Interlaced/Progressive question regarding ts files

[uncertainty]

I'm currently using Megui (along with the built in avisynth) to convert my ts collection to x.264. All the ts material is HDTV both in 720p and 1080i flavor. The one item that intrigues me is how can some of my 1080i ts files be progressive when viewed frame by frame and also megui's analyzer determines it to be progressive also. I guess I would have thought any material that is 1920x1080i would have to be some flavor of interlaced and I'm still trying to understand how it can be progressive?

thanks

[Awatef]

This is something we usually encounter in PAL DVDs: progressive content that is encoded in interlaced mode, that's all there is to it ;)
So don't worry, as long as you don't see any combing, your source is truly progressive and you can skip deinterlacing alright :)

[Mug Funky]

the way something is encoded does not always relate to what the footage actually is :)

especially in broadcast, you can never be sure if a signal is interlaced or progressive. even with a pure progressive source, any glitch in the chain will cause brief moments of interlace (tape glitch, bad connections, etc). at the present time most TV stations still use tapes and hardware to broadcast digital content. this means everything is encoded as it plays, meaning one can't take the time to see what they're actually encoding. so they play it safe and set the encoder to interlaced for everything.

in the next few years this situation is likely to change to server based playback - rather like an mp3 playlist. this means things can be encoded offline in better quality and with settings customized to each source. but the only station i know of that does this type of broadcast is currently making a complete balls-up of it, so you'll have to wait a bit for it to be really perfect.