A little help about exporting 720p 50fps video (PAL), I tried to find answer here but...

Hi,

I need your little help about exporting video which had been originally shooted on 50 fps with around 42496 data rate and it is already synchronized in Adobe Premiere perfectly with audio (external audio, and not from the source, of course). Video needs to be conform to PAL standard and it will be used for broadcasting purpose, probably 25 fps. But now I am afraid of dropping too much frames after exporting and loosing its sync after it, so I need your advice since I searched a forum about similar questions, but I am still not sure what I exactly to do to this right ? I just got shooted material and I can't change anything, I need to find right solution in post. I made a list of possible codecs which broadcaster possible accept:

• Apple Pro Res 422/ HQ (but how to deal with an alpha channel ?)

• XDCAM HD422 1080i 50 (50mb/s)

• XDCAM HD720p25 (50mb/s)

• MPEG IMX 625/50 (50mb/s)

• DV PAL

• HDV 1080i50

• HDV 720p25

• DVCPRO 50 PAL

What codec I need to choose to fit my purpose the best?

My client wants perfect sync with audio in the exported version with normal playback speed, but I am afraid of the possibility of getting a unusual speed changes after export or just loosing that video/audio sync, because of dropping the frame rate caused by wrong codec applied! What I need to do ? We cannot shooted all thing again, take this in consideration please.

Thank you very much.