Go Back   FileForums > Game Backup > PC Games > PC Games - CD/DVD Conversions > Conversion Tutorials

Reply
 
Thread Tools Display Modes
  #1  
Old 25-08-2015, 12:01
Razor12911's Avatar
Razor12911 Razor12911 is offline
Noob
 
Join Date: Jul 2012
Location: South Africa
Posts: 3,746
Thanks: 2,141
Thanked 11,095 Times in 2,295 Posts
Razor12911 is on a distinguished road
Information about Precomp

Hi guys. I am here to explain and give extra information about precomp.

First of all, a whole lot of newbies think that precomp compresses files, "If you use precomp you get better results", well I am here to clarify that.

Pecomp is not a compressor, it's more like a decompressor with the aim of decompressesing zlib and deflate streams that exist in a certain file meaning the output is suppose to be bigger than input.

Q: Why must the output be bigger than input?
A: So that there must be a lot of repetitions and similarities within the file that when you apply step or stronger compression such as LZMA which targets those repetition and similarities to make the output much smaller.

Q: Why does precomp take so long to process a file?
A: Data is represented as binary zeroes and ones, there are so many of them within a file, precomp has to scan for headers/traces of zlib or deflate streams then decompress them then looks for another.

Q: Why does precomp stop working sometimes.
A: it may be cause by a false detected stream within the file and when precomp tries to decompress it, an exception is raised because the stream was falsely detected via file headers.

Q: What if there were no streams detected?
A: Then do not use precomp for that particular file.

Q: How to know the count of streams found?
A: After precomp has processed a file, it shows a summary.

Q: How to know before precomp finishes that the results will be excellent?
A1: use verbose command -v. Turn it on.
A2: look at the temp file, original file and current progress, if temp is bigger than original file while precomp is still working then expect great results but if temp is more or less equal in comparison to original file and progress percentage agrees with the division of both then it is wise to stop process and remove precomp from method.

Last edited by Razor12911; 31-08-2015 at 17:07.
Reply With Quote
The Following 16 Users Say Thank You to Razor12911 For This Useful Post:
78372 (19-06-2017), Andrey167 (30-08-2015), bastien360 (27-08-2015), Bilawal (26-08-2015), EzzEldin16 (27-09-2017), gozarck (25-08-2015), Lucas65 (18-02-2016), mamed3000 (19-09-2015), mausschieber (25-08-2015), mikey26 (26-08-2015), RamiroCruzo (25-08-2015), S-Ghost (22-10-2017), Sarvagya (30-08-2015), Stor31 (01-09-2015), toto621 (03-09-2015), y_thelastknight (26-08-2015)
Sponsored Links
  #2  
Old 30-08-2015, 01:47
Sarvagya's Avatar
Sarvagya Sarvagya is offline
Registered User
 
Join Date: Oct 2014
Location: Home
Posts: 35
Thanks: 101
Thanked 22 Times in 16 Posts
Sarvagya is on a distinguished road
Thanks for the explanation but i have one question is precomp good for gta v or reflate
__________________
Don't Judge Me
Reply With Quote
  #3  
Old 31-08-2015, 16:57
Razor12911's Avatar
Razor12911 Razor12911 is offline
Noob
 
Join Date: Jul 2012
Location: South Africa
Posts: 3,746
Thanks: 2,141
Thanked 11,095 Times in 2,295 Posts
Razor12911 is on a distinguished road
I don't know, I don't have that game but many claim that reflate is better.
Reply With Quote
The Following User Says Thank You to Razor12911 For This Useful Post:
Sarvagya (01-09-2015)
  #4  
Old 31-08-2015, 17:07
Razor12911's Avatar
Razor12911 Razor12911 is offline
Noob
 
Join Date: Jul 2012
Location: South Africa
Posts: 3,746
Thanks: 2,141
Thanked 11,095 Times in 2,295 Posts
Razor12911 is on a distinguished road
I was compressing Need For Speed The Run the other day.
Input was 15GB and final size was 4.34GB, precomp did all this.
Precomp made the input 29GB which is good.

Code:
Precomp v0.4.3 - ALPHA version - USE FOR TESTING ONLY
Free for non-commercial use - Copyright 2006-2012 by Christian Schneider

Input file: $$arcdatafile$$.tmp
Output file: $$arcpackedfile$$.tmp

Using packjpg25.dll for JPG recompression.
--> packJPG library v2.5a (12/12/2011) by Matthias Stirner / Se <--
More about PackJPG here: http://www.elektronik.htw-aalen.de/packjpg

100.00% - New size: 30842644270 instead of 16086403253

Done.
Time: 11 hour(s), 16 minute(s), 3 second(s)

Recompressed streams: 1122066/1369521
PNG streams (multi): 0/3
JPG streams: 0/8
JPG streams (progressive): 0/78
zLib streams (intense mode): 1122066/1369432

You can speed up Precomp for THIS FILE with these parameters:
-zl98 -d0

Fast mode does exactly the same for this file, only faster.

Errorlevel=0
There were more than 1 million zlib streams to precompress which is good for srep to find matches and similarities in data which brought 29GB down to 8GB.

Code:
Compressing 30,842,644,270 bytes with srep  -m5f $$arcdatafile$$.tmp $$arcpackedfile$$.tmp
SREP 3.91 beta (June 27, 2013): input size 29413 mb, memory used 2503 mb, -m5f -l512 -c256 -a4/4 -hash=vmac -b8mb
100%: 30,842,644,270 -> 9,054,126,014: 29.36%.  Cpu 21 mb/s (1383.016  sec), real 2 mb/s (12086.196 sec)
from that, a strong compressor LZMA was applied, NanoZIP or PAQ can be applied to bring the size better than LZMA but doesn't show progress (Working on that)

Compressed 172 files, 16,086,403,253 => 4,670,475,225 bytes. Ratio 29.0%
Compression time: cpu 8678.03 secs, real 64392.04 secs. Speed 250 kB/s

Compression took 18 hours thanks to precomp which took 11 hours meaning you are disadvantaged with time but not with space.
Reply With Quote
The Following 5 Users Say Thank You to Razor12911 For This Useful Post:
Bilawal (31-08-2015), EzzEldin16 (26-08-2017), mamed3000 (19-09-2015), Sarvagya (01-09-2015), Stor31 (01-09-2015)
  #5  
Old 01-09-2015, 11:51
mikey26 mikey26 is offline
Registered User
 
Join Date: Dec 2008
Location: south africa
Posts: 276
Thanks: 124
Thanked 110 Times in 61 Posts
mikey26 is on a distinguished road
Send a message via AIM to mikey26 Send a message via Yahoo to mikey26
@Sarvagya guys do post sometimes on how long it sometimes takes to do conversion and the post the required files u need so i dont see a problem but do u know how many types of combinations of machine specs are out there.its near impossible to calculate how long its going to take to do a conversion everything can only be speculated.then u get guys that want the best compression possible and they running a pentium 2 with 256mb ram and wonder why conversion crash and take so long.look for thread for GTA V the game has been out for just over 2 months now and guys are still trying to figure out what is the best compression .when they find the best compression the complain it takes to long to install.then 2 weeks later a 5gb patch comes out and they want a update to the conversion the very next day its a no win situation for converters and coders.they do the best they can and guys should be grateful with what they get.or the should do the conversion themselves and read up on compression and how it works.i dont mean to be rude but thats how it is mate.
Reply With Quote
  #6  
Old 01-09-2015, 12:19
mikey26 mikey26 is offline
Registered User
 
Join Date: Dec 2008
Location: south africa
Posts: 276
Thanks: 124
Thanked 110 Times in 61 Posts
mikey26 is on a distinguished road
Send a message via AIM to mikey26 Send a message via Yahoo to mikey26
@Razor hi bud hope u well.i have been reading a bit on the forums it looks like that the guy that was developing nanozip (Sami Runsas) might have actually abandoned the project.there are bugs in nanozip but is a great archiver i gonna play around with it and see how compression works.i sure you will work out the progress level issues with it.but then again do we actually need to see progress i mean we will all know when its done working and a conversion is done :-)
Reply With Quote
  #7  
Old 02-09-2015, 17:10
Razor12911's Avatar
Razor12911 Razor12911 is offline
Noob
 
Join Date: Jul 2012
Location: South Africa
Posts: 3,746
Thanks: 2,141
Thanked 11,095 Times in 2,295 Posts
Razor12911 is on a distinguished road
I am working on it, I can only do things in ASC. I managed with reflate, I can try working on nanozip too, at least in ASC to implement this like this is easy unlike in Inno Setup.
Reply With Quote
The Following 4 Users Say Thank You to Razor12911 For This Useful Post:
Bilawal (03-09-2015), mikey26 (03-09-2015), Stor31 (03-09-2015), toto621 (03-09-2015)
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Commands use in Srep and Precomp red01 PC Games 2 18-06-2013 06:55
CheatHappens (or fan) still hacks forum (Was WARNING: Public information compromised) Yokhss Game Trainers 1 25-05-2010 12:53
Frequently Asked Questions Joe Forster/STA PC Games - Frequently Asked Questions 0 29-11-2005 10:48
FairLight-Patch for XIII now shrunked to 189 KB !!! WeakSector PC Games 54 21-01-2004 12:09
information dreamcastgal DC Games 2 26-07-2001 10:06



All times are GMT -7. The time now is 17:00.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 2000-2020, FileForums @ https://fileforums.com