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  1. Originally Posted by pandy View Post
    Originally Posted by Sharc View Post
    Perhaps a bit off topic, but once we are at it:
    Does anybody know how today's TVs or HW deinterlacers process one field phase-shifted "interlaced" video? Do they match the fields and hence restore the original progressive frames perfectly, or do they deinterlace it (producing unavoidable artefacts)?
    Most of modern reputable brands TV's are equipped with some form of motion detection so they should be able to deal with odd cases (but not always without issues). And TV's usually don't know flag (i mean by this that multimedia and TV reception functions are usually processed in different circuit than video thus video processor almost always perform blind deinterlacing). It is mandatory to have motion detection in all framerate converting TV's (and many of them are in fact asynchronous internally with fixed refresh rate when compared to incoming video). IMHO Better brands trying almost everything in approach toward good deinterlacing.
    (and they are quite good, can observe SD interlace on very old LG TV, and interlace they can be seen only in very fast motion areas with relatively low contrast like light gray on white - then some lines can be visible but on limited area - this LG TV is at least 6 years old and modern TV should be way better).
    Thank you. Apparently one has to try what exactly the TV etc. does with interlaced footage - especially with "odd cases". The magic depends on the manufacturer, but I agree that deinterlacers are darn good nowadays, driven by interlaced HDTV broadcast . In DVD player times it was possible to draw conclusions on the processing based on few commonly used chip sets.
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  2. Originally Posted by Sharc View Post
    Thank you. Apparently one has to try what exactly the TV etc. does with interlaced footage - especially with "odd cases". The magic depends on the manufacturer, but I agree that deinterlacers are darn good nowadays, driven by interlaced HDTV broadcast . In DVD player times it was possible to draw conclusions on the processing based on few commonly used chip sets.
    Once again - DVD player is Source, TV is receiver (display) as such they operate on different signal. DVD use "flags" where TV use only incoming signal usually blindly (as some video interfaces don't carry explicit field flag).
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  3. Originally Posted by pandy View Post
    Originally Posted by Sharc View Post
    Thank you. Apparently one has to try what exactly the TV etc. does with interlaced footage - especially with "odd cases". The magic depends on the manufacturer, but I agree that deinterlacers are darn good nowadays, driven by interlaced HDTV broadcast . In DVD player times it was possible to draw conclusions on the processing based on few commonly used chip sets.
    Once again - DVD player is Source, TV is receiver (display) as such they operate on different signal. DVD use "flags" where TV use only incoming signal usually blindly (as some video interfaces don't carry explicit field flag).
    Ok, thanks. Got it
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    Originally Posted by johnmeyer View Post
    Originally Posted by Bernix View Post
    Understand properly, that movie recorded as progressive (or simpler on classical film) then translated as interlaced, has each field from different time ?
    Have to think twice next time
    Not quite. A 24 fps movie is translated to 30 fps video by adding pulldown fields. These are simply duplicates of existing fields.
    OP is in Europe - that doesn't apply there. Europe is 50Hz country. There, the film is sped up from 24fps to 25 fps and every two successive fields scan the same frame. In that instance, deinterlacing is not even necessary, but, if you had to deinterlace (e.g. because you want progressive video file), it does not degrade the video quality at all, as another poster said above so vehemently, since there is no temporal change in the image data between the 2 fields.

    In summary, OP, if you are transferring material that originated on film, you can safely deinterlace from 50i to 25p and your quality will not suffer. Bonus points for restoring the frame rate from 25fps to the film's native 24fps
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  5. Originally Posted by briantw View Post
    in Europe - that doesn't apply there. Europe is 50Hz country. There, the film is sped up from 24fps to 25 fps and every two successive fields scan the same frame.
    Not always. There are many different ways film gets to PAL video. And hence, many different ways of restoring it to the original film frames.
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  6. Scharfis_Brain - Exotic Interlacing (Exotisches Interlacing) is a nice read about strange NTSC->PAL conversions,..
    users currently on my ignore list: deadrats, Stears555
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  7. The OP posted 2.5 years ago. Exactly what was the point of resurrecting this finished thread???

    As jagabo points out, not all 24 fps film to 25 fps PAL conversions were just straightforward speed ups.
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  8. Originally Posted by briantw View Post
    Europe is 50Hz country. There, the film is sped up from 24fps to 25 fps...
    Not always.
    Originally Posted by briantw View Post
    ...and every two successive fields scan the same frame
    Not always.
    Originally Posted by briantw View Post
    ...but, if you had to deinterlace (e.g. because you want progressive video file), it does not degrade the video quality at all
    That's just plain wrong. Deinterlacing always degrades a video, even if it's already progressive.
    Originally Posted by briantw View Post
    Bonus points for restoring the frame rate from 25fps to the film's native 24fps
    That's about the only thing you said with which I agree. Did you sign up here and resurrect a dead thread just to post misleading claims?
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    I have an alternative, what's everyone's thoughts please? Around 2006 I bought an expensive ( $2,500) Sony "DA5200ES" Surround Amp with a "Faroudja DCDi Cinema" upscaler built in. (Wikipedia: Faroudja DCDi Cinema was developed around higher performance 10-bit processing with extended picture enhancement controls, an active color management system and 3D Noise Reduction. In addition, Response Time Correction (RTC) technology is included to compensate for the motion blur prevalent in LCD flat panels.

    I already have a HDMI to USB 3.0 capture adapter for my high end PC. I could play from my VHS player in PAL through this amp and record the 720p or 1080p HDMI output directly to hard drive in real time. My PC would store the capture temporarily in high quality MJPEG format for editing . Then I can save as H264 or H265 format as required.

    I do know that watching regular old DVD's through this amp on a 100inch screen in 1080p does look very good considering its a DVD. I'm always amazed.

    Would this method recording VHS via Faroudja DCDi Cinema" upscaler to HDMI be a good compromise ? TIA
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  10. Faroudja was a company which only produced amazing signal processing stuff. Their $12,000 line doubler was so legendary that I actually made a trip to CES Las Vegas back in the early 90s just to see a demo. It was mind-blowing (for that time).

    I see no downside to using the output of that unit for capture. I don't know that particular model, but I suspect it might have time base correction included.

    The only flaw in your proposed idea is the capture in "high quality MJPEG format." JPEG is still a lossy format, and the DCT transform is the same thing used in DV which is widely reviled in this forum. Part of the reason for the negative reviews of DV is its poor NTSC color quality, something MJPEG sholdn't have, but people also don't like the DCT DV artifacts, something you will get with MJPEG.

    Having said that, maybe you can turn the MPJEG quality all the way up and get something similar to a modern lossless codec. That will depend on your MJPEG encoder, and there is no way for me to predict the results.
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    This is an old if still a useful thread. For those who are interested Topaz labs have added deinterlacing to their fancy Topaz Video Enhance software.
    Although if you are purists you may be horrified but the AI algorithms can do amazing things with video to enhance, denoise and upscale it. I have no idea how the deinterlace works but it can result in a nice 50fps 1080p from an interlaced 576i miniDV or PAL recording.

    It recreates details, which can look so clean there is a setting to add noise back in to the video to make it look natural. If you turn up the AI correction too much faces can start to look unnatural (like Max Headroom for my older readers).

    Here is a still from a 1992 2nd generation VHS copy (left image) . My cheap VCR did the deinterlacing on this example but you can see how the Topaz software cleans up the colour noise and "recreates" the patterns on the dress and removes the jaggies and cleans up the purple block on the t shirt ( right image).

    https://forum.videohelp.com/attachment.php?attachmentid=58563&stc=1&d=1619161215

    They sometimes have sales as its usually $300

    https://www.topazlabs.com/video-enhance-ai
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  12. You probably could do better with Avisynth/Vapoursynth and the right filter combination and some knowledge about image/video processing&co, but Topaz's software is an easy way to archive decent results. So I see how it might be interesting to some.
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    Is there any program that will take uncompressed interlaced video, do simple weaving, and produce simple uncompressed output? This is for video that was ORIGINALLY 1080p30 but converted to 1080i60 to go over component cables or HDMI, then recorded by a Blackmagic Intensity Pro 4k

    FFMPEG can't do it, Handbrake can't do it! OBS can record the feed but doesn't offer any real deinterlacing method, only several that throw away data and interpolate to create 1080p.
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  14. Originally Posted by daygecko View Post
    Is there any program that will take uncompressed interlaced video, do simple weaving, and produce simple uncompressed output? This is for video that was ORIGINALLY 1080p30 but converted to 1080i60 to go over component cables or HDMI, then recorded by a Blackmagic Intensity Pro 4k

    FFMPEG can't do it, Handbrake can't do it! OBS can record the feed but doesn't offer any real deinterlacing method, only several that throw away data and interpolate to create 1080p.

    ffmpeg sends interleaved frames. 2 fields in 1 frame.

    If you recorded fields in order, then it's already aligned "1080p30 in 60i" . ie. They are already weaved and in order, in the proper arrangement. Then you should see no combing. It's already progressive content.

    If fields are misaligned, then used -vf fieldmatch to put align and weave them

    If you don't know what you did, post a sample
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    Originally Posted by poisondeathray View Post
    Originally Posted by daygecko View Post
    Is there any program that will take uncompressed interlaced video, do simple weaving, and produce simple uncompressed output? This is for video that was ORIGINALLY 1080p30 but converted to 1080i60 to go over component cables or HDMI, then recorded by a Blackmagic Intensity Pro 4k

    FFMPEG can't do it, Handbrake can't do it! OBS can record the feed but doesn't offer any real deinterlacing method, only several that throw away data and interpolate to create 1080p.

    ffmpeg sends interleaved frames. 2 fields in 1 frame.

    If you recorded fields in order, then it's already aligned "1080p30 in 60i" . ie. They are already weaved and in order, in the proper arrangement. Then you should see no combing. It's already progressive content.

    If fields are misaligned, then used -vf fieldmatch to put align and weave them

    If you don't know what you did, post a sample
    Thanks, I tried -vf fieldmatch and it works! On a short clip from CNN it looked perfect, and then they had an effect that seemed interlaced so it had combing. I think it's doing exactly what I want. I'll experiment with some other clips
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