I'm updating an application to be 64-bit-compatible, but I'm having a little difficulty with our movie recording code. We have a FireWire camera that feeds YUV frames into our application, which we process and encode out to disk within an MPEG4 movie. Currently, we are using the C-based QuickTime API to do this (using Image Compression Manager, etc.), but the old QuickTime API does not have support for 64 bit.
My first attempt was to use QTKit's QTMovie and encode individual frames using -addImage:forDuration:withAttributes:, but that requires the creation of an NSImage for each frame (which is computationally expensive) and it does not do temporal compression, so it doesn't generate the most compact files.
I'd like to use something like QTKit Capture's QTCaptureMovieFileOutput, but I can't figure out how to feed raw frames into that which aren't associated with a QTCaptureInput. We can't use our camera directly with QTKit Capture because of our need to manually control the gain, exposure, etc. for it.
On Lion, we now have the AVAssetWriter class in AVFoundation which lets you do this, but I still have to target Snow Leopard for the time being, so I'm trying to find a solution that works there as well.
Therefore, is there a way to do non-QuickTime frame-by-frame recording of video that is more efficient than QTMovie's -addImage:forDuration:withAttributes: and produces file sizes comparable to what the older QuickTime API can?