一,代码片段
BOOL appendSuccess = [self appendToAdapter:_adaptor
pixelBuffer:pixelBuffer
atTime:_presentTime
withInput:_writerInput];
NSAssert(appendSuccess, @"Failed to append");
==========
NSParameterAssert(_writerInput);
NSParameterAssert([_videoWriter canAddInput:_writerInput]);
原文:http://www.cnblogs.com/xuqf2iOS/p/5895440.html