I tried to encode some videos to MP4-SP with the intention that they would work with the iPod, mp4-capable cellphones (e.g. the latest Symbian ones) and the PSP. No cake. Each one of these use their own version (or part) of mpeg4 and so they are not really compatible with eachother. I tried a gazillion front-ends and backends and encoders and muxers, but none creates a universally accepted MP4-SP format. Even the highly acclaimed ‘PSP Video 9′ utility produced an SP-CBR MP4 video that won’t even play on PSP’s latest firmware. I am ok with the differences between the XviD and MP4-SP formats, but when you have incompatibilities between the supposedly same kind of MP4-SP format, that really pisses me off. And it’s all the MPEG Groups’ fault for allowing their licensees to take apart the standard and only implement bits and pieces as they see fit, resulting in this shameful incompatibility. Who wants to have a different copy of the same video for their iPod, their PSP and their cellphone? Transcoding a movie takes about 1.5 hours! Imaging having to do that 3 times.