Having a delegate can lead to black video output

[gsabran]

I don't understand the reason well, but setting a delegate can lead to the result being black. I've noticed that having a delegate leads to extra things being run: https://github.com/rs/SDAVAssetExportSession/blob/master/SDAVAssetExportSession.m#L243-L254

so that's probably creating the issue, even though I'm not sure how

[joshbax]

I believe it's because the delegate uses a AVAssetWriterInputPixelBufferAdaptor with hardcoded attributes. Try modifying these lines. On iOS, this might work: (id)kCVPixelBufferPixelFormatTypeKey : @(kCVPixelFormatType_420YpCbCr8BiPlanarFullRange)

[shahen94]

@joshbax i tried your suggestion, it doesn't fix the issue

[sjmueller]

We are experiencing this as well. Happens about every 6-8 videos. Any other suggestions?

[sjmueller]

A bit more info, it's actually not an intermittent problem as I previously thought. For us, the front camera works fine, but the back camera always renders black. If you look closely, our videos have a 1 pixel vertical line in which you see part of the video playing while the rest is black. Audio works fine.

We tried @joshbax suggestion, and also tried changes made in this PR: https://github.com/rs/SDAVAssetExportSession/pull/58/files#diff-31ccfacb15a054f36d2e5b7b1d4ec6d2R137

Unfortunately, nothing worked and we haven't found a solution yet.

[gsabran]

I personally ended up changing the delegate to just be exportSession:renderFrame:withPresentationTime: ie ditching the buffer property and its computation that was causing the issue since I didn't need it