Help with creating an editable file from 60i AVCHD

[archiveresearch]

I have a ton of 60i .MTS files from a number of different camcorders. As I understand it, if I want to lose as little quality as possible in the editing process, I'll need to convert the raw files to an intermediary format like DNxHD before I dump them into Resolve. Am I right in saying that I'd need to field-shift at that stage as well, running AviSynth within FFMPEG, in order to avoid quality loss from the NLE's built in deinterlacing algorithm?

[Sharc]

I have a ton of 60i .MTS files from a number of different camcorders. As I understand it, if I want to lose as little quality as possible in the editing process, I'll need to convert the raw files to an intermediary format like DNxHD before I dump them into Resolve. Am I right in saying that I'd need to field-shift at that stage as well, running AviSynth within FFMPEG, in order to avoid quality loss from the NLE's built in deinterlacing algorithm?

Why would you want to field-shift? I think your files are regular interlaced video which you can process in your NLE, rather than field-shifted progressive video. What exactly do you mean by edit? If it is more than just cutting some parts you will inevitably get some losses by the subsequent re-encoding.

[Bwaak]

If your NLE can handle AVCHD, and your delivery format is also 1080i, and you don't need to generate many intermediate renders to shuttle there and back with other editors, then you don't really need to use an intermediate codec. Your NLE will internally uncompress the video and will lay all the effects on top of that uncompressed video. Some NLEs explicitly convert to intermediate codec.

OTOH, if you want to convert from 1080i to progressive or to resize, then you need to deinterlace, and an external deinterlacer may produce better results than what is built into your NLE. At this point it makes sense to use a lossless or visually-lossless intermediate codec for editing.

[archiveresearch]

I have a ton of 60i .MTS files from a number of different camcorders. As I understand it, if I want to lose as little quality as possible in the editing process, I'll need to convert the raw files to an intermediary format like DNxHD before I dump them into Resolve. Am I right in saying that I'd need to field-shift at that stage as well, running AviSynth within FFMPEG, in order to avoid quality loss from the NLE's built in deinterlacing algorithm?

Why would you want to field-shift? I think your files are regular interlaced video which you can process in your NLE, rather than field-shifted progressive video.

I think I misunderstood what field shifting is.

What exactly do you mean by edit? If it is more than just cutting some parts you will inevitably get some losses by the subsequent re-encoding.

I'm talking pretty intensive layering of video (at times 5+ tracks) with chroma-key, etc. So after all of that and re-encoding... I know I'm going to be losing a noticeable amount of quality. So I'm trying to get ahead of the game by preserving as much as I can up until that final render.

OTOH, if you want to convert from 1080i to progressive or to resize, then you need to deinterlace, and an external deinterlacer may produce better results than what is built into your NLE. At this point it makes sense to use a lossless or visually-lossless intermediate codec for editing.

Yeah, unfortunately that's my problem - I want the final product to be 1080p.

I know I can't recreate what wasn't there in the first place. But I also just now am learning about the more sophisticated algorithms, like TempGaussMC. I have experimented with Bob and Yadif in the past, just in VLC, and got... OK results at best. But now it looks like I'm going to have to do some more test encodes armed with this new knowledge.

Thank you both for your help!

[Bwaak]

This is Vegas "interpolate" mode vs MSU Deinterlacer: https://imgsli.com/MjQ3NjAx

[Sharc]

I think I misunderstood what field shifting is.

You probably meant field order or field parity or field dominance. Yes, the field order has to be set right for deinterlacing. Incorrect field order would result in jerky playback. NLEs usually allow to set the field order (TFF, BFF).

The pictures that make up interlaced fields have a correct order relative to each other. In fact there is both a spatial order, meaning which should be the top or bottom field, as well as a temporal order, or which one represents an earlier moment in time. If either one or both of these is incorrect it can cause playback problems from jerky motion to blurred edges.