[mediafreak]

Hi there,

first I'd like to say thanks for all your work on xbmc, imho the best media center out there!!

Some months ago I bought a HD capable beamer and connected it using the Hi-Def AV Pack. XBMC looks really nice in 720p! However there are some issues playing back videos. There is no default Interlaced handling setting that really fits the needs for progressive output of mixed content.

When using "Auto", xbmc tries to sync interlaces videos, which of cause is pointless when using progressive output and causes interlacing artifacts. When using "DeInterlace", this works well for interlaced videos. But this also does deinterlace all progressive content, effectively cutting vertical resolution in half. Progressive videos look really much worse then, especially on large HD output.

I have hundrets of music videos, there is no chance to set interlaced handling for all of them individually. I'd really need a setting that does deinterlace interlaced video but leave progressive content untouched! This would be really great for all users with progressive / HD displays!!


One more suggestion: In the video settings it is possible to set a different output resolution for videos. This does offer 720p, 480p and NTSC for me. As the mplayer deinterlacer is not so great, I had the idea to play videos in NTSC, leaving the deinterlacing to my beamer which has really nice hardware deinterlacing built in. However, if I set to NTSC, I still get 480p output, not NTSC (480i). Is it possible to add real 480i output when using progressive modes? Then one could use the sync modes on interlaced video and leave deinterlacing to the TV sets.

[mediafreak]

Sorry to bump this up, but I think this is a serious issue, how come noone responded yet? I am sure I'm not the only user with progressive/HD output, there should be quite many xbmc users affected.

Basically, no matter what deinterlace setting you use as default, you will either have *all* content being deinterlaced (also progressive video, leaving many artifacts when using HD out), or you have interlaced videos without any deinterlacing. So no matter what you choose, you will have degraded image quality on either interlaced or on progressive video files.

Am I the only one feeling uncomfortable with this? I mean it can't be that hard to disable deinterlacing in case the video is not interlaced, is it? The selected deinterlacing mode should only be applied if the video actually is interlaced imho.

[elupus]

the problem is to know if a video is interlaced. it isn't as simple as you'd think. you have to analyse the fields in comparison to eachother. It takes memory and alot of cpu power, not to mention i'm not sure how to do it.

"Is it possible to add real 480i output when using progressive modes?"
contradiction in terms.. 480i is not progressive.. but i can't see why you shouldn't be able to set 480i even if you have a hd pack.

[mediafreak]

the problem is to know if a video is interlaced. it isn't as simple as you'd think. you have to analyse the fields in comparison to eachother.

Hm that would be bad... I don't know mplayer, but in Directshow you can easily get a VideoInfo(2) structure containing format info such as resolution, aspect ratio, framerate and frame format (progressive/interlaced). This information is taken directly from the video stream headers. Some of this information is displayed in xbmc when pressing "info", so I thought it would not be too hard to get the frame format, too...?

Also, can't this be distinguished to some degree by checking the video codec? Mpeg1 does not allow interlaced content at all for example. And xvid/divx does not (or at least should not) contain interlaced material. The only formats that do really support interlacing are mpeg2 and h.264.

"Is it possible to add real 480i output when using progressive modes?"
contradiction in terms.. 480i is not progressive.. but i can't see why you shouldn't be able to set 480i even if you have a hd pack.

Oops I ment to output 480i with HD/component kit connected. But this now works with the latest version. Prevoiusly I had 480p when selecting NTSC or PAL.

[elupus]

currently that is what we try to do.. mpeg1 can't store interlaced content efficiently, however nothing hinders stupid encoders to store it as interlaced.

mpeg2 can natively store interlaced content efficiently, however it does require that whoever encoded the content set all flags properly, which is quite as common as one would hope.

[mediafreak]

Hm okay I understand that it is not easy. But simply deinterlacing everything just because you can't be sure it is progressive seems wrong to me. That way you will definately have many files handled wrong.

I would simply disable deinterlacing for *any* kind of format except mpeg2. At least when "Auto" mode is selected. And perhaps deinterlace mpeg2 only if it is not tagged progressive. From my experience most wrongly tagged mpeg2 files only have wrong frame order or something like that.

Mpeg1 music videos already look horribly on a beamer, but wrongly deinterlaced mpeg1 videos (resulting in half vertical res) will get you eye cancer for sure. Same goes for divx/xvid files, deinterlacing them cuts resolution in half and adds artifacts...