Question about Realtime vs Non-Relatime.

i have Tandberg real-time encoder 5930 and 5990 for broadcasting service. but i need to prepare another vod service. my question is does non real-time encoder (like mainconcept, ateme, etc) obviously improves the picture quality than real-time encoder for VOD? i know non real-time encoder has the function of two-pass encoder for good quality, but i wonder does it really effect.

:) Conventional wisdom would assume that given the lack of broadcast time constraints, one could achieve superior quality with a high quality 2 pass encode. Just my 2 cents :)

A few things to consider though :if a comparison is made, it must be done at the highest fps/resolution at which the hardware encoder still manage realtime ( else, it would be underused, since it can't go faster than the video ) you can do two passes in realtime. Just put two encoders one ahead of the other by a few frames, and make them communicate together. For CBR, you don't need the whole movie to properly use a two passes algorithm ( or, rather, the smallness of the CPB prevent you from trying to distribute bitrate over more than a few frames ). CBR mode in x264 isn't imho ready to be compared with professionnal encoders. x264 does a very good job for two passes & CRF encodings ( in comparison to professionnal encoders ), but CBR isn't usually an interesting subject for the open source community, and hence suffers from the lack of attention.