Video won't play in QuickTime X

We have server, that stored videos in QuickTime mov format, encoded by proprietary codec. We can download this videos and after that open it locally, or we can just play it streamed directly from server. In the client, user has one component for QuickTime for streaming handling and another component - codec for decoding video. Streaming handling component implemented as old Carbon 32 bit component. Codec implemented as 32 bit component too. For QuckTime 7 all works as expected, but in QuickTime X we can hear only audio, without video. How to solve problem with incorrect video playing for QuickTime X, with backward compatibility to QuickTime 7?