When rendering out still frames with movie function of Matinee, output files are always of size 0x0 and have always extension bmp, no matter which filetype has been selected.
UE Editor 4.1, OSX 10.9.2
Hey,
Thanks for your report! files being output as .bmp regardless of file type selected is a known issue that has been fixed in our latest internal build, so you will hopefully see that change soon.
.bmp files being resized to 0x0 seems to be Mac only. I was able to replicate issue, and have entered a report in our database so our developers can take a look at it. Thanks for letting us know you found issue!
Thank you for nice words, will try to dive a bit deeper in code.