DrScotsman
9th July 2005, 01:16
I'm currently using YATTA on a part telecined part interlaced MPEG2 (from a DVD) to get a mixed fps MKV. Now when making it through, I discovered this very strange part:
The part. Compressed with FFMpeg, but given the XviD fourcc. (http://www.nuticulus.net/drscotsman/!trash/clip.avi)
I see it like this. If you feed this through AviSynth and use SeparateFields on it, you'll see it follows a pattern like this:
Even fields: A1 B D E1 G
Odd fields: A2 C E2 F H
Where for example A1 and A2 are the even and odd fields of frame A, E2 and E1 are the odd and even fields of frame E, and the rest are individual fields. If it helps, here's regular telecine for comparison:
Even fields: A1 B1 B1 C1 D1
Odd fields: A2 B2 C2 D2 D2
If to say telecining is converting 24p to 60i, then to me, this looks like a 48p to 60i conversion, as for every 10 fields you get 8 frames (although not FULL frames). Seems they sped up the 24p source to 48p then converted it to 60i.
Sorry if I've messed up the explaination, but I'm tired right now so I hope you can figure it out what I mean =P. Look at the clip if you're confused. Feel free to correct me if I'm wrong.
Anyway to the point, what's the best way to fix this? Although I'm using YATTA to created a mixed FPS MKV, it'd be very easy for me if the framerate I achieve for this part is either 24 or 30, as it'd take a lot of manual calculations for other framerates.
One way I can think of is to resize up the individual fields to frames, thus gaining frames A-H (B-D and F-H just being fields with double the height of course) and then selecting every 2nd frame, i.e. A, C, E, H (so only every 2nd frame is low quality). However for the latter part of the clip where there is little motion (after the scroll up), this is probably the worst method. Hence why I'm asking here for the best AviSynth method.
Thanks in advance, if you need more information then just ask.
The part. Compressed with FFMpeg, but given the XviD fourcc. (http://www.nuticulus.net/drscotsman/!trash/clip.avi)
I see it like this. If you feed this through AviSynth and use SeparateFields on it, you'll see it follows a pattern like this:
Even fields: A1 B D E1 G
Odd fields: A2 C E2 F H
Where for example A1 and A2 are the even and odd fields of frame A, E2 and E1 are the odd and even fields of frame E, and the rest are individual fields. If it helps, here's regular telecine for comparison:
Even fields: A1 B1 B1 C1 D1
Odd fields: A2 B2 C2 D2 D2
If to say telecining is converting 24p to 60i, then to me, this looks like a 48p to 60i conversion, as for every 10 fields you get 8 frames (although not FULL frames). Seems they sped up the 24p source to 48p then converted it to 60i.
Sorry if I've messed up the explaination, but I'm tired right now so I hope you can figure it out what I mean =P. Look at the clip if you're confused. Feel free to correct me if I'm wrong.
Anyway to the point, what's the best way to fix this? Although I'm using YATTA to created a mixed FPS MKV, it'd be very easy for me if the framerate I achieve for this part is either 24 or 30, as it'd take a lot of manual calculations for other framerates.
One way I can think of is to resize up the individual fields to frames, thus gaining frames A-H (B-D and F-H just being fields with double the height of course) and then selecting every 2nd frame, i.e. A, C, E, H (so only every 2nd frame is low quality). However for the latter part of the clip where there is little motion (after the scroll up), this is probably the worst method. Hence why I'm asking here for the best AviSynth method.
Thanks in advance, if you need more information then just ask.