.rar compression for subtitles in Robot4Rip question

[Staz]

Hey!

I have selected the option in robot4rip preferences to compress the .sub file using winrar. A .rar file is created just fine. However it is not at all compressed, (basically stored as .rar). What would be causing this? I would like there to be at least some compression :D

Could it be because I have created a default compression profile inside winrar?? This default compression profile is set to store as .rar without compression.

Thanks alot!

[CWR03]

Could it be because I have created a default compression profile inside winrar?? This default compression profile is set to store as .rar without compression.You've asked and answered your own question. :) Any .rar files you make without altering your default profile will be created with that profile's specifications.

[Staz]

Thankks CWR03 :D

So what is the recommended compression method for subs then?

Fastest, Fast, Normal, Good, Best?

[unskinnyboy]

Best.

[CWR03]

Please follow rule #12: do not ask "what's best." (Just kidding...)

The amount of compression mainly only affects the time it takes to compress/decompress, as well as the file size. There's also a higher chance of corruption with more compression.

[Staz]

Thanks, hopefully I don't get any corruption :D
I do have a tick in the checkbox "test archived files" however.

[unskinnyboy]

There's also a higher chance of corruption with more compression.
Could you substantiate this please? Because this is news to me.

[iradic]

although winrar isn't creating solid archives by default (if i remember correctly) aren't "not solid" archives safer than "solid" ones?
or i'm wrong?

otherwise it shouldn't matter "more" or "less" compression... i think

[unskinnyboy]

Winrar doesn't create solid archives by default, yes. But what exactly do you mean by solid archives are not "safe"? I always use solid archives and I have experienced nothing "unsafe" about them. And solid archives result in more compression than non-solid ones. Perhaps a definition of solid archives is in order here to clear the confusion:

Solid archives are supported by some formats that allow for the inclusion of several files. In a solid archive, all files are compressed as if they were one large file. This improves compression ratio most of the time because compression algorithms tend to require a certain minimum size for input files in order to work well. Concatenating many small files results in one large file which can then be compressed. This works better than compressing each small file independently from the others. As an example, a tar archive of many smaller files compressed with gzip is typically compressed better than a zip file with the same entries, although both use the Deflate algorithm.

Solid archiving comes at the cost of not being able to extract a single file without decompressing everything that comes before it in the archive. However, in many cases this is not a problem, because typically the complete archive is extracted anyway. Some archivers also rearrange the input files in the solid archive in a way to have all files of a certain data type to be adjacent, which sometimes improves compression ratio even more.
Source: http://schmidt.devlib.org/file-formats/archive-file-formats.html
Similar source: http://www.win-rar.com/solidarchive.html

[iradic]

NOTE: Author of the text bellow says its from winrar help ... but i dont know for sure

A solid archive is a RAR archive packed by a special compression method, which treats all files, within the archive, as one continuous data stream. Solid archives are supported only by the RAR archiving format, ZIP archives are always non-solid. The archiving method for RAR archives is a user selectable option and may be Solid or non-Solid.
Solid archiving significantly increases compression, especially when adding a large number of small, similar files.

But it also has a few important disadvantages:
slower updating of existing solid archives;
· to extract a single file from a solid archive all preceding files must be analyzed. This makes extraction from the middle of a solid archive slower than extraction from a normal archive, but, if all files are to be extracted from a solid archive, the extraction speed will not be affected.
· if any file in a solid archive is damaged, it will be impossible to extract all files which follow the damaged area. Thus if a solid archive is stored to media such as diskette, it is recommended to make use of the recovery record.

Solid archiving is preferable if:

· the archive is updated rarely;
· it is not necessary to frequently extract a single file or only part of the files from the archive;
· compression ratio is more important than compression speed.

[Staz]

Another question, regarding subtitles:

How do you go about subtitles with a 2CD XviD encode?
Here's my guess, but perhaps there is a less complicated way you know of?

As normal after the Robot4Rip process, I will end up with a .sub and .idx file. I have chosen not to use winrar to compress the .sub file during this process.

I then use winrar to compress the .sub file into a .rar file.

In Gordian Knot, I add the AC3 Audio, and the two sub files. (.rar and .idx) to determine the appropriate video bitrate for the 2CD encode.

Once the encode is finished I am left with 2 video files, one for each CD.
I then extract the .rar file (containing .sub) and use vobsub splitter to split the .sub and .idx at the appropriate place.

I then use winrar to compress each of the splitted .sub files.

But there could be problems with this??

For example say the Video on CD1 of my Xvid encode is longer than that of CD2. This could mean that the filesize of the sub files for CD1 is larger than CD2? Could this create oversize problems, when fitting the .avi, .rar and .idx on CD1? Or does GordianKnot somehow take this into account when splitting the video? Maybe it splits the .avi filesizes slightly unevenly to account for a larger sub filesize on one cd than another?

I'd love to know exactly how it all works.
Thanks so much!

[jggimi]

Staz, I merged your new question (regarding splitting) into this thread, because you're really asking about the same process - R4R and compressed subs.

[Staz]

Cool, thanks jggimi!