AVF Batch Converter fails to copy video tracks

[mcorke]

In the AVF Batch Converter app, if you choose "Don't Recompress Video" and then select "Copy video tracks from files" you end up with the resulting file having no video track and being automatically trashed due to an error in the process. I haven't really dug in and spent a ton of time finding an elegant fix, but I have a solution that seems to work. At issue is that in VVAVFTranscoder.m, in transcodeFileAtPath, the variable 'imgBufferIsFineOrIrrelevant' is set to NO if 'tmpImgBuffer' is NULL. I'm assuming there's no 'tmpImgBuffer' when copying a video track, and therefore with 'imgBufferIsFineOrIrrelevant' being set to NO it doesn't copy the track, throws an error, and the resulting output file is automatically trashed. I have added a relatively crude fix that checks for 'transcodeThisTrack' in addition to checking if 'tmpImgBuffer' is NULL. If the track isn't being transcoded - i.e. it is being copied - then 'imgBufferIsFineOrIrrelevant' remains == YES and the process succeeds with no error. This requires adding a local variable for 'transcodeThisTrack'. N.B. I haven't done exhaustive testing on this, but so far seems OK.