[IanD]

Unless you want to purchase a standalone player or media player that supports frame rate conversion for output (with associated artifacts), I think your only practical solution is to decode->process->re-encode.

IIRC BD does not support 25p, only 50i: that is why titles are authored as 50i even though they might be shot at 25p or 50i native. If truly 25p, then you only need to weave the fields, slow down the video and adjust the audio. If 50i native, you will need a more complicated de-interlacing step.

50i does not use pulldown flags, so there is nothing to remove from the original stream to convert to 24fps. I don't think there is even any indication as to whether the source was 25p or 50i: it's just 50i and the display has to handle it as best it can.

Because it is encoded as 50i, it is not possible to simply convert 25p->24p in TsMuxer et al: that's why you only get half height video if you attempt it as it is just pulling off only the even or odd fields to get the 25p frame rate.

There are quite a number of titles authored at 50i, so you are likely to come across this issue on occasion when purchasing documentaries (or even Doctor Who) from Europe, although the majority are 24p.

I know it involves re-encoding, but you can decode DTS-HD MA to LPCM and resample to adjust length, then use the multi-channel LPCM for playback as Bluray supports it (although it occupies more space than the original DTS soundtrack).

Use this experience as a learning exercise not to purchase further 50i titles from the UK. Often they have a converted alternative available in the USA that is compatible with USA players.