I have a set of images that are quite wide, that exceed 16384 pixels in width.
On Mac OSX10.11 and using AVAssetWriter, I can write these images as frames to a AVFileTypeQuickTimeMovie file using AVVideoCodecJPEG, AVVideoCodecAppleProRes422 or AVVideoCodecAppleProRes4444 codecs. There is no issue during that process, no errors are presented. (AVVideoCodecH264 fails above 8688-width, but that's another story).
However, trying to open the resulting file afterwards using AVAssetReader fails... which is also the case with QuickTime Player. It appears black in QuickTime Player 10.4. I assume this is a limitation of AVFoundation in both these cases (the file appears white in QuickTimePro 7).
And yet that same file will open fine with something like MPEGStreamClip.
The same behaviour is seen if I use OSX Finder Services to convert a wide source movie to ProRes format, say... many movies work fine, but ones over 16384 in width don't work with QTPlayer/Pro7-- but, again, the resulting file can be opened in MPEGStreamClip.
In all cases, if I keep the file to 16384-width, I can open it just fine in both QTPlayer/Pro7.
So.... AVAssetWriter can produce something that AVAssetReader can't use? Can anyone provide any insight on this matter?
