By default, wmv, avi, mpg/ts/m2ts files are streamable, except in case of srt/sub file present with the same file name. All videos can be transcoded, as each streamable video appears once into its folder, and once into a special folder "#Transcoded#" present in each sub folder, with different options (audio/subtitles/other transcoding tools maybe) so you can choose what's working best on ps3. For the audio part, only ogg, flac, mpc audio files and such can be transcoded: You can however force or skip transcode for specific file extensions (check the transcode settings panel)