"Canon HV20" - 24p 3:2-Pulldown-Removal

ChrisKron

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Hello everyone,

my old Canon HV20 Camcorder (1080 60i) has a 24p-mode which internally records 24fps, but turns them into 29.97fps and also gives out 29.97fps when transferred to the PC. So all videos I get with "HDVSplit" are 29.97fps, no matter if actually having been recorded in 24fps.
It all happens through a so called 3:2 or 2:3 pulldown. When you pause the video you see 3 full frames, then 2 interlaced (or blurry images).

I used to use a software from "Cineform" which had an option "3:2 pulldown removal" and transferred my footage with 24fps-progressive to my PC.
When I use "HDVSplit" I always get 29.97fps (as stated above), also the video is interlaced. When being played by my video player (e.g. potplayer) it displays the video accordingly (it also automatically de-interlaces), but it still states that the video is 29.97fps and interlaced.

"Handbrake" offers the filter called "de-telecine", which may be the solution. But it doesn't seem to matter if on or off. When I use de-interlace or de-telecine, I will get 4 frames, followed by a stillframe (and so on). So I compared that to a hollywood movie (24p). It had no filler-frame or choppiness...just smooth 24p. Is it impossible to get with the HV20, even though it was the selling-point?

In Adobe Premiere, when "interpreting footage", there is an option for "3:2 pulldown" or so, but it is greyed out and I cannot touch it somehow...

What would be the correct way to get TRUE 24P? De-Interlace the video? De-telecine? both? Set the destination framerate to 23.97fps? or leave at 29.97 when I also checked de-interlace? How do I even know which of my tranferred footage was recorded in 23.97fps and which in 29.97 - if HDVSplit (and other software) get you only 29.97fps anyway? Is there a way to differentiate between these two? As it is now I only can guess by the choppiness if it is supposed to be in 23.97 or not.
When working in your editing software you cannot have videos which internally may be 23.97fps but are recognized as 29.97fps (and interlaced).

My goal is to get the best quality, preferrably without much encoding processes being done. The "cineform" videos I got back in the days were around 40GB in size (compared to HDVSplit's 12GB) and around 60Mbit (HDVSplit is 25Mbit). I believe the HV20 didn't record in 60Mbit, so I wanted to capture my videos once more with HDVSplit to reduce the sizes to their original Mbits and sizes.

Also the videos are recorded in 1440x1080 (should I turn them into 1920x1080?).

Thanks for any hints on how I can solve my little problems. :)
 
Are you transferring these files to the PC directly as files from the camcorder, or by some capture/re-encoding?

If they are direct then you can try (no warranty!):

- tsMuxeR. Add the file, set the "remove pulldown" flag and remux. Should take a few seconds. This does not do any re-encoding. Test the output. If it's good, all done. If not:

- Avidemux. Open the file, set up a suitable video encoding scheme to suit your needs (which may be a bit complex to do). If your machine has a compatible graphics chip (eg NVidia) then use the relevant encoding option - it will be quicker. Use the filter Resample fps - set it to 23.976 (film). You can leave the audio at "copy" if you wish. And choose a muxer that suits your needs (eg mkv, mp4). This will re-encode the video (so it will take time) and force the frame rate as set. Whether it correctly chooses which frames to drop - you'll work that out in the output. If you do want to pad these out to 1920w then there is a filter for that also - Fit to Size.

Both are free apps.
 
Are you transferring these files to the PC directly as files from the camcorder, or by some capture/re-encoding?

If they are direct then you can try (no warranty!):

- tsMuxeR. Add the file, set the "remove pulldown" flag and remux. Should take a few seconds. This does not do any re-encoding. Test the output. If it's good, all done. If not:

- Avidemux. Open the file, set up a suitable video encoding scheme to suit your needs (which may be a bit complex to do). If your machine has a compatible graphics chip (eg NVidia) then use the relevant encoding option - it will be quicker. Use the filter Resample fps - set it to 23.976 (film). You can leave the audio at "copy" if you wish. And choose a muxer that suits your needs (eg mkv, mp4). This will re-encode the video (so it will take time) and force the frame rate as set. Whether it correctly chooses which frames to drop - you'll work that out in the output. If you do want to pad these out to 1920w then there is a filter for that also - Fit to Size.

Both are free apps.
Wow, those options sound interesting.
I already transferred several tapes to my PC via Firewire and the program called "HDVSplit".
Can I directly transfer and perform the Pulldown while transferring I wonder? "Cineform" allowed for that back in the days (as described above).

So, I tried tsMuxeR first. I have to add my previously transferred video files. My files are in the M2T, AVI, etc.
The program doesn't allow for .M2T, .mpeg, .avi, .dv or any other video files I have it seems, getting an error. When I rename the type to .TS, I get a more compliant error message, which doesn't evoke much hope anyways - at least the file seems to be somehow added (video and audio track are visible). The remove pulldown option is greyed out though - reminds me of Adobe Premiere, in which the same thing is the case. Why, I wonder...

Edit: I used AviDemux to pack one of my .m2t files into a mkv-container and tsMuxeR let me add it. The Remove Pulldown is still greyed out though...

Then I tried "AviDemux", which I almost use every day, but never for any encoding jobs, but to flawlessly cut and merge videos without any re-encoding. I followed your advice (source: 29.97fps, goal: 23.97fps). Though I don't know if I should put source at 23.97fps, if it was recorded, but doesn't show the 23.97fps the camcorder recorded at.
I don't feel any difference in framerate after having encoded it...maybe because the encoded video files looks horribly mushy and lacking much of the detail (check the back of the white shirt). I encoded with nvidia h264 and 18Mbit (slow). I tried different codecs but they all seem to end up a similar bad way. Encoding with AviDemux seems pretty rough.
garb.png
The initial worry of mine stays... whether a video file is 23.97fps or 29.97fps in the first place. When I use AviDemux and check under "Auto" - "check24fps" it says NTSC:100, PAL: 0, Film: 0, Other: 0. Does that mean it is a 24fps video indeed, or does it mean it is merely Ntsc (which it is of course)?

I wish the first program worked. I hate encoding if I don't have to, and getting these results makes my heart cry. ;_;
 

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The tsMuXeR images are revealing. On 2 & 3 it shows the original frame rate of the source file to be 29.97. If it were genuinely 23.976, with pulldown flags (as you might find on a commercial NTSC SD-DVD movie encode) IIRC it would say 29.97 (pulldown), and would allow the pulldown flag to be removed.

You may find the information tool MediaInfo helpful in analysing the true content. It will report the true file structure, frame rate, codec, etc., etc., and audio codec. By knowing what you actually have, you may then work out the best way to handle it. And/or a different way to transfer it to the PC.

Guesswork (since I don't have such a camcorder): that possibly the content of the tape is indeed 24p but the firewire interface and software are making into true 29.97 interlaced (as distinct from 23.976+pulldown) during transfer and that is what you end up with on your PC. If so, then a different way of getting the raw data off the tape would be needed (unless the software used allows such settings - I don't know).

To answer your question "I don't know if I should put source at 23.97fps, if it was recorded, but doesn't show the 23.97fps the camcorder recorded at" - it should be left at what is detected as source properties of the file on your PC irrespective of how it got there - which I guess is presently 29.97. I think to do otherwise would alter the playback speed.

Beyond the previous suggestion of frame rate resampling in Avidemux, I can't offer anything else to get a 29.97 source file to 23.976p. You mention the white shirt, but didn't mention whether the output is (still) jerky and/or with extra or missing frames. If it's smooth then this approach is working in principle.

Whilst I haven't done what you are attempting here, I can say that in my experience, the NVidia H264 encoder produces re-encoded output that is hard or impossible to distinguish on-screen from the source - as long as you give it enough bit-rate (trial and error). You might try increasing the bit rate for the encoded output.

HTH
 
The tsMuXeR images are revealing. On 2 & 3 it shows the original frame rate of the source file to be 29.97. If it were genuinely 23.976, with pulldown flags (as you might find on a commercial NTSC SD-DVD movie encode) IIRC it would say 29.97 (pulldown), and would allow the pulldown flag to be removed.

You may find the information tool MediaInfo helpful in analysing the true content. It will report the true file structure, frame rate, codec, etc., etc., and audio codec. By knowing what you actually have, you may then work out the best way to handle it. And/or a different way to transfer it to the PC.

Guesswork (since I don't have such a camcorder): that possibly the content of the tape is indeed 24p but the firewire interface and software are making into true 29.97 interlaced (as distinct from 23.976+pulldown) during transfer and that is what you end up with on your PC. If so, then a different way of getting the raw data off the tape would be needed (unless the software used allows such settings - I don't know).

To answer your question "I don't know if I should put source at 23.97fps, if it was recorded, but doesn't show the 23.97fps the camcorder recorded at" - it should be left at what is detected as source properties of the file on your PC irrespective of how it got there - which I guess is presently 29.97. I think to do otherwise would alter the playback speed.

Beyond the previous suggestion of frame rate resampling in Avidemux, I can't offer anything else to get a 29.97 source file to 23.976p. You mention the white shirt, but didn't mention whether the output is (still) jerky and/or with extra or missing frames. If it's smooth then this approach is working in principle.

Whilst I haven't done what you are attempting here, I can say that in my experience, the NVidia H264 encoder produces re-encoded output that is hard or impossible to distinguish on-screen from the source - as long as you give it enough bit-rate (trial and error). You might try increasing the bit rate for the encoded output.

HTH
Thanks again for those swift answers, really appreciate it (and I'm learning so much here).

This is what I tried: I found "Cineform" transferred footage (23.97fps) and the corresponding original tape. I tranferred this exact tape with "HDVSplit" and got a 29.97fps video (as usual).

So I tried "MediaInfo", dragged the "Cineform" (23.97fps) footage in, and it states 23.97fps. Then I dragged in the "HDVSplit" (29.97fps) video - and it apparently is ....29.97fps.
Either the program is just stating the very obvious (just the current specs of the video that I already see), or (back in the days) I made a mistake and checked pulldown removal when there was no pulldown removal to be had or forcing some 24fps option on a 29.97fps tape).

Then I remembered a program called "GSpot", which always seemed to show the true specs of a video. Again I threw in the Cineform video (23.97fps). Sadly it didn't accept .m2t video files, so I again put it into an .mkv container, which worked. GSpot states it being 23.97fps and the HDVSplit one being 29.97fps, no surprises here, same as with MediaInfo.

Adobe Premiere also just shows me the same obvious fps info on those 2 videos (pulldown removal is greyed out for both the 29.97fps and 23.97fps video). Either this video truly wasn't recorded in 23.97fps or these programs just can't detect the true specs.

Obviously I really want to know if I recorded a tape by using the "24PF" or regular 29.97fps mode.
This whole 3:2 pulldown crap gives me headaches. :\ Is there truly no way to find out the "true" framerate?

As you stated, there might be some program out there that offers that pulldown removal simultaneously while transferring. That's what I got with "Cineform Neo3D" (as stated before), but I cannot get it to work again (can't even start the setup.exe, get an error message), most likely it's incompatible with Windows 10 (last time I used it was in 2008). But then again, I am not sure if this Cineform software offered that "Pulldown Removal" option for all footage or just for those it was applicable to (e.g. being greyed out when not needed). Damn, which again leads to the need to know which tapes were recorded in 23.97fps...-_-

And with "tsMuxeR GUI", why doesn't it accept most of my video files? I listed the formats I tried to feed it, but I is really picky there. I tried to open the cineform 23.97fps video (same one I was talking about above), but .m2t videos aren't working with tsMuxeR GUI (even though there is an output option for M2TS muxing)... is there a more compatible version of this program?

"Beyond the previous suggestion of frame rate resampling in Avidemux, I can't offer anything else to get a 29.97 source file to 23.976p. You mention the white shirt, but didn't mention whether the output is (still) jerky and/or with extra or missing frames. If it's smooth then this approach is working in principle."

I uploaded a comparison screenshot of the original footage and the encoded one. You can see shadows on the backside of the white shirt, where in the encoded shot you just see a white smoothed out surface. I would assume a bitrate of 18000kbit/s would more than suffice to have a decent picture (after all the source bitrate is 25000kbit/sec). :)

"Whilst I haven't done what you are attempting here, I can say that in my experience, the NVidia H264 encoder produces re-encoded output that is hard or impossible to distinguish on-screen from the source - as long as you give it enough bit-rate (trial and error). You might try increasing the bit rate for the encoded output."

Yes, I can't explain why it looked that bad. I encode stuff daily and never got such bad results , but then again I never used AviDemux for encodes...
 
This is what I tried: I found "Cineform" transferred footage (23.97fps) and the corresponding original tape
So if the file that results on your computer using this app. is 23.976, then I'm guessing that would be as right as it can be. Is that not the case in fact? If it is, then use that as your source for any further process. Or am I missing something?

As to your two images (comparision) they aren't of the same frame, and that on its own might account for the difference in appearance of the shirt.

==================================

Aside and in case it's of any further help/information:

3:2 pulldown is a technique used primarily for true film content (eg movies) for use on NTSC TVs. For historic reasons (which I won't expand on here),
a) TV signals were interlaced
b) in NTSC land they were shown at 29.97 frames per second, interlaced into 59.94 fields each containing half the image in alternate lines.

Films are typically shot at exactly 24 fps.

Films historically transferred for video use in NTSC-land were telecine'd marginally slower at 23.976 fps (which is close enough to 24 as makes no material difference, yet which converts readily to 29.97) and every fourth frame was duplicated. So 4 becomes 5. Or, the frame sequence becomes 1234456788....... (The term 3:2 pulldown comes from this sequence; alternate pairs of 2 original frames are made into 3).

Along came digital media (eg DVD). How to encode true film (24 fps) content so that it can be played on an NTSC TV (i.e. is 29.97fps, interlaced into 59.94 fields)? The method most often used was to encode the film video at 23.976fps and then artifically add markers (pulldown flags) to the file to instruct the player when and where to add those extra frames. And to interlace the output as 59.94 fields.

It follows, then, that such a file can be easily restored to it's original frame sequence, by (simply) removing those flags. That's what pulldown removal is.

None of the above applies to true NTSC video. NTSC video cameras run natively at 29.97 fps and the resulting content is precisely, and unalterably, that. Some may even run at 59.97 fields per second, interlaced. And again, nothing lossless can be done to change that.

In other words, what you can do (without some degrading effect) to the source depends on the source itself.
 
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