Memory problems with [AVAssetWriterInput requestMediaDataWhenReadyOnQueue:usingBlock:]

Question

I’m writing a library to export assets to a file using AVFoundation. I create a reader, a writer, connect the inputs and outputs to these and then call the requestMedi

Answer 1

Seeing the same (similar) issue. iOS5 happy, iOS4.3.5, not happy. Interested to learn what you ultimately find.

Got around it by explicitly retaining writer, writer input, reader, reader output before the requestMedatWhenReadyOnQueue block and explicitly releasing all four at the very end of the else clause.

The doc does say that after marking finished, "The block should then exit." Maybe they are not kidding. If you do anything other than exit, it is an error. The above workaround seems to work though.

UPDATE: I still found that it occasionally crashed even after retaining and releasing all of the asset objects. As your question observes, it crashes shortly after you mark the writer input as finished it is as if the block itself is being deallocated. Rather than just pass the block as part of the function. I create a copied block property that is part of a long lived object. I initialize it with Block_copy and only release it in the destructor of the long lived object. This seems to do the trick. I haven't seen any 4.3.5 crashes since.