Start assetWriter with video buffer

[jnoh]

Bug: The video frequently begins with a black screen.

Only start the assetWriter with a video sample. Otherwise, the output video may be missing video frames at the start of the movie. Current fix ensures that no video frames are missing.

[remirobert]

thanks for you contribution ! 🎉

[patthehuman]

This fix will still leave still frames at the beginning of the video. The problem is with the thread it's on. If you wrap the appendBuffer function block in dispatch_async(dispatch_get_main_queue()) { it will work better.

[remirobert]

I noticed that. It's because I use a different queue. 🤔

[patthehuman]

I'm still looking deeper into the issue. Looks like my solution doesn't work all the time. I'm going to try wrapping it in the pods queue to see what happens.. Do you have any suggestions @remirobert ?

[remirobert]

I am also still looking on it. queue issue for sure here.

[patthehuman]

@remirobert here is the solution: wrap the entire function block in a conditional for if CMSampleBufferDataIsReady(sampleBuffer)

Works perfectly. Would you like me to pull down changes and PR?

[remirobert]

@patthehuman awwwwww !! Yes sure go ahead with a PR