2014-12-26, 22:39
I compared MCDI on my various Haswell systems (i3, i5, i7, etc.). While I agree that it looks great on pure 100% interlaced content, it does struggle with mixed progressive/interlaced content. Here in USA, most premium channels like HBO, SHO, etc. perform a soft-telecine where they use MPEG2 field repeat flags to save bandwidth. Inside the compressed stream they have mostly 24 fps data with flags indicating when to repeat fields to get back to the 29.97 rate specified in the MPEG2 sequence header. Because their soft-telecine is not perfect, the pattern is not regular and some frames are stored interlaced instead of progressive.
When you feed such data into many deinterlacers, you get visible stutter and not smooth motion compared to playing this content on original set-top-box.
To get around this problem, you need to honor those field repeat flags and convert all frames to constant 29.97 fps (this requires copying fields from previous frames when required according to the flags). When you do this, the deinterlacer will now see a hard-telecine video stream that runs at a constant frame rate. Usually this produces 100% smooth motion with most hardware deinterlacing systems.
Essentially, you need a pull-up filter in the chain to convert all interlaced content to a constant frame rate. I have no idea if there is currently a way to do this in Kodi. I only tested it inside my own development video player.
Another feature I have in my player is to pass-through interlaced content without deinterlacing at all. This way, I let my TV or external video processor handle it. In this case, you also need to apply the pull-up filter so that you're always sending a constant FPS over HDMI with the correct top/bottom fields displayed.
I wish I could add some of these features to Kodi but I'm not really a Linux expert and don't have much free time. I mostly work on game consoles and Windows.
When you feed such data into many deinterlacers, you get visible stutter and not smooth motion compared to playing this content on original set-top-box.
To get around this problem, you need to honor those field repeat flags and convert all frames to constant 29.97 fps (this requires copying fields from previous frames when required according to the flags). When you do this, the deinterlacer will now see a hard-telecine video stream that runs at a constant frame rate. Usually this produces 100% smooth motion with most hardware deinterlacing systems.
Essentially, you need a pull-up filter in the chain to convert all interlaced content to a constant frame rate. I have no idea if there is currently a way to do this in Kodi. I only tested it inside my own development video player.
Another feature I have in my player is to pass-through interlaced content without deinterlacing at all. This way, I let my TV or external video processor handle it. In this case, you also need to apply the pull-up filter so that you're always sending a constant FPS over HDMI with the correct top/bottom fields displayed.
I wish I could add some of these features to Kodi but I'm not really a Linux expert and don't have much free time. I mostly work on game consoles and Windows.
