Encoding...to deinterlace, or not deinterlace...that is the question?

[Ronstang 294]

This has been driving me CRAZY for a long time.  I have a lot of recorded TV shows that I have been manually editing the commercials out of and stacking them up to be encoded.  Some are progressive content yet many are interlaced.  The problem with the ones that are interlaced is they are not always consistent.  Some are definitely telecined, yet others have a telecined pattern in one part yet lots of combing with no pattern in other parts.  This is creating a lot of issues for me trying to figure out how to encode, because if you get it wrong you end up with a video that plays choppy or lower quality.

Since this is such a time waster and my head is about to explode I did some playback testing in emby.  Now no matter how I deinterlace, BWDIF or YADIFF...on auto, TFF of BFF...all play in emby in Chrome without needing deinterlacing when the raw recoded video does require transcoding to deinterlace.  I assume I could leave either filter on auto and hope for the best...but is that really reliable.  I don't know but...

Encoding with all ffmpeg settings the same except deinterlacing or no deinterlacing result in a file of about the same size, only IVTC results in a smaller file which makes sense since it is removing frames.  That being said, if I play encoded file with no deinterlacing in emby on any of my TVs it direct plays because the TV is set to handle the interlacing.  Also if I play the file on my Android phone in emby it direct plays with no need to transcode to deinterlace so I assume the Android phone can play interlaced video also.  

Since the only way I will use this content is on a TV or my phone (extremely rare) then why am I bothering with trying to figure out how to deinterlace while encoding at all?  My only goal here is to avoid transcoding in emby and playback of interlaced content on my TVs and Android don't require transcoding so am I correct to assume I should just encode with no deinterlacing?  Is there any other device or situation that I am missing where transcoding would be required....iPhone?  I don't know, I don't have on to test>

Edited January 16, 2024 by Ronstang

[visproduction 315]

When you edit out ads on encoded video, the edit might be inbetween I frames.  This means playback will no longer have correct I frames before B frames for a segment and that throws the player off and gives you artifacts, until it resyncs.  What that does to interlaced video, I am not sure.  Perhaps the hickup is only a few seconds.  It's not ideal.  In post production for clients, we would prefer to edit on masters with uncompressed video and avoid editing compressed video at all.

Telecine, you mean perhaps 3:2 pulldown on 29.97 fps.  The first step to correct for that is to change the framerate to 23.976 fps. (29.97 x 4 / 5).  That can remove the 3:2 pulldown, but it can fail if the original video is not a master quality copy and has had previous edits.  So, typically you add frame blending, as well.

Interlace play through to a standard TV, should work, so don't bother encoding, but I think if the codec is not h.264 inside a .mp4 container, then encoding will probably turn on automatically becuase that is how it is setup.  Once encoding starts, whatever the default setting is for checking for interlace and running some blur feature will happen.  If you can adjust that option, fine.  I don't know if it's possible.  I don't use auto encoding.  I pre encode each video manually to h.264 .mp4 and AAC audio.

Removing interlace for progressive playback or internet browser / computer view, is possible to either run some feature that auto blurs everything.  You could instead reduce the height by 50% (240px for US NTSC) to an uncompressed (squashed look) copy A and then expand it back to 640 x 480 for for a compressed copy B in h.264 mp4, so you won't have to reencode again.  Interlace will be gone and you will have a clean looking video, still a little blurry.  I don't think anyone bothers ever doing this, because of the effort and storage size to make an large uncompressed copy A and then a extra encoding step and video generation loss.  Most interlace removal features try to do it all in one generation and they are pretty good, but not really ideal.  In post production for clients, we would just request a master - high res or original negative and would not even mention any other options.

Hope that makes some sense and maybe is helpful.

[EsposaHermosa 0]

10 hours ago, visproduction said:

Hope that makes some sense and maybe is helpful.

Thank you....but yes I completely understand all of this.  I have been running an IVTC routine on cable recorded movies for years.  The problem with recording TV shows from several different stations is not only is their interlacing inconsistent it can also be hybrid due to the adds mixed in etc.  It makes good results difficult on marginal quality TV uncompressed.  It makes a solution tedious at best and almost impossible at worst.  

I got really confused when I had a TV show that looked like it as 3:2 pulldown that I determined by loading in Avidemux and advancing a frame at a time looking for the combed frames and a pattern.  Yet once I encoded it the video had choppy playback occasionally.  I uploaded a sample video clip on Video Help Forum  of the uncompressed as recorded video of the area that was choppy after encoding and everyone said it was progressive.  So here I had a video that is hybrid but didn't know it.  Yes I could run a standard deinterlacing filter and set it to only process interlace frames but I never watch movies or TV shows on the computer in a browser except to check them and since a TV handles the interlacing on it's own and so does my phone I simple decided to skip something that can be different on each channel and even different between programs on the same channel.  The History Channel is the worst for creating issues of changing resolution etc.

I tested and tweaked my settings in ffmpeg yesterday and now I have higher quality encoded TV shows about the same files size as before using default HEVC that are not deinterlaced and all direct play on all my devices.  The benefit is I just queue up a bunch of edited TV shows and push encode and leave it for a day or two now.  All TV shows are treated the same and I don't have to waste time determining something that is unnecessary in the first place.  

BTW, I never edit the commercials out after I encode.  I always and only edit the as recorded TS files before I load then into FFmpeg Batch AV Converter which is the best program out there for those of us that use custom profiles and don't need the GUI to do all the work.....those programs result in lower quality video every time.  I have personally (online) worked with the developer to tweak this program to make it more useable over the last couple of years.  A lot of the newer features he added after I asked for them and then did all the testing for him on a daily basis.  He is a great guy and his program is top notch.

I also only use VideoReDo TV Suite to do all my editing because even though the developer died last year and the program is no longer being developed or updated it is hands down the best editor and the only one the does the things it does and easily.  It is truly a frame accurate editor.

[Ronstang 294]

Sorry, I was still logged in on the new account I created for my wife to set up her new TV a couple hours ago so the above post is actually mine.  LOL...

[pwhodges 2012]

8 hours ago, EsposaHermosa said:

I also only use VideoReDo TV Suite to do all my editing because even though the developer died last year and the program is no longer being developed or updated it is hands down the best editor and the only one the does the things it does and easily.  It is truly a frame accurate editor.

However, it also can no longer be downloaded, bought or activated online (though someone has set up a manual system that enables owners with a licence key to re-activate it, and there's a temporary download of the latest, for people who have a key).  Details here.

What is particularly frustrating is that the developer is still alive and kicking - it is the business owner, who dealt with licensing and the web site, who has died.  But the developer has said he doesn't have the information to pick up the other functions, and so the project is dead.

Paul

Edited January 18, 2024 by pwhodges