canvas size of 21360 X 720
this is not a standard Video frame size at All ! and that's why you are getting a BLACK frame as an output
assuming you know what you are doing when rendering that many pixels - if it's that many pixels you cannot view this file in it's entirety on a monitor or get a decent playback. you need to reduce it's size for the preview. I believe that with that many pixels there is also no projector that could play it as a one single piece, and usually you have a number of projectors screening overlapping parts of the image. but this is another matter. hopefully you know what you are doing and the problem right now is just to get a decent preview
10% of 21360x720 is 2136x72 and this is makes more sense for previewing for your client. you could easily set it up by taking your master composition of 21360x720 and placing it inside another - this now will be your preview comp. now you need to reduce it's size - u can use the built in script - "Scale Composition". (file->scale composition) and enter a scale factor of 0.1.
now you have a composition of 2136x72 - send it to AME, choose a preset, and there you go.
I have an AE project that I'm working on for a client with a canvas size of 21360 X 720, and the output movie spec is either AVI MOV or MP4 with the same aspect ratio. I'm not getting anything to work.
Because the spec is probably nonsense. If there is a specific device-dependent CoDec of some dedicated playback hardware involved, your client has to provide it, but that seems doubtful, because most likely they don't know what they are asking for themselves and only forward info from a third party. Likewise, if there is another means or method for playing back the file(s) via multiple synced recorders and signal splitters involved, you have to inquire about it and produce the relevant output. This issue has nothing to do with AE and can't be solved there nor can it be solved by attempting to force some CoDecs to do what they are not designed for. Sorry, but again, such odd and illogical requirements really come across like there is several people involved and nobody has the slightest clue what is actualyl needed to make it work. I guess you have to talk...
Hi All thanks for the input! We think that is the answer I calculated all the different aspect ratios the client is asking for and many are relly off the wall. Either we are dealing with multiple displays, typing errors, or the client doesn't know whats needed. Thanks for all your help!