The look of 1080i@50fps not playing back correctly on all players

EighthGear

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Currently XBMC 11.04 Eden, PowerDVD 12 and TotalMedia Theatre 5 all playback the Top Gear Hanger scenes (intro, the news, star in a car...) with that very smooth 50 frames per second look. But VLC (1.1.12 & 2.0), MPlayerX and Mac BluRay Player do not and look very choppy.

What processing is and isn't going on between these players that make the playback look either extremely smooth (like motion interpolation) or relatively choppy.

I am watching on a 60Hz North American LCD TV.

Thanks guys.
 
Let's wait for the Germans to chime in. Meanwhile Doom9 forums might be a better place to ask.
 
It could be because we don't release the VFR (variable frame rate) versions of the 1080i file. Hangar scenes are a different fps than the non-Hangar scenes. VFR allows for that disparity.
The frame-rate is a constant 50i, but i think BBC HD uses a technique called MBAFF, whereby interlaced and progressive frames can be displayed in the same source. With de-interlacing disabled, interlacing is visible in the sections mentioned by the OP, but not in the film sections (50 vs 25). Because the progressive sections are displayed at 25fps rather than 50 there is in theory no more required bandwidth. Just my thoughts :D, feel free to correct.

In response to the OP, it may be useful to check what de-interlacing settings are being applied in each program. It could be that in VLC, a filter such as discard is being used, whereby the hanger sections would be reduced to 25fps; making them slightly choppy as described. The best filter that I have observed in any program is yadif2x in VLC. It requires a capable machine but delivers fantastic results.
 
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Brilliant! Yadif (2x) does appear to produce the smoothing effect! problem is my MacBook Air i7 1.8Ghz is not powerful enough and is dropping frames with it turned on :mad:

Now I must figure out what exactly is going on in the Yadif (2x) de-interlace filter and XBMC, PowerDVD etc. that smooths out 50i so well.

I assume if anyone from the UK that watches Top Gear straight from cable instead of these torrents would be seeing a very smooth image being processed by their cable box or TV. Come to think of it I wunder if I can get my TV to do the de-interlacing instead of my computer, I suppose that 's another topic I must research.

I do really enjoy the smooth look of the interlaced 50fps scenes.

thanks a bunch guys!
 
After watching the 720p torrent version I found it in fact does not have the smooth effect. And I must say besides loosing the smoothness that I like, I also find the 720p conversion far inferior to the 1080i file. Guess my critical eye has become much better tuned to discern quality these days. :p
 
After watching the 720p torrent version I found it in fact does not have the smooth effect. And I must say besides loosing the smoothness that I like, I also find the 720p conversion far inferior to the 1080i file. Guess my critical eye has become much better tuned to discern quality these days. :p

Ok, I put this on my FTP in the TG S18 folder: Top Gear S18E01 720p HDTV VFR x264-CtrlHD.mkv (2.03 GB)

Let us know what you think.
 
Ah success! the VFR 720p file is just as fluid and smooth as the 1080i file with Yadif(2) or Bob interlacing! Just the 720p does not need on the fly interlacing obviously so it doesn't take nearly as much CPU and GPU power to play.

Though now I have the best of both worlds. I took the 1080i file and ran it through Handbrake with Bob DeComb and poof, 1080p50fps progressive during the hanger scenes and 1080p25fps during the cinematic scenes. This is nice because my computer drops some frames with Yadif (2x) and I can stream the .mov file to my Blu-Ray player.
 
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