[11.02rc1] 7z as Zip Packer - Compression level 10 is Deflate64 instead of LZMA

[Biozynotiker]

If you use the Packer Configuration Dialog and use compression level 10, tcmd warns you that LZMA is using...
So i expect that LZMA compression is used in every created Zip Archive.

- If you use the internal Zip Packer, the result is a LZMA compressed Zip.
- If you use 7z as Zip Packer, then the result is a DEFLATE64 compressed Zip.

I also checked the command line parameters, that passed through 7z...
The parameter "-mm=deflate64" is used intead of "-mm=lzma".

[ghisler(Author)]

It's indeed Deflate64. I think the confusion comes from the fact that internally ZIP uses 10 as the value for LZMA.

[AntonyD]

2ghisler(Author)

But where does it say LZMA?

as Biozynotiker says:

If you use the Packer Configuration Dialog and use compression level 10, tcmd warns you that LZMA is using...
So i expect that LZMA compression is used in every created Zip Archive.

And this is a completely logical statement. After all, you have already been told several times that the set of elements on this settings page
and their interaction when selecting one or another element on it is done in an unfriendly manner (((.
There is no intuitiveness about WHAT exactly happens or will happen as a result of choosing this or that option.
IF it turns out that for the 7z archiver you are forced to make completely different support EVEN for just working with one type of archives - ZIP,
out of all the many types it supports - then the settings page should be configured EITHER to support internal toolkit(pack+UPpack) options
OR to support 7z archiver. Exclusively!
And now you have basically everything allowed for everything. And thus any clarifications described in the help actually do not have any
special impact on the intuitiveness and ease of use of this settings page.

[Biozynotiker]

It's indeed Deflate64. I think the confusion comes from the fact that internally ZIP uses 10 as the value for LZMA.

Seriously, i don't get it. Why is 7z even supported as internal zip replacement, if it don't act the same as documented in the tcmd help?
If i search the tcmd help, there is no hit for "deflate64". The whole purpose to use 7z as zip packer, is to get around the super slow
internal solution (because there is no multitheading support).

The whole packer dialog is also a confusing:
1. Activate the checkbox "use internal ZIP packer"
2. Why is it possible to activate the checkbox "7z" or "Zip-NT" at the same time? >Should be a switch for internal/external packer
3. Why is it possible to interact with the path input in this state? >Should be greyed out
- or -
1. If "7z" is checked and "use internal ZIP packer" is unckecked
2. Why is the section of compression level is still labeled as "internal zip compression (0-9)"?

If it's designed to be deflate64 and not lzma, than please documented it. So poweruser like me can write a
7z-wrapper that filter out and replace all forced command line parameter from tcmd.

[AntonyD]

2Biozynotiker

than please documented it.

You described practically my post with your own words. That’s right. The ZIP Settings dialog is very non-intuitive at the moment. And unfortunately - your proposal to add documentation will not simplify and improve the overall picture. You forget that we still need to fairly easily translate into other supported languages. And of course, a lot of people work with the program on the principle of "what is visible and understandable - then I use it". And no one will go looking in the help something "like completely clear and ordinary".
We have to change the entire settings tab. Enter exclusion groupboxes/actions as you said: 2) + 3)

[ghisler(Author)]

I have changed the help as follows:
LzmaAllowed=0 1: ZIP packer: Allow Deflate64 compression (not recommended, needs WinZip >=12 to unpack). When enabled, you can choose a pack rate of 10 for Deflate64.

[petermad]

I have changed the help as follows:
LzmaAllowed=0 1: ZIP packer: Allow Deflate64 compression (not recommended, needs WinZip >=12 to unpack). When enabled, you can choose a pack rate of 10 for Deflate64.

Confirmed changed in TC11.02rc2

[white]

I have changed the help as follows:
LzmaAllowed=0 1: ZIP packer: Allow Deflate64 compression (not recommended, needs WinZip >=12 to unpack). When enabled, you can choose a pack rate of 10 for Deflate64.

Confirmed changed in TC11.02rc2

Shouldn't the setting be renamed to Deflate64Allowed and keep LzmaAllowed for compatibility?

And the warning still says LZMA:

If you use the Packer Configuration Dialog and use compression level 10, tcmd warns you that LZMA is using...

1727="Warning: Files packed with strength 10 (LZMA) can not be unpacked by all ZIP unpackers! Continue?"

[AntonyD]

But LZMA IS NOT a Deflate64!
We can't say that if we allowed this method this means that we just
set level 10 of compression ratio for Deflate64 algo!
No! LZMA is a standalone algo! It has already LZMA2 variation!

For ex. as we know 7-Zip can, on request, generate zip files using Deflate64, BZip2, LZMA
in most cases of user's choices. Which means that TC also should support on a DIFFERENT
way packing/unpacking of files with Deflate64/LZMA algos. And do not mess in one radio box
compression ratio for these 2 separate algos.

[ghisler(Author)]

I know that Deflate64 and LZMA are not the same. I don't know why the ini entry was misnamed, but I don't want to change that now.
I also don't want to contact all translators now just for this warning, it would take months to get replies from all of them.

Moderator message

Moved to will not be changed

[AntonyD]

Those it turns out that we are not increasing the compression level for the Deflate64 algorithm, but simply using a completely different algorithm, using the theoretically correctly named option in the INI file, but at the same time in the GUI settings we are doing this in a completely wrong place (the settings concern ONLY ZIP format) and in an incorrect way (we select a non-existent compression level in the combobox for a completely different algorithm).

You are right - here it is not necessary to connect translators, but to redo the entire settings page in order to finally clarify how and what we archive. WHERE 7z works - for what/what formats, WHERE and how can the LZMA algorithm be connected clearly and understandably for the user.

[white]

I know that Deflate64 and LZMA are not the same. I don't know why the ini entry was misnamed, but I don't want to change that now.
I also don't want to contact all translators now just for this warning, it would take months to get replies from all of them.

Since then, version 11.02 was released, followed by version 11.03, and now we are in the release candidate phase of version 11.50, but the confusing ini setting and misleading warning message remain unchanged. Are there plans to update any of this in a future version?

[AntonyD]

IMHO 1) of all we should move this truly BUG into the BUG section of this forum.

[ghisler(Author)]

I will have another look at it.

[ghisler(Author)]

This should be fixed now in RC4, please try it!

23.12.24 Fixed: ZIP packer: When packing with compression rate 10 with 7zg.exe, it created archives with DEFLATE64 compression instead of LZMA (32/64)