Winrar Question

**exfarmer** · March 29th, 2014, 02:14 PM

I've used winrar to compress a 1.29gb file and at the same time split it into chunks of 400mb but I've finished up with four files totaling 1.38gb.

Why is that? surely it should be less in size than the original, I always thought that was the point of those programs like winrar.

The file unrars/zips perfectly and gives me the original, playable video so there's no corruption anywhere. But the difference in size is confusing me.

**Jism Jim** · March 29th, 2014, 04:06 PM

Have you inadvertently added recovery data to the rars? That is an option you can switch off.
Anyway I am curious about the file size when you create uncompressed rars.

**exfarmer** · March 29th, 2014, 10:25 PM

Umm..I don't know. Sorry I'm not very technically minded.

On this W8 machine I just right click the video file then select add to archive.

Quote:

Originally Posted by Jism Jim

Anyway I am curious about the file size when you create uncompressed rars.

I thought all rars were compressed, isn't that what the program does?

I've just made new rar files from the video and they've come out as the correct size so you must be correct and I've somehow added recovery data to the first ones. I don't know how though because I did it the same way I always do, anyway I've uploaded the vid and will upload the new rars to FF overnight then replace the links in the post tomorrow.

**exfarmer** · March 30th, 2014, 12:32 AM

It gets weirder, the four part rar file on my PC says it's 1.28gb but the upload to FF says 1.38gb.

**NIN** · March 30th, 2014, 01:05 AM

I've also noticed upload sizes to FF can be different, they say it's a 200Mb max for free users, but I successfully (&mistakenly) Ul'd a file of 208Mb the other day

pigulici · March 30th, 2014, 07:36 AM

You must make the difference between MB(megabyte) and Mb(megabit), 1MB=8Mb, also different partition format(fat32,ntfs,ext3) will report different occupied size on disk(also different OS), and this is because the information(bytes) are grouped on storage(hdd,ssd,usb stick) in cluster(a group of bytes), like you have a hdd with clusters of 4mb each, if you write a 4mb file will have 1 cluster occupied, if you write a 3mb file you will have 1 clsuter occupied, if you have 5mb file you will have 2 clusters occupied, but if a cluster have already data but not full occupied, like 5mb file on cluster of 4mb(second cluster will have only 1mb occupied), the OS will not write in second cluster when you will add another file, so yes , you will loose 3mb of space from second not full occupied cluster, if you look at proprietiers of any file in windows you will se 2 fields "size"(the real size of file) and "size on disk"(how much space of storage the file occupied), and allways second will be greater;the cluster size can be modified; also the video files and mp3 files can not be compressed(not much, with some luck max 1%), this files are already compressed files(the video files are a bunch of jpg files), so if you try to compress a movie you will never gain space, but it will be even bigger because the archive software add some info to file(to reduce the size of movie you must sacrifice the quality of image, of jpgs from movie); in short you can not gain space compressing a movie file without loosing quality...

**Jism Jim** · March 30th, 2014, 08:10 AM

Quote:

Originally Posted by exfarmer

I thought all rars were compressed, isn't that what the program does?

You can choose the compression ratio and set that ratio to zero. I often do that because it's faster and you can't gain much anyway by compressing data that has already been compressed, like jpeg, mpeg, divx etc. On the other hand Winrar is said to be the best at compressing media files. So if it's not recovery data, I can't answer your question.

~~bigbobnobody~~ · March 31st, 2014, 03:38 AM

Don't use Winrar, on the premise of uploading a smaller file. Use it to
cut a file into smaller pieces, and always use the uncompressed setting.
Besides taking forever for a file to "pack up" into it's rars, the extra time
it takes is not worth the meager gain, if there is any at all. It'll all depend
on how much processing speed your computer has, but for an example with
me on my computer, a 1 gig file compressed at the "best" setting, takes
between 6-7 minutes to put into a rar. That same 1 gig file under no compression,
is less than a minute. And what's that extra 5-6 minutes of waiting get
you? With me, there was less than 1.5 mb difference between the 2 rar
files containing the same file. Also.....when you use a higher compression
setting to rar a file.....it'll take that much longer to unpack it as well.

**knobby109** · March 31st, 2014, 08:13 AM

There are two versions of MB in use , 1000000 bytes and 1048576 bytes (the last from a binary number , computers use binary)

March 29th, 2014, 02:14 PM	#1
exfarmer avvie pic by Estreeter Join Date: Jan 2009 Location: Essex, England Posts: 13,737 Thanks: 109,422 Thanked 182,658 Times in 13,045 Posts	Winrar Question I've used winrar to compress a 1.29gb file and at the same time split it into chunks of 400mb but I've finished up with four files totaling 1.38gb. Why is that? surely it should be less in size than the original, I always thought that was the point of those programs like winrar. The file unrars/zips perfectly and gives me the original, playable video so there's no corruption anywhere. But the difference in size is confusing me. __________________ I no longer have time to upload videos, sorry.

March 29th, 2014, 04:06 PM	#2
Jism Jim Sourcer of Smut Join Date: Aug 2007 Posts: 8,832 Thanks: 83,610 Thanked 341,680 Times in 8,424 Posts	Have you inadvertently added recovery data to the rars? That is an option you can switch off. Anyway I am curious about the file size when you create uncompressed rars. __________________ To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. Feel free to post my scans to the relevant model threads, but do give credit

March 30th, 2014, 12:32 AM	#4
exfarmer avvie pic by Estreeter Join Date: Jan 2009 Location: Essex, England Posts: 13,737 Thanks: 109,422 Thanked 182,658 Times in 13,045 Posts	It gets weirder, the four part rar file on my PC says it's 1.28gb but the upload to FF says 1.38gb. __________________ I no longer have time to upload videos, sorry.

March 30th, 2014, 01:05 AM	#5
NIN Banned Join Date: Dec 2009 Posts: 8,823 Thanks: 200,569 Thanked 131,967 Times in 9,045 Posts	I've also noticed upload sizes to FF can be different, they say it's a 200Mb max for free users, but I successfully (&mistakenly) Ul'd a file of 208Mb the other day

March 30th, 2014, 07:36 AM	#6
pigulici Senior Member Join Date: Apr 2007 Posts: 131 Thanks: 4,343 Thanked 787 Times in 125 Posts	You must make the difference between MB(megabyte) and Mb(megabit), 1MB=8Mb, also different partition format(fat32,ntfs,ext3) will report different occupied size on disk(also different OS), and this is because the information(bytes) are grouped on storage(hdd,ssd,usb stick) in cluster(a group of bytes), like you have a hdd with clusters of 4mb each, if you write a 4mb file will have 1 cluster occupied, if you write a 3mb file you will have 1 clsuter occupied, if you have 5mb file you will have 2 clusters occupied, but if a cluster have already data but not full occupied, like 5mb file on cluster of 4mb(second cluster will have only 1mb occupied), the OS will not write in second cluster when you will add another file, so yes , you will loose 3mb of space from second not full occupied cluster, if you look at proprietiers of any file in windows you will se 2 fields "size"(the real size of file) and "size on disk"(how much space of storage the file occupied), and allways second will be greater;the cluster size can be modified; also the video files and mp3 files can not be compressed(not much, with some luck max 1%), this files are already compressed files(the video files are a bunch of jpg files), so if you try to compress a movie you will never gain space, but it will be even bigger because the archive software add some info to file(to reduce the size of movie you must sacrifice the quality of image, of jpgs from movie); in short you can not gain space compressing a movie file without loosing quality...

March 31st, 2014, 03:38 AM	#8
~~bigbobnobody~~ Banned! Join Date: Dec 2009 Location: not here Posts: 3,018 Thanks: 4,467 Thanked 94,236 Times in 3,111 Posts	Don't use Winrar, on the premise of uploading a smaller file. Use it to cut a file into smaller pieces, and always use the uncompressed setting. Besides taking forever for a file to "pack up" into it's rars, the extra time it takes is not worth the meager gain, if there is any at all. It'll all depend on how much processing speed your computer has, but for an example with me on my computer, a 1 gig file compressed at the "best" setting, takes between 6-7 minutes to put into a rar. That same 1 gig file under no compression, is less than a minute. And what's that extra 5-6 minutes of waiting get you? With me, there was less than 1.5 mb difference between the 2 rar files containing the same file. Also.....when you use a higher compression setting to rar a file.....it'll take that much longer to unpack it as well.

March 31st, 2014, 08:13 AM	#9
knobby109 Vintage Member Join Date: Apr 2008 Posts: 1,736 Thanks: 144 Thanked 14,338 Times in 1,702 Posts	There are two versions of MB in use , 1000000 bytes and 1048576 bytes (the last from a binary number , computers use binary)