Hi All,I'm not sure if this is in the correct place since the new forums organisation, mods feel free to move if not.So i am Using AVFoundation to capture video and audio from an external device and to write to a ProRes encoded *.mov file.I started with an application that only writes video buffers to a file, and this works fine, producing a ProRes encoded .mov as expected.However when i add the Audio AssetWriterInput to the AssetWriter, the file that gets created appears to be invalid.I have checked all the return values for each step of the operation, and everything appears to be ok, it's not until i call finishWriting on the assetWriter at the very end of things that i get an error. Sadly checking this error reveals the -11800 AVErrorUnkown error, which isn't much help.Now, a few things to note- I am trying to create a file with multiple tracks of uncompressed audio. Eg 48Khz, 16-bit, however for the sake of simplicity currently my sample only uses 1 track, which means only 1 AVAssetWriterIput for the audi