Hi - I thought I'd have a bash at implementing the BMediaFormats class in the Media Kit. I've started with the helper functions. GetBeOSFormatFor , etc. Now, for example, the GetBeOSFormatFor routine takes an argument fourcc, of type uint32, (it used to be called 'format', but it's name changed in R5). The question is - what do I do with this argument?/ For types like B_MEDIA_RAW_AUDIO, there is a corresponding 'format' variable in a subfield of the media_formats type, but other than that I'm somewhat lost. I've asked Marcus Overhagen about it, and he said to ask you guys. Can anyone tell me what I should do? Thanks, John