I'm trying to rencode a video capture using MeGui. I didn't actually capture the video, but MeGUI keeps saying that it can't determine the source type.
Here is mediainfo log for the file
I'm terrible when it comes to source type. I usually just let MEGUI do it for me, but this time it can't figure it out and i don't know enough about source etc to figure it out. Can someone help me?
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Well, something is strange about it.
It says it is HDV (and it is MPEG2 MP@HL in a TS), but it also says it has:
1. Variable GOP - HDV has a fixed med/short (6-, 12- or 15- frame) GOP sequence, though this could be due to editing.
2. Variable Bitrate - HDV is fixed at 25Mbps for 1080 and 19Mbps for 720
3. AC3 audio - HDV uses Mp2 audio
4. TV rating - clearly tacked on because of it being broadcast (not part of original HDV)
5. two subtitle/text tracks - also tacked on...
So, it's a hybrid MPEG2 HD encode in an MPEG-TS container.
Last edited by Cornucopia; 2nd Sep 2014 at 20:58.
Open and index the video (DGIndex) and then the script creator with a preview. Step through frames one at a time in a section of the video where there's motion. If nothing looks amiss it's progressive (no de-interlacing required). If you see combing like this in every frame (where there's motion) then it's interlaced and you'd select "Interlaced" as the source type. If there's combing like the pic but it comes and goes in a 3:2 pattern as you step through the frames it's film which requires pulldown removal and you'd select "film" as the de-interlacing option.
If the video is "progressive", "interlaced" or "film" from start to finish you're done (select the appropriate method). Sometimes though, it can be different in different sections of the video.....
If you can navigate to different parts of the video and see different results as you step through the frames (different combing patterns) it's probably some sort of "hybrid" where parts are interlaced and parts are film etc.
For progressive and interlaced combinations, you can select either "interlaced" or "partially interlaced" (they don't de-interlace any differently).
For combinations of film and interlaced you'd select one of the hybrid options.
Selecting "mostly film" would convert it all to 23.976fps progressive. "Mostly interlaced" would convert it all to 29.970fps progressive. Which method you'd use would depend on whether it's err..... mostly film or mostly interlaced.
"Hybrid, Mostly film" and "partially film" add the same de-interlacing to the script.
There's other pulldown patterns used on occasion (aside from the 3:2 pattern), but MeGUI tends not to get them right at the best of times and it has no method of handling them correctly by selecting one of the script creator's de-interlacing options. You need to manually change the de-interlacing method in the script. Not that you need to worry about that for the moment.
Once you've selected a "source type" you can use the "preview avs script" button to check the result. The de-interlacing method MeGUI defaults to for each source type is usually the one to use (TIVTC for "film" etc). One exception would be the option for "interlaced". It defaults to "Yadif". If however, the source is 100% interlaced, I'd recommend "Yadif with Bob". Instead of de-interlacing to 29.970fps progressive (for NTSC), "Yadif with Bob" de-interlaces to 59.940fps progressive, and motion should look much smoother.
I looked through it and it didn't look like the Star Trek picture you showed. It kind of looks progressive. I looked through a lot of the video and none of it looked like that.
If i wanted to make it 23.976fps what would be the best thing to do with the progressive video? Also how would i make the source audio go in sync with the 23fps video? MeGUI usually does all this for me. I don't plan on rencoding the audio. I plan on using the source AC3 or would MeGUI figure out how to sync it even with changing the source FPS?
MeGUI itself doesn't change the source FPS. It uses AVISynth scripts. The script would have to tell AVISynth to change the fps somehow.
Some forms of changing FPS will change the duration, some won't.
The ones that DO will mess up the sync with audio. The ones that don't WON'T<edit>SHOULDN'T</edit> mess up the sync. Simple as that.
Pulldown (telecine) & Reverse Pulldown (inverse telecine) does not change the duration, so it doesn't mess with the sync.
However, pulled-down material will have small moments where A & V might not be in EXACT sync because of the frame repetition. And any subsequent programs that have editing involving portions (or all) of pulled-down material might also have those "moments".
Assuming it IS what it says it is, and you've looked at it and it looks (to you) to be progressive.
To make it 30p (actually 29.97p), you would use something like:
Video60p=AVISource("YourMovieHere.avi").AssumeFPS("ntsc_double") Video60p=AssumeFrameBased(Video60p) Video60p=AssumeTFF(Video60p) Video30p=SelectEven(Video60p) return Video30p
LoadPlugin("decomb.dll") Video60p=AVISource("YourMovieHere.avi").AssumeFPS("ntsc_double") Video60p=AssumeFrameBased(Video60p) Video60p=AssumeTFF(Video60p) VideoITVC=Telecide(Video60p, post=0) Video24p=Decimate(VideoITVC, cycle=5) return Video24p
I replied to Cornucopia's post above while for some reason having it in my head the source video was 29.970fps progressive, when it's 59.940fps, and therefore my reply was wrong.
Last edited by hello_hello; 3rd Sep 2014 at 04:08.
Mind you I'm not sure converting it is necessarily the best idea. If it's really 59.940fps progressive and you live in a land of 59.940Hz refresh rates, I'm not sure why converting it to 23.976 would make it look better. Or even 29.970fps for that matter.
MeGUI doesn't always convert to 23.976fps. Sometimes the output will be 29.970fps. It depends on the content. For DVDs, removing pulldown for a 23.976fps output would probably be more the norm these days, especially for movies, but not always. If the video is predominantly interlaced the output would be 29.970fps. When it's a hybrid, converting it all to one constant frame rate (23.976 or 29.970) is generally a compromise (for the same reasons as mentioned in the ConvertFPS section of the Avisynth page here).
Normally you're probably converting 59.970 interlaced video when MeGUI is doing it all for you, or film converted to NTSC using pulldown, but in this case you're working with 59.940fps progressive video (apparently).
Last edited by hello_hello; 3rd Sep 2014 at 04:08.
@hello_hello, I guess you'll have to chalk it up to you being a PAL guy and not used to NTSC. But you should still have understood that 1st script, because it would have worked the same way using 50p->25p (adjusting for "pal_double").
Yes, it halves the # of frames, but each frame is then 1/2 the framerate (double the hold time) = same duration. I just checked again: it plays correctly & AVISynth info shows correct (new half) framerate + correct duration.
Granted, I don't use the 2nd script very often, but that is basically STRAIGHT from AVISynth's (and Neuron2's) wiki.
Again, that script is intended for a clean, pure 60p source that can be faithfully restored to a 24p pre-source.
<edit>There are other ways to do this: you could use a combination of SelectEvery() along with a new AssumeFPS()...</edit>
Maybe you misunderstood - neither of those deal with interlace or de-interlacing. Just frame decimation & IVTC. From what I could tell, that's what the OP was asking (30p and 24p outputs respectively, and his source is empirically 60p).
You can continue your NTSC-bashing, just like we NTSC'ers can continue our PAL "lower framerate flicker is killing me" bashing. But I think both attitudes are pointless. One can easily (and fairly quickly, I might add) get used to either one with exposure. And neither one is ultimately "superior". Roughly 1/2 the world is just "use to it" being one way, roughly the other half is used to the other way. Big deal. Maybe in 20 years we can get to some common ground (150p, 300p? = evenly divisible by 25 and 30; 600p? = evenly divisible by 24, 25 & 30; & 4kUHD or 8kUHD2)
Last edited by Cornucopia; 3rd Sep 2014 at 04:20.
The post following the one I deleted..... I also edited it at the same time. Initially I'd mentioned a few efforts to repair 29.970fps progressive video in the past, for some reason still having it in my head the OP's source was just that, but after unclogging my brain I deleted that in case it confused the issue. Naturally I also corrected the references to converting 29.970fps progressive to 23.976fps progressive at the same time, for the same reason. Maybe that's what you read?
What if I have a bit of a rant regarding Euro pulldown later on? Would it make you feel better