Zipping a File

Some file types are already compressed and can't be compressed much or any further without losing quality. Zip and other generic compression formats are lossless.

(55866)

From my understanding, when Apple says compress, it actually mean "zip". Is that incorrect?

It's correct.

is there something out there that will allow me to zip the file without any quality loss?

Zip is always lossless. What it can't do is achieve a significant compression of already compressed data; this is the tradeoff for lossless compression methods.

(55867)

Zip is lossless. But if you are trying to compress a picture or movie, or some other file format that is already stored in a compressed format, then the zip file will not be smaller, and in some cases might even get larger.

If you do wish to reduce the size of a picture or movie, then your only option is to re-render the image or movie using a different more efficient lossy compression codec or reducing the number of pixels in the image or movie.

If you could tell us what you are trying to compress it might help with the quality of the answer that can be given.

I'm trying to zip a movie file that was exported as a Prores 422 HQ. The file size is about 6 GB. I'm looking to transfer it via dropbox.

A movie file is already hightly compressed. Zip will not affect its size.

Your only choice it to re-process the move using either an different encoding format, or to re-process the movie using fewer frames/second or reduce the number of pixels per frame (like going from 30 frames/second to 15 frames/second, or going from 720p to 480p, etc...).

The other alternative is to pay dropbox for more space, or find a different free upload service that will accept the large sized file.

But zip and every other lossless compression tool is not going to do anything with a movie file.

Are you sending the file to be just viewed by somebody or is it being sent for further editing? I ask as according to wikipedia it's an intermediary format aimed at editing hence the larger size. If you are sending the file just so it can be watched it is likely that you can get a much better size by using H.264 and a mp4 container. If you're sending the file to be edited you're probably best burning a copy to a DL-DVD and simply posting the disk.

HGO Guy wrote:
I'm trying to zip a movie file that was exported as a Prores 422 HQ. The file size is about 6 GB. I'm looking to transfer it via dropbox.

OK, well like the others are saying, you need to figure out what the real goal is here, since you have a file already compressed with Prores. Also, you need to decide whether this is something you need to do often.

*If the file is being transferred just to be watched*, Prores 422 HQ is the wrong compression to export it. It is too large, preserving too much quality unnecessarily. Go back and get it exported to a more appropriate, more lossy codec like h.265. And/or reduce the resolution if the full resolution is not needed. Those will get the file size under 1GB for sure.

*If the file is being transferred to be edited*, you're not going to get this done with Dropbox because it won't fit as it is and you can't afford to lose any more quality. Use another transfer service with a higher capacity.

*If the file is being transferred to be edited and you will be doing this often*, the real answer is to upgrade your Dropbox account to the 50GB level or higher depending on how much/how often you need to transfer footage like this.