.  So we're outputting standard def widescreen to each screen.  Premiere automatically creates the final output through nesting the 2560 x 540 sequence twice in a DVCPROHD 1080i sequence of standard size.  The two 2560 x 540 sequences, one on video layer 1 and the other on video layer 2 are positioned so that the video that corresponds to screen one is positioned top-far right and the second instance of the sequence is positioned bottom far left. The final output file is an avi in the Canopus HQ codec at 1920 x 1080.  This output file is a video that is actually four standard def videos in one 1920 x 1080 video. The Grass Valley Turbo 2 outputs this standard hi-def  file to a Vista Spyder which will isolate and project the four videos-in-one, to the appropriate four screens.
This type of project would not have been possible without CS5 and Mercury.  Premiere is handling this oddity extremely well.
One minor issue for the support gurus:
When we render the Desktop mode square pixel 2560 x 540 sequence timeline, we get what appears to be random, mixed render results.  Sometimes this odd shape renders perfectly, other times it renders out to small dimension that is less than half size.  Other times if renders out with pieces of the elements small. but positioned with spaces between them.  Playing around with sequence render settings and playback resolution, sometimes SEEMS to cause the render to correct itself.  Sometimes a computer restart SEEMS to correct the issue.  Any thoughts?

Answer 1

Colin Brougham wrote:
Barring previewing, are you able to export to your intermediate/final movie without problems?
The final exported video is 1920 x 1080. I have test exported in a number of formats without any problems at all.
The 2560 x 540 version, (BEFORE it is "processed" through 2 instances of itself in a standard DVCPROHD sequence) is for editing purposes only, so we can actually see how the video will play across four projection screens.
The remaining issue I'm trying to work out is, how to best get the finished video into the grass valley Turbo 2.  The Turbo 2 takes an AVI file transcoded into the Canopus HQ codec natively without having to transcode.  The only way to get an avi from Premiere Pro CS5 into the Canopus HQ codec is to first export the finished video as an uncompressed avi from Premiere, import it into either "Edius" or "Procoder 3" and export in the HQ codec.  The export from Premiere CS5 + Mercury takes 15 minutes.  The export (HQ encoded file) from the trial version of Edius takes around 10 minutes.  IMO grass valley should create a plug-in for Premiere CS5 and shouldn't allow the quickest export to be Canopus exclusive.  I seriously doubt many Premiere CS5 users will switching to Edius any time soon.
According to grass valley, the Turbo 2 will accept an MPEG-2 Pgm Stream, whatever the heck a Pgm Stream is???.  I did a Google search without success.  Of course Premiere will export an MPEG-2 file, but how the Pgm Stream relates to this, I have no idea. There are a mind boggling array of settings and the preset seems to export a rather compressed looking video.
My current thinking is to try to convince the boss to buy Procoder 3.
BTW:
the 3840 x 540 version sequence renders fine part of the time and then for whatever reason starts creating a preview that is about 35% of the correct dimension... So back to the original Sequence settings of 2560 x 540