MeGUI includes the following deinterlacing filters: Yadif, Yadif (with Bob), TDeint, TDeint (with Bob), TDeint (with EDI), TDeint (with EDI + Bob), LeakKernelDeint, TomsMoComp, Field Deinterlace, Field Deinterlace (no blend).
Is QTGMC with it's default settings and parameters, a better quality deinterlacer than those included with MeGUI ?
Is it worth it to switch from Yadif to QTGMC ?
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Last edited by codemaster; 25th Aug 2013 at 16:07.
Yes.Our inventions are wont to be pretty toys, which distract our attention from serious things. They are but improved means to an unimproved end. -- Henry David Thoreau
But, if mediainfo says that source is 25fps interlaced top field first, and QTGMC makes 50 fps, then all frames will get 1/2 of the vertical resolution ? Because, in order to maintain an aspect ratio close to source, I don't want to upscale, I only downscale, to avoid interpolation. And if I add SelectEven(), I'll have 25fps, and all frames will have 1/2 of the vertical resolution, while Yadif keeps the vertical resolution intact ?
No, all frames would use half the vertical resolution and interpolate a full image from there. Yadif used in the same way will do the same thing. Think about it. Even if you keep all the frames, deinterlacers separate fields. Fields have 1/2 the vertical resolution of the original frame. A full image is interpolated from that 1/2 image to get a full image, even if you keep all the frames. That's why people often ask: why are you deinterlacing?Our inventions are wont to be pretty toys, which distract our attention from serious things. They are but improved means to an unimproved end. -- Henry David Thoreau
And if I add SelectEven(), I'll have 25fps, and all frames will have 1/2 of the vertical resolution, while Yadif keeps the vertical resolution intact ?
In any event, it's always better not to deinterlace progressive material.
I agree. I use MeGUI myself, but these days I mainly de-interlace with QTGMC and try not to spend too much time regretting the number of old encodes where I didn't.
If a picture is worth a thousand words, I guess a video sample must be worth a few more. Have a look at the ones I posted in this thread (posts 8 and 20) comparing QTGMC to Yadif at both 25 and 50fps. In the first samples, keep your eye on the blinds as the camera moves.
Even though it's primarily a de-interlacer, it has a progressive mode, so I often use it when re-encoding badly de-interlaced progressive video and even as a pseudo noise filter. In progressive mode it tends to "stabilise" the picture, including the noise, rather than remove it as such, but once again that means it doesn't blur as noise filters often do.
If you're interested (getting off the actual topic of de-interlacing a little) I posted some sample encodes here comparing standard noise filtering to runing QTGMC in progressive mode. It didn't seem to attract much interest, but I've been using QTGMC as a "psuedo" noise filter more and more. Currently I'm using it in progressive mode while re-encoding some old TV captures and I'm very pleased with the result. For most I've not used additional noise filtering, while for the really noisy ones I'm using QTGMC's EZDenoise.
Last edited by hello_hello; 2nd Sep 2013 at 02:34.
I caught your noise reduction demo earlier. Nice post. I find QTGMC's script to be a useful learning tool for studying ways that many of its support files can be used as stand-alone plugins. Some of it is a bit cryptic for most users (including myself), but it's still a good source of info. Thanks for sharing.Our inventions are wont to be pretty toys, which distract our attention from serious things. They are but improved means to an unimproved end. -- Henry David Thoreau
I ran some more comparison encodes between QTGMC in progressive mode, and the two script-based denoisers I've been playing with, TemporalDegrain, and FastDegrain. I used the default settings for each, but also adding QTGMC's EZDenoise function into the mix. The source videos (old TV captures) range from average quality to very poor quality with lots of noise.
TemporalDegrain's default settings and QTGMC+EZDenoise4.0 seem to produce almost identical results (also confirmed by the almost identical output file size). Occasionally when comparing the two frame by frame I thought I preferred the TemporalDegrain encodes, but the differences were very slight and could possibly be due to x264's compression (I didn't check if I was comparing B frames with B frames etc, although I used the same encoder settings each time). Over-all though, I preferred QTGMC+EZDenoise4.0 as the picture itself was a little more stable (once again though the difference was very small) however QTGMC+EZDenoise4.0 repaired more of the "bad-deinterlacing" nastiness. And in single threaded mode, it seems to be marginally faster than TemporalDegrain (only around 1fps faster for me).
FastDegrain seems to be pretty similar to QTGMC+EZDenoise=2.0 when it comes to noise removal, and it's much faster (QTGMC in single threaded mode) but at the same time doesn't come close to QTGMC's ability to stabilise the picture.
If the slow speed doesn't bother you, for removal of lighter noise, QTGMC in progressive mode without EZDenoise enabled is definitely my preference. It removes most of the noise while stabilising the picture and doesn't blur it as FastDegrain and TemporalDegrain do. If anything, it'll sharpen fine detail a little. For heavier noise sometimes just "stabilising" it isn't enough as it doesn't look natural, so it's not a magic fix which eliminates the need for noise removal, but even with it's own noise removal enabled, I still prefer QTGMC.
I did some tests on my source. I got satisfactory results only withCode:
Last edited by codemaster; 1st Sep 2013 at 23:41.
is the same as
I probably should check that to make sure there aren't any differences, but either way you're de-interlacing to "half frame rate".
If I'm correct regarding the above, then
Would be the same as
Because "slower" is the default speed preset.
Have you tried de-interlacing to "full frame rate" instead?
I think the idea behind FPSDivisor and ShutterBlur etc is to add a little motion blur when de-interlacing to "half frame rate" to make motion appear a little smoother, but in my opinion "full frame rate" is the way to go. I haven't played around with the motion blur settings as once I discovered full frame rate de-interlacing...... Most/many current devices should play 50fps/60fps video (both the Bluray players in this house do) and when using CRF encoding it actually doesn't increase the file size all that much, and full frame rate de-interlacing looks so much better.
As a quick experiment, because I had some PAL concert footage handy (lots of flashing lights and motion, hard to de-interlace well) I ran two encodes using a 3 minute section of the video. Same cropping and resizing each time.
Produced exactly the same output as
At least as best as I could tell, but the output bitrate was the same and the final file sizes only differed by about 1KB. (CRF18 and default x264 settings each time).
If choosing doubled frame rate, will this make it unnecessary to compensate with motion blur tweaks ?