Can you explain the difference between "resolution playback" and "proxy"?

[OleksandrTovmachenko]

Suppose we did transcoding for a video in ProRes, for example. The question is if there is any sense in making another proxy for this video if we can use "playback resolution 1/2 or 1/4"?
For proxy is the same video with the resolution but smaller than the source. If I proxy for transcoded video, even in lesser resolution, it will use extra main memory because two files will use different codes and thus take a lot of memory. So is it necessary to make a proxy if you can use "playback resolution"?

[R Neil Haugen]

A few misconceptions there.

When using lower res playback,  and using intraframe media like ProRes, Cineform, and DNx, that media can be "reduced" in size for playback during decompression, typically without any real re-computing. So if you've got 6-8K clips, and set 1/4 res playback, makes it much easier on the CPU and subsystems to work.

But if you have interframe, say long-GOP, a whole series of frames have to be completely decoded and reconstructed from the matrix information first, before a recomputation can make the 1/4 res image. Which actually adds to the computing load.

Some 'heavy' RAW/log media can also throw a load onto the the system, enough that doing a transcode or proxy operation is simply easier during editing.

So ... in general, if you've got good editing format/codec media to begin with such as ProRes, Cineform, or a DNx, then lowering res in playback can help in many situations.

If you have H.264/5 long-GOP interframe media, or 'heavy' RAW/log media, then making proxies can help.

You seem to assume the program reads both the proxies and the original media at the same time, which I don't get. If you've toggled to the proxies, it only reads the proxies not the main media. If you haven't toggled to proxies, it reads only the main media. There's no reason whatever for the program to be reading both at the same time.

Perhaps you think that the 'instructions' for what to do with the clip on a sequence are stored in the original media? Which isn't correct. All your work is stored as meta within the sequence information within Premiere. Not 'within' the media file.

Neil

[OleksandrTovmachenko · Accepted solution]

Thank you for your answer. But what to do in my situation? I have 100 1920x1080 videos in H.264 which weigh 28.3 GB, and I transcoded them to ProRes 422 LT; now, the new videos weigh 108 GB . And I wonder if it makes sense to transcode all these videos again, but with smaller resolution for example 1280x720 but as proxy, if you can do "blayback resolution" 1/4 or 1/2?

[R Neil Haugen · Accepted solution]

Everyone's mileage always varies.

So you'd have to test on your gear. Like Warren, I would suspect that ProRes 422LT will play back pretty decently with most effects ... though Warp by itself, let alone combined with Lumetri and time-ramping! .... will overload even 'heavy iron' computers.

So probably you can work without proxies, may need to render a segment of a timeline now & then.

And make proxies if an when/where needed.

Neil

[Warren Heaton]

No, you do not need to make a Proxy if your Full Resolution footage plays back well.